* Re: [PATCH V2 2/2] mm/pgtable/debug: Add test validating architecture page table helpers
From: Gerald Schaefer @ 2019-09-18 18:22 UTC (permalink / raw)
To: Christophe Leroy
Cc: Mark Rutland, linux-ia64, linux-sh, Peter Zijlstra, James Hogan,
Tetsuo Handa, Heiko Carstens, Michal Hocko, linux-mm,
Paul Mackerras, sparclinux, Thomas Gleixner, linux-s390,
Michael Ellerman, x86, Russell King - ARM Linux, Matthew Wilcox,
Steven Price, Jason Gunthorpe, linux-arm-kernel, linux-snps-arc,
Kees Cook, Anshuman Khandual, Masahiro Yamada, Mark Brown,
Kirill A . Shutemov, Dan Williams, Vlastimil Babka,
Sri Krishna chowdary, Ard Biesheuvel, Greg Kroah-Hartman,
Dave Hansen, linux-mips, Ralf Baechle, linux-kernel, Paul Burton,
Mike Rapoport, Vineet Gupta, Martin Schwidefsky, Andrew Morton,
linuxppc-dev, David S. Miller
In-Reply-To: <64504101-d9dd-f273-02f9-e9a8b178eecc@c-s.fr>
On Wed, 18 Sep 2019 18:26:03 +0200
Christophe Leroy <christophe.leroy@c-s.fr> wrote:
[..]
> My suggestion was not to completely drop the #ifdef but to do like you
> did in pgd_clear_tests() for instance, ie to add the following test on
> top of the function:
>
> if (mm_pud_folded(mm) || is_defined(__ARCH_HAS_5LEVEL_HACK))
> return;
>
Ah, very nice, this would also fix the remaining issues for s390. Since
we have dynamic page table folding, neither __PAGETABLE_PXX_FOLDED nor
__ARCH_HAS_XLEVEL_HACK is defined, but mm_pxx_folded() will work.
mm_alloc() returns with a 3-level page table by default on s390, so we
will run into issues in p4d_clear/populate_tests(), and also at the end
with p4d/pud_free() (double free).
So, adding the mm_pud_folded() check to p4d_clear/populate_tests(),
and also adding mm_p4d/pud_folded() checks at the end before calling
p4d/pud_free(), would make it all work on s390.
BTW, regarding p4d/pud_free(), I'm not sure if we should rather check
the folding inside our s390 functions, similar to how we do it for
p4d/pud_free_tlb(), instead of relying on not being called for folded
p4d/pud. So far, I see no problem with this behavior, all callers of
p4d/pud_free() should be fine because of our folding check within
p4d/pud_present/none(). But that doesn't mean that it is correct not
to check for the folding inside p4d/pud_free(). At least, with this
test module we do now have a caller of p4d/pud_free() on potentially
folded entries, so instead of adding pxx_folded() checks to this
test module, we could add them to our p4d/pud_free() functions.
Any thoughts on this?
Regards,
Gerald
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* Re: [PATCH v10 5/6] virtio-balloon: Pull page poisoning config out of free page hinting
From: Alexander Duyck @ 2019-09-18 18:05 UTC (permalink / raw)
To: Michael S. Tsirkin, Alexander Duyck
Cc: yang.zhang.wz, pagupta, kvm, david, mhocko, linux-mm, aarcange,
virtio-dev, konrad.wilk, willy, wei.w.wang, vbabka, riel,
dan.j.williams, lcapitulino, linux-arm-kernel, osalvador, nitesh,
dave.hansen, linux-kernel, pbonzini, akpm, mgorman
In-Reply-To: <20190918135833-mutt-send-email-mst@kernel.org>
On Wed, 2019-09-18 at 13:58 -0400, Michael S. Tsirkin wrote:
> On Wed, Sep 18, 2019 at 10:53:05AM -0700, Alexander Duyck wrote:
> > From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> >
> > Currently the page poisoning setting wasn't being enabled unless free page
> > hinting was enabled. However we will need the page poisoning tracking logic
> > as well for unused page reporting. As such pull it out and make it a
> > separate bit of config in the probe function.
> >
> > In addition we can actually wrap the code in a check for NO_SANITY. If we
> > don't care what is actually in the page we can just default to 0 and leave
> > it there.
> >
> > Reviewed-by: David Hildenbrand <david@redhat.com>
> > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
>
> I think this one can go in directly. Do you want me to merge it now?
That sounds good to me.
Do you know if you can also pull in QEMU 1/3 into QEMU as well since the
feature wasn't pulled into QEMU originally?
https://lore.kernel.org/lkml/20190918175342.23606.12400.stgit@localhost.localdomain/
Thanks.
- Alex
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* Re: [PATCH v4 3/3] mm: fix double page fault on arm64 if PTE_AF is cleared
From: Catalin Marinas @ 2019-09-18 18:00 UTC (permalink / raw)
To: Kirill A. Shutemov
Cc: Mark Rutland, linux-mm, Punit Agrawal, Will Deacon,
Alex Van Brunt, Jia He, Marc Zyngier, Anshuman Khandual,
Matthew Wilcox, Jun Yao, Kaly Xin, hejianet, Ralph Campbell,
Suzuki Poulose, Jérôme Glisse, Thomas Gleixner,
linux-arm-kernel, linux-kernel, James Morse, Andrew Morton,
Robin Murphy, Kirill A. Shutemov
In-Reply-To: <20190918140027.ckj32xnryyyesc23@box>
On Wed, Sep 18, 2019 at 05:00:27PM +0300, Kirill A. Shutemov wrote:
> On Wed, Sep 18, 2019 at 09:19:14PM +0800, Jia He wrote:
> > @@ -2152,20 +2163,34 @@ static inline void cow_user_page(struct page *dst, struct page *src, unsigned lo
> > */
> > if (unlikely(!src)) {
> > void *kaddr = kmap_atomic(dst);
> > - void __user *uaddr = (void __user *)(va & PAGE_MASK);
> > + void __user *uaddr = (void __user *)(addr & PAGE_MASK);
> > + pte_t entry;
> >
> > /*
> > * This really shouldn't fail, because the page is there
> > * in the page tables. But it might just be unreadable,
> > * in which case we just give up and fill the result with
> > - * zeroes.
> > + * zeroes. On architectures with software "accessed" bits,
> > + * we would take a double page fault here, so mark it
> > + * accessed here.
> > */
> > + if (arch_faults_on_old_pte() && !pte_young(vmf->orig_pte)) {
> > + spin_lock(vmf->ptl);
> > + if (likely(pte_same(*vmf->pte, vmf->orig_pte))) {
> > + entry = pte_mkyoung(vmf->orig_pte);
> > + if (ptep_set_access_flags(vma, addr,
> > + vmf->pte, entry, 0))
> > + update_mmu_cache(vma, addr, vmf->pte);
> > + }
>
> I don't follow.
>
> So if pte has changed under you, you don't set the accessed bit, but never
> the less copy from the user.
>
> What makes you think it will not trigger the same problem?
>
> I think we need to make cow_user_page() fail in this case and caller --
> wp_page_copy() -- return zero. If the fault was solved by other thread, we
> are fine. If not userspace would re-fault on the same address and we will
> handle the fault from the second attempt.
It would be nice to clarify the semantics of this function and do as
you suggest but the current comment is slightly confusing:
/*
* If the source page was a PFN mapping, we don't have
* a "struct page" for it. We do a best-effort copy by
* just copying from the original user address. If that
* fails, we just zero-fill it. Live with it.
*/
Would any user-space rely on getting a zero-filled page here instead of
a recursive fault?
--
Catalin
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* Re: [PATCH v10 5/6] virtio-balloon: Pull page poisoning config out of free page hinting
From: Michael S. Tsirkin @ 2019-09-18 17:58 UTC (permalink / raw)
To: Alexander Duyck
Cc: yang.zhang.wz, pagupta, kvm, david, mhocko, linux-mm,
alexander.h.duyck, aarcange, virtio-dev, konrad.wilk, willy,
wei.w.wang, vbabka, riel, dan.j.williams, lcapitulino,
linux-arm-kernel, osalvador, nitesh, dave.hansen, linux-kernel,
pbonzini, akpm, mgorman
In-Reply-To: <20190918175305.23474.34783.stgit@localhost.localdomain>
On Wed, Sep 18, 2019 at 10:53:05AM -0700, Alexander Duyck wrote:
> From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
>
> Currently the page poisoning setting wasn't being enabled unless free page
> hinting was enabled. However we will need the page poisoning tracking logic
> as well for unused page reporting. As such pull it out and make it a
> separate bit of config in the probe function.
>
> In addition we can actually wrap the code in a check for NO_SANITY. If we
> don't care what is actually in the page we can just default to 0 and leave
> it there.
>
> Reviewed-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
I think this one can go in directly. Do you want me to merge it now?
> ---
> drivers/virtio/virtio_balloon.c | 22 +++++++++++++++-------
> 1 file changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index 226fbb995fb0..501a8d0ebf86 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -842,7 +842,6 @@ static int virtio_balloon_register_shrinker(struct virtio_balloon *vb)
> static int virtballoon_probe(struct virtio_device *vdev)
> {
> struct virtio_balloon *vb;
> - __u32 poison_val;
> int err;
>
> if (!vdev->config->get) {
> @@ -909,11 +908,18 @@ static int virtballoon_probe(struct virtio_device *vdev)
> VIRTIO_BALLOON_CMD_ID_STOP);
> spin_lock_init(&vb->free_page_list_lock);
> INIT_LIST_HEAD(&vb->free_page_list);
> - if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) {
> - memset(&poison_val, PAGE_POISON, sizeof(poison_val));
> - virtio_cwrite(vb->vdev, struct virtio_balloon_config,
> - poison_val, &poison_val);
> - }
> + }
> + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) {
> + __u32 poison_val;
> +
> + /*
> + * Let the hypervisor know that we are expecting a
> + * specific value to be written back in unused pages.
> + */
> + memset(&poison_val, PAGE_POISON, sizeof(poison_val));
> +
> + virtio_cwrite(vb->vdev, struct virtio_balloon_config,
> + poison_val, &poison_val);
> }
> /*
> * We continue to use VIRTIO_BALLOON_F_DEFLATE_ON_OOM to decide if a
> @@ -1014,7 +1020,9 @@ static int virtballoon_restore(struct virtio_device *vdev)
>
> static int virtballoon_validate(struct virtio_device *vdev)
> {
> - if (!page_poisoning_enabled())
> + /* Tell the host whether we care about poisoned pages. */
> + if (IS_ENABLED(CONFIG_PAGE_POISONING_NO_SANITY) ||
> + !page_poisoning_enabled())
> __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_POISON);
>
> __virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM);
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* [PATCH v10 QEMU 3/3] virtio-balloon: Provide a interface for unused page reporting
From: Alexander Duyck @ 2019-09-18 17:53 UTC (permalink / raw)
To: virtio-dev, kvm, mst, david, dave.hansen, linux-kernel, willy,
mhocko, linux-mm, vbabka, akpm, mgorman, linux-arm-kernel,
osalvador
Cc: yang.zhang.wz, pagupta, riel, konrad.wilk, lcapitulino,
wei.w.wang, aarcange, nitesh, pbonzini, dan.j.williams,
alexander.h.duyck
In-Reply-To: <20190918175109.23474.67039.stgit@localhost.localdomain>
From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Add support for what I am referring to as "unused page reporting".
Basically the idea is to function very similar to how the balloon works
in that we basically end up madvising the page as not being used. However
we don't really need to bother with any deflate type logic since the page
will be faulted back into the guest when it is read or written to.
This is meant to be a simplification of the existing balloon interface
to use for providing hints to what memory needs to be freed. I am assuming
this is safe to do as the deflate logic does not actually appear to do very
much other than tracking what subpages have been released and which ones
haven't.
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---
hw/virtio/virtio-balloon.c | 46 ++++++++++++++++++++++++++++++++++--
include/hw/virtio/virtio-balloon.h | 2 +-
2 files changed, 45 insertions(+), 3 deletions(-)
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 003b3ebcfdfb..7a30df63bc77 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -320,6 +320,40 @@ static void balloon_stats_set_poll_interval(Object *obj, Visitor *v,
balloon_stats_change_timer(s, 0);
}
+static void virtio_balloon_handle_report(VirtIODevice *vdev, VirtQueue *vq)
+{
+ VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
+ VirtQueueElement *elem;
+
+ while ((elem = virtqueue_pop(vq, sizeof(VirtQueueElement)))) {
+ unsigned int i;
+
+ for (i = 0; i < elem->in_num; i++) {
+ void *addr = elem->in_sg[i].iov_base;
+ size_t size = elem->in_sg[i].iov_len;
+ ram_addr_t ram_offset;
+ size_t rb_page_size;
+ RAMBlock *rb;
+
+ if (qemu_balloon_is_inhibited() || dev->poison_val)
+ continue;
+
+ rb = qemu_ram_block_from_host(addr, false, &ram_offset);
+ rb_page_size = qemu_ram_pagesize(rb);
+
+ /* For now we will simply ignore unaligned memory regions */
+ if ((ram_offset | size) & (rb_page_size - 1))
+ continue;
+
+ ram_block_discard_range(rb, ram_offset, size);
+ }
+
+ virtqueue_push(vq, elem, 0);
+ virtio_notify(vdev, vq);
+ g_free(elem);
+ }
+}
+
static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
@@ -627,7 +661,8 @@ static size_t virtio_balloon_config_size(VirtIOBalloon *s)
return sizeof(struct virtio_balloon_config);
}
if (virtio_has_feature(features, VIRTIO_BALLOON_F_PAGE_POISON) ||
- virtio_has_feature(features, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
+ virtio_has_feature(features, VIRTIO_BALLOON_F_FREE_PAGE_HINT) ||
+ virtio_has_feature(features, VIRTIO_BALLOON_F_REPORTING)) {
return sizeof(struct virtio_balloon_config);
}
return offsetof(struct virtio_balloon_config, free_page_report_cmd_id);
@@ -715,7 +750,8 @@ static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f,
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
f |= dev->host_features;
virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ);
- if (virtio_has_feature(f, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
+ if (virtio_has_feature(f, VIRTIO_BALLOON_F_FREE_PAGE_HINT) ||
+ virtio_has_feature(f, VIRTIO_BALLOON_F_REPORTING)) {
virtio_add_feature(&f, VIRTIO_BALLOON_F_PAGE_POISON);
}
@@ -805,6 +841,10 @@ static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);
+ if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_REPORTING)) {
+ s->rvq = virtio_add_queue(vdev, 32, virtio_balloon_handle_report);
+ }
+
if (virtio_has_feature(s->host_features,
VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
s->free_page_vq = virtio_add_queue(vdev, VIRTQUEUE_MAX_SIZE,
@@ -931,6 +971,8 @@ static Property virtio_balloon_properties[] = {
*/
DEFINE_PROP_BOOL("qemu-4-0-config-size", VirtIOBalloon,
qemu_4_0_config_size, false),
+ DEFINE_PROP_BIT("unused-page-reporting", VirtIOBalloon, host_features,
+ VIRTIO_BALLOON_F_REPORTING, true),
DEFINE_PROP_LINK("iothread", VirtIOBalloon, iothread, TYPE_IOTHREAD,
IOThread *),
DEFINE_PROP_END_OF_LIST(),
diff --git a/include/hw/virtio/virtio-balloon.h b/include/hw/virtio/virtio-balloon.h
index 7fe78e5c14d7..db5bf7127112 100644
--- a/include/hw/virtio/virtio-balloon.h
+++ b/include/hw/virtio/virtio-balloon.h
@@ -42,7 +42,7 @@ enum virtio_balloon_free_page_report_status {
typedef struct VirtIOBalloon {
VirtIODevice parent_obj;
- VirtQueue *ivq, *dvq, *svq, *free_page_vq;
+ VirtQueue *ivq, *dvq, *svq, *free_page_vq, *rvq;
uint32_t free_page_report_status;
uint32_t num_pages;
uint32_t actual;
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* [PATCH v10 QEMU 2/3] virtio-balloon: Add bit to notify guest of unused page reporting
From: Alexander Duyck @ 2019-09-18 17:53 UTC (permalink / raw)
To: virtio-dev, kvm, mst, david, dave.hansen, linux-kernel, willy,
mhocko, linux-mm, vbabka, akpm, mgorman, linux-arm-kernel,
osalvador
Cc: yang.zhang.wz, pagupta, riel, konrad.wilk, lcapitulino,
wei.w.wang, aarcange, nitesh, pbonzini, dan.j.williams,
alexander.h.duyck
In-Reply-To: <20190918175109.23474.67039.stgit@localhost.localdomain>
From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Add a bit for the page reporting feature provided by virtio-balloon.
This patch should be replaced once the feature is added to the Linux kernel
and the bit is backported into this exported kernel header.
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---
include/standard-headers/linux/virtio_balloon.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/include/standard-headers/linux/virtio_balloon.h b/include/standard-headers/linux/virtio_balloon.h
index 9375ca2a70de..1c5f6d6f2de6 100644
--- a/include/standard-headers/linux/virtio_balloon.h
+++ b/include/standard-headers/linux/virtio_balloon.h
@@ -36,6 +36,7 @@
#define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */
#define VIRTIO_BALLOON_F_FREE_PAGE_HINT 3 /* VQ to report free pages */
#define VIRTIO_BALLOON_F_PAGE_POISON 4 /* Guest is using page poisoning */
+#define VIRTIO_BALLOON_F_REPORTING 5 /* Page reporting virtqueue */
/* Size of a PFN in the balloon interface. */
#define VIRTIO_BALLOON_PFN_SHIFT 12
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* [PATCH v10 QEMU 1/3] virtio-ballon: Implement support for page poison tracking feature
From: Alexander Duyck @ 2019-09-18 17:53 UTC (permalink / raw)
To: virtio-dev, kvm, mst, david, dave.hansen, linux-kernel, willy,
mhocko, linux-mm, vbabka, akpm, mgorman, linux-arm-kernel,
osalvador
Cc: yang.zhang.wz, pagupta, riel, konrad.wilk, lcapitulino,
wei.w.wang, aarcange, nitesh, pbonzini, dan.j.williams,
alexander.h.duyck
In-Reply-To: <20190918175109.23474.67039.stgit@localhost.localdomain>
From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
We need to make certain to advertise support for page poison tracking if
we want to actually get data on if the guest will be poisoning pages. So
if free page hinting is active we should add page poisoning support and
let the guest disable it if it isn't using it.
Page poisoning will result in a page being dirtied on free. As such we
cannot really avoid having to copy the page at least one more time since
we will need to write the poison value to the destination. As such we can
just ignore free page hinting if page poisoning is enabled as it will
actually reduce the work we have to do.
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---
hw/virtio/virtio-balloon.c | 25 +++++++++++++++++++++----
include/hw/virtio/virtio-balloon.h | 1 +
2 files changed, 22 insertions(+), 4 deletions(-)
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 25de15430710..003b3ebcfdfb 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -530,6 +530,15 @@ static void virtio_balloon_free_page_start(VirtIOBalloon *s)
return;
}
+ /*
+ * If page poisoning is enabled then we probably shouldn't bother with
+ * the hinting since the poisoning will dirty the page and invalidate
+ * the work we are doing anyway.
+ */
+ if (virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) {
+ return;
+ }
+
if (s->free_page_report_cmd_id == UINT_MAX) {
s->free_page_report_cmd_id =
VIRTIO_BALLOON_FREE_PAGE_REPORT_CMD_ID_MIN;
@@ -617,12 +626,10 @@ static size_t virtio_balloon_config_size(VirtIOBalloon *s)
if (s->qemu_4_0_config_size) {
return sizeof(struct virtio_balloon_config);
}
- if (virtio_has_feature(features, VIRTIO_BALLOON_F_PAGE_POISON)) {
+ if (virtio_has_feature(features, VIRTIO_BALLOON_F_PAGE_POISON) ||
+ virtio_has_feature(features, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
return sizeof(struct virtio_balloon_config);
}
- if (virtio_has_feature(features, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
- return offsetof(struct virtio_balloon_config, poison_val);
- }
return offsetof(struct virtio_balloon_config, free_page_report_cmd_id);
}
@@ -633,6 +640,7 @@ static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
config.num_pages = cpu_to_le32(dev->num_pages);
config.actual = cpu_to_le32(dev->actual);
+ config.poison_val = cpu_to_le32(dev->poison_val);
if (dev->free_page_report_status == FREE_PAGE_REPORT_S_REQUESTED) {
config.free_page_report_cmd_id =
@@ -696,6 +704,8 @@ static void virtio_balloon_set_config(VirtIODevice *vdev,
qapi_event_send_balloon_change(vm_ram_size -
((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT));
}
+ dev->poison_val = virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON) ?
+ le32_to_cpu(config.poison_val) : 0;
trace_virtio_balloon_set_config(dev->actual, oldactual);
}
@@ -705,6 +715,9 @@ static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f,
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
f |= dev->host_features;
virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ);
+ if (virtio_has_feature(f, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
+ virtio_add_feature(&f, VIRTIO_BALLOON_F_PAGE_POISON);
+ }
return f;
}
@@ -846,6 +859,8 @@ static void virtio_balloon_device_reset(VirtIODevice *vdev)
g_free(s->stats_vq_elem);
s->stats_vq_elem = NULL;
}
+
+ s->poison_val = 0;
}
static void virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status)
@@ -908,6 +923,8 @@ static Property virtio_balloon_properties[] = {
VIRTIO_BALLOON_F_DEFLATE_ON_OOM, false),
DEFINE_PROP_BIT("free-page-hint", VirtIOBalloon, host_features,
VIRTIO_BALLOON_F_FREE_PAGE_HINT, false),
+ DEFINE_PROP_BIT("x-page-poison", VirtIOBalloon, host_features,
+ VIRTIO_BALLOON_F_PAGE_POISON, false),
/* QEMU 4.0 accidentally changed the config size even when free-page-hint
* is disabled, resulting in QEMU 3.1 migration incompatibility. This
* property retains this quirk for QEMU 4.1 machine types.
diff --git a/include/hw/virtio/virtio-balloon.h b/include/hw/virtio/virtio-balloon.h
index d1c968d2376e..7fe78e5c14d7 100644
--- a/include/hw/virtio/virtio-balloon.h
+++ b/include/hw/virtio/virtio-balloon.h
@@ -70,6 +70,7 @@ typedef struct VirtIOBalloon {
uint32_t host_features;
bool qemu_4_0_config_size;
+ uint32_t poison_val;
} VirtIOBalloon;
#endif
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^ permalink raw reply related
* [PATCH v10 6/6] virtio-balloon: Add support for providing unused page reports to host
From: Alexander Duyck @ 2019-09-18 17:53 UTC (permalink / raw)
To: virtio-dev, kvm, mst, david, dave.hansen, linux-kernel, willy,
mhocko, linux-mm, vbabka, akpm, mgorman, linux-arm-kernel,
osalvador
Cc: yang.zhang.wz, pagupta, riel, konrad.wilk, lcapitulino,
wei.w.wang, aarcange, nitesh, pbonzini, dan.j.williams,
alexander.h.duyck
In-Reply-To: <20190918175109.23474.67039.stgit@localhost.localdomain>
From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Add support for the page reporting feature provided by virtio-balloon.
Reporting differs from the regular balloon functionality in that is is
much less durable than a standard memory balloon. Instead of creating a
list of pages that cannot be accessed the pages are only inaccessible
while they are being indicated to the virtio interface. Once the
interface has acknowledged them they are placed back into their respective
free lists and are once again accessible by the guest system.
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---
drivers/virtio/Kconfig | 1 +
drivers/virtio/virtio_balloon.c | 65 +++++++++++++++++++++++++++++++++++
include/uapi/linux/virtio_balloon.h | 1 +
3 files changed, 67 insertions(+)
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 078615cf2afc..4b2dd8259ff5 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -58,6 +58,7 @@ config VIRTIO_BALLOON
tristate "Virtio balloon driver"
depends on VIRTIO
select MEMORY_BALLOON
+ select PAGE_REPORTING
---help---
This driver supports increasing and decreasing the amount
of memory within a KVM guest.
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 501a8d0ebf86..40a6dcaf368f 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -19,6 +19,7 @@
#include <linux/mount.h>
#include <linux/magic.h>
#include <linux/pseudo_fs.h>
+#include <linux/page_reporting.h>
/*
* Balloon device works in 4K page units. So each page is pointed to by
@@ -37,6 +38,9 @@
#define VIRTIO_BALLOON_FREE_PAGE_SIZE \
(1 << (VIRTIO_BALLOON_FREE_PAGE_ORDER + PAGE_SHIFT))
+/* limit on the number of pages that can be on the reporting vq */
+#define VIRTIO_BALLOON_VRING_HINTS_MAX 16
+
#ifdef CONFIG_BALLOON_COMPACTION
static struct vfsmount *balloon_mnt;
#endif
@@ -46,6 +50,7 @@ enum virtio_balloon_vq {
VIRTIO_BALLOON_VQ_DEFLATE,
VIRTIO_BALLOON_VQ_STATS,
VIRTIO_BALLOON_VQ_FREE_PAGE,
+ VIRTIO_BALLOON_VQ_REPORTING,
VIRTIO_BALLOON_VQ_MAX
};
@@ -113,6 +118,10 @@ struct virtio_balloon {
/* To register a shrinker to shrink memory upon memory pressure */
struct shrinker shrinker;
+
+ /* Unused page reporting device */
+ struct virtqueue *reporting_vq;
+ struct page_reporting_dev_info ph_dev_info;
};
static struct virtio_device_id id_table[] = {
@@ -152,6 +161,32 @@ static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq)
}
+void virtballoon_unused_page_report(struct page_reporting_dev_info *ph_dev_info,
+ unsigned int nents)
+{
+ struct virtio_balloon *vb =
+ container_of(ph_dev_info, struct virtio_balloon, ph_dev_info);
+ struct virtqueue *vq = vb->reporting_vq;
+ unsigned int unused, err;
+
+ /* We should always be able to add these buffers to an empty queue. */
+ err = virtqueue_add_inbuf(vq, ph_dev_info->sg, nents, vb,
+ GFP_NOWAIT | __GFP_NOWARN);
+
+ /*
+ * In the extremely unlikely case that something has changed and we
+ * are able to trigger an error we will simply display a warning
+ * and exit without actually processing the pages.
+ */
+ if (WARN_ON(err))
+ return;
+
+ virtqueue_kick(vq);
+
+ /* When host has read buffer, this completes via balloon_ack */
+ wait_event(vb->acked, virtqueue_get_buf(vq, &unused));
+}
+
static void set_page_pfns(struct virtio_balloon *vb,
__virtio32 pfns[], struct page *page)
{
@@ -476,6 +511,7 @@ static int init_vqs(struct virtio_balloon *vb)
names[VIRTIO_BALLOON_VQ_DEFLATE] = "deflate";
names[VIRTIO_BALLOON_VQ_STATS] = NULL;
names[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
+ names[VIRTIO_BALLOON_VQ_REPORTING] = NULL;
if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {
names[VIRTIO_BALLOON_VQ_STATS] = "stats";
@@ -487,11 +523,19 @@ static int init_vqs(struct virtio_balloon *vb)
callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
}
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) {
+ names[VIRTIO_BALLOON_VQ_REPORTING] = "reporting_vq";
+ callbacks[VIRTIO_BALLOON_VQ_REPORTING] = balloon_ack;
+ }
+
err = vb->vdev->config->find_vqs(vb->vdev, VIRTIO_BALLOON_VQ_MAX,
vqs, callbacks, names, NULL, NULL);
if (err)
return err;
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING))
+ vb->reporting_vq = vqs[VIRTIO_BALLOON_VQ_REPORTING];
+
vb->inflate_vq = vqs[VIRTIO_BALLOON_VQ_INFLATE];
vb->deflate_vq = vqs[VIRTIO_BALLOON_VQ_DEFLATE];
if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {
@@ -930,12 +974,30 @@ static int virtballoon_probe(struct virtio_device *vdev)
if (err)
goto out_del_balloon_wq;
}
+
+ vb->ph_dev_info.report = virtballoon_unused_page_report;
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) {
+ unsigned int capacity;
+
+ capacity = min_t(unsigned int,
+ virtqueue_get_vring_size(vb->reporting_vq),
+ VIRTIO_BALLOON_VRING_HINTS_MAX);
+ vb->ph_dev_info.capacity = capacity;
+
+ err = page_reporting_register(&vb->ph_dev_info);
+ if (err)
+ goto out_unregister_shrinker;
+ }
+
virtio_device_ready(vdev);
if (towards_target(vb))
virtballoon_changed(vdev);
return 0;
+out_unregister_shrinker:
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM))
+ virtio_balloon_unregister_shrinker(vb);
out_del_balloon_wq:
if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
destroy_workqueue(vb->balloon_wq);
@@ -964,6 +1026,8 @@ static void virtballoon_remove(struct virtio_device *vdev)
{
struct virtio_balloon *vb = vdev->priv;
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING))
+ page_reporting_unregister(&vb->ph_dev_info);
if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM))
virtio_balloon_unregister_shrinker(vb);
spin_lock_irq(&vb->stop_update_lock);
@@ -1035,6 +1099,7 @@ static int virtballoon_validate(struct virtio_device *vdev)
VIRTIO_BALLOON_F_DEFLATE_ON_OOM,
VIRTIO_BALLOON_F_FREE_PAGE_HINT,
VIRTIO_BALLOON_F_PAGE_POISON,
+ VIRTIO_BALLOON_F_REPORTING,
};
static struct virtio_driver virtio_balloon_driver = {
diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
index a1966cd7b677..19974392d324 100644
--- a/include/uapi/linux/virtio_balloon.h
+++ b/include/uapi/linux/virtio_balloon.h
@@ -36,6 +36,7 @@
#define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */
#define VIRTIO_BALLOON_F_FREE_PAGE_HINT 3 /* VQ to report free pages */
#define VIRTIO_BALLOON_F_PAGE_POISON 4 /* Guest is using page poisoning */
+#define VIRTIO_BALLOON_F_REPORTING 5 /* Page reporting virtqueue */
/* Size of a PFN in the balloon interface. */
#define VIRTIO_BALLOON_PFN_SHIFT 12
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^ permalink raw reply related
* [PATCH v10 5/6] virtio-balloon: Pull page poisoning config out of free page hinting
From: Alexander Duyck @ 2019-09-18 17:53 UTC (permalink / raw)
To: virtio-dev, kvm, mst, david, dave.hansen, linux-kernel, willy,
mhocko, linux-mm, vbabka, akpm, mgorman, linux-arm-kernel,
osalvador
Cc: yang.zhang.wz, pagupta, riel, konrad.wilk, lcapitulino,
wei.w.wang, aarcange, nitesh, pbonzini, dan.j.williams,
alexander.h.duyck
In-Reply-To: <20190918175109.23474.67039.stgit@localhost.localdomain>
From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Currently the page poisoning setting wasn't being enabled unless free page
hinting was enabled. However we will need the page poisoning tracking logic
as well for unused page reporting. As such pull it out and make it a
separate bit of config in the probe function.
In addition we can actually wrap the code in a check for NO_SANITY. If we
don't care what is actually in the page we can just default to 0 and leave
it there.
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---
drivers/virtio/virtio_balloon.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 226fbb995fb0..501a8d0ebf86 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -842,7 +842,6 @@ static int virtio_balloon_register_shrinker(struct virtio_balloon *vb)
static int virtballoon_probe(struct virtio_device *vdev)
{
struct virtio_balloon *vb;
- __u32 poison_val;
int err;
if (!vdev->config->get) {
@@ -909,11 +908,18 @@ static int virtballoon_probe(struct virtio_device *vdev)
VIRTIO_BALLOON_CMD_ID_STOP);
spin_lock_init(&vb->free_page_list_lock);
INIT_LIST_HEAD(&vb->free_page_list);
- if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) {
- memset(&poison_val, PAGE_POISON, sizeof(poison_val));
- virtio_cwrite(vb->vdev, struct virtio_balloon_config,
- poison_val, &poison_val);
- }
+ }
+ if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) {
+ __u32 poison_val;
+
+ /*
+ * Let the hypervisor know that we are expecting a
+ * specific value to be written back in unused pages.
+ */
+ memset(&poison_val, PAGE_POISON, sizeof(poison_val));
+
+ virtio_cwrite(vb->vdev, struct virtio_balloon_config,
+ poison_val, &poison_val);
}
/*
* We continue to use VIRTIO_BALLOON_F_DEFLATE_ON_OOM to decide if a
@@ -1014,7 +1020,9 @@ static int virtballoon_restore(struct virtio_device *vdev)
static int virtballoon_validate(struct virtio_device *vdev)
{
- if (!page_poisoning_enabled())
+ /* Tell the host whether we care about poisoned pages. */
+ if (IS_ENABLED(CONFIG_PAGE_POISONING_NO_SANITY) ||
+ !page_poisoning_enabled())
__virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_POISON);
__virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM);
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^ permalink raw reply related
* [PATCH v10 4/6] mm: Add device side and notifier for unused page reporting
From: Alexander Duyck @ 2019-09-18 17:52 UTC (permalink / raw)
To: virtio-dev, kvm, mst, david, dave.hansen, linux-kernel, willy,
mhocko, linux-mm, vbabka, akpm, mgorman, linux-arm-kernel,
osalvador
Cc: yang.zhang.wz, pagupta, riel, konrad.wilk, lcapitulino,
wei.w.wang, aarcange, nitesh, pbonzini, dan.j.williams,
alexander.h.duyck
In-Reply-To: <20190918175109.23474.67039.stgit@localhost.localdomain>
From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
With this patch we are adding the pieces needed to enable the reporting of
pages to a specific device. That device needs to register a page reporting
device that can be used to handle notifications that that pages are unused.
Registering the device will in turn enable the notifications and allow page
reporting to be active. When the the device is unregistered it will disable
page reporting notifications. For now we only allow one page reporting
device to be registered at a time.
The determination of when to start reporting is based on the tracking of
the number of free pages in a given area versus the number of reported
pages in that area. We keep track of the number of reported pages per
free_area in a separate zone specific area. We do this to avoid modifying
the free_area structure as this can lead to false sharing for the highest
order with the zone lock which leads to a noticeable performance
degradation.
Once reporting has started get_unreported_pages will use the
reported_boundary pointers to track where it should resume processing the
free lists. It will go through and either set the index if it finds a
reported page, or it will attempt to isolate the page so that it can be
reported.
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---
include/linux/page_reporting.h | 31 ++++
mm/Makefile | 1
mm/page_alloc.c | 10 +
mm/page_reporting.c | 350 ++++++++++++++++++++++++++++++++++++++++
mm/page_reporting.h | 46 +++++
5 files changed, 436 insertions(+), 2 deletions(-)
create mode 100644 include/linux/page_reporting.h
create mode 100644 mm/page_reporting.c
diff --git a/include/linux/page_reporting.h b/include/linux/page_reporting.h
new file mode 100644
index 000000000000..afa214f7beaf
--- /dev/null
+++ b/include/linux/page_reporting.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_PAGE_REPORTING_H
+#define _LINUX_PAGE_REPORTING_H
+
+#include <linux/mmzone.h>
+
+struct page_reporting_dev_info {
+ /* function that alters pages to make them "reported" */
+ void (*report)(struct page_reporting_dev_info *phdev,
+ unsigned int nents);
+
+ /* scatterlist containing pages to be processed */
+ struct scatterlist *sg;
+
+ /*
+ * Upper limit on the number of pages that the react function
+ * expects to be placed into the batch list to be processed.
+ */
+ unsigned long capacity;
+
+ /* work struct for processing reports */
+ struct delayed_work work;
+
+ /* The number of zones requesting reporting */
+ atomic_t refcnt;
+};
+
+/* Tear-down and bring-up for page reporting devices */
+void page_reporting_unregister(struct page_reporting_dev_info *phdev);
+int page_reporting_register(struct page_reporting_dev_info *phdev);
+#endif /*_LINUX_PAGE_REPORTING_H */
diff --git a/mm/Makefile b/mm/Makefile
index d996846697ef..fc4fa17b6c83 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -107,3 +107,4 @@ obj-$(CONFIG_PERCPU_STATS) += percpu-stats.o
obj-$(CONFIG_ZONE_DEVICE) += memremap.o
obj-$(CONFIG_HMM_MIRROR) += hmm.o
obj-$(CONFIG_MEMFD_CREATE) += memfd.o
+obj-$(CONFIG_PAGE_REPORTING) += page_reporting.o
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index ed0128c65936..b4189d9cc729 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1073,6 +1073,14 @@ static inline void __free_one_page(struct page *page,
add_to_free_list_tail(page, zone, order, migratetype);
else
add_to_free_list(page, zone, order, migratetype);
+
+ /*
+ * No need to notify on a reported page as the total count of
+ * unreported pages will not have increased since we have essentially
+ * merged the reported page with one or more unreported pages.
+ */
+ if (!reported)
+ page_reporting_notify_free(zone, order);
}
/*
@@ -2262,8 +2270,6 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
}
#ifdef CONFIG_PAGE_REPORTING
-struct list_head **reported_boundary __read_mostly;
-
/**
* free_reported_page - Return a now-reported page back where we got it
* @page: Page that was reported
diff --git a/mm/page_reporting.c b/mm/page_reporting.c
new file mode 100644
index 000000000000..3e36f250d2d6
--- /dev/null
+++ b/mm/page_reporting.c
@@ -0,0 +1,350 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/page_reporting.h>
+#include <linux/gfp.h>
+#include <linux/export.h>
+#include <linux/delay.h>
+#include <linux/scatterlist.h>
+
+#include "page_reporting.h"
+#include "internal.h"
+
+static struct page_reporting_dev_info __rcu *ph_dev_info __read_mostly;
+struct list_head **reported_boundary __read_mostly;
+
+#define for_each_reporting_migratetype_order(_order, _type) \
+ for (_order = MAX_ORDER; _order-- != PAGE_REPORTING_MIN_ORDER;) \
+ for (_type = MIGRATE_TYPES; _type--;) \
+ if (!is_migrate_isolate(_type))
+
+static void page_reporting_populate_metadata(struct zone *zone)
+{
+ size_t size;
+ int node;
+
+ /*
+ * We need to make sure we have somewhere to store the tracking
+ * data for how many reported pages are in the zone. To do that
+ * we need to make certain zone->reported_pages is populated.
+ */
+ if (zone->reported_pages)
+ return;
+
+ node = zone_to_nid(zone);
+ size = (MAX_ORDER - PAGE_REPORTING_MIN_ORDER) * sizeof(unsigned long);
+ zone->reported_pages = kzalloc_node(size, GFP_KERNEL, node);
+}
+
+static void page_reporting_reset_all_boundaries(struct zone *zone)
+{
+ unsigned int order, mt;
+
+ /* Update boundary data to reflect the zone we are currently working */
+ for_each_reporting_migratetype_order(order, mt)
+ page_reporting_reset_boundary(zone, order, mt);
+}
+
+static struct page *
+get_unreported_page(struct zone *zone, unsigned int order, int mt)
+{
+ struct list_head *list = &zone->free_area[order].free_list[mt];
+ struct list_head *tail = get_unreported_tail(zone, order, mt);
+ unsigned long index = get_reporting_index(order, mt);
+ struct page *page;
+
+ /* Find a page of the appropriate size in the preferred list */
+ page = list_last_entry(tail, struct page, lru);
+ list_for_each_entry_from_reverse(page, list, lru) {
+ /* If we entered this loop then the "raw" list isn't empty */
+
+ /*
+ * We are going to skip over the reported pages. Make
+ * certain that the index of those pages are correct
+ * as we will later be moving the boundary into place
+ * above them.
+ */
+ if (PageReported(page)) {
+ page->index = index;
+ tail = &page->lru;
+ continue;
+ }
+
+ /* Drop reference to page if isolate fails */
+ if (__isolate_free_page(page, order))
+ goto out;
+
+ break;
+ }
+
+ page = NULL;
+out:
+ /* Update the boundary */
+ reported_boundary[index] = tail;
+
+ return page;
+}
+
+static void
+__page_reporting_cancel(struct zone *zone,
+ struct page_reporting_dev_info *phdev)
+{
+ /* processing of the zone is complete, we can disable boundaries */
+ page_reporting_disable_boundaries(zone);
+
+ /*
+ * If there are no longer enough free pages to fully populate
+ * the scatterlist, then we can just shut it down for this zone.
+ */
+ __clear_bit(ZONE_PAGE_REPORTING_REQUESTED, &zone->flags);
+ atomic_dec(&phdev->refcnt);
+}
+
+static unsigned int
+page_reporting_fill(struct zone *zone, struct page_reporting_dev_info *phdev)
+{
+ struct scatterlist *sg = phdev->sg;
+ unsigned int order, mt, count = 0;
+
+ sg_init_table(phdev->sg, phdev->capacity);
+
+ /* Make sure the boundaries are enabled */
+ if (!__test_and_set_bit(ZONE_PAGE_REPORTING_ACTIVE, &zone->flags))
+ page_reporting_reset_all_boundaries(zone);
+
+ for_each_reporting_migratetype_order(order, mt) {
+ struct page *page;
+
+ /*
+ * Pull pages from free list until we have drained
+ * it or we have reached capacity.
+ */
+ while ((page = get_unreported_page(zone, order, mt))) {
+ sg_set_page(&sg[count], page, PAGE_SIZE << order, 0);
+
+ if (++count == phdev->capacity)
+ return phdev->capacity;
+ }
+ }
+
+ /* mark end of scatterlist due to underflow */
+ if (count)
+ sg_mark_end(&sg[count - 1]);
+
+ /* We ran out of pages so we can stop now */
+ __page_reporting_cancel(zone, phdev);
+
+ return count;
+}
+
+static void page_reporting_drain(struct page_reporting_dev_info *phdev)
+{
+ struct scatterlist *sg = phdev->sg;
+
+ /*
+ * Drain the now reported pages back into their respective
+ * free lists/areas. We assume at least one page is populated.
+ */
+ do {
+ free_reported_page(sg_page(sg), get_order(sg->length));
+ } while (!sg_is_last(sg++));
+}
+
+/*
+ * The page reporting cycle consists of 4 stages, fill, report, drain, and
+ * idle. We will cycle through the first 3 stages until we fail to obtain any
+ * pages, in that case we will switch to idle.
+ */
+static void
+page_reporting_cycle(struct zone *zone, struct page_reporting_dev_info *phdev)
+{
+ /*
+ * Guarantee boundaries and stats are populated before we
+ * start placing reported pages in the zone.
+ */
+ page_reporting_populate_metadata(zone);
+
+ spin_lock_irq(&zone->lock);
+
+ /* Cancel the request if we failed to populate zone metadata */
+ if (!zone->reported_pages) {
+ __page_reporting_cancel(zone, phdev);
+ goto zone_not_ready;
+ }
+
+ do {
+ /* Pull pages out of allocator into a scaterlist */
+ unsigned int nents = page_reporting_fill(zone, phdev);
+
+ /* no pages were acquired, give up */
+ if (!nents)
+ break;
+
+ spin_unlock_irq(&zone->lock);
+
+ /* begin processing pages in local list */
+ phdev->report(phdev, nents);
+
+ spin_lock_irq(&zone->lock);
+
+ /*
+ * We should have a scatterlist of pages that have been
+ * processed. Return them to their original free lists.
+ */
+ page_reporting_drain(phdev);
+
+ /* keep pulling pages till there are none to pull */
+ } while (test_bit(ZONE_PAGE_REPORTING_REQUESTED, &zone->flags));
+zone_not_ready:
+ spin_unlock_irq(&zone->lock);
+}
+
+static void page_reporting_process(struct work_struct *work)
+{
+ struct delayed_work *d_work = to_delayed_work(work);
+ struct page_reporting_dev_info *phdev =
+ container_of(d_work, struct page_reporting_dev_info, work);
+ struct zone *zone = first_online_pgdat()->node_zones;
+
+ do {
+ if (test_bit(ZONE_PAGE_REPORTING_REQUESTED, &zone->flags))
+ page_reporting_cycle(zone, phdev);
+
+ /* Move to next zone, if at end of list start over */
+ zone = next_zone(zone) ? : first_online_pgdat()->node_zones;
+
+ /*
+ * As long as refcnt has not reached zero there are still
+ * zones to be processed.
+ */
+ } while (atomic_read(&phdev->refcnt));
+}
+
+/* request page reporting on this zone */
+void __page_reporting_request(struct zone *zone)
+{
+ struct page_reporting_dev_info *phdev;
+
+ rcu_read_lock();
+
+ /*
+ * We use RCU to protect the ph_dev_info pointer. In almost all
+ * cases this should be present, however in the unlikely case of
+ * a shutdown this will be NULL and we should exit.
+ */
+ phdev = rcu_dereference(ph_dev_info);
+ if (unlikely(!phdev))
+ goto out;
+
+ /*
+ * We can use separate test and set operations here as there
+ * is nothing else that can set or clear this bit while we are
+ * holding the zone lock. The advantage to doing it this way is
+ * that we don't have to dirty the cacheline unless we are
+ * changing the value.
+ */
+ __set_bit(ZONE_PAGE_REPORTING_REQUESTED, &zone->flags);
+
+ /*
+ * Delay the start of work to allow a sizable queue to
+ * build. For now we are limiting this to running no more
+ * than 10 times per second.
+ */
+ if (!atomic_fetch_inc(&phdev->refcnt))
+ schedule_delayed_work(&phdev->work, HZ / 10);
+out:
+ rcu_read_unlock();
+}
+
+static DEFINE_MUTEX(page_reporting_mutex);
+DEFINE_STATIC_KEY_FALSE(page_reporting_notify_enabled);
+
+void page_reporting_unregister(struct page_reporting_dev_info *phdev)
+{
+ mutex_lock(&page_reporting_mutex);
+
+ if (rcu_access_pointer(ph_dev_info) == phdev) {
+ /* Disable page reporting notification */
+ static_branch_disable(&page_reporting_notify_enabled);
+ RCU_INIT_POINTER(ph_dev_info, NULL);
+ synchronize_rcu();
+
+ /* Flush any existing work, and lock it out */
+ cancel_delayed_work_sync(&phdev->work);
+
+ /* Free scatterlist */
+ kfree(phdev->sg);
+ phdev->sg = NULL;
+
+ /* Free boundaries */
+ kfree(reported_boundary);
+ reported_boundary = NULL;
+ }
+
+ mutex_unlock(&page_reporting_mutex);
+}
+EXPORT_SYMBOL_GPL(page_reporting_unregister);
+
+int page_reporting_register(struct page_reporting_dev_info *phdev)
+{
+ struct zone *zone;
+ int err = 0;
+
+ /* No point in enabling this if it cannot handle any pages */
+ if (WARN_ON(!phdev->capacity))
+ return -EINVAL;
+
+ mutex_lock(&page_reporting_mutex);
+
+ /* nothing to do if already in use */
+ if (rcu_access_pointer(ph_dev_info)) {
+ err = -EBUSY;
+ goto err_out;
+ }
+
+ /*
+ * Allocate space to store the boundaries for the zone we are
+ * actively reporting on. We will need to store one boundary
+ * pointer per migratetype, and then we need to have one of these
+ * arrays per order for orders greater than or equal to
+ * PAGE_REPORTING_MIN_ORDER.
+ */
+ reported_boundary = kcalloc(get_reporting_index(MAX_ORDER, 0),
+ sizeof(struct list_head *), GFP_KERNEL);
+ if (!reported_boundary) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+
+ /* allocate scatterlist to store pages being reported on */
+ phdev->sg = kcalloc(phdev->capacity, sizeof(*phdev->sg), GFP_KERNEL);
+ if (!phdev->sg) {
+ err = -ENOMEM;
+
+ kfree(reported_boundary);
+ reported_boundary = NULL;
+
+ goto err_out;
+ }
+
+
+ /* initialize refcnt and work structures */
+ atomic_set(&phdev->refcnt, 0);
+ INIT_DELAYED_WORK(&phdev->work, &page_reporting_process);
+
+ /* assign device, and begin initial flush of populated zones */
+ rcu_assign_pointer(ph_dev_info, phdev);
+ for_each_populated_zone(zone) {
+ spin_lock_irq(&zone->lock);
+ __page_reporting_request(zone);
+ spin_unlock_irq(&zone->lock);
+ }
+
+ /* enable page reporting notification */
+ static_branch_enable(&page_reporting_notify_enabled);
+err_out:
+ mutex_unlock(&page_reporting_mutex);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(page_reporting_register);
diff --git a/mm/page_reporting.h b/mm/page_reporting.h
index c5e1bb58ad96..acc6dafc74a1 100644
--- a/mm/page_reporting.h
+++ b/mm/page_reporting.h
@@ -23,6 +23,48 @@ static inline void page_reporting_reset_zone(struct zone *zone)
zone->reported_pages = NULL;
}
+DECLARE_STATIC_KEY_FALSE(page_reporting_notify_enabled);
+void __page_reporting_request(struct zone *zone);
+
+/**
+ * page_reporting_notify_free - Free page notification to start page processing
+ * @zone: Pointer to current zone of last page processed
+ * @order: Order of last page added to zone
+ *
+ * This function is meant to act as a screener for __page_reporting_request
+ * which will determine if a give zone has crossed over the high-water mark
+ * that will justify us beginning page treatment. If we have crossed that
+ * threshold then it will start the process of pulling some pages and
+ * placing them in the batch list for treatment.
+ */
+static inline void page_reporting_notify_free(struct zone *zone, int order)
+{
+ unsigned long nr_reported;
+
+ /* Called from hot path in __free_one_page() */
+ if (!static_branch_unlikely(&page_reporting_notify_enabled))
+ return;
+
+ /* Limit notifications only to higher order pages */
+ if (order < PAGE_REPORTING_MIN_ORDER)
+ return;
+
+ /* Do not bother with tests if we have already requested reporting */
+ if (test_bit(ZONE_PAGE_REPORTING_REQUESTED, &zone->flags))
+ return;
+
+ /* If reported_pages is not populated, assume 0 */
+ nr_reported = zone->reported_pages ?
+ zone->reported_pages[order - PAGE_REPORTING_MIN_ORDER] : 0;
+
+ /* Only request it if we have enough to begin the page reporting */
+ if (zone->free_area[order].nr_free < nr_reported + PAGE_REPORTING_HWM)
+ return;
+
+ /* This is slow, but should be called very rarely */
+ __page_reporting_request(zone);
+}
+
/* Boundary functions */
static inline pgoff_t
get_reporting_index(unsigned int order, unsigned int migratetype)
@@ -142,6 +184,10 @@ static inline void page_reporting_reset_zone(struct zone *zone)
{
}
+static inline void page_reporting_notify_free(struct zone *zone, int order)
+{
+}
+
static inline void
page_reporting_free_area_release(struct zone *zone, unsigned int order, int mt)
{
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related
* [PATCH v10 3/6] mm: Introduce Reported pages
From: Alexander Duyck @ 2019-09-18 17:52 UTC (permalink / raw)
To: virtio-dev, kvm, mst, david, dave.hansen, linux-kernel, willy,
mhocko, linux-mm, vbabka, akpm, mgorman, linux-arm-kernel,
osalvador
Cc: yang.zhang.wz, pagupta, riel, konrad.wilk, lcapitulino,
wei.w.wang, aarcange, nitesh, pbonzini, dan.j.williams,
alexander.h.duyck
In-Reply-To: <20190918175109.23474.67039.stgit@localhost.localdomain>
From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
In order to pave the way for free page reporting in virtualized
environments we will need a way to get pages out of the free lists and
identify those pages after they have been returned. To accomplish this,
this patch adds the concept of a Reported Buddy, which is essentially
meant to just be the Uptodate flag used in conjunction with the Buddy
page type.
It adds a set of pointers we shall call "reported_boundary" which
represent the upper boundary between the unreported and reported pages.
The general idea is that in order for a page to cross from one side of the
boundary to the other it will need to verify that it went through the
reporting process. Ultimately a free list has been fully processed when
the boundary has been moved from the tail all they way up to occupying the
first entry in the list.
One limitation to this approach is that it is essentially a linear search
and in the case of the free lists we can have pages added to either the
head or the tail of the list. In order to place limits on this we only
allow pages to be added before the reported_boundary instead of adding
to the tail itself. An added advantage to this approach is that we should
be reducing the overall memory footprint of the guest as it will be more
likely to recycle warm pages versus trying to allocate the reported pages
that were likely evicted from the guest memory.
Since we will only be reporting one zone at a time we keep the boundary
limited to being defined for just the zone we are currently reporting pages
from. Doing this we can keep the number of additional pointers needed quite
small. To flag that the boundaries are in place we use a single bit
in the zone to indicate that reporting and the boundaries are active.
We store the index of the boundary pointer used to track the reported page
in the page->index value. Doing this we can avoid unnecessary computation
to determine the index value again. There should be no issues with this as
the value is unused when the page is in the buddy allocator, and is reset
as soon as the page is removed from the free list.
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---
include/linux/mmzone.h | 16 ++++
include/linux/page-flags.h | 11 +++
mm/Kconfig | 11 +++
mm/compaction.c | 5 +
mm/memory_hotplug.c | 2
mm/page_alloc.c | 67 +++++++++++++++--
mm/page_reporting.h | 178 ++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 283 insertions(+), 7 deletions(-)
create mode 100644 mm/page_reporting.h
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 270a7b493174..53922c30b8d8 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -463,6 +463,14 @@ struct zone {
seqlock_t span_seqlock;
#endif
+#ifdef CONFIG_PAGE_REPORTING
+ /*
+ * Pointer to reported page tracking statistics array. The size of
+ * the array is MAX_ORDER - PAGE_REPORTING_MIN_ORDER. NULL when
+ * unused page reporting is not present.
+ */
+ unsigned long *reported_pages;
+#endif
int initialized;
/* Write-intensive fields used from the page allocator */
@@ -538,6 +546,14 @@ enum zone_flags {
ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks.
* Cleared when kswapd is woken.
*/
+ ZONE_PAGE_REPORTING_ACTIVE, /* zone enabled page reporting and is
+ * activly flushing the data out of
+ * higher order pages.
+ */
+ ZONE_PAGE_REPORTING_REQUESTED, /* zone enabled page reporting and has
+ * requested flushing the data out of
+ * higher order pages.
+ */
};
static inline unsigned long zone_managed_pages(struct zone *zone)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index f91cb8898ff0..759a3b3956f2 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -163,6 +163,9 @@ enum pageflags {
/* non-lru isolated movable page */
PG_isolated = PG_reclaim,
+
+ /* Buddy pages. Used to track which pages have been reported */
+ PG_reported = PG_uptodate,
};
#ifndef __GENERATING_BOUNDS_H
@@ -432,6 +435,14 @@ static inline bool set_hwpoison_free_buddy_page(struct page *page)
#endif
/*
+ * PageReported() is used to track reported free pages within the Buddy
+ * allocator. We can use the non-atomic version of the test and set
+ * operations as both should be shielded with the zone lock to prevent
+ * any possible races on the setting or clearing of the bit.
+ */
+__PAGEFLAG(Reported, reported, PF_NO_COMPOUND)
+
+/*
* On an anonymous page mapped into a user virtual memory area,
* page->mapping points to its anon_vma, not to a struct address_space;
* with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h.
diff --git a/mm/Kconfig b/mm/Kconfig
index a5dae9a7eb51..0419b2a9be3e 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -237,6 +237,17 @@ config COMPACTION
linux-mm@kvack.org.
#
+# support for unused page reporting
+config PAGE_REPORTING
+ bool "Allow for reporting of unused pages"
+ def_bool n
+ help
+ Unused page reporting allows for the incremental acquisition of
+ unused pages from the buddy allocator for the purpose of reporting
+ those pages to another entity, such as a hypervisor, so that the
+ memory can be freed up for other uses.
+
+#
# support for page migration
#
config MIGRATION
diff --git a/mm/compaction.c b/mm/compaction.c
index ce08b39d85d4..60e064330b3a 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -24,6 +24,7 @@
#include <linux/page_owner.h>
#include <linux/psi.h>
#include "internal.h"
+#include "page_reporting.h"
#ifdef CONFIG_COMPACTION
static inline void count_compact_event(enum vm_event_item item)
@@ -1325,6 +1326,8 @@ static int next_search_order(struct compact_control *cc, int order)
continue;
spin_lock_irqsave(&cc->zone->lock, flags);
+ page_reporting_free_area_release(cc->zone, order,
+ MIGRATE_MOVABLE);
freelist = &area->free_list[MIGRATE_MOVABLE];
list_for_each_entry_reverse(freepage, freelist, lru) {
unsigned long pfn;
@@ -1681,6 +1684,8 @@ static unsigned long fast_find_migrateblock(struct compact_control *cc)
continue;
spin_lock_irqsave(&cc->zone->lock, flags);
+ page_reporting_free_area_release(cc->zone, order,
+ MIGRATE_MOVABLE);
freelist = &area->free_list[MIGRATE_MOVABLE];
list_for_each_entry(freepage, freelist, lru) {
unsigned long free_pfn;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 49f7bf91c25a..09c6f52e2bc5 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -41,6 +41,7 @@
#include "internal.h"
#include "shuffle.h"
+#include "page_reporting.h"
/*
* online_page_callback contains pointer to current page onlining function.
@@ -1613,6 +1614,7 @@ static int __ref __offline_pages(unsigned long start_pfn,
if (!populated_zone(zone)) {
zone_pcp_reset(zone);
build_all_zonelists(NULL);
+ page_reporting_reset_zone(zone);
} else
zone_pcp_update(zone);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f8271ec8e06e..ed0128c65936 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -74,6 +74,7 @@
#include <asm/div64.h>
#include "internal.h"
#include "shuffle.h"
+#include "page_reporting.h"
/* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
static DEFINE_MUTEX(pcp_batch_high_lock);
@@ -891,10 +892,15 @@ static inline void add_to_free_list(struct page *page, struct zone *zone,
static inline void add_to_free_list_tail(struct page *page, struct zone *zone,
unsigned int order, int migratetype)
{
- struct free_area *area = &zone->free_area[order];
+ struct list_head *tail = get_unreported_tail(zone, order, migratetype);
- list_add_tail(&page->lru, &area->free_list[migratetype]);
- area->nr_free++;
+ /*
+ * To prevent the unreported pages from slipping behind our iterator
+ * we will force them to be inserted in front of it. By doing this
+ * we should only need to make one pass through the freelist.
+ */
+ list_add_tail(&page->lru, tail);
+ zone->free_area[order].nr_free++;
}
/* Used for pages which are on another list */
@@ -903,12 +909,20 @@ static inline void move_to_free_list(struct page *page, struct zone *zone,
{
struct free_area *area = &zone->free_area[order];
+ /* Make certain the page isn't occupying the boundary */
+ if (unlikely(PageReported(page)))
+ __del_page_from_reported_list(page, zone);
+
list_move(&page->lru, &area->free_list[migratetype]);
}
static inline void del_page_from_free_list(struct page *page, struct zone *zone,
unsigned int order)
{
+ /* remove page from reported list, and clear reported state */
+ if (unlikely(PageReported(page)))
+ del_page_from_reported_list(page, zone, order);
+
list_del(&page->lru);
__ClearPageBuddy(page);
set_page_private(page, 0);
@@ -972,7 +986,7 @@ static inline void del_page_from_free_list(struct page *page, struct zone *zone,
static inline void __free_one_page(struct page *page,
unsigned long pfn,
struct zone *zone, unsigned int order,
- int migratetype)
+ int migratetype, bool reported)
{
struct capture_control *capc = task_capc(zone);
unsigned long uninitialized_var(buddy_pfn);
@@ -1048,7 +1062,9 @@ static inline void __free_one_page(struct page *page,
done_merging:
set_page_order(page, order);
- if (is_shuffle_order(order))
+ if (reported)
+ to_tail = true;
+ else if (is_shuffle_order(order))
to_tail = shuffle_pick_tail();
else
to_tail = buddy_merge_likely(pfn, buddy_pfn, page, order);
@@ -1367,7 +1383,7 @@ static void free_pcppages_bulk(struct zone *zone, int count,
if (unlikely(isolated_pageblocks))
mt = get_pageblock_migratetype(page);
- __free_one_page(page, page_to_pfn(page), zone, 0, mt);
+ __free_one_page(page, page_to_pfn(page), zone, 0, mt, false);
trace_mm_page_pcpu_drain(page, 0, mt);
}
spin_unlock(&zone->lock);
@@ -1383,7 +1399,7 @@ static void free_one_page(struct zone *zone,
is_migrate_isolate(migratetype))) {
migratetype = get_pfnblock_migratetype(page, pfn);
}
- __free_one_page(page, pfn, zone, order, migratetype);
+ __free_one_page(page, pfn, zone, order, migratetype, false);
spin_unlock(&zone->lock);
}
@@ -2245,6 +2261,43 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
return NULL;
}
+#ifdef CONFIG_PAGE_REPORTING
+struct list_head **reported_boundary __read_mostly;
+
+/**
+ * free_reported_page - Return a now-reported page back where we got it
+ * @page: Page that was reported
+ * @order: Order of the reported page
+ *
+ * This function will pull the migratetype and order information out
+ * of the page and attempt to return it where it found it. If the page
+ * is added to the free list without changes we will mark it as being
+ * reported.
+ */
+void free_reported_page(struct page *page, unsigned int order)
+{
+ struct zone *zone = page_zone(page);
+ unsigned long pfn;
+ unsigned int mt;
+
+ /* zone lock should be held when this function is called */
+ lockdep_assert_held(&zone->lock);
+
+ pfn = page_to_pfn(page);
+ mt = get_pfnblock_migratetype(page, pfn);
+ __free_one_page(page, pfn, zone, order, mt, true);
+
+ /*
+ * If page was not comingled with another page we can consider
+ * the result to be "reported" since part of the page hasn't been
+ * modified, otherwise we would need to report on the new larger
+ * page.
+ */
+ if (PageBuddy(page) && page_order(page) == order)
+ add_page_to_reported_list(page, zone, order, mt);
+}
+#endif /* CONFIG_PAGE_REPORTING */
+
/*
* This array describes the order lists are fallen back to when
* the free lists for the desirable migrate type are depleted
diff --git a/mm/page_reporting.h b/mm/page_reporting.h
new file mode 100644
index 000000000000..c5e1bb58ad96
--- /dev/null
+++ b/mm/page_reporting.h
@@ -0,0 +1,178 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _MM_PAGE_REPORTING_H
+#define _MM_PAGE_REPORTING_H
+
+#include <linux/mmzone.h>
+#include <linux/pageblock-flags.h>
+#include <linux/page-isolation.h>
+#include <linux/jump_label.h>
+#include <linux/slab.h>
+#include <asm/pgtable.h>
+
+#define PAGE_REPORTING_MIN_ORDER pageblock_order
+#define PAGE_REPORTING_HWM 32
+
+#ifdef CONFIG_PAGE_REPORTING
+/* Reported page accessors, defined in page_alloc.c */
+void free_reported_page(struct page *page, unsigned int order);
+
+/* Free reported_pages and reset reported page tracking count to 0 */
+static inline void page_reporting_reset_zone(struct zone *zone)
+{
+ kfree(zone->reported_pages);
+ zone->reported_pages = NULL;
+}
+
+/* Boundary functions */
+static inline pgoff_t
+get_reporting_index(unsigned int order, unsigned int migratetype)
+{
+ /*
+ * We will only ever be dealing with pages greater-than or equal to
+ * PAGE_REPORTING_MIN_ORDER. Since that is the case we can avoid
+ * allocating unused space by limiting our index range to only the
+ * orders that are supported for page reporting.
+ */
+ return (order - PAGE_REPORTING_MIN_ORDER) * MIGRATE_TYPES + migratetype;
+}
+
+extern struct list_head **reported_boundary __read_mostly;
+
+static inline void
+page_reporting_reset_boundary(struct zone *zone, unsigned int order, int mt)
+{
+ int index;
+
+ if (order < PAGE_REPORTING_MIN_ORDER)
+ return;
+ if (!test_bit(ZONE_PAGE_REPORTING_ACTIVE, &zone->flags))
+ return;
+
+ index = get_reporting_index(order, mt);
+ reported_boundary[index] = &zone->free_area[order].free_list[mt];
+}
+
+static inline void page_reporting_disable_boundaries(struct zone *zone)
+{
+ /* zone lock should be held when this function is called */
+ lockdep_assert_held(&zone->lock);
+
+ __clear_bit(ZONE_PAGE_REPORTING_ACTIVE, &zone->flags);
+}
+
+static inline void
+page_reporting_free_area_release(struct zone *zone, unsigned int order, int mt)
+{
+ page_reporting_reset_boundary(zone, order, mt);
+}
+
+/*
+ * Method for obtaining the tail of the free list. Using this allows for
+ * tail insertions of unreported pages into the region that is currently
+ * being scanned so as to avoid interleaving reported and unreported pages.
+ */
+static inline struct list_head *
+get_unreported_tail(struct zone *zone, unsigned int order, int migratetype)
+{
+ if (order >= PAGE_REPORTING_MIN_ORDER &&
+ test_bit(ZONE_PAGE_REPORTING_ACTIVE, &zone->flags))
+ return reported_boundary[get_reporting_index(order,
+ migratetype)];
+
+ return &zone->free_area[order].free_list[migratetype];
+}
+
+/*
+ * Functions for adding/removing reported pages to the freelist.
+ * All of them expect the zone lock to be held to maintain
+ * consistency of the reported list as a subset of the free list.
+ */
+static inline void
+add_page_to_reported_list(struct page *page, struct zone *zone,
+ unsigned int order, unsigned int mt)
+{
+ /*
+ * Default to using index 0, this will be updated later if the zone
+ * is still being processed.
+ */
+ page->index = 0;
+
+ /* flag page as reported */
+ __SetPageReported(page);
+
+ /* update areated page accounting */
+ zone->reported_pages[order - PAGE_REPORTING_MIN_ORDER]++;
+}
+
+static inline void page_reporting_pull_boundary(struct page *page)
+{
+ struct list_head **tail = &reported_boundary[page->index];
+
+ if (*tail == &page->lru)
+ *tail = page->lru.next;
+}
+
+static inline void
+__del_page_from_reported_list(struct page *page, struct zone *zone)
+{
+ /*
+ * Since the page is being pulled from the list we need to update
+ * the boundary, after that we can just update the index so that
+ * the correct boundary will be checked in the future.
+ */
+ if (test_bit(ZONE_PAGE_REPORTING_ACTIVE, &zone->flags))
+ page_reporting_pull_boundary(page);
+}
+
+static inline void
+del_page_from_reported_list(struct page *page, struct zone *zone,
+ unsigned int order)
+{
+ __del_page_from_reported_list(page, zone);
+
+ /* page_private will contain the page order, so just use it directly */
+ zone->reported_pages[order - PAGE_REPORTING_MIN_ORDER]--;
+
+ /* clear the flag so we can report on it when it returns */
+ __ClearPageReported(page);
+}
+
+#else /* CONFIG_PAGE_REPORTING */
+static inline void page_reporting_reset_zone(struct zone *zone)
+{
+}
+
+static inline void
+page_reporting_free_area_release(struct zone *zone, unsigned int order, int mt)
+{
+}
+
+static inline struct list_head *
+get_unreported_tail(struct zone *zone, unsigned int order, int migratetype)
+{
+ return &zone->free_area[order].free_list[migratetype];
+}
+
+static inline void
+add_page_to_reported_list(struct page *page, struct zone *zone,
+ int order, int migratetype)
+{
+}
+
+static inline void
+__del_page_from_reported_list(struct page *page, struct zone *zone)
+{
+}
+
+static inline void
+del_page_from_reported_list(struct page *page, struct zone *zone,
+ unsigned int order)
+{
+}
+
+static inline void
+move_page_to_reported_list(struct page *page, struct zone *zone, int dest_mt)
+{
+}
+#endif /* CONFIG_PAGE_REPORTING */
+#endif /*_MM_PAGE_REPORTING_H */
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^ permalink raw reply related
* [PATCH v10 2/6] mm: Use zone and order instead of free area in free_list manipulators
From: Alexander Duyck @ 2019-09-18 17:52 UTC (permalink / raw)
To: virtio-dev, kvm, mst, david, dave.hansen, linux-kernel, willy,
mhocko, linux-mm, vbabka, akpm, mgorman, linux-arm-kernel,
osalvador
Cc: yang.zhang.wz, pagupta, riel, konrad.wilk, lcapitulino,
wei.w.wang, aarcange, nitesh, pbonzini, dan.j.williams,
alexander.h.duyck
In-Reply-To: <20190918175109.23474.67039.stgit@localhost.localdomain>
From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
In order to enable the use of the zone from the list manipulator functions
I will need access to the zone pointer. As it turns out most of the
accessors were always just being directly passed &zone->free_area[order]
anyway so it would make sense to just fold that into the function itself
and pass the zone and order as arguments instead of the free area.
In order to be able to reference the zone we need to move the declaration
of the functions down so that we have the zone defined before we define the
list manipulation functions. Since the functions are only used in the file
mm/page_alloc.c we can just move them there to reduce noise in the header.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---
include/linux/mmzone.h | 32 -----------------------
mm/page_alloc.c | 68 +++++++++++++++++++++++++++++++++++-------------
2 files changed, 49 insertions(+), 51 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 125f300981c6..270a7b493174 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -100,29 +100,6 @@ struct free_area {
unsigned long nr_free;
};
-/* Used for pages not on another list */
-static inline void add_to_free_area(struct page *page, struct free_area *area,
- int migratetype)
-{
- list_add(&page->lru, &area->free_list[migratetype]);
- area->nr_free++;
-}
-
-/* Used for pages not on another list */
-static inline void add_to_free_area_tail(struct page *page, struct free_area *area,
- int migratetype)
-{
- list_add_tail(&page->lru, &area->free_list[migratetype]);
- area->nr_free++;
-}
-
-/* Used for pages which are on another list */
-static inline void move_to_free_area(struct page *page, struct free_area *area,
- int migratetype)
-{
- list_move(&page->lru, &area->free_list[migratetype]);
-}
-
static inline struct page *get_page_from_free_area(struct free_area *area,
int migratetype)
{
@@ -130,15 +107,6 @@ static inline struct page *get_page_from_free_area(struct free_area *area,
struct page, lru);
}
-static inline void del_page_from_free_area(struct page *page,
- struct free_area *area)
-{
- list_del(&page->lru);
- __ClearPageBuddy(page);
- set_page_private(page, 0);
- area->nr_free--;
-}
-
static inline bool free_area_empty(struct free_area *area, int migratetype)
{
return list_empty(&area->free_list[migratetype]);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 268a25830114..f8271ec8e06e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -877,6 +877,44 @@ static inline struct capture_control *task_capc(struct zone *zone)
}
#endif /* CONFIG_COMPACTION */
+/* Used for pages not on another list */
+static inline void add_to_free_list(struct page *page, struct zone *zone,
+ unsigned int order, int migratetype)
+{
+ struct free_area *area = &zone->free_area[order];
+
+ list_add(&page->lru, &area->free_list[migratetype]);
+ area->nr_free++;
+}
+
+/* Used for pages not on another list */
+static inline void add_to_free_list_tail(struct page *page, struct zone *zone,
+ unsigned int order, int migratetype)
+{
+ struct free_area *area = &zone->free_area[order];
+
+ list_add_tail(&page->lru, &area->free_list[migratetype]);
+ area->nr_free++;
+}
+
+/* Used for pages which are on another list */
+static inline void move_to_free_list(struct page *page, struct zone *zone,
+ unsigned int order, int migratetype)
+{
+ struct free_area *area = &zone->free_area[order];
+
+ list_move(&page->lru, &area->free_list[migratetype]);
+}
+
+static inline void del_page_from_free_list(struct page *page, struct zone *zone,
+ unsigned int order)
+{
+ list_del(&page->lru);
+ __ClearPageBuddy(page);
+ set_page_private(page, 0);
+ zone->free_area[order].nr_free--;
+}
+
/*
* If this is not the largest possible page, check if the buddy
* of the next-highest order is free. If it is, it's possible
@@ -939,7 +977,6 @@ static inline void __free_one_page(struct page *page,
struct capture_control *capc = task_capc(zone);
unsigned long uninitialized_var(buddy_pfn);
unsigned long combined_pfn;
- struct free_area *area;
unsigned int max_order;
struct page *buddy;
bool to_tail;
@@ -977,7 +1014,7 @@ static inline void __free_one_page(struct page *page,
if (page_is_guard(buddy))
clear_page_guard(zone, buddy, order, migratetype);
else
- del_page_from_free_area(buddy, &zone->free_area[order]);
+ del_page_from_free_list(buddy, zone, order);
combined_pfn = buddy_pfn & pfn;
page = page + (combined_pfn - pfn);
pfn = combined_pfn;
@@ -1011,16 +1048,15 @@ static inline void __free_one_page(struct page *page,
done_merging:
set_page_order(page, order);
- area = &zone->free_area[order];
if (is_shuffle_order(order))
to_tail = shuffle_pick_tail();
else
to_tail = buddy_merge_likely(pfn, buddy_pfn, page, order);
if (to_tail)
- add_to_free_area_tail(page, area, migratetype);
+ add_to_free_list_tail(page, zone, order, migratetype);
else
- add_to_free_area(page, area, migratetype);
+ add_to_free_list(page, zone, order, migratetype);
}
/*
@@ -2024,13 +2060,11 @@ void __init init_cma_reserved_pageblock(struct page *page)
* -- nyc
*/
static inline void expand(struct zone *zone, struct page *page,
- int low, int high, struct free_area *area,
- int migratetype)
+ int low, int high, int migratetype)
{
unsigned long size = 1 << high;
while (high > low) {
- area--;
high--;
size >>= 1;
VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
@@ -2044,7 +2078,7 @@ static inline void expand(struct zone *zone, struct page *page,
if (set_page_guard(zone, &page[size], high, migratetype))
continue;
- add_to_free_area(&page[size], area, migratetype);
+ add_to_free_list(&page[size], zone, high, migratetype);
set_page_order(&page[size], high);
}
}
@@ -2202,8 +2236,8 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
page = get_page_from_free_area(area, migratetype);
if (!page)
continue;
- del_page_from_free_area(page, area);
- expand(zone, page, order, current_order, area, migratetype);
+ del_page_from_free_list(page, zone, current_order);
+ expand(zone, page, order, current_order, migratetype);
set_pcppage_migratetype(page, migratetype);
return page;
}
@@ -2211,7 +2245,6 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
return NULL;
}
-
/*
* This array describes the order lists are fallen back to when
* the free lists for the desirable migrate type are depleted
@@ -2277,7 +2310,7 @@ static int move_freepages(struct zone *zone,
VM_BUG_ON_PAGE(page_zone(page) != zone, page);
order = page_order(page);
- move_to_free_area(page, &zone->free_area[order], migratetype);
+ move_to_free_list(page, zone, order, migratetype);
page += 1 << order;
pages_moved += 1 << order;
}
@@ -2393,7 +2426,6 @@ static void steal_suitable_fallback(struct zone *zone, struct page *page,
unsigned int alloc_flags, int start_type, bool whole_block)
{
unsigned int current_order = page_order(page);
- struct free_area *area;
int free_pages, movable_pages, alike_pages;
int old_block_type;
@@ -2464,8 +2496,7 @@ static void steal_suitable_fallback(struct zone *zone, struct page *page,
return;
single_page:
- area = &zone->free_area[current_order];
- move_to_free_area(page, area, start_type);
+ move_to_free_list(page, zone, current_order, start_type);
}
/*
@@ -3136,7 +3167,6 @@ void split_page(struct page *page, unsigned int order)
int __isolate_free_page(struct page *page, unsigned int order)
{
- struct free_area *area = &page_zone(page)->free_area[order];
unsigned long watermark;
struct zone *zone;
int mt;
@@ -3162,7 +3192,7 @@ int __isolate_free_page(struct page *page, unsigned int order)
/* Remove page from free list */
- del_page_from_free_area(page, area);
+ del_page_from_free_list(page, zone, order);
/*
* Set the pageblock if the isolated page is at least half of a
@@ -8583,7 +8613,7 @@ void zone_pcp_reset(struct zone *zone)
pr_info("remove from free list %lx %d %lx\n",
pfn, 1 << order, end_pfn);
#endif
- del_page_from_free_area(page, &zone->free_area[order]);
+ del_page_from_free_list(page, zone, order);
for (i = 0; i < (1 << order); i++)
SetPageReserved((page+i));
pfn += (1 << order);
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^ permalink raw reply related
* [PATCH v10 1/6] mm: Adjust shuffle code to allow for future coalescing
From: Alexander Duyck @ 2019-09-18 17:52 UTC (permalink / raw)
To: virtio-dev, kvm, mst, david, dave.hansen, linux-kernel, willy,
mhocko, linux-mm, vbabka, akpm, mgorman, linux-arm-kernel,
osalvador
Cc: yang.zhang.wz, pagupta, riel, konrad.wilk, lcapitulino,
wei.w.wang, aarcange, nitesh, pbonzini, dan.j.williams,
alexander.h.duyck
In-Reply-To: <20190918175109.23474.67039.stgit@localhost.localdomain>
From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Move the head/tail adding logic out of the shuffle code and into the
__free_one_page function since ultimately that is where it is really
needed anyway. By doing this we should be able to reduce the overhead
and can consolidate all of the list addition bits in one spot.
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---
include/linux/mmzone.h | 12 --------
mm/page_alloc.c | 71 ++++++++++++++++++++++++++++--------------------
mm/shuffle.c | 12 ++++----
mm/shuffle.h | 6 ++++
4 files changed, 54 insertions(+), 47 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index bda20282746b..125f300981c6 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -116,18 +116,6 @@ static inline void add_to_free_area_tail(struct page *page, struct free_area *ar
area->nr_free++;
}
-#ifdef CONFIG_SHUFFLE_PAGE_ALLOCATOR
-/* Used to preserve page allocation order entropy */
-void add_to_free_area_random(struct page *page, struct free_area *area,
- int migratetype);
-#else
-static inline void add_to_free_area_random(struct page *page,
- struct free_area *area, int migratetype)
-{
- add_to_free_area(page, area, migratetype);
-}
-#endif
-
/* Used for pages which are on another list */
static inline void move_to_free_area(struct page *page, struct free_area *area,
int migratetype)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3334a769eb91..268a25830114 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -878,6 +878,36 @@ static inline struct capture_control *task_capc(struct zone *zone)
#endif /* CONFIG_COMPACTION */
/*
+ * If this is not the largest possible page, check if the buddy
+ * of the next-highest order is free. If it is, it's possible
+ * that pages are being freed that will coalesce soon. In case,
+ * that is happening, add the free page to the tail of the list
+ * so it's less likely to be used soon and more likely to be merged
+ * as a higher order page
+ */
+static inline bool
+buddy_merge_likely(unsigned long pfn, unsigned long buddy_pfn,
+ struct page *page, unsigned int order)
+{
+ struct page *higher_page, *higher_buddy;
+ unsigned long combined_pfn;
+
+ if (order >= MAX_ORDER - 2)
+ return false;
+
+ if (!pfn_valid_within(buddy_pfn))
+ return false;
+
+ combined_pfn = buddy_pfn & pfn;
+ higher_page = page + (combined_pfn - pfn);
+ buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1);
+ higher_buddy = higher_page + (buddy_pfn - combined_pfn);
+
+ return pfn_valid_within(buddy_pfn) &&
+ page_is_buddy(higher_page, higher_buddy, order + 1);
+}
+
+/*
* Freeing function for a buddy system allocator.
*
* The concept of a buddy system is to maintain direct-mapped table
@@ -906,11 +936,13 @@ static inline void __free_one_page(struct page *page,
struct zone *zone, unsigned int order,
int migratetype)
{
- unsigned long combined_pfn;
+ struct capture_control *capc = task_capc(zone);
unsigned long uninitialized_var(buddy_pfn);
- struct page *buddy;
+ unsigned long combined_pfn;
+ struct free_area *area;
unsigned int max_order;
- struct capture_control *capc = task_capc(zone);
+ struct page *buddy;
+ bool to_tail;
max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
@@ -979,35 +1011,16 @@ static inline void __free_one_page(struct page *page,
done_merging:
set_page_order(page, order);
- /*
- * If this is not the largest possible page, check if the buddy
- * of the next-highest order is free. If it is, it's possible
- * that pages are being freed that will coalesce soon. In case,
- * that is happening, add the free page to the tail of the list
- * so it's less likely to be used soon and more likely to be merged
- * as a higher order page
- */
- if ((order < MAX_ORDER-2) && pfn_valid_within(buddy_pfn)
- && !is_shuffle_order(order)) {
- struct page *higher_page, *higher_buddy;
- combined_pfn = buddy_pfn & pfn;
- higher_page = page + (combined_pfn - pfn);
- buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1);
- higher_buddy = higher_page + (buddy_pfn - combined_pfn);
- if (pfn_valid_within(buddy_pfn) &&
- page_is_buddy(higher_page, higher_buddy, order + 1)) {
- add_to_free_area_tail(page, &zone->free_area[order],
- migratetype);
- return;
- }
- }
-
+ area = &zone->free_area[order];
if (is_shuffle_order(order))
- add_to_free_area_random(page, &zone->free_area[order],
- migratetype);
+ to_tail = shuffle_pick_tail();
else
- add_to_free_area(page, &zone->free_area[order], migratetype);
+ to_tail = buddy_merge_likely(pfn, buddy_pfn, page, order);
+ if (to_tail)
+ add_to_free_area_tail(page, area, migratetype);
+ else
+ add_to_free_area(page, area, migratetype);
}
/*
diff --git a/mm/shuffle.c b/mm/shuffle.c
index 3ce12481b1dc..923af4fe887e 100644
--- a/mm/shuffle.c
+++ b/mm/shuffle.c
@@ -183,11 +183,11 @@ void __meminit __shuffle_free_memory(pg_data_t *pgdat)
shuffle_zone(z);
}
-void add_to_free_area_random(struct page *page, struct free_area *area,
- int migratetype)
+bool shuffle_pick_tail(void)
{
static u64 rand;
static u8 rand_bits;
+ bool ret;
/*
* The lack of locking is deliberate. If 2 threads race to
@@ -198,10 +198,10 @@ void add_to_free_area_random(struct page *page, struct free_area *area,
rand = get_random_u64();
}
- if (rand & 1)
- add_to_free_area(page, area, migratetype);
- else
- add_to_free_area_tail(page, area, migratetype);
+ ret = rand & 1;
+
rand_bits--;
rand >>= 1;
+
+ return ret;
}
diff --git a/mm/shuffle.h b/mm/shuffle.h
index 777a257a0d2f..4d79f03b6658 100644
--- a/mm/shuffle.h
+++ b/mm/shuffle.h
@@ -22,6 +22,7 @@ enum mm_shuffle_ctl {
DECLARE_STATIC_KEY_FALSE(page_alloc_shuffle_key);
extern void page_alloc_shuffle(enum mm_shuffle_ctl ctl);
extern void __shuffle_free_memory(pg_data_t *pgdat);
+extern bool shuffle_pick_tail(void);
static inline void shuffle_free_memory(pg_data_t *pgdat)
{
if (!static_branch_unlikely(&page_alloc_shuffle_key))
@@ -44,6 +45,11 @@ static inline bool is_shuffle_order(int order)
return order >= SHUFFLE_ORDER;
}
#else
+static inline bool shuffle_pick_tail(void)
+{
+ return false;
+}
+
static inline void shuffle_free_memory(pg_data_t *pgdat)
{
}
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^ permalink raw reply related
* [PATCH v10 0/6] mm / virtio: Provide support for unused page reporting
From: Alexander Duyck @ 2019-09-18 17:52 UTC (permalink / raw)
To: virtio-dev, kvm, mst, david, dave.hansen, linux-kernel, willy,
mhocko, linux-mm, vbabka, akpm, mgorman, linux-arm-kernel,
osalvador
Cc: yang.zhang.wz, pagupta, riel, konrad.wilk, lcapitulino,
wei.w.wang, aarcange, nitesh, pbonzini, dan.j.williams,
alexander.h.duyck
This series provides an asynchronous means of reporting to a hypervisor
that a guest page is no longer in use and can have the data associated
with it dropped. To do this I have implemented functionality that allows
for what I am referring to as unused page reporting. The advantage of
unused page reporting is that we can support a significant amount of
memory over-commit with improved performance as we can avoid having to
write/read memory from swap as the VM will instead actively participate
in freeing unused memory so it doesn't have to be written.
The functionality for this is fairly simple. When enabled it will allocate
statistics to track the number of reported pages in a given free area.
When the number of free pages exceeds this value plus a high water value,
currently 32, it will begin performing page reporting which consists of
pulling non-reported pages off of the free lists of a given zone and
placing them into a scatterlist. The scatterlist is then given to the page
reporting device and it will perform the required action to make the pages
"reported", in the case of virtio-balloon this results in the pages being
madvised as MADV_DONTNEED. After this they are placed back on their
original free list. If they are not merged in freeing an additional bit is
set indicating that they are a "reported" buddy page instead of a standard
buddy page. The cycle then repeats with additional non-reported pages
being pulled until the free areas all consist of reported pages.
In order to try and keep the time needed to find a non-reported page to
a minimum we maintain a "reported_boundary" pointer. This pointer is used
by the get_unreported_pages iterator to determine at what point it should
resume searching for non-reported pages. In order to guarantee pages do
not get past the scan I have modified add_to_free_list_tail so that it
will not insert pages behind the reported_boundary.
If another process needs to perform a massive manipulation of the free
list, such as compaction, it can either reset a given individual boundary
which will push the boundary back to the list_head, or it can clear the
bit indicating the zone is actively processing which will result in the
reporting process resetting all of the boundaries for a given zone.
I am leaving a number of things hard-coded such as limiting the lowest
order processed to pageblock_order, and have left it up to the guest to
determine what the limit is on how many pages it wants to allocate to
process the hints. The upper limit for this is based on the size of the
queue used to store the scatterlist.
I wanted to avoid gaming the performance testing for this. As far as
possible gain a significant performance improvement should be visible in
cases where guests are forced to write/read from swap. As such, testing
it would be more of a benchmark of copying a page from swap versus just
allocating a zero page. I have been verifying that the memory is being
freed using memhog to allocate all the memory on the guest, and then
watching /proc/meminfo to verify the host sees the memory returned after
the test completes.
As far as possible regressions I have focused on cases where performing
the hinting would be non-optimal, such as cases where the code isn't
needed as memory is not over-committed, or the functionality is not in
use. I have been using the will-it-scale/page_fault1 test running with 16
vcpus and have modified it to use Transparent Huge Pages. With this I see
almost no difference with the patches applied and the feature disabled.
Likewise I see almost no difference with the feature enabled, but the
madvise disabled in the hypervisor due to a device being assigned. With
the feature fully enabled in both guest and hypervisor I see a regression
between -1.86% and -8.84% versus the baseline. I found that most of the
overhead was due to the page faulting/zeroing that comes as a result of
the pages having been evicted from the guest.
For info on earlier versions you will need to follow the links provided
with the respective versions.
Changes from v9:
https://lore.kernel.org/lkml/20190907172225.10910.34302.stgit@localhost.localdomain/
Updated cover page
Dropped per-cpu page randomization entropy patch
Added "to_tail" boolean value to __free_one_page to improve readability
Renamed __shuffle_pick_tail to shuffle_pick_tail, avoiding extra inline function
Dropped arm64 HUGLE_TLB_ORDER movement patch since it is no longer needed
Significant rewrite of page reporting functionality
Updated logic to support interruptions from compaction
get_unreported_page will now walk through reported sections
Moved free_list manipulators out of mmzone.h and into page_alloc.c
Removed page_reporting.h include from mmzone.h
Split page_reporting.h between include/linux/ and mm/
Added #include <asm/pgtable.h>" to mm/page_reporting.h
Renamed page_reporting_startup/shutdown to page_reporting_register/unregister
Updated comments related to virtio page poison tracking feature
---
Alexander Duyck (6):
mm: Adjust shuffle code to allow for future coalescing
mm: Use zone and order instead of free area in free_list manipulators
mm: Introduce Reported pages
mm: Add device side and notifier for unused page reporting
virtio-balloon: Pull page poisoning config out of free page hinting
virtio-balloon: Add support for providing unused page reports to host
drivers/virtio/Kconfig | 1
drivers/virtio/virtio_balloon.c | 87 ++++++++-
include/linux/mmzone.h | 60 ++----
include/linux/page-flags.h | 11 +
include/linux/page_reporting.h | 31 +++
include/uapi/linux/virtio_balloon.h | 1
mm/Kconfig | 11 +
mm/Makefile | 1
mm/compaction.c | 5 +
mm/memory_hotplug.c | 2
mm/page_alloc.c | 194 +++++++++++++++----
mm/page_reporting.c | 350 +++++++++++++++++++++++++++++++++++
mm/page_reporting.h | 224 ++++++++++++++++++++++
mm/shuffle.c | 12 +
mm/shuffle.h | 6 +
15 files changed, 893 insertions(+), 103 deletions(-)
create mode 100644 include/linux/page_reporting.h
create mode 100644 mm/page_reporting.c
create mode 100644 mm/page_reporting.h
--
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply
* [PATCH v2 8/8] dt-bindings: pwm: Convert Samsung PWM bindings to json-schema
From: Krzysztof Kozlowski @ 2019-09-18 17:31 UTC (permalink / raw)
To: Rob Herring, Mark Rutland, Thierry Reding, Matt Mackall,
Herbert Xu, Wim Van Sebroeck, Guenter Roeck, linux-clk,
devicetree, linux-kernel, dri-devel, linux-leds, linux-arm-kernel,
linux-samsung-soc, linux-pwm, linux-tegra,
bcm-kernel-feedback-list, linux-rpi-kernel, linux-amlogic,
linux-mediatek, linux-rockchip, linux-riscv, linux-stm32,
linux-crypto, linux-watchdog
Cc: Krzysztof Kozlowski
In-Reply-To: <20190918173141.4314-1-krzk@kernel.org>
Convert Samsung PWM (S3C, S5P and Exynos SoCs) bindings to DT schema
format using json-schema.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
Changes since v1:
1. Indent example with four spaces (more readable),
2. Fix samsung,pwm-outputs after review,
3. Remove double-quotes from clock names.
---
.../devicetree/bindings/pwm/pwm-samsung.txt | 51 ---------
.../devicetree/bindings/pwm/pwm-samsung.yaml | 107 ++++++++++++++++++
2 files changed, 107 insertions(+), 51 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/pwm/pwm-samsung.txt
create mode 100644 Documentation/devicetree/bindings/pwm/pwm-samsung.yaml
diff --git a/Documentation/devicetree/bindings/pwm/pwm-samsung.txt b/Documentation/devicetree/bindings/pwm/pwm-samsung.txt
deleted file mode 100644
index 5538de9c2007..000000000000
--- a/Documentation/devicetree/bindings/pwm/pwm-samsung.txt
+++ /dev/null
@@ -1,51 +0,0 @@
-* Samsung PWM timers
-
-Samsung SoCs contain PWM timer blocks which can be used for system clock source
-and clock event timers, as well as to drive SoC outputs with PWM signal. Each
-PWM timer block provides 5 PWM channels (not all of them can drive physical
-outputs - see SoC and board manual).
-
-Be aware that the clocksource driver supports only uniprocessor systems.
-
-Required properties:
-- compatible : should be one of following:
- samsung,s3c2410-pwm - for 16-bit timers present on S3C24xx SoCs
- samsung,s3c6400-pwm - for 32-bit timers present on S3C64xx SoCs
- samsung,s5p6440-pwm - for 32-bit timers present on S5P64x0 SoCs
- samsung,s5pc100-pwm - for 32-bit timers present on S5PC100, S5PV210,
- Exynos4210 rev0 SoCs
- samsung,exynos4210-pwm - for 32-bit timers present on Exynos4210,
- Exynos4x12, Exynos5250 and Exynos5420 SoCs
-- reg: base address and size of register area
-- interrupts: list of timer interrupts (one interrupt per timer, starting at
- timer 0)
-- clock-names: should contain all following required clock names:
- - "timers" - PWM base clock used to generate PWM signals,
- and any subset of following optional clock names:
- - "pwm-tclk0" - first external PWM clock source,
- - "pwm-tclk1" - second external PWM clock source.
- Note that not all IP variants allow using all external clock sources.
- Refer to SoC documentation to learn which clock source configurations
- are available.
-- clocks: should contain clock specifiers of all clocks, which input names
- have been specified in clock-names property, in same order.
-- #pwm-cells: should be 3. See pwm.txt in this directory for a description of
- the cells format. The only third cell flag supported by this binding is
- PWM_POLARITY_INVERTED.
-
-Optional properties:
-- samsung,pwm-outputs: list of PWM channels used as PWM outputs on particular
- platform - an array of up to 5 elements being indices of PWM channels
- (from 0 to 4), the order does not matter.
-
-Example:
- pwm@7f006000 {
- compatible = "samsung,s3c6400-pwm";
- reg = <0x7f006000 0x1000>;
- interrupt-parent = <&vic0>;
- interrupts = <23>, <24>, <25>, <27>, <28>;
- clocks = <&clock 67>;
- clock-names = "timers";
- samsung,pwm-outputs = <0>, <1>;
- #pwm-cells = <3>;
- }
diff --git a/Documentation/devicetree/bindings/pwm/pwm-samsung.yaml b/Documentation/devicetree/bindings/pwm/pwm-samsung.yaml
new file mode 100644
index 000000000000..06d11faabff6
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-samsung.yaml
@@ -0,0 +1,107 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/pwm-samsung.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung SoC PWM timers
+
+maintainers:
+ - Thierry Reding <thierry.reding@gmail.com>
+ - Krzysztof Kozlowski <krzk@kernel.org>
+
+description: |+
+ Samsung SoCs contain PWM timer blocks which can be used for system clock source
+ and clock event timers, as well as to drive SoC outputs with PWM signal. Each
+ PWM timer block provides 5 PWM channels (not all of them can drive physical
+ outputs - see SoC and board manual).
+
+ Be aware that the clocksource driver supports only uniprocessor systems.
+
+allOf:
+ - $ref: pwm.yaml#
+
+properties:
+ compatible:
+ enum:
+ - samsung,s3c2410-pwm # 16-bit, S3C24xx
+ - samsung,s3c6400-pwm # 32-bit, S3C64xx
+ - samsung,s5p6440-pwm # 32-bit, S5P64x0
+ - samsung,s5pc100-pwm # 32-bit, S5PC100, S5PV210, Exynos4210 rev0 SoCs
+ - samsung,exynos4210-pwm # 32-bit, Exynos
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ minItems: 1
+ maxItems: 3
+
+ clock-names:
+ description: |
+ Should contain all following required clock names:
+ - "timers" - PWM base clock used to generate PWM signals,
+ and any subset of following optional clock names:
+ - "pwm-tclk0" - first external PWM clock source,
+ - "pwm-tclk1" - second external PWM clock source.
+ Note that not all IP variants allow using all external clock sources.
+ Refer to SoC documentation to learn which clock source configurations
+ are available.
+ oneOf:
+ - items:
+ - const: timers
+ - items:
+ - const: timers
+ - const: pwm-tclk0
+ - items:
+ - const: timers
+ - const: pwm-tclk1
+ - items:
+ - const: timers
+ - const: pwm-tclk0
+ - const: pwm-tclk1
+
+ interrupts:
+ description:
+ One interrupt per timer, starting at timer 0.
+ minItems: 1
+ maxItems: 5
+
+ "#pwm-cells":
+ description:
+ The only third cell flag supported by this binding
+ is PWM_POLARITY_INVERTED.
+ const: 3
+
+ samsung,pwm-outputs:
+ description:
+ A list of PWM channels used as PWM outputs on particular platform.
+ It is an array of up to 5 elements being indices of PWM channels
+ (from 0 to 4), the order does not matter.
+ allOf:
+ - $ref: /schemas/types.yaml#/definitions/uint32-array
+ - uniqueItems: true
+ - items:
+ minimum: 0
+ maximum: 4
+
+required:
+ - clocks
+ - clock-names
+ - compatible
+ - interrupts
+ - "#pwm-cells"
+ - reg
+
+examples:
+ - |
+ pwm@7f006000 {
+ compatible = "samsung,s3c6400-pwm";
+ reg = <0x7f006000 0x1000>;
+ interrupt-parent = <&vic0>;
+ interrupts = <23>, <24>, <25>, <27>, <28>;
+ clocks = <&clock 67>;
+ clock-names = "timers";
+ samsung,pwm-outputs = <0>, <1>;
+ #pwm-cells = <3>;
+ };
--
2.17.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related
* [PATCH v2 7/8] dt-bindings: pwm: Convert PWM bindings to json-schema
From: Krzysztof Kozlowski @ 2019-09-18 17:31 UTC (permalink / raw)
To: Rob Herring, Mark Rutland, Thierry Reding, Matt Mackall,
Herbert Xu, Wim Van Sebroeck, Guenter Roeck, linux-clk,
devicetree, linux-kernel, dri-devel, linux-leds, linux-arm-kernel,
linux-samsung-soc, linux-pwm, linux-tegra,
bcm-kernel-feedback-list, linux-rpi-kernel, linux-amlogic,
linux-mediatek, linux-rockchip, linux-riscv, linux-stm32,
linux-crypto, linux-watchdog
Cc: Krzysztof Kozlowski
In-Reply-To: <20190918173141.4314-1-krzk@kernel.org>
Convert generic PWM bindings to DT schema format using json-schema. The
consumer bindings are split to separate file.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
Changes since v1:
1. Indent example with four spaces (more readable),
2. Change pattern for pwm nodes,
3. Remove $ref from #cells.
---
.../devicetree/bindings/clock/pwm-clock.txt | 2 +-
.../bindings/display/bridge/ti,sn65dsi86.txt | 2 +-
.../devicetree/bindings/display/ssd1307fb.txt | 2 +-
.../bindings/leds/backlight/pwm-backlight.txt | 2 +-
.../devicetree/bindings/leds/leds-pwm.txt | 2 +-
.../devicetree/bindings/mfd/max77693.txt | 2 +-
.../bindings/pwm/atmel-hlcdc-pwm.txt | 2 +-
.../devicetree/bindings/pwm/atmel-pwm.txt | 2 +-
.../devicetree/bindings/pwm/atmel-tcb-pwm.txt | 2 +-
.../bindings/pwm/brcm,bcm7038-pwm.txt | 2 +-
.../bindings/pwm/brcm,iproc-pwm.txt | 2 +-
.../devicetree/bindings/pwm/brcm,kona-pwm.txt | 2 +-
.../devicetree/bindings/pwm/img-pwm.txt | 2 +-
.../devicetree/bindings/pwm/imx-pwm.txt | 2 +-
.../devicetree/bindings/pwm/imx-tpm-pwm.txt | 2 +-
.../bindings/pwm/lpc1850-sct-pwm.txt | 2 +-
.../devicetree/bindings/pwm/mxs-pwm.txt | 2 +-
.../bindings/pwm/nvidia,tegra20-pwm.txt | 2 +-
.../bindings/pwm/nxp,pca9685-pwm.txt | 2 +-
.../devicetree/bindings/pwm/pwm-bcm2835.txt | 2 +-
.../devicetree/bindings/pwm/pwm-berlin.txt | 2 +-
.../bindings/pwm/pwm-consumers.yaml | 76 +++++++++++++++++++
.../devicetree/bindings/pwm/pwm-fsl-ftm.txt | 2 +-
.../devicetree/bindings/pwm/pwm-hibvt.txt | 2 +-
.../devicetree/bindings/pwm/pwm-lp3943.txt | 2 +-
.../devicetree/bindings/pwm/pwm-mediatek.txt | 2 +-
.../devicetree/bindings/pwm/pwm-meson.txt | 2 +-
.../devicetree/bindings/pwm/pwm-mtk-disp.txt | 2 +-
.../bindings/pwm/pwm-omap-dmtimer.txt | 2 +-
.../devicetree/bindings/pwm/pwm-rockchip.txt | 2 +-
.../devicetree/bindings/pwm/pwm-sifive.txt | 2 +-
.../devicetree/bindings/pwm/pwm-stm32-lp.txt | 2 +-
.../devicetree/bindings/pwm/pwm-stm32.txt | 2 +-
.../devicetree/bindings/pwm/pwm-tiecap.txt | 2 +-
.../devicetree/bindings/pwm/pwm-tiehrpwm.txt | 2 +-
.../devicetree/bindings/pwm/pwm-zx.txt | 2 +-
Documentation/devicetree/bindings/pwm/pwm.txt | 69 -----------------
.../devicetree/bindings/pwm/pwm.yaml | 29 +++++++
.../bindings/pwm/renesas,pwm-rcar.txt | 2 +-
.../bindings/pwm/renesas,tpu-pwm.txt | 4 +-
.../devicetree/bindings/pwm/spear-pwm.txt | 2 +-
.../devicetree/bindings/pwm/st,stmpe-pwm.txt | 2 +-
.../devicetree/bindings/pwm/ti,twl-pwm.txt | 2 +-
.../devicetree/bindings/pwm/ti,twl-pwmled.txt | 2 +-
.../devicetree/bindings/pwm/vt8500-pwm.txt | 2 +-
.../bindings/regulator/pwm-regulator.txt | 2 +-
.../devicetree/bindings/timer/ingenic,tcu.txt | 2 +-
47 files changed, 150 insertions(+), 114 deletions(-)
create mode 100644 Documentation/devicetree/bindings/pwm/pwm-consumers.yaml
delete mode 100644 Documentation/devicetree/bindings/pwm/pwm.txt
create mode 100644 Documentation/devicetree/bindings/pwm/pwm.yaml
diff --git a/Documentation/devicetree/bindings/clock/pwm-clock.txt b/Documentation/devicetree/bindings/clock/pwm-clock.txt
index 83db876b3b90..8a791b6d76a9 100644
--- a/Documentation/devicetree/bindings/clock/pwm-clock.txt
+++ b/Documentation/devicetree/bindings/clock/pwm-clock.txt
@@ -3,7 +3,7 @@ Binding for an external clock signal driven by a PWM pin.
This binding uses the common clock binding[1] and the common PWM binding[2].
[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
-[2] Documentation/devicetree/bindings/pwm/pwm.txt
+[2] Documentation/devicetree/bindings/pwm/pwm-consumers.yaml
Required properties:
- compatible : shall be "pwm-clock".
diff --git a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi86.txt b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi86.txt
index 0a3fbb53a16e..8ec4a7f2623a 100644
--- a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi86.txt
+++ b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi86.txt
@@ -21,7 +21,7 @@ Optional properties:
- #gpio-cells : Should be two. The first cell is the pin number and
the second cell is used to specify flags.
See ../../gpio/gpio.txt for more information.
-- #pwm-cells : Should be one. See ../../pwm/pwm.txt for description of
+- #pwm-cells : Should be one. See ../../pwm/pwm.yaml for description of
the cell formats.
- clock-names: should be "refclk"
diff --git a/Documentation/devicetree/bindings/display/ssd1307fb.txt b/Documentation/devicetree/bindings/display/ssd1307fb.txt
index 27333b9551b3..da9b28153a3c 100644
--- a/Documentation/devicetree/bindings/display/ssd1307fb.txt
+++ b/Documentation/devicetree/bindings/display/ssd1307fb.txt
@@ -37,7 +37,7 @@ Optional properties:
- solomon,area-color-enable: Display uses color mode
- solomon,low-power. Display runs in low power mode
-[0]: Documentation/devicetree/bindings/pwm/pwm.txt
+[0]: Documentation/devicetree/bindings/pwm/pwm-consumers.yaml
Examples:
ssd1307: oled@3c {
diff --git a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
index 64fa2fbd98c9..8dbbadd3af96 100644
--- a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
+++ b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
@@ -28,7 +28,7 @@ Optional properties:
having to list out every possible value in the
brightness-level array.
-[0]: Documentation/devicetree/bindings/pwm/pwm.txt
+[0]: Documentation/devicetree/bindings/pwm/pwm-consumers.yaml
[1]: Documentation/devicetree/bindings/gpio/gpio.txt
Example:
diff --git a/Documentation/devicetree/bindings/leds/leds-pwm.txt b/Documentation/devicetree/bindings/leds/leds-pwm.txt
index 6c6583c35f2f..aeaa250668d5 100644
--- a/Documentation/devicetree/bindings/leds/leds-pwm.txt
+++ b/Documentation/devicetree/bindings/leds/leds-pwm.txt
@@ -11,7 +11,7 @@ LED sub-node properties:
specify the period time to be used: <&phandle id period_ns>;
- pwm-names : (optional) Name to be used by the PWM subsystem for the PWM device
For the pwms and pwm-names property please refer to:
- Documentation/devicetree/bindings/pwm/pwm.txt
+ Documentation/devicetree/bindings/pwm/pwm-consumers.yaml
- max-brightness : Maximum brightness possible for the LED
- active-low : (optional) For PWMs where the LED is wired to supply
rather than ground.
diff --git a/Documentation/devicetree/bindings/mfd/max77693.txt b/Documentation/devicetree/bindings/mfd/max77693.txt
index a3c60a7a3be1..1e6318695eb2 100644
--- a/Documentation/devicetree/bindings/mfd/max77693.txt
+++ b/Documentation/devicetree/bindings/mfd/max77693.txt
@@ -38,7 +38,7 @@ Optional properties:
PWM properties should be named "pwms". And number of cell is different
for each pwm device.
To get more information, please refer to documentation.
- [*] refer Documentation/devicetree/bindings/pwm/pwm.txt
+ [*] refer Documentation/devicetree/bindings/pwm/pwm-consumers.yaml
- charger : Node configuring the charger driver.
If present, required properties:
diff --git a/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt b/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
index cfda0d57d302..afa501bf7f94 100644
--- a/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
@@ -10,7 +10,7 @@ Required properties:
- pinctrl-0: should contain the pinctrl states described by pinctrl
default.
- #pwm-cells: should be set to 3. This PWM chip use the default 3 cells
- bindings defined in pwm.txt in this directory.
+ bindings defined in pwm.yaml in this directory.
Example:
diff --git a/Documentation/devicetree/bindings/pwm/atmel-pwm.txt b/Documentation/devicetree/bindings/pwm/atmel-pwm.txt
index 591ecdd39c7b..fbb5325be1f0 100644
--- a/Documentation/devicetree/bindings/pwm/atmel-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/atmel-pwm.txt
@@ -7,7 +7,7 @@ Required properties:
- "atmel,sama5d2-pwm"
- "microchip,sam9x60-pwm"
- reg: physical base address and length of the controller's registers
- - #pwm-cells: Should be 3. See pwm.txt in this directory for a
+ - #pwm-cells: Should be 3. See pwm.yaml in this directory for a
description of the cells format.
Example:
diff --git a/Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt b/Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt
index 8031148bcf85..985fcc65f8c4 100644
--- a/Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt
@@ -2,7 +2,7 @@ Atmel TCB PWM controller
Required properties:
- compatible: should be "atmel,tcb-pwm"
-- #pwm-cells: should be 3. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 3. See pwm.yaml in this directory for a description of
the cells format. The only third cell flag supported by this binding is
PWM_POLARITY_INVERTED.
- tc-block: The Timer Counter block to use as a PWM chip.
diff --git a/Documentation/devicetree/bindings/pwm/brcm,bcm7038-pwm.txt b/Documentation/devicetree/bindings/pwm/brcm,bcm7038-pwm.txt
index d9254a6da5ed..0e662d7f6bd1 100644
--- a/Documentation/devicetree/bindings/pwm/brcm,bcm7038-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/brcm,bcm7038-pwm.txt
@@ -4,7 +4,7 @@ Required properties:
- compatible: must be "brcm,bcm7038-pwm"
- reg: physical base address and length for this controller
-- #pwm-cells: should be 2. See pwm.txt in this directory for a description
+- #pwm-cells: should be 2. See pwm.yaml in this directory for a description
of the cells format
- clocks: a phandle to the reference clock for this block which is fed through
its internal variable clock frequency generator
diff --git a/Documentation/devicetree/bindings/pwm/brcm,iproc-pwm.txt b/Documentation/devicetree/bindings/pwm/brcm,iproc-pwm.txt
index 21f75bbd6dae..655f6cd4ef46 100644
--- a/Documentation/devicetree/bindings/pwm/brcm,iproc-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/brcm,iproc-pwm.txt
@@ -6,7 +6,7 @@ Required Properties :
- compatible: must be "brcm,iproc-pwm"
- reg: physical base address and length of the controller's registers
- clocks: phandle + clock specifier pair for the external clock
-- #pwm-cells: Should be 3. See pwm.txt in this directory for a
+- #pwm-cells: Should be 3. See pwm.yaml in this directory for a
description of the cells format.
Refer to clocks/clock-bindings.txt for generic clock consumer properties.
diff --git a/Documentation/devicetree/bindings/pwm/brcm,kona-pwm.txt b/Documentation/devicetree/bindings/pwm/brcm,kona-pwm.txt
index 8eae9fe7841c..c42eecfc81ed 100644
--- a/Documentation/devicetree/bindings/pwm/brcm,kona-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/brcm,kona-pwm.txt
@@ -6,7 +6,7 @@ Required Properties :
- compatible: should contain "brcm,kona-pwm"
- reg: physical base address and length of the controller's registers
- clocks: phandle + clock specifier pair for the external clock
-- #pwm-cells: Should be 3. See pwm.txt in this directory for a
+- #pwm-cells: Should be 3. See pwm.yaml in this directory for a
description of the cells format.
Refer to clocks/clock-bindings.txt for generic clock consumer properties.
diff --git a/Documentation/devicetree/bindings/pwm/img-pwm.txt b/Documentation/devicetree/bindings/pwm/img-pwm.txt
index fade5f26fcac..9db6de97317d 100644
--- a/Documentation/devicetree/bindings/pwm/img-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/img-pwm.txt
@@ -8,7 +8,7 @@ Required properties:
- clock-names: Must include the following entries.
- pwm: PWM operating clock.
- sys: PWM system interface clock.
- - #pwm-cells: Should be 2. See pwm.txt in this directory for the
+ - #pwm-cells: Should be 2. See pwm.yaml in this directory for the
description of the cells format.
- img,cr-periph: Must contain a phandle to the peripheral control
syscon node which contains PWM control registers.
diff --git a/Documentation/devicetree/bindings/pwm/imx-pwm.txt b/Documentation/devicetree/bindings/pwm/imx-pwm.txt
index c61bdf8cd41b..22f1c3d8b773 100644
--- a/Documentation/devicetree/bindings/pwm/imx-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/imx-pwm.txt
@@ -6,7 +6,7 @@ Required properties:
- "fsl,imx1-pwm" for PWM compatible with the one integrated on i.MX1
- "fsl,imx27-pwm" for PWM compatible with the one integrated on i.MX27
- reg: physical base address and length of the controller's registers
-- #pwm-cells: 2 for i.MX1 and 3 for i.MX27 and newer SoCs. See pwm.txt
+- #pwm-cells: 2 for i.MX1 and 3 for i.MX27 and newer SoCs. See pwm.yaml
in this directory for a description of the cells format.
- clocks : Clock specifiers for both ipg and per clocks.
- clock-names : Clock names should include both "ipg" and "per"
diff --git a/Documentation/devicetree/bindings/pwm/imx-tpm-pwm.txt b/Documentation/devicetree/bindings/pwm/imx-tpm-pwm.txt
index 3ba958d764ff..5bf20950a24e 100644
--- a/Documentation/devicetree/bindings/pwm/imx-tpm-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/imx-tpm-pwm.txt
@@ -3,7 +3,7 @@ Freescale i.MX TPM PWM controller
Required properties:
- compatible : Should be "fsl,imx7ulp-pwm".
- reg: Physical base address and length of the controller's registers.
-- #pwm-cells: Should be 3. See pwm.txt in this directory for a description of the cells format.
+- #pwm-cells: Should be 3. See pwm.yaml in this directory for a description of the cells format.
- clocks : The clock provided by the SoC to drive the PWM.
- interrupts: The interrupt for the PWM controller.
diff --git a/Documentation/devicetree/bindings/pwm/lpc1850-sct-pwm.txt b/Documentation/devicetree/bindings/pwm/lpc1850-sct-pwm.txt
index 36e49d4325cd..43d9f4f08a2e 100644
--- a/Documentation/devicetree/bindings/pwm/lpc1850-sct-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/lpc1850-sct-pwm.txt
@@ -7,7 +7,7 @@ Required properties:
See ../clock/clock-bindings.txt for details.
- clock-names: Must include the following entries.
- pwm: PWM operating clock.
- - #pwm-cells: Should be 3. See pwm.txt in this directory for the description
+ - #pwm-cells: Should be 3. See pwm.yaml in this directory for the description
of the cells format.
Example:
diff --git a/Documentation/devicetree/bindings/pwm/mxs-pwm.txt b/Documentation/devicetree/bindings/pwm/mxs-pwm.txt
index 96cdde5f6208..1b06f86a7091 100644
--- a/Documentation/devicetree/bindings/pwm/mxs-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/mxs-pwm.txt
@@ -3,7 +3,7 @@ Freescale MXS PWM controller
Required properties:
- compatible: should be "fsl,imx23-pwm"
- reg: physical base address and length of the controller's registers
-- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 2. See pwm.yaml in this directory for a description of
the cells format.
- fsl,pwm-number: the number of PWM devices
diff --git a/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt b/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt
index c57e11b8d937..0a69eadf44ce 100644
--- a/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt
@@ -10,7 +10,7 @@ Required properties:
- "nvidia,tegra210-pwm", "nvidia,tegra20-pwm": for Tegra210
- "nvidia,tegra186-pwm": for Tegra186
- reg: physical base address and length of the controller's registers
-- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 2. See pwm.yaml in this directory for a description of
the cells format.
- clocks: Must contain one entry, for the module clock.
See ../clocks/clock-bindings.txt for details.
diff --git a/Documentation/devicetree/bindings/pwm/nxp,pca9685-pwm.txt b/Documentation/devicetree/bindings/pwm/nxp,pca9685-pwm.txt
index f84ec9d291ea..f21b55c95738 100644
--- a/Documentation/devicetree/bindings/pwm/nxp,pca9685-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/nxp,pca9685-pwm.txt
@@ -3,7 +3,7 @@ NXP PCA9685 16-channel 12-bit PWM LED controller
Required properties:
- compatible: "nxp,pca9685-pwm"
- - #pwm-cells: Should be 2. See pwm.txt in this directory for a description of
+ - #pwm-cells: Should be 2. See pwm.yaml in this directory for a description of
the cells format.
The index 16 is the ALLCALL channel, that sets all PWM channels at the same
time.
diff --git a/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt b/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt
index 8cf87d1bfca5..f5753b3f79df 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt
@@ -6,7 +6,7 @@ Required properties:
- clocks: This clock defines the base clock frequency of the PWM hardware
system, the period and the duty_cycle of the PWM signal is a multiple of
the base period.
-- #pwm-cells: Should be 3. See pwm.txt in this directory for a description of
+- #pwm-cells: Should be 3. See pwm.yaml in this directory for a description of
the cells format.
Examples:
diff --git a/Documentation/devicetree/bindings/pwm/pwm-berlin.txt b/Documentation/devicetree/bindings/pwm/pwm-berlin.txt
index 82cbe16fcbbc..f01e993a498a 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-berlin.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-berlin.txt
@@ -4,7 +4,7 @@ Required properties:
- compatible: should be "marvell,berlin-pwm"
- reg: physical base address and length of the controller's registers
- clocks: phandle to the input clock
-- #pwm-cells: should be 3. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 3. See pwm.yaml in this directory for a description of
the cells format.
Example:
diff --git a/Documentation/devicetree/bindings/pwm/pwm-consumers.yaml b/Documentation/devicetree/bindings/pwm/pwm-consumers.yaml
new file mode 100644
index 000000000000..39c844fe6338
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-consumers.yaml
@@ -0,0 +1,76 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/pwm-consumers.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Specifying PWM information for devices
+
+maintainers:
+ - Thierry Reding <thierry.reding@gmail.com>
+
+description: |
+ PWM properties should be named "pwms". The exact meaning of each pwms
+ property must be documented in the device tree binding for each device.
+ An optional property "pwm-names" may contain a list of strings to label
+ each of the PWM devices listed in the "pwms" property. If no "pwm-names"
+ property is given, the name of the user node will be used as fallback.
+
+ Drivers for devices that use more than a single PWM device can use the
+ "pwm-names" property to map the name of the PWM device requested by the
+ pwm_get() call to an index into the list given by the "pwms" property.
+
+properties:
+ pwms:
+ $ref: /schemas/types.yaml#/definitions/phandle-array
+ description: |
+ Phandle to PWM controller node and pwm-specifier (controller specific).
+ pwm-specifier typically encodes the chip-relative PWM number and the PWM
+ period in nanoseconds.
+ Optionally, the pwm-specifier can encode a number of flags (defined in
+ <dt-bindings/pwm/pwm.h>) in a third cell:
+ - PWM_POLARITY_INVERTED: invert the PWM signal polarity
+
+ pwm-names:
+ $ref: /schemas/types.yaml#/definitions/string-array
+ description:
+ A list of strings to label each of the PWM devices listed in the "pwms"
+ property. If no "pwm-names" property is given, the name of the user node
+ will be used as fallback.
+
+required:
+ - pwms
+
+dependencies:
+ pwm-names: [ pwms ]
+
+examples:
+ - |
+ // The following example could be used to describe a PWM-based
+ // backlight device:
+
+ pwm: pwm {
+ #pwm-cells = <2>;
+ };
+
+ bl: backlight {
+ pwms = <&pwm 0 5000000>;
+ pwm-names = "backlight";
+ };
+
+ // Note that in the example above, specifying the "pwm-names" is redundant
+ // because the name "backlight" would be used as fallback anyway.
+
+ - |
+ // Example with optional PWM specifier for inverse polarity
+
+ #include <dt-bindings/pwm/pwm.h>
+
+ pwm2: pwm {
+ #pwm-cells = <3>;
+ };
+
+ backlight {
+ pwms = <&pwm2 0 5000000 PWM_POLARITY_INVERTED>;
+ pwm-names = "backlight";
+ };
diff --git a/Documentation/devicetree/bindings/pwm/pwm-fsl-ftm.txt b/Documentation/devicetree/bindings/pwm/pwm-fsl-ftm.txt
index 576ad002bc83..36532cd5ab25 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-fsl-ftm.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-fsl-ftm.txt
@@ -21,7 +21,7 @@ Required properties:
- "fsl,vf610-ftm-pwm" for PWM compatible with the one integrated on VF610
- "fsl,imx8qm-ftm-pwm" for PWM compatible with the one integrated on i.MX8QM
- reg: Physical base address and length of the controller's registers
-- #pwm-cells: Should be 3. See pwm.txt in this directory for a description of
+- #pwm-cells: Should be 3. See pwm.yaml in this directory for a description of
the cells format.
- clock-names: Should include the following module clock source entries:
"ftm_sys" (module clock, also can be used as counter clock),
diff --git a/Documentation/devicetree/bindings/pwm/pwm-hibvt.txt b/Documentation/devicetree/bindings/pwm/pwm-hibvt.txt
index daedfef09bb6..54dbc2a0e648 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-hibvt.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-hibvt.txt
@@ -10,7 +10,7 @@ Required properties:
- reg: physical base address and length of the controller's registers.
- clocks: phandle and clock specifier of the PWM reference clock.
- resets: phandle and reset specifier for the PWM controller reset.
-- #pwm-cells: Should be 3. See pwm.txt in this directory for a description of
+- #pwm-cells: Should be 3. See pwm.yaml in this directory for a description of
the cells format.
Example:
diff --git a/Documentation/devicetree/bindings/pwm/pwm-lp3943.txt b/Documentation/devicetree/bindings/pwm/pwm-lp3943.txt
index 7bd9d3b12ce1..f214305a8f5e 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-lp3943.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-lp3943.txt
@@ -2,7 +2,7 @@ TI/National Semiconductor LP3943 PWM controller
Required properties:
- compatible: "ti,lp3943-pwm"
- - #pwm-cells: Should be 2. See pwm.txt in this directory for a
+ - #pwm-cells: Should be 2. See pwm.yaml in this directory for a
description of the cells format.
Note that this hardware limits the period length to the
range 6250~1600000.
diff --git a/Documentation/devicetree/bindings/pwm/pwm-mediatek.txt b/Documentation/devicetree/bindings/pwm/pwm-mediatek.txt
index 991728cb46cb..8caf01d0dd5e 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-mediatek.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-mediatek.txt
@@ -7,7 +7,7 @@ Required properties:
- "mediatek,mt7623-pwm": found on mt7623 SoC.
- "mediatek,mt7628-pwm": found on mt7628 SoC.
- reg: physical base address and length of the controller's registers.
- - #pwm-cells: must be 2. See pwm.txt in this directory for a description of
+ - #pwm-cells: must be 2. See pwm.yaml in this directory for a description of
the cell format.
- clocks: phandle and clock specifier of the PWM reference clock.
- clock-names: must contain the following, except for MT7628 which
diff --git a/Documentation/devicetree/bindings/pwm/pwm-meson.txt b/Documentation/devicetree/bindings/pwm/pwm-meson.txt
index 891632354065..bd02b0a1496f 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-meson.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-meson.txt
@@ -10,7 +10,7 @@ Required properties:
or "amlogic,meson-g12a-ee-pwm"
or "amlogic,meson-g12a-ao-pwm-ab"
or "amlogic,meson-g12a-ao-pwm-cd"
-- #pwm-cells: Should be 3. See pwm.txt in this directory for a description of
+- #pwm-cells: Should be 3. See pwm.yaml in this directory for a description of
the cells format.
Optional properties:
diff --git a/Documentation/devicetree/bindings/pwm/pwm-mtk-disp.txt b/Documentation/devicetree/bindings/pwm/pwm-mtk-disp.txt
index 6f8af2bcc7b7..0521957c253f 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-mtk-disp.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-mtk-disp.txt
@@ -6,7 +6,7 @@ Required properties:
- "mediatek,mt6595-disp-pwm": found on mt6595 SoC.
- "mediatek,mt8173-disp-pwm": found on mt8173 SoC.
- reg: physical base address and length of the controller's registers.
- - #pwm-cells: must be 2. See pwm.txt in this directory for a description of
+ - #pwm-cells: must be 2. See pwm.yaml in this directory for a description of
the cell format.
- clocks: phandle and clock specifier of the PWM reference clock.
- clock-names: must contain the following:
diff --git a/Documentation/devicetree/bindings/pwm/pwm-omap-dmtimer.txt b/Documentation/devicetree/bindings/pwm/pwm-omap-dmtimer.txt
index 5ccfcc82da08..d722ae3be363 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-omap-dmtimer.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-omap-dmtimer.txt
@@ -4,7 +4,7 @@ Required properties:
- compatible: Shall contain "ti,omap-dmtimer-pwm".
- ti,timers: phandle to PWM capable OMAP timer. See timer/ti,timer.txt for info
about these timers.
-- #pwm-cells: Should be 3. See pwm.txt in this directory for a description of
+- #pwm-cells: Should be 3. See pwm.yaml in this directory for a description of
the cells format.
Optional properties:
diff --git a/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
index 2c5e52a5bede..f70956dea77b 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
@@ -14,7 +14,7 @@ Required properties:
- For newer hardware (rk3328 and future socs): specified by name
- "pwm": This is used to derive the functional clock.
- "pclk": This is the APB bus clock.
- - #pwm-cells: must be 2 (rk2928) or 3 (rk3288). See pwm.txt in this directory
+ - #pwm-cells: must be 2 (rk2928) or 3 (rk3288). See pwm.yaml in this directory
for a description of the cell format.
Example:
diff --git a/Documentation/devicetree/bindings/pwm/pwm-sifive.txt b/Documentation/devicetree/bindings/pwm/pwm-sifive.txt
index 36447e3c9378..3d1dd7b06efc 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-sifive.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-sifive.txt
@@ -17,7 +17,7 @@ Required properties:
Please refer to sifive-blocks-ip-versioning.txt for details.
- reg: physical base address and length of the controller's registers
- clocks: Should contain a clock identifier for the PWM's parent clock.
-- #pwm-cells: Should be 3. See pwm.txt in this directory
+- #pwm-cells: Should be 3. See pwm.yaml in this directory
for a description of the cell format.
- interrupts: one interrupt per PWM channel
diff --git a/Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt b/Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt
index 6521bc44a74e..4cecb8e456b6 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt
@@ -8,7 +8,7 @@ See ../mfd/stm32-lptimer.txt for details about the parent node.
Required parameters:
- compatible: Must be "st,stm32-pwm-lp".
- #pwm-cells: Should be set to 3. This PWM chip uses the default 3 cells
- bindings defined in pwm.txt.
+ bindings defined in pwm.yaml.
Optional properties:
- pinctrl-names: Set to "default". An additional "sleep" state can be
diff --git a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
index a8690bfa5e1f..f390a5ba3d3a 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
@@ -9,7 +9,7 @@ Required parameters:
- pinctrl-0: List of phandles pointing to pin configuration nodes for PWM module.
For Pinctrl properties see ../pinctrl/pinctrl-bindings.txt
- #pwm-cells: Should be set to 3. This PWM chip uses the default 3 cells
- bindings defined in pwm.txt.
+ bindings defined in pwm.yaml.
Optional parameters:
- st,breakinput: One or two <index level filter> to describe break input configurations.
diff --git a/Documentation/devicetree/bindings/pwm/pwm-tiecap.txt b/Documentation/devicetree/bindings/pwm/pwm-tiecap.txt
index b9a1d7402128..c7c4347a769a 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-tiecap.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-tiecap.txt
@@ -8,7 +8,7 @@ Required properties:
for dra746 - compatible = "ti,dra746-ecap", "ti,am3352-ecap";
for 66ak2g - compatible = "ti,k2g-ecap", "ti,am3352-ecap";
for am654 - compatible = "ti,am654-ecap", "ti,am3352-ecap";
-- #pwm-cells: should be 3. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 3. See pwm.yaml in this directory for a description of
the cells format. The PWM channel index ranges from 0 to 4. The only third
cell flag supported by this binding is PWM_POLARITY_INVERTED.
- reg: physical base address and size of the registers map.
diff --git a/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt b/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt
index 31c4577157dd..c7e28f6d28be 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt
@@ -7,7 +7,7 @@ Required properties:
for am654 - compatible = "ti,am654-ehrpwm", "ti-am3352-ehrpwm";
for da850 - compatible = "ti,da850-ehrpwm", "ti-am3352-ehrpwm", "ti,am33xx-ehrpwm";
for dra746 - compatible = "ti,dra746-ehrpwm", "ti-am3352-ehrpwm";
-- #pwm-cells: should be 3. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 3. See pwm.yaml in this directory for a description of
the cells format. The only third cell flag supported by this binding is
PWM_POLARITY_INVERTED.
- reg: physical base address and size of the registers map.
diff --git a/Documentation/devicetree/bindings/pwm/pwm-zx.txt b/Documentation/devicetree/bindings/pwm/pwm-zx.txt
index a6bcc75c9164..3c8fe7aa8269 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-zx.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-zx.txt
@@ -7,7 +7,7 @@ Required properties:
- clock-names: "pclk" for PCLK, "wclk" for WCLK to the PWM controller. The
PCLK is for register access, while WCLK is the reference clock for
calculating period and duty cycles.
- - #pwm-cells: Should be 3. See pwm.txt in this directory for a description of
+ - #pwm-cells: Should be 3. See pwm.yaml in this directory for a description of
the cells format.
Example:
diff --git a/Documentation/devicetree/bindings/pwm/pwm.txt b/Documentation/devicetree/bindings/pwm/pwm.txt
deleted file mode 100644
index 8556263b8502..000000000000
--- a/Documentation/devicetree/bindings/pwm/pwm.txt
+++ /dev/null
@@ -1,69 +0,0 @@
-Specifying PWM information for devices
-======================================
-
-1) PWM user nodes
------------------
-
-PWM users should specify a list of PWM devices that they want to use
-with a property containing a 'pwm-list':
-
- pwm-list ::= <single-pwm> [pwm-list]
- single-pwm ::= <pwm-phandle> <pwm-specifier>
- pwm-phandle : phandle to PWM controller node
- pwm-specifier : array of #pwm-cells specifying the given PWM
- (controller specific)
-
-PWM properties should be named "pwms". The exact meaning of each pwms
-property must be documented in the device tree binding for each device.
-An optional property "pwm-names" may contain a list of strings to label
-each of the PWM devices listed in the "pwms" property. If no "pwm-names"
-property is given, the name of the user node will be used as fallback.
-
-Drivers for devices that use more than a single PWM device can use the
-"pwm-names" property to map the name of the PWM device requested by the
-pwm_get() call to an index into the list given by the "pwms" property.
-
-The following example could be used to describe a PWM-based backlight
-device:
-
- pwm: pwm {
- #pwm-cells = <2>;
- };
-
- [...]
-
- bl: backlight {
- pwms = <&pwm 0 5000000>;
- pwm-names = "backlight";
- };
-
-Note that in the example above, specifying the "pwm-names" is redundant
-because the name "backlight" would be used as fallback anyway.
-
-pwm-specifier typically encodes the chip-relative PWM number and the PWM
-period in nanoseconds.
-
-Optionally, the pwm-specifier can encode a number of flags (defined in
-<dt-bindings/pwm/pwm.h>) in a third cell:
-- PWM_POLARITY_INVERTED: invert the PWM signal polarity
-
-Example with optional PWM specifier for inverse polarity
-
- bl: backlight {
- pwms = <&pwm 0 5000000 PWM_POLARITY_INVERTED>;
- pwm-names = "backlight";
- };
-
-2) PWM controller nodes
------------------------
-
-PWM controller nodes must specify the number of cells used for the
-specifier using the '#pwm-cells' property.
-
-An example PWM controller might look like this:
-
- pwm: pwm@7000a000 {
- compatible = "nvidia,tegra20-pwm";
- reg = <0x7000a000 0x100>;
- #pwm-cells = <2>;
- };
diff --git a/Documentation/devicetree/bindings/pwm/pwm.yaml b/Documentation/devicetree/bindings/pwm/pwm.yaml
new file mode 100644
index 000000000000..aad99d505bb0
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm.yaml
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: PWM controllers (providers)
+
+maintainers:
+ - Thierry Reding <thierry.reding@gmail.com>
+
+properties:
+ $nodename:
+ pattern: "^pwm(@.*|-[0-9a-f])*$"
+
+ "#pwm-cells":
+ description:
+ Number of cells in a PWM specifier.
+
+required:
+ - "#pwm-cells"
+
+examples:
+ - |
+ pwm: pwm@7000a000 {
+ compatible = "nvidia,tegra20-pwm";
+ reg = <0x7000a000 0x100>;
+ #pwm-cells = <2>;
+ };
diff --git a/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt b/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt
index fbd6a4f943ce..a29137869f7a 100644
--- a/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt
+++ b/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt
@@ -20,7 +20,7 @@ Required Properties:
- "renesas,pwm-r8a77990": for R-Car E3
- "renesas,pwm-r8a77995": for R-Car D3
- reg: base address and length of the registers block for the PWM.
-- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 2. See pwm.yaml in this directory for a description of
the cells format.
- clocks: clock phandle and specifier pair.
- pinctrl-0: phandle, referring to a default pin configuration node.
diff --git a/Documentation/devicetree/bindings/pwm/renesas,tpu-pwm.txt b/Documentation/devicetree/bindings/pwm/renesas,tpu-pwm.txt
index 848a92b53d81..966994968069 100644
--- a/Documentation/devicetree/bindings/pwm/renesas,tpu-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/renesas,tpu-pwm.txt
@@ -19,11 +19,11 @@ Required Properties:
- reg: Base address and length of each memory resource used by the PWM
controller hardware module.
- - #pwm-cells: should be 3. See pwm.txt in this directory for a description of
+ - #pwm-cells: should be 3. See pwm.yaml in this directory for a description of
the cells format. The only third cell flag supported by this binding is
PWM_POLARITY_INVERTED.
-Please refer to pwm.txt in this directory for details of the common PWM bindings
+Please refer to pwm-consumers.yaml in this directory for details of the common PWM bindings
used by client devices.
Example: R8A7740 (R-Mobile A1) TPU controller node
diff --git a/Documentation/devicetree/bindings/pwm/spear-pwm.txt b/Documentation/devicetree/bindings/pwm/spear-pwm.txt
index b486de2c3fe3..95894128b62f 100644
--- a/Documentation/devicetree/bindings/pwm/spear-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/spear-pwm.txt
@@ -5,7 +5,7 @@ Required properties:
- "st,spear320-pwm"
- "st,spear1340-pwm"
- reg: physical base address and length of the controller's registers
-- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 2. See pwm.yaml in this directory for a description of
the cells format.
Example:
diff --git a/Documentation/devicetree/bindings/pwm/st,stmpe-pwm.txt b/Documentation/devicetree/bindings/pwm/st,stmpe-pwm.txt
index cb209646bf13..f401316e0248 100644
--- a/Documentation/devicetree/bindings/pwm/st,stmpe-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/st,stmpe-pwm.txt
@@ -7,7 +7,7 @@ subdevices of the STMPE MFD device.
Required properties:
- compatible: should be:
- "st,stmpe-pwm"
-- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 2. See pwm.yaml in this directory for a description of
the cells format.
Example:
diff --git a/Documentation/devicetree/bindings/pwm/ti,twl-pwm.txt b/Documentation/devicetree/bindings/pwm/ti,twl-pwm.txt
index 4e32bee11201..d97ca1964e94 100644
--- a/Documentation/devicetree/bindings/pwm/ti,twl-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/ti,twl-pwm.txt
@@ -6,7 +6,7 @@ On TWL6030 series: PWM0 and PWM1
Required properties:
- compatible: "ti,twl4030-pwm" or "ti,twl6030-pwm"
-- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 2. See pwm.yaml in this directory for a description of
the cells format.
Example:
diff --git a/Documentation/devicetree/bindings/pwm/ti,twl-pwmled.txt b/Documentation/devicetree/bindings/pwm/ti,twl-pwmled.txt
index 9f4b46090782..31ca1b032ef0 100644
--- a/Documentation/devicetree/bindings/pwm/ti,twl-pwmled.txt
+++ b/Documentation/devicetree/bindings/pwm/ti,twl-pwmled.txt
@@ -6,7 +6,7 @@ On TWL6030 series: LED PWM (mainly used as charging indicator LED)
Required properties:
- compatible: "ti,twl4030-pwmled" or "ti,twl6030-pwmled"
-- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 2. See pwm.yaml in this directory for a description of
the cells format.
Example:
diff --git a/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt b/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt
index a76390e6df2e..4fba93ce1985 100644
--- a/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt
@@ -3,7 +3,7 @@ VIA/Wondermedia VT8500/WM8xxx series SoC PWM controller
Required properties:
- compatible: should be "via,vt8500-pwm"
- reg: physical base address and length of the controller's registers
-- #pwm-cells: should be 3. See pwm.txt in this directory for a description of
+- #pwm-cells: should be 3. See pwm.yaml in this directory for a description of
the cells format. The only third cell flag supported by this binding is
PWM_POLARITY_INVERTED.
- clocks: phandle to the PWM source clock
diff --git a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
index 3d78d507e29f..252edcc2e381 100644
--- a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
@@ -27,7 +27,7 @@ Required properties:
--------------------
- compatible: Should be "pwm-regulator"
-- pwms: PWM specification (See: ../pwm/pwm.txt)
+- pwms: PWM specification (See: ../pwm/pwm-consumers.yaml)
Only required for Voltage Table Mode:
- voltage-table: Voltage and Duty-Cycle table consisting of 2 cells
diff --git a/Documentation/devicetree/bindings/timer/ingenic,tcu.txt b/Documentation/devicetree/bindings/timer/ingenic,tcu.txt
index 5a4b9ddd9470..0c7bd51c19eb 100644
--- a/Documentation/devicetree/bindings/timer/ingenic,tcu.txt
+++ b/Documentation/devicetree/bindings/timer/ingenic,tcu.txt
@@ -42,7 +42,7 @@ Required properties:
- compatible: Must be one of:
* ingenic,jz4740-pwm
* ingenic,jz4725b-pwm
-- #pwm-cells: Should be 3. See ../pwm/pwm.txt for a description of the cell
+- #pwm-cells: Should be 3. See ../pwm/pwm.yaml for a description of the cell
format.
- clocks: List of phandle & clock specifiers for the TCU clocks.
- clock-names: List of name strings for the TCU clocks.
--
2.17.1
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related
* [PATCH v2 6/8] dt-bindings: watchdog: Add missing clocks requirement in Samsung SoC watchdog
From: Krzysztof Kozlowski @ 2019-09-18 17:31 UTC (permalink / raw)
To: Rob Herring, Mark Rutland, Thierry Reding, Matt Mackall,
Herbert Xu, Wim Van Sebroeck, Guenter Roeck, linux-clk,
devicetree, linux-kernel, dri-devel, linux-leds, linux-arm-kernel,
linux-samsung-soc, linux-pwm, linux-tegra,
bcm-kernel-feedback-list, linux-rpi-kernel, linux-amlogic,
linux-mediatek, linux-rockchip, linux-riscv, linux-stm32,
linux-crypto, linux-watchdog
Cc: Krzysztof Kozlowski
In-Reply-To: <20190918173141.4314-1-krzk@kernel.org>
The Samsung SoC watchdog driver always required providing a clock
(either through platform data or from DT). However when bindings were
added in commit 9487a9cc7140 ("watchdog: s3c2410: Add support for device
tree based probe"), they missed the requirement of clock.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
---
Changes since v1:
1. Indent example with four spaces (more readable),
2. Add also missing required entries for clocks.
---
.../devicetree/bindings/watchdog/samsung-wdt.yaml | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/Documentation/devicetree/bindings/watchdog/samsung-wdt.yaml b/Documentation/devicetree/bindings/watchdog/samsung-wdt.yaml
index 3ea3c9fe8390..311f9dc83fdb 100644
--- a/Documentation/devicetree/bindings/watchdog/samsung-wdt.yaml
+++ b/Documentation/devicetree/bindings/watchdog/samsung-wdt.yaml
@@ -26,6 +26,13 @@ properties:
reg:
maxItems: 1
+ clocks:
+ maxItems: 1
+
+ clock-names:
+ items:
+ - const: watchdog
+
interrupts:
maxItems: 1
@@ -40,6 +47,8 @@ properties:
required:
- compatible
+ - clocks
+ - clock-names
- interrupts
- reg
--
2.17.1
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related
* [PATCH v2 5/8] dt-bindings: watchdog: Convert Samsung SoC watchdog bindings to json-schema
From: Krzysztof Kozlowski @ 2019-09-18 17:31 UTC (permalink / raw)
To: Rob Herring, Mark Rutland, Thierry Reding, Matt Mackall,
Herbert Xu, Wim Van Sebroeck, Guenter Roeck, linux-clk,
devicetree, linux-kernel, dri-devel, linux-leds, linux-arm-kernel,
linux-samsung-soc, linux-pwm, linux-tegra,
bcm-kernel-feedback-list, linux-rpi-kernel, linux-amlogic,
linux-mediatek, linux-rockchip, linux-riscv, linux-stm32,
linux-crypto, linux-watchdog
Cc: Krzysztof Kozlowski
In-Reply-To: <20190918173141.4314-1-krzk@kernel.org>
Convert Samsung S3C/S5P/Exynos watchdog bindings to DT schema format
using json-schema.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
Changes since v1:
1. Indent example with four spaces (more readable),
2. Remove unneeded timeout-sec description.
---
.../bindings/watchdog/samsung-wdt.txt | 35 ----------
.../bindings/watchdog/samsung-wdt.yaml | 67 +++++++++++++++++++
2 files changed, 67 insertions(+), 35 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
create mode 100644 Documentation/devicetree/bindings/watchdog/samsung-wdt.yaml
diff --git a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
deleted file mode 100644
index 46dcb48e75b4..000000000000
--- a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
+++ /dev/null
@@ -1,35 +0,0 @@
-* Samsung's Watchdog Timer Controller
-
-The Samsung's Watchdog controller is used for resuming system operation
-after a preset amount of time during which the WDT reset event has not
-occurred.
-
-Required properties:
-- compatible : should be one among the following
- - "samsung,s3c2410-wdt" for S3C2410
- - "samsung,s3c6410-wdt" for S3C6410, S5PV210 and Exynos4
- - "samsung,exynos5250-wdt" for Exynos5250
- - "samsung,exynos5420-wdt" for Exynos5420
- - "samsung,exynos7-wdt" for Exynos7
-
-- reg : base physical address of the controller and length of memory mapped
- region.
-- interrupts : interrupt number to the cpu.
-- samsung,syscon-phandle : reference to syscon node (This property required only
- in case of compatible being "samsung,exynos5250-wdt" or "samsung,exynos5420-wdt".
- In case of Exynos5250 and 5420 this property points to syscon node holding the PMU
- base address)
-
-Optional properties:
-- timeout-sec : contains the watchdog timeout in seconds.
-
-Example:
-
-watchdog@101d0000 {
- compatible = "samsung,exynos5250-wdt";
- reg = <0x101D0000 0x100>;
- interrupts = <0 42 0>;
- clocks = <&clock 336>;
- clock-names = "watchdog";
- samsung,syscon-phandle = <&pmu_syscon>;
-};
diff --git a/Documentation/devicetree/bindings/watchdog/samsung-wdt.yaml b/Documentation/devicetree/bindings/watchdog/samsung-wdt.yaml
new file mode 100644
index 000000000000..3ea3c9fe8390
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/samsung-wdt.yaml
@@ -0,0 +1,67 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/watchdog/samsung-wdt.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung SoC Watchdog Timer Controller
+
+maintainers:
+ - Krzysztof Kozlowski <krzk@kernel.org>
+
+description: |+
+ The Samsung's Watchdog controller is used for resuming system operation
+ after a preset amount of time during which the WDT reset event has not
+ occurred.
+
+properties:
+ compatible:
+ enum:
+ - samsung,s3c2410-wdt # for S3C2410
+ - samsung,s3c6410-wdt # for S3C6410, S5PV210 and Exynos4
+ - samsung,exynos5250-wdt # for Exynos5250
+ - samsung,exynos5420-wdt # for Exynos5420
+ - samsung,exynos7-wdt # for Exynos7
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ samsung,syscon-phandle:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description:
+ Phandle to the PMU system controller node (in case of Exynos5250
+ and Exynos5420).
+
+ timeout-sec:
+ $ref: /schemas/types.yaml#/definitions/uint32
+
+required:
+ - compatible
+ - interrupts
+ - reg
+
+allOf:
+ - if:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - samsung,exynos5250-wdt
+ - samsung,exynos5420-wdt
+ then:
+ required:
+ - samsung,syscon-phandle
+
+examples:
+ - |
+ watchdog@101d0000 {
+ compatible = "samsung,exynos5250-wdt";
+ reg = <0x101D0000 0x100>;
+ interrupts = <0 42 0>;
+ clocks = <&clock 336>;
+ clock-names = "watchdog";
+ samsung,syscon-phandle = <&pmu_syscon>;
+ };
--
2.17.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related
* [PATCH v2 4/8] dt-bindings: memory-controllers: Convert Samsung Exynos SROM bindings to json-schema
From: Krzysztof Kozlowski @ 2019-09-18 17:31 UTC (permalink / raw)
To: Rob Herring, Mark Rutland, Thierry Reding, Matt Mackall,
Herbert Xu, Wim Van Sebroeck, Guenter Roeck, linux-clk,
devicetree, linux-kernel, dri-devel, linux-leds, linux-arm-kernel,
linux-samsung-soc, linux-pwm, linux-tegra,
bcm-kernel-feedback-list, linux-rpi-kernel, linux-amlogic,
linux-mediatek, linux-rockchip, linux-riscv, linux-stm32,
linux-crypto, linux-watchdog
Cc: Krzysztof Kozlowski
In-Reply-To: <20190918173141.4314-1-krzk@kernel.org>
Convert Samsung Exynos SROM controller bindings to DT schema format
using json-schema.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
Changes since v1:
1. Indent example with four spaces (more readable),
2. Split examples into two,
3. Fix pattern for subnode name,
4. Remove checks for #address-cells-ranges-#size-cells,
5. Add "additionalProperties" so the wrongly named subnodes would be
matched.
---
.../memory-controllers/exynos-srom.txt | 79 -----------
.../memory-controllers/exynos-srom.yaml | 128 ++++++++++++++++++
2 files changed, 128 insertions(+), 79 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/memory-controllers/exynos-srom.txt
create mode 100644 Documentation/devicetree/bindings/memory-controllers/exynos-srom.yaml
diff --git a/Documentation/devicetree/bindings/memory-controllers/exynos-srom.txt b/Documentation/devicetree/bindings/memory-controllers/exynos-srom.txt
deleted file mode 100644
index f633b5d0f8ca..000000000000
--- a/Documentation/devicetree/bindings/memory-controllers/exynos-srom.txt
+++ /dev/null
@@ -1,79 +0,0 @@
-SAMSUNG Exynos SoCs SROM Controller driver.
-
-Required properties:
-- compatible : Should contain "samsung,exynos4210-srom".
-
-- reg: offset and length of the register set
-
-Optional properties:
-The SROM controller can be used to attach external peripherals. In this case
-extra properties, describing the bus behind it, should be specified as below:
-
-- #address-cells: Must be set to 2 to allow device address translation.
- Address is specified as (bank#, offset).
-
-- #size-cells: Must be set to 1 to allow device size passing
-
-- ranges: Must be set up to reflect the memory layout with four integer values
- per bank:
- <bank-number> 0 <parent address of bank> <size>
-
-Sub-nodes:
-The actual device nodes should be added as subnodes to the SROMc node. These
-subnodes, in addition to regular device specification, should contain the following
-properties, describing configuration of the relevant SROM bank:
-
-Required properties:
-- reg: bank number, base address (relative to start of the bank) and size of
- the memory mapped for the device. Note that base address will be
- typically 0 as this is the start of the bank.
-
-- samsung,srom-timing : array of 6 integers, specifying bank timings in the
- following order: Tacp, Tcah, Tcoh, Tacc, Tcos, Tacs.
- Each value is specified in cycles and has the following
- meaning and valid range:
- Tacp : Page mode access cycle at Page mode (0 - 15)
- Tcah : Address holding time after CSn (0 - 15)
- Tcoh : Chip selection hold on OEn (0 - 15)
- Tacc : Access cycle (0 - 31, the actual time is N + 1)
- Tcos : Chip selection set-up before OEn (0 - 15)
- Tacs : Address set-up before CSn (0 - 15)
-
-Optional properties:
-- reg-io-width : data width in bytes (1 or 2). If omitted, default of 1 is used.
-
-- samsung,srom-page-mode : if page mode is set, 4 data page mode will be configured,
- else normal (1 data) page mode will be set.
-
-Example: basic definition, no banks are configured
- memory-controller@12570000 {
- compatible = "samsung,exynos4210-srom";
- reg = <0x12570000 0x14>;
- };
-
-Example: SROMc with SMSC911x ethernet chip on bank 3
- memory-controller@12570000 {
- #address-cells = <2>;
- #size-cells = <1>;
- ranges = <0 0 0x04000000 0x20000 // Bank0
- 1 0 0x05000000 0x20000 // Bank1
- 2 0 0x06000000 0x20000 // Bank2
- 3 0 0x07000000 0x20000>; // Bank3
-
- compatible = "samsung,exynos4210-srom";
- reg = <0x12570000 0x14>;
-
- ethernet@3,0 {
- compatible = "smsc,lan9115";
- reg = <3 0 0x10000>; // Bank 3, offset = 0
- phy-mode = "mii";
- interrupt-parent = <&gpx0>;
- interrupts = <5 8>;
- reg-io-width = <2>;
- smsc,irq-push-pull;
- smsc,force-internal-phy;
-
- samsung,srom-page-mode;
- samsung,srom-timing = <9 12 1 9 1 1>;
- };
- };
diff --git a/Documentation/devicetree/bindings/memory-controllers/exynos-srom.yaml b/Documentation/devicetree/bindings/memory-controllers/exynos-srom.yaml
new file mode 100644
index 000000000000..cdfe3f7f0ea9
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/exynos-srom.yaml
@@ -0,0 +1,128 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/exynos-srom.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung Exynos SoC SROM Controller driver
+
+maintainers:
+ - Krzysztof Kozlowski <krzk@kernel.org>
+
+description: |+
+ The SROM controller can be used to attach external peripherals. In this case
+ extra properties, describing the bus behind it, should be specified.
+
+properties:
+ compatible:
+ items:
+ - const: samsung,exynos4210-srom
+
+ reg:
+ maxItems: 1
+
+ "#address-cells":
+ const: 2
+
+ "#size-cells":
+ const: 1
+
+ ranges:
+ description: |
+ Reflects the memory layout with four integer values per bank. Format:
+ <bank-number> 0 <parent address of bank> <size>
+ Up to four banks are supported.
+
+patternProperties:
+ "^.*@[0-3],[a-f0-9]+$":
+ type: object
+ description:
+ The actual device nodes should be added as subnodes to the SROMc node.
+ These subnodes, in addition to regular device specification, should
+ contain the following properties, describing configuration
+ of the relevant SROM bank.
+
+ properties:
+ reg:
+ description:
+ Bank number, base address (relative to start of the bank) and size
+ of the memory mapped for the device. Note that base address will be
+ typically 0 as this is the start of the bank.
+ maxItems: 1
+
+ reg-io-width:
+ allOf:
+ - $ref: /schemas/types.yaml#/definitions/uint32
+ - enum: [1, 2]
+ description:
+ Data width in bytes (1 or 2). If omitted, default of 1 is used.
+
+ samsung,srom-page-mode:
+ description:
+ If page mode is set, 4 data page mode will be configured,
+ else normal (1 data) page mode will be set.
+ type: boolean
+
+ samsung,srom-timing:
+ allOf:
+ - $ref: /schemas/types.yaml#/definitions/uint32-array
+ - items:
+ minItems: 6
+ maxItems: 6
+ description: |
+ Array of 6 integers, specifying bank timings in the following order:
+ Tacp, Tcah, Tcoh, Tacc, Tcos, Tacs.
+ Each value is specified in cycles and has the following meaning
+ and valid range:
+ Tacp: Page mode access cycle at Page mode (0 - 15)
+ Tcah: Address holding time after CSn (0 - 15)
+ Tcoh: Chip selection hold on OEn (0 - 15)
+ Tacc: Access cycle (0 - 31, the actual time is N + 1)
+ Tcos: Chip selection set-up before OEn (0 - 15)
+ Tacs: Address set-up before CSn (0 - 15)
+
+ required:
+ - reg
+ - samsung,srom-timing
+
+required:
+ - compatible
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ // Example: basic definition, no banks are configured
+ memory-controller@12560000 {
+ compatible = "samsung,exynos4210-srom";
+ reg = <0x12560000 0x14>;
+ };
+
+ - |
+ // Example: SROMc with SMSC911x ethernet chip on bank 3
+ memory-controller@12570000 {
+ #address-cells = <2>;
+ #size-cells = <1>;
+ ranges = <0 0 0x04000000 0x20000 // Bank0
+ 1 0 0x05000000 0x20000 // Bank1
+ 2 0 0x06000000 0x20000 // Bank2
+ 3 0 0x07000000 0x20000>; // Bank3
+
+ compatible = "samsung,exynos4210-srom";
+ reg = <0x12570000 0x14>;
+
+ ethernet@3,0 {
+ compatible = "smsc,lan9115";
+ reg = <3 0 0x10000>; // Bank 3, offset = 0
+ phy-mode = "mii";
+ interrupt-parent = <&gpx0>;
+ interrupts = <5 8>;
+ reg-io-width = <2>;
+ smsc,irq-push-pull;
+ smsc,force-internal-phy;
+
+ samsung,srom-page-mode;
+ samsung,srom-timing = <9 12 1 9 1 1>;
+ };
+ };
--
2.17.1
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related
* [PATCH v2 3/8] dt-bindings: sram: Convert Samsung Exynos SYSRAM bindings to json-schema
From: Krzysztof Kozlowski @ 2019-09-18 17:31 UTC (permalink / raw)
To: Rob Herring, Mark Rutland, Thierry Reding, Matt Mackall,
Herbert Xu, Wim Van Sebroeck, Guenter Roeck, linux-clk,
devicetree, linux-kernel, dri-devel, linux-leds, linux-arm-kernel,
linux-samsung-soc, linux-pwm, linux-tegra,
bcm-kernel-feedback-list, linux-rpi-kernel, linux-amlogic,
linux-mediatek, linux-rockchip, linux-riscv, linux-stm32,
linux-crypto, linux-watchdog
Cc: Krzysztof Kozlowski
In-Reply-To: <20190918173141.4314-1-krzk@kernel.org>
Convert Samsung Exynos SYSRAM bindings to DT schema format using
json-schema.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
TODO:
The node naming should be probably fixed (sysram->sram)
Changes since v1:
1. Indent example with four spaces (more readable).
---
.../devicetree/bindings/sram/samsung-sram.txt | 38 ------------
.../bindings/sram/samsung-sram.yaml | 58 +++++++++++++++++++
MAINTAINERS | 2 +-
3 files changed, 59 insertions(+), 39 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/sram/samsung-sram.txt
create mode 100644 Documentation/devicetree/bindings/sram/samsung-sram.yaml
diff --git a/Documentation/devicetree/bindings/sram/samsung-sram.txt b/Documentation/devicetree/bindings/sram/samsung-sram.txt
deleted file mode 100644
index 61a9bbed303d..000000000000
--- a/Documentation/devicetree/bindings/sram/samsung-sram.txt
+++ /dev/null
@@ -1,38 +0,0 @@
-Samsung Exynos SYSRAM for SMP bringup:
-------------------------------------
-
-Samsung SMP-capable Exynos SoCs use part of the SYSRAM for the bringup
-of the secondary cores. Once the core gets powered up it executes the
-code that is residing at some specific location of the SYSRAM.
-
-Therefore reserved section sub-nodes have to be added to the mmio-sram
-declaration. These nodes are of two types depending upon secure or
-non-secure execution environment.
-
-Required sub-node properties:
-- compatible : depending upon boot mode, should be
- "samsung,exynos4210-sysram" : for Secure SYSRAM
- "samsung,exynos4210-sysram-ns" : for Non-secure SYSRAM
-
-The rest of the properties should follow the generic mmio-sram discription
-found in Documentation/devicetree/bindings/sram/sram.txt
-
-Example:
-
- sysram@2020000 {
- compatible = "mmio-sram";
- reg = <0x02020000 0x54000>;
- #address-cells = <1>;
- #size-cells = <1>;
- ranges = <0 0x02020000 0x54000>;
-
- smp-sysram@0 {
- compatible = "samsung,exynos4210-sysram";
- reg = <0x0 0x1000>;
- };
-
- smp-sysram@53000 {
- compatible = "samsung,exynos4210-sysram-ns";
- reg = <0x53000 0x1000>;
- };
- };
diff --git a/Documentation/devicetree/bindings/sram/samsung-sram.yaml b/Documentation/devicetree/bindings/sram/samsung-sram.yaml
new file mode 100644
index 000000000000..f49b3b58eb5c
--- /dev/null
+++ b/Documentation/devicetree/bindings/sram/samsung-sram.yaml
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sram/samsung-sram.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung Exynos SoC SYSRAM for SMP bringup
+
+maintainers:
+ - Krzysztof Kozlowski <krzk@kernel.org>
+
+description: |+
+ Samsung SMP-capable Exynos SoCs use part of the SYSRAM for the bringup
+ of the secondary cores. Once the core gets powered up it executes the
+ code that is residing at some specific location of the SYSRAM.
+
+ Therefore reserved section sub-nodes have to be added to the mmio-sram
+ declaration. These nodes are of two types depending upon secure or
+ non-secure execution environment.
+
+allOf:
+ - $ref: "sram.yaml#"
+
+properties:
+ $nodename:
+ pattern: "^sysram(@.*)?"
+
+patternProperties:
+ "^([a-z]*-)?sysram@[a-f0-9]$":
+ type: object
+
+ properties:
+ compatible:
+ description:
+ Depending upon boot mode
+ enum:
+ - samsung,exynos4210-sysram # for Secure SYSRAM
+ - samsung,exynos4210-sysram-ns # for Non-secure SYSRAM
+
+examples:
+ - |
+ sysram@2020000 {
+ compatible = "mmio-sram";
+ reg = <0x02020000 0x54000>;
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0 0x02020000 0x54000>;
+
+ smp-sysram@0 {
+ compatible = "samsung,exynos4210-sysram";
+ reg = <0x0 0x1000>;
+ };
+
+ smp-sysram@53000 {
+ compatible = "samsung,exynos4210-sysram-ns";
+ reg = <0x53000 0x1000>;
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 9cec4494b9a8..c49d35dce088 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2225,7 +2225,7 @@ F: drivers/soc/samsung/
F: include/linux/soc/samsung/
F: Documentation/arm/samsung/
F: Documentation/devicetree/bindings/arm/samsung/
-F: Documentation/devicetree/bindings/sram/samsung-sram.txt
+F: Documentation/devicetree/bindings/sram/samsung-sram.yaml
F: Documentation/devicetree/bindings/power/pd-samsung.txt
N: exynos
--
2.17.1
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related
* [PATCH v2 2/8] dt-bindings: sram: Convert SRAM bindings to json-schema
From: Krzysztof Kozlowski @ 2019-09-18 17:31 UTC (permalink / raw)
To: Rob Herring, Mark Rutland, Thierry Reding, Matt Mackall,
Herbert Xu, Wim Van Sebroeck, Guenter Roeck, linux-clk,
devicetree, linux-kernel, dri-devel, linux-leds, linux-arm-kernel,
linux-samsung-soc, linux-pwm, linux-tegra,
bcm-kernel-feedback-list, linux-rpi-kernel, linux-amlogic,
linux-mediatek, linux-rockchip, linux-riscv, linux-stm32,
linux-crypto, linux-watchdog
Cc: Krzysztof Kozlowski
In-Reply-To: <20190918173141.4314-1-krzk@kernel.org>
Convert generic mmio-sram bindings to DT schema format using
json-schema.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
Changes since v1:
1. Indent example with four spaces (more readable).
---
.../devicetree/bindings/sram/sram.txt | 80 ----------
.../devicetree/bindings/sram/sram.yaml | 138 ++++++++++++++++++
2 files changed, 138 insertions(+), 80 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/sram/sram.txt
create mode 100644 Documentation/devicetree/bindings/sram/sram.yaml
diff --git a/Documentation/devicetree/bindings/sram/sram.txt b/Documentation/devicetree/bindings/sram/sram.txt
deleted file mode 100644
index e98908bd4227..000000000000
--- a/Documentation/devicetree/bindings/sram/sram.txt
+++ /dev/null
@@ -1,80 +0,0 @@
-Generic on-chip SRAM
-
-Simple IO memory regions to be managed by the genalloc API.
-
-Required properties:
-
-- compatible : mmio-sram or atmel,sama5d2-securam
-
-- reg : SRAM iomem address range
-
-Reserving sram areas:
----------------------
-
-Each child of the sram node specifies a region of reserved memory. Each
-child node should use a 'reg' property to specify a specific range of
-reserved memory.
-
-Following the generic-names recommended practice, node names should
-reflect the purpose of the node. Unit address (@<address>) should be
-appended to the name.
-
-Required properties in the sram node:
-
-- #address-cells, #size-cells : should use the same values as the root node
-- ranges : standard definition, should translate from local addresses
- within the sram to bus addresses
-
-Optional properties in the sram node:
-
-- no-memory-wc : the flag indicating, that SRAM memory region has not to
- be remapped as write combining. WC is used by default.
-
-Required properties in the area nodes:
-
-- reg : iomem address range, relative to the SRAM range
-
-Optional properties in the area nodes:
-
-- compatible : standard definition, should contain a vendor specific string
- in the form <vendor>,[<device>-]<usage>
-- pool : indicates that the particular reserved SRAM area is addressable
- and in use by another device or devices
-- export : indicates that the reserved SRAM area may be accessed outside
- of the kernel, e.g. by bootloader or userspace
-- protect-exec : Same as 'pool' above but with the additional
- constraint that code wil be run from the region and
- that the memory is maintained as read-only, executable
- during code execution. NOTE: This region must be page
- aligned on start and end in order to properly allow
- manipulation of the page attributes.
-- label : the name for the reserved partition, if omitted, the label
- is taken from the node name excluding the unit address.
-- clocks : a list of phandle and clock specifier pair that controls the
- single SRAM clock.
-
-Example:
-
-sram: sram@5c000000 {
- compatible = "mmio-sram";
- reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */
-
- #address-cells = <1>;
- #size-cells = <1>;
- ranges = <0 0x5c000000 0x40000>;
-
- smp-sram@100 {
- compatible = "socvendor,smp-sram";
- reg = <0x100 0x50>;
- };
-
- device-sram@1000 {
- reg = <0x1000 0x1000>;
- pool;
- };
-
- exported@20000 {
- reg = <0x20000 0x20000>;
- export;
- };
-};
diff --git a/Documentation/devicetree/bindings/sram/sram.yaml b/Documentation/devicetree/bindings/sram/sram.yaml
new file mode 100644
index 000000000000..8d9d6ce494b2
--- /dev/null
+++ b/Documentation/devicetree/bindings/sram/sram.yaml
@@ -0,0 +1,138 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sram/sram.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic on-chip SRAM
+
+maintainers:
+ - FIXME <who@should.it.be>
+
+description: |+
+ Simple IO memory regions to be managed by the genalloc API.
+
+ Each child of the sram node specifies a region of reserved memory. Each
+ child node should use a 'reg' property to specify a specific range of
+ reserved memory.
+
+ Following the generic-names recommended practice, node names should
+ reflect the purpose of the node. Unit address (@<address>) should be
+ appended to the name.
+
+properties:
+ $nodename:
+ pattern: "^sram(@.*)?"
+
+ compatible:
+ items:
+ - enum:
+ - mmio-sram
+ - atmel,sama5d2-securam
+
+ reg:
+ maxItems: 1
+
+ "#address-cells":
+ description: Should use the same values as the root node.
+
+ "#size-cells":
+ description: Should use the same values as the root node.
+
+ ranges:
+ description:
+ Should translate from local addresses within the sram to bus addresses.
+
+ no-memory-wc:
+ description:
+ The flag indicating, that SRAM memory region has not to be remapped
+ as write combining. WC is used by default.
+ type: boolean
+
+ # TODO: additionalProperties: false
+
+patternProperties:
+ "^([a-z]*-)?sram@[a-f0-9]$":
+ type: object
+ description:
+ Each child of the sram node specifies a region of reserved memory.
+ properties:
+ reg:
+ description:
+ IO mem address range, relative to the SRAM range.
+
+ compatible:
+ $ref: /schemas/types.yaml#/definitions/string
+ description:
+ Should contain a vendor specific string in the form
+ <vendor>,[<device>-]<usage>
+
+ pool:
+ description:
+ Indicates that the particular reserved SRAM area is addressable
+ and in use by another device or devices.
+ type: boolean
+
+ export:
+ description:
+ Indicates that the reserved SRAM area may be accessed outside
+ of the kernel, e.g. by bootloader or userspace.
+ type: boolean
+
+ protect-exec:
+ description: |
+ Same as 'pool' above but with the additional constraint that code
+ will be run from the region and that the memory is maintained as
+ read-only, executable during code execution. NOTE: This region must
+ be page aligned on start and end in order to properly allow
+ manipulation of the page attributes.
+ type: boolean
+
+ label:
+ $ref: /schemas/types.yaml#/definitions/string
+ description:
+ The name for the reserved partition, if omitted, the label is taken
+ from the node name excluding the unit address.
+
+ clocks:
+ description:
+ A list of phandle and clock specifier pair that controls the
+ single SRAM clock.
+
+ # TODO: additionalProperties: false
+
+ required:
+ - reg
+
+required:
+ - compatible
+ - reg
+ - "#address-cells"
+ - "#size-cells"
+ - ranges
+
+examples:
+ - |
+ sram: sram@5c000000 {
+ compatible = "mmio-sram";
+ reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */
+
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0 0x5c000000 0x40000>;
+
+ smp-sram@100 {
+ compatible = "socvendor,smp-sram";
+ reg = <0x100 0x50>;
+ };
+
+ device-sram@1000 {
+ reg = <0x1000 0x1000>;
+ pool;
+ };
+
+ exported@20000 {
+ reg = <0x20000 0x20000>;
+ export;
+ };
+ };
--
2.17.1
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related
* [PATCH v2 1/8] dt-bindings: rng: exynos4-rng: Convert Exynos PRNG bindings to json-schema
From: Krzysztof Kozlowski @ 2019-09-18 17:31 UTC (permalink / raw)
To: Rob Herring, Mark Rutland, Thierry Reding, Matt Mackall,
Herbert Xu, Wim Van Sebroeck, Guenter Roeck, linux-clk,
devicetree, linux-kernel, dri-devel, linux-leds, linux-arm-kernel,
linux-samsung-soc, linux-pwm, linux-tegra,
bcm-kernel-feedback-list, linux-rpi-kernel, linux-amlogic,
linux-mediatek, linux-rockchip, linux-riscv, linux-stm32,
linux-crypto, linux-watchdog
Cc: Krzysztof Kozlowski
Convert Samsung Exynos Pseudo Random Number Generator bindings to DT
schema format using json-schema.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
Changes since v1:
1. Indent example with four spaces (more readable).
---
.../bindings/rng/samsung,exynos4-rng.txt | 19 ---------
.../bindings/rng/samsung,exynos4-rng.yaml | 41 +++++++++++++++++++
MAINTAINERS | 2 +-
3 files changed, 42 insertions(+), 20 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/rng/samsung,exynos4-rng.txt
create mode 100644 Documentation/devicetree/bindings/rng/samsung,exynos4-rng.yaml
diff --git a/Documentation/devicetree/bindings/rng/samsung,exynos4-rng.txt b/Documentation/devicetree/bindings/rng/samsung,exynos4-rng.txt
deleted file mode 100644
index a13fbdb4bd88..000000000000
--- a/Documentation/devicetree/bindings/rng/samsung,exynos4-rng.txt
+++ /dev/null
@@ -1,19 +0,0 @@
-Exynos Pseudo Random Number Generator
-
-Required properties:
-
-- compatible : One of:
- - "samsung,exynos4-rng" for Exynos4210 and Exynos4412
- - "samsung,exynos5250-prng" for Exynos5250+
-- reg : Specifies base physical address and size of the registers map.
-- clocks : Phandle to clock-controller plus clock-specifier pair.
-- clock-names : "secss" as a clock name.
-
-Example:
-
- rng@10830400 {
- compatible = "samsung,exynos4-rng";
- reg = <0x10830400 0x200>;
- clocks = <&clock CLK_SSS>;
- clock-names = "secss";
- };
diff --git a/Documentation/devicetree/bindings/rng/samsung,exynos4-rng.yaml b/Documentation/devicetree/bindings/rng/samsung,exynos4-rng.yaml
new file mode 100644
index 000000000000..2d075d6c87b6
--- /dev/null
+++ b/Documentation/devicetree/bindings/rng/samsung,exynos4-rng.yaml
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rng/samsung,exynos4-rng.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung Exynos SoC Pseudo Random Number Generator
+
+maintainers:
+ - Krzysztof Kozlowski <krzk@kernel.org>
+
+properties:
+ compatible:
+ enum:
+ - samsung,exynos4-rng # for Exynos4210 and Exynos4412
+ - samsung,exynos5250-prng # for Exynos5250+
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ clock-names:
+ items:
+ - const: secss
+
+required:
+ - compatible
+ - reg
+ - clock-names
+ - clocks
+
+examples:
+ - |
+ rng@10830400 {
+ compatible = "samsung,exynos4-rng";
+ reg = <0x10830400 0x200>;
+ clocks = <&clock 255>; // CLK_SSS
+ clock-names = "secss";
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 00969a90f94c..9cec4494b9a8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14181,7 +14181,7 @@ L: linux-crypto@vger.kernel.org
L: linux-samsung-soc@vger.kernel.org
S: Maintained
F: drivers/crypto/exynos-rng.c
-F: Documentation/devicetree/bindings/rng/samsung,exynos4-rng.txt
+F: Documentation/devicetree/bindings/rng/samsung,exynos4-rng.yaml
SAMSUNG EXYNOS TRUE RANDOM NUMBER GENERATOR (TRNG) DRIVER
M: Łukasz Stelmach <l.stelmach@samsung.com>
--
2.17.1
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related
* Re: [PATCH] hwrng: iproc-rng200 - Use devm_platform_ioremap_resource() in iproc_rng200_probe()
From: Florian Fainelli @ 2019-09-18 17:13 UTC (permalink / raw)
To: Markus Elfring, linux-crypto, linux-arm-kernel,
bcm-kernel-feedback-list, Arnd Bergmann, Greg Kroah-Hartman,
Herbert Xu, Matt Mackall, Ray Jui, Scott Branden
Cc: Bartosz Golaszewski, kernel-janitors, LKML, Himanshu Jha
In-Reply-To: <0ecb0679-0558-6cbe-af2f-6ee9122a4a7e@web.de>
On 9/18/19 12:19 AM, Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Wed, 18 Sep 2019 09:09:22 +0200
>
> Simplify this function implementation by using a known wrapper function.
>
> This issue was detected by using the Coccinelle software.
>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
--
Florian
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^ permalink raw reply
* Re: [PATCH V6 1/2] dt-bindings: mailbox: add binding doc for the ARM SMC/HVC mailbox
From: Andre Przywara @ 2019-09-18 17:06 UTC (permalink / raw)
To: Jassi Brar
Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, Peng Fan,
f.fainelli@gmail.com, linux-kernel@vger.kernel.org,
robh+dt@kernel.org, dl-linux-imx, sudeep.holla@arm.com,
linux-arm-kernel@lists.infradead.org
In-Reply-To: <CABb+yY3gJpK5ghS1u-e=f-msO+=oVvX=zDNj3Jg2i0-uJHrLiA@mail.gmail.com>
On Wed, 18 Sep 2019 10:31:57 -0500
Jassi Brar <jassisinghbrar@gmail.com> wrote:
Hi,
> On Wed, Sep 18, 2019 at 9:46 AM Andre Przywara <andre.przywara@arm.com> wrote:
> >
> > On Wed, 18 Sep 2019 09:19:46 -0500
> > Jassi Brar <jassisinghbrar@gmail.com> wrote:
> >
> > Hi,
> >
> > > On Wed, Sep 18, 2019 at 4:44 AM Andre Przywara <andre.przywara@arm.com> wrote:
> > >
> > > >
> > > > > which needs 9 arguments to work. The fact that the fist argument is
> > > > > always going to be same on a platform is just the way we use this
> > > > > instruction.
> > > > >
> > > > > > We should be as strict as possible to avoid any security issues.
> > > > > >
> > > > > Any example of such a security issue?
> > > >
> > > > Someone finds a way to trick some mailbox client to send a crafted message to the mailbox.
> > > >
> > > What if someone finds a way to trick the block layer to erase 'sda' ?
> >
> > Yes, the Linux block driver control the whole block device, it can do whatever it wants.
> >
> Sorry, it doesn't make any sense.
What I meant is that in contrast to a block driver the SMC interface is a shared resource. The mailbox controller is just using a tiny part of that. We must make sure to not interfere with the other services offered by firmware.
> > > That is called "bug in the code".
> > > It does happen in every subsystem but we don't stop implementing new
> > > features .... we write flexible code and then fix any bug.
> > >
> > >
> > > > Do you have any example of a use case where the mailbox client needs to provide the function ID?
> > > >
> > > FSL_SIP_SCMI_1/2 ?
> >
> > Huh? Where does the SCPI or SCMI driver provide this? Those clients don't even provide any arguments. Adding some would defeat the whole point of having this mailbox in the first place, which was to provide a drop-in replacement for a hardware mailbox device used on other platforms.
> >
> SCPI/SCMI implementation is broken. I did NAK it.
> With the 'smc' mailbox you may get away without have to program the
> channel before transmit, but not every controller is natively so.
>
> > > But that is not the main point, which is to be consistent (not
> > > ignoring first argument because someone may find a bug to exploit) and
> > > flexible.
> >
> > Please read the SMCCC[1]: The first argument is in r1/w1/x1. r0/w0 is the function ID, and this is a specific value (fixed by the firmware implementation, see Peng's ATF patch) and not up to be guessed by a client.
> >
> The first argument of smc call is the function-id
> arm_smccc_hvc(function_id, arg0, arg1, arg2, arg3, arg4, arg5, 0, &res);
As I wrote we can't safely use a bare smc call. We must comply with the SMCCC, because there are a possible multitude of services the firmware offers. PSCI is a one obvious example.
And SMCCC says:
When an SMC32/HVC32 call is made from AArch32:
• A Function Identifier is passed in register R0.
• Arguments are passed in registers R1-R6.
• Results are returned in R0-R3.
...
(similar for SMC64)
So arguments start from r1/x1.
> >
> > That's why I think the function ID (which is part of the SMCCC protocol, not of the mailbox service!) should just be set in the controller DT node and nowhere else.
> >
> Actually that is the very reason func-id should be a client thing and
> passed via client's DT node :)
> It is general understanding that protocol specific bits should not be
> a part of controller driver, but the client(protocol) driver.
There are *two* protocols to consider here:
One is the outer SMCCC protocol, which establishes communication between the mailbox controller driver and the firmware. SMCCC defines very precisely the meaning of r0/w0 for that, but leaves the rest (x1-x6) to the user. Think of the function ID being the equivalent of an MMIO base address. You can use it to select several instances of one type of mailbox. It's the task of the controller driver to abstract from that. Surely you wouldn't provide the MMIO base address of the particular mailbox in the client's DT node.
The *client* protocol is then wrapped inside this, using the six argument registers that SMCCC gives us. This is indeed up to the client to use and it dictates its meaning.
Maybe there is some misunderstanding that this mailbox is really a SMCCC mailbox rather than a pure SMC mailbox? Should we use a different naming like smccc_mailbox or firmware_mbox instead?
> Page-7 Function-ID specifies :-
> 1) The service to be invoked.
> 2) The function to be invoked.
"Service" is the term used for a "group of functions". PSCI is one service, for instance. It's typically determined by some upper bits. Inside this service there are several functions, like CPU_ON or SYSTEM_RESET, typically using low order bits.
In our case the service is the mailbox, and there is just one function, the actual doorbell. We could have introduced more functions (like disocvery, information or statistics), but there is no real need for that.
Cheers,
Andre.
> 3) The calling convention (32-bit or 64-bit) that is in use.
> 4) The call type (fast or yielding) that is in use.
>
> Even if we turn blind to 2,3 & 4, but (1) shouts like a runtime property.
>
> Thanks.
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^ permalink raw reply
* Re: [PATCH v4 1/3] arm64: cpufeature: introduce helper cpu_has_hw_af()
From: Catalin Marinas @ 2019-09-18 16:49 UTC (permalink / raw)
To: Matthew Wilcox
Cc: Mark Rutland, Kaly Xin, Ralph Campbell, Jia He, Andrew Morton,
Suzuki Poulose, Marc Zyngier, Anshuman Khandual, linux-kernel,
Jun Yao, linux-mm, Jérôme Glisse, James Morse,
linux-arm-kernel, Punit Agrawal, hejianet, Thomas Gleixner,
Will Deacon, Alex Van Brunt, Kirill A. Shutemov, Robin Murphy
In-Reply-To: <20190918142017.GC9880@bombadil.infradead.org>
On Wed, Sep 18, 2019 at 07:20:17AM -0700, Matthew Wilcox wrote:
> On Wed, Sep 18, 2019 at 09:19:12PM +0800, Jia He wrote:
> > +/* Decouple AF from AFDBM. */
> > +bool cpu_has_hw_af(void)
> > +{
> > + return (read_cpuid(ID_AA64MMFR1_EL1) & 0xf);
> > +}
> > +
>
> Do you really want to call read_cpuid() every time? I would have thought
> you'd want to use the static branch mechanism to do the right thing at
> boot time. See Documentation/static-keys.txt.
We do have a static branch mechanism for other CPU features but mostly
because on some big.LITTLE systems, the CPUs may differ slightly so we
only advertise the common features.
I guess here the additional instructions for reading and checking the
CPUID here would be lost in the noise compared to the actual page
copying.
--
Catalin
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