* Re: [PATCH] powerpc/xmon: Change printk() to pr_cont()
From: Joe Perches @ 2020-12-04 15:55 UTC (permalink / raw)
To: Michael Ellerman, Christophe Leroy, Benjamin Herrenschmidt,
Paul Mackerras
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <87h7p1vnym.fsf@mpe.ellerman.id.au>
On Fri, 2020-12-04 at 21:56 +1100, Michael Ellerman wrote:
> Christophe Leroy <christophe.leroy@csgroup.eu> writes:
> > Since some time now, printk() adds carriage return, leading to
> > unusable xmon output:
> >
> > [ 54.288722] sysrq: Entering xmon
> > [ 54.292209] Vector: 0 at [cace3d2c]
> > [ 54.292274] pc:
> > [ 54.292331] c0023650
>
> ...
>
> > diff --git a/arch/powerpc/xmon/nonstdio.c b/arch/powerpc/xmon/nonstdio.c
> > index 5c1a50912229..9b0d85bff021 100644
> > --- a/arch/powerpc/xmon/nonstdio.c
> > +++ b/arch/powerpc/xmon/nonstdio.c
> > @@ -178,7 +178,7 @@ void xmon_printf(const char *format, ...)
> >
> >
> > if (n && rc == 0) {
> > /* No udbg hooks, fallback to printk() - dangerous */
> > - printk("%s", xmon_outbuf);
> > + pr_cont("%s", xmon_outbuf);
> > }
>
> Ah OK, in the case where there's no udbg backend. We basically always
> have a udbg backend on 64-bit, via hvc console. Which explains why we
> haven't noticed it.
>
> Will pick up the patch.
>
> cheers
Perhaps all of these bare printks should be inspected for defects:
$ git grep -P -n '\bprintk\s*\(\s*(?!KERN_\w+)"[^\\n]*"' arch/powerpc
arch/powerpc/kernel/process.c:1475: printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
arch/powerpc/kernel/process.c:1479: printk("MSR: "REG" ", regs->msr);
arch/powerpc/kernel/process.c:1513: printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
arch/powerpc/kernel/process.c:1514: printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
arch/powerpc/kernel/process.c:2157: printk("%s["REG"] ["REG"] %pS",
arch/powerpc/kernel/traps.c:621: printk("Caused by (from MCSR=%lx): ", reason);
arch/powerpc/kernel/traps.c:726: printk("Caused by (from MCSR=%lx): ", reason);
arch/powerpc/kernel/traps.c:766: printk("Caused by (from MCSR=%lx): ", reason);
arch/powerpc/kernel/traps.c:791: printk("Caused by (from SRR1=%lx): ", reason);
arch/powerpc/kernel/udbg.c:95: printk("%s", s);
arch/powerpc/math-emu/fabs.c:13: printk("%s: D %p, B %p: ", __func__, frD, frB);
arch/powerpc/math-emu/fctiw.c:22: printk("%s: D %p, B %p: ", __func__, frD, frB);
arch/powerpc/math-emu/fctiwz.c:29: printk("%s: D %p, B %p: ", __func__, frD, frB);
arch/powerpc/math-emu/fmr.c:13: printk("%s: D %p, B %p: ", __func__, frD, frB);
arch/powerpc/math-emu/fnabs.c:13: printk("%s: D %p, B %p: ", __func__, frD, frB);
arch/powerpc/math-emu/fneg.c:13: printk("%s: D %p, B %p: ", __func__, frD, frB);
arch/powerpc/math-emu/lfd.c:15: printk("%s: D %p, ea %p: ", __func__, frD, ea);
arch/powerpc/math-emu/stfd.c:11: printk("%s: S %p, ea %p: ", __func__, frS, ea);
arch/powerpc/mm/nohash/44x.c:192: printk("%d ", i);
arch/powerpc/platforms/4xx/machine_check.c:19: printk("Data");
arch/powerpc/platforms/chrp/pci.c:256: printk(" at %llx", (unsigned long long)r.start);
arch/powerpc/platforms/embedded6xx/ls_uart.c:47: printk("%c", in_8(avr_addr + UART_RX));
arch/powerpc/platforms/powermac/pfunc_core.c:83: printk("%s", title);
arch/powerpc/platforms/powermac/pfunc_core.c:85: printk("%02x ", *((u8 *)blob));
arch/powerpc/platforms/powernv/pci-ioda.c:81: printk("%spci %s: [PE# %.2x] %pV",
arch/powerpc/sysdev/tsi108_pci.c:63: printk("PCI CFG write : ");
arch/powerpc/sysdev/tsi108_pci.c:64: printk("%d:0x%x:0x%x ", bus->number, devfunc, offset);
arch/powerpc/sysdev/tsi108_pci.c:65: printk("%d ADDR=0x%08x ", len, (uint) cfg_addr);
arch/powerpc/sysdev/tsi108_pci.c:164: printk("PCI CFG read : ");
arch/powerpc/sysdev/tsi108_pci.c:165: printk("%d:0x%x:0x%x ", bus->number, devfn, offset);
arch/powerpc/sysdev/tsi108_pci.c:166: printk("%d ADDR=0x%08x ", len, (uint) cfg_addr);
arch/powerpc/sysdev/tsi108_pci.c:315: printk("cfg_ctl=0x%08x ", temp);
arch/powerpc/xmon/nonstdio.c:181: printk("%s", xmon_outbuf);
^ permalink raw reply
* Re: [PATCH 13/29] powerpc/pseries/mobility: use stop_machine for join/suspend
From: Nathan Lynch @ 2020-12-04 16:01 UTC (permalink / raw)
To: Michael Ellerman, linuxppc-dev; +Cc: tyreld, ajd, mmc, cforno12, drt, brking
In-Reply-To: <875z5hvilq.fsf@mpe.ellerman.id.au>
Hi Michael,
Michael Ellerman <mpe@ellerman.id.au> writes:
> Nathan Lynch <nathanl@linux.ibm.com> writes:
>> The partition suspend sequence as specified in the platform
>> architecture requires that all active processor threads call
>> H_JOIN, which:
> ...
>> diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
>> index 1b8ae221b98a..44ca7d4e143d 100644
>> --- a/arch/powerpc/platforms/pseries/mobility.c
>> +++ b/arch/powerpc/platforms/pseries/mobility.c
>> @@ -412,6 +414,128 @@ static int wait_for_vasi_session_suspending(u64 handle)
> ...
>
>> +
>> +static int do_join(void *arg)
>> +{
>> + atomic_t *counter = arg;
>> + long hvrc;
>> + int ret;
>> +
>> + /* Must ensure MSR.EE off for H_JOIN. */
>> + hard_irq_disable();
>
> Didn't stop_machine() already do that for us?
>
> In the state machine in multi_cpu_stop().
Yes, but I didn't want to rely on something that seems like an
implementation detail of stop_machine(). I assumed it's benign and in
keeping with hard_irq_disable()'s intended semantics to make multiple
calls to it within a critical section.
I don't feel strongly about this though. If I remove this
hard_irq_disable() I'll modify the comment to indicate that this
function relies on stop_machine() to satisfy this condition for H_JOIN.
>> + hvrc = plpar_hcall_norets(H_JOIN);
>> +
>> + switch (hvrc) {
>> + case H_CONTINUE:
>> + /*
>> + * All other CPUs are offline or in H_JOIN. This CPU
>> + * attempts the suspend.
>> + */
>> + ret = do_suspend();
>> + break;
>> + case H_SUCCESS:
>> + /*
>> + * The suspend is complete and this cpu has received a
>> + * prod.
>> + */
>> + ret = 0;
>> + break;
>> + case H_BAD_MODE:
>> + case H_HARDWARE:
>> + default:
>> + ret = -EIO;
>> + pr_err_ratelimited("H_JOIN error %ld on CPU %i\n",
>> + hvrc, smp_processor_id());
>> + break;
>> + }
>> +
>> + if (atomic_inc_return(counter) == 1) {
>> + pr_info("CPU %u waking all threads\n", smp_processor_id());
>> + prod_others();
>> + }
>
> Do we even need the counter? IIUC only one CPU receives H_CONTINUE. So
> couldn't we just have that CPU do the prodding of others?
CPUs may exit H_JOIN due to system reset interrupt at any time, and
H_JOIN may return H_HARDWARE to a caller after other CPUs have entered
the join state successfully. In these cases the counter ensures exactly
one thread performs the prod sequence.
>
>> + /*
>> + * Execution may have been suspended for several seconds, so
>> + * reset the watchdog.
>> + */
>> + touch_nmi_watchdog();
>> + return ret;
>> +}
>> +
>> +static int pseries_migrate_partition(u64 handle)
>> +{
>> + atomic_t counter = ATOMIC_INIT(0);
>> + int ret;
>> +
>> + ret = wait_for_vasi_session_suspending(handle);
>> + if (ret)
>> + goto out;
>
> Direct return would be clearer IMHO.
OK, I can change this.
^ permalink raw reply
* Re: [PATCH 16/29] powerpc/rtas: dispatch partition migration requests to pseries
From: Nathan Lynch @ 2020-12-04 16:04 UTC (permalink / raw)
To: Michael Ellerman, linuxppc-dev; +Cc: tyreld, ajd, mmc, cforno12, drt, brking
In-Reply-To: <874kl1vilh.fsf@mpe.ellerman.id.au>
Michael Ellerman <mpe@ellerman.id.au> writes:
> Nathan Lynch <nathanl@linux.ibm.com> writes:
>> sys_rtas() cannot call ibm,suspend-me directly in the same way it
>> handles other inputs. Instead it must dispatch the request to code
>> that can first perform the H_JOIN sequence before any call to
>> ibm,suspend-me can succeed. Over time kernel/rtas.c has accreted a fair
>> amount of platform-specific code to implement this.
>>
>> Since a different, more robust implementation of the suspend sequence
>> is now in the pseries platform code, we want to dispatch the request
>> there while minimizing additional dependence on pseries.
>>
>> Use a weak function that only pseries overrides.
>
> Over the years weak functions have caused their fair share of problems.
>
> There are cases where they are the cleanest option, but for intra-arch
> code like this I think and ifdef is much simpler.
Fair enough, I wasn't all that confident about this anyway.
>> diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
>> index fdefe6a974eb..be0fc2536673 100644
>> --- a/arch/powerpc/include/asm/rtas.h
>> +++ b/arch/powerpc/include/asm/rtas.h
>> @@ -260,6 +260,7 @@ extern int rtas_suspend_cpu(struct rtas_suspend_me_data *data);
>> extern int rtas_suspend_last_cpu(struct rtas_suspend_me_data *data);
>> int rtas_ibm_suspend_me_unsafe(u64 handle);
>> int rtas_ibm_suspend_me(int *fw_status);
>> +int rtas_syscall_dispatch_ibm_suspend_me(u64 handle);
>
> ie. we'd just do:
>
> #ifdef CONFIG_PPC_PSERIES
> int rtas_syscall_dispatch_ibm_suspend_me(u64 handle);
> #else
> int rtas_syscall_dispatch_ibm_suspend_me(u64 handle)
> {
> return -EINVAL;
> }
> #endif
Yep will do.
^ permalink raw reply
* Re: [PATCH] powerpc/book3s_hv_uvmem: Check for failed page migration
From: Ram Pai @ 2020-12-04 16:52 UTC (permalink / raw)
To: Bharata B Rao; +Cc: Alistair Popple, linuxppc-dev
In-Reply-To: <20201204101841.GA621541@in.ibm.com>
On Fri, Dec 04, 2020 at 03:48:41PM +0530, Bharata B Rao wrote:
> On Thu, Dec 03, 2020 at 04:08:12PM +1100, Alistair Popple wrote:
> > migrate_vma_pages() may still clear MIGRATE_PFN_MIGRATE on pages which
> > are not able to be migrated. Drivers may safely copy data prior to
> > calling migrate_vma_pages() however a remote mapping must not be
> > established until after migrate_vma_pages() has returned as the
> > migration could still fail.
> >
> > UV_PAGE_IN_in both copies and maps the data page, therefore it should
> > only be called after checking the results of migrate_vma_pages().
> >
> > Signed-off-by: Alistair Popple <alistair@popple.id.au>
> > ---
> > arch/powerpc/kvm/book3s_hv_uvmem.c | 7 ++++---
> > 1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
> > index 84e5a2dc8be5..08aa6a90c525 100644
> > --- a/arch/powerpc/kvm/book3s_hv_uvmem.c
> > +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
> > @@ -762,7 +762,10 @@ static int kvmppc_svm_page_in(struct vm_area_struct *vma,
> > goto out_finalize;
> > }
> >
> > - if (pagein) {
> > + *mig.dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
> > + migrate_vma_pages(&mig);
> > +
> > + if ((*mig.src & MIGRATE_PFN_MIGRATE) && pagein) {
> > pfn = *mig.src >> MIGRATE_PFN_SHIFT;
> > spage = migrate_pfn_to_page(*mig.src);
> > if (spage) {
> > @@ -773,8 +776,6 @@ static int kvmppc_svm_page_in(struct vm_area_struct *vma,
> > }
> > }
> >
> > - *mig.dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
> > - migrate_vma_pages(&mig);
> > out_finalize:
> > migrate_vma_finalize(&mig);
> > return ret;
This patch certainly looks like the problem, that has been hurting
us for a while. Let me run this patch through my SVM tests. Looks very
promising.
BTW: The code does a similar thing while paging out. It pages out from the
UV, and then does the migration. Is there a bug there aswell?
RP
^ permalink raw reply
* Re: [PATCH v8 11/12] mm/vmalloc: Hugepage vmalloc mappings
From: Edgecombe, Rick P @ 2020-12-04 18:33 UTC (permalink / raw)
To: npiggin@gmail.com, linux-mm@kvack.org, akpm@linux-foundation.org
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
hch@infradead.org, lizefan@huawei.com,
Jonathan.Cameron@Huawei.com, linuxppc-dev@lists.ozlabs.org
In-Reply-To: <1607068679.lfd133za4h.astroid@bobo.none>
On Fri, 2020-12-04 at 18:12 +1000, Nicholas Piggin wrote:
> Excerpts from Edgecombe, Rick P's message of December 1, 2020 6:21
> am:
> > On Sun, 2020-11-29 at 01:25 +1000, Nicholas Piggin wrote:
> > > Support huge page vmalloc mappings. Config option
> > > HAVE_ARCH_HUGE_VMALLOC
> > > enables support on architectures that define HAVE_ARCH_HUGE_VMAP
> > > and
> > > supports PMD sized vmap mappings.
> > >
> > > vmalloc will attempt to allocate PMD-sized pages if allocating
> > > PMD
> > > size
> > > or larger, and fall back to small pages if that was unsuccessful.
> > >
> > > Allocations that do not use PAGE_KERNEL prot are not permitted to
> > > use
> > > huge pages, because not all callers expect this (e.g., module
> > > allocations vs strict module rwx).
> >
> > Several architectures (x86, arm64, others?) allocate modules
> > initially
> > with PAGE_KERNEL and so I think this test will not exclude module
> > allocations in those cases.
>
> Ah, thanks. I guess archs must additionally ensure that their
> PAGE_KERNEL allocations are suitable for huge page mappings before
> enabling the option.
>
> If there is interest from those archs to support this, I have an
> early (un-posted) patch that adds an explicit VM_HUGE flag that could
> override the pessemistic arch default. It's not much trouble to add
> this
> to the large system hash allocations. It's very out of date now but
> I
> can at least give what I have to anyone doing an arch support that
> wants it.
Ahh, sorry, I totally missed that this was only enabled for powerpc.
That patch might be useful for me actually. Or maybe a VM_NOHUGE, since
there are only a few places where executable vmallocs are created? I'm
not sure what the other issues are.
I am endeavoring to have small module allocations share large pages, so
this infrastructure is a big help already.
https://lore.kernel.org/lkml/20201120202426.18009-1-rick.p.edgecombe@intel.com/
Thanks!
^ permalink raw reply
* [PATCH] powerpc/powermac: Fix low_sleep_handler with CONFIG_VMAP_STACK
From: Christophe Leroy @ 2020-12-04 18:55 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
giuseppe
Cc: linuxppc-dev, linux-kernel
low_sleep_handler() can't restore the context from standard
stack because the stack can hardly be accessed with MMU OFF.
Store everything in a global storage area instead of storing
a pointer to the stack in that global storage area.
To avoid a complete churn of the function, still use r1 as
the pointer to the storage area during restore.
Reported-by: Giuseppe Sacco <giuseppe@sguazz.it>
Fixes: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
This is only build tested. Giuseppe can you test it ? Thanks.
---
arch/powerpc/platforms/Kconfig.cputype | 2 +-
arch/powerpc/platforms/powermac/sleep.S | 130 +++++++++++-------------
2 files changed, 59 insertions(+), 73 deletions(-)
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index c194c4ae8bc7..32a9c4c09b98 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -36,7 +36,7 @@ config PPC_BOOK3S_6xx
select PPC_HAVE_PMU_SUPPORT
select PPC_HAVE_KUEP
select PPC_HAVE_KUAP
- select HAVE_ARCH_VMAP_STACK if !ADB_PMU
+ select HAVE_ARCH_VMAP_STACK
config PPC_85xx
bool "Freescale 85xx"
diff --git a/arch/powerpc/platforms/powermac/sleep.S b/arch/powerpc/platforms/powermac/sleep.S
index 7e0f8ba6e54a..ce56082a392a 100644
--- a/arch/powerpc/platforms/powermac/sleep.S
+++ b/arch/powerpc/platforms/powermac/sleep.S
@@ -44,7 +44,8 @@
#define SL_TB 0xa0
#define SL_R2 0xa8
#define SL_CR 0xac
-#define SL_R12 0xb0 /* r12 to r31 */
+#define SL_LR 0xb0
+#define SL_R12 0xb4 /* r12 to r31 */
#define SL_SIZE (SL_R12 + 80)
.section .text
@@ -63,105 +64,107 @@ _GLOBAL(low_sleep_handler)
blr
#else
mflr r0
- stw r0,4(r1)
- stwu r1,-SL_SIZE(r1)
+ lis r11,sleep_storage@ha
+ addis r11,r11,sleep_storage@l
+ stw r0,SL_LR(r11)
mfcr r0
- stw r0,SL_CR(r1)
- stw r2,SL_R2(r1)
- stmw r12,SL_R12(r1)
+ stw r0,SL_CR(r11)
+ stw r1,SL_SP(r11)
+ stw r2,SL_R2(r11)
+ stmw r12,SL_R12(r11)
/* Save MSR & SDR1 */
mfmsr r4
- stw r4,SL_MSR(r1)
+ stw r4,SL_MSR(r11)
mfsdr1 r4
- stw r4,SL_SDR1(r1)
+ stw r4,SL_SDR1(r11)
/* Get a stable timebase and save it */
1: mftbu r4
- stw r4,SL_TB(r1)
+ stw r4,SL_TB(r11)
mftb r5
- stw r5,SL_TB+4(r1)
+ stw r5,SL_TB+4(r11)
mftbu r3
cmpw r3,r4
bne 1b
/* Save SPRGs */
mfsprg r4,0
- stw r4,SL_SPRG0(r1)
+ stw r4,SL_SPRG0(r11)
mfsprg r4,1
- stw r4,SL_SPRG0+4(r1)
+ stw r4,SL_SPRG0+4(r11)
mfsprg r4,2
- stw r4,SL_SPRG0+8(r1)
+ stw r4,SL_SPRG0+8(r11)
mfsprg r4,3
- stw r4,SL_SPRG0+12(r1)
+ stw r4,SL_SPRG0+12(r11)
/* Save BATs */
mfdbatu r4,0
- stw r4,SL_DBAT0(r1)
+ stw r4,SL_DBAT0(r11)
mfdbatl r4,0
- stw r4,SL_DBAT0+4(r1)
+ stw r4,SL_DBAT0+4(r11)
mfdbatu r4,1
- stw r4,SL_DBAT1(r1)
+ stw r4,SL_DBAT1(r11)
mfdbatl r4,1
- stw r4,SL_DBAT1+4(r1)
+ stw r4,SL_DBAT1+4(r11)
mfdbatu r4,2
- stw r4,SL_DBAT2(r1)
+ stw r4,SL_DBAT2(r11)
mfdbatl r4,2
- stw r4,SL_DBAT2+4(r1)
+ stw r4,SL_DBAT2+4(r11)
mfdbatu r4,3
- stw r4,SL_DBAT3(r1)
+ stw r4,SL_DBAT3(r11)
mfdbatl r4,3
- stw r4,SL_DBAT3+4(r1)
+ stw r4,SL_DBAT3+4(r11)
mfibatu r4,0
- stw r4,SL_IBAT0(r1)
+ stw r4,SL_IBAT0(r11)
mfibatl r4,0
- stw r4,SL_IBAT0+4(r1)
+ stw r4,SL_IBAT0+4(r11)
mfibatu r4,1
- stw r4,SL_IBAT1(r1)
+ stw r4,SL_IBAT1(r11)
mfibatl r4,1
- stw r4,SL_IBAT1+4(r1)
+ stw r4,SL_IBAT1+4(r11)
mfibatu r4,2
- stw r4,SL_IBAT2(r1)
+ stw r4,SL_IBAT2(r11)
mfibatl r4,2
- stw r4,SL_IBAT2+4(r1)
+ stw r4,SL_IBAT2+4(r11)
mfibatu r4,3
- stw r4,SL_IBAT3(r1)
+ stw r4,SL_IBAT3(r11)
mfibatl r4,3
- stw r4,SL_IBAT3+4(r1)
+ stw r4,SL_IBAT3+4(r11)
BEGIN_MMU_FTR_SECTION
mfspr r4,SPRN_DBAT4U
- stw r4,SL_DBAT4(r1)
+ stw r4,SL_DBAT4(r11)
mfspr r4,SPRN_DBAT4L
- stw r4,SL_DBAT4+4(r1)
+ stw r4,SL_DBAT4+4(r11)
mfspr r4,SPRN_DBAT5U
- stw r4,SL_DBAT5(r1)
+ stw r4,SL_DBAT5(r11)
mfspr r4,SPRN_DBAT5L
- stw r4,SL_DBAT5+4(r1)
+ stw r4,SL_DBAT5+4(r11)
mfspr r4,SPRN_DBAT6U
- stw r4,SL_DBAT6(r1)
+ stw r4,SL_DBAT6(r11)
mfspr r4,SPRN_DBAT6L
- stw r4,SL_DBAT6+4(r1)
+ stw r4,SL_DBAT6+4(r11)
mfspr r4,SPRN_DBAT7U
- stw r4,SL_DBAT7(r1)
+ stw r4,SL_DBAT7(r11)
mfspr r4,SPRN_DBAT7L
- stw r4,SL_DBAT7+4(r1)
+ stw r4,SL_DBAT7+4(r11)
mfspr r4,SPRN_IBAT4U
- stw r4,SL_IBAT4(r1)
+ stw r4,SL_IBAT4(r11)
mfspr r4,SPRN_IBAT4L
- stw r4,SL_IBAT4+4(r1)
+ stw r4,SL_IBAT4+4(r11)
mfspr r4,SPRN_IBAT5U
- stw r4,SL_IBAT5(r1)
+ stw r4,SL_IBAT5(r11)
mfspr r4,SPRN_IBAT5L
- stw r4,SL_IBAT5+4(r1)
+ stw r4,SL_IBAT5+4(r11)
mfspr r4,SPRN_IBAT6U
- stw r4,SL_IBAT6(r1)
+ stw r4,SL_IBAT6(r11)
mfspr r4,SPRN_IBAT6L
- stw r4,SL_IBAT6+4(r1)
+ stw r4,SL_IBAT6+4(r11)
mfspr r4,SPRN_IBAT7U
- stw r4,SL_IBAT7(r1)
+ stw r4,SL_IBAT7(r11)
mfspr r4,SPRN_IBAT7L
- stw r4,SL_IBAT7+4(r1)
+ stw r4,SL_IBAT7+4(r11)
END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
/* Backup various CPU config stuffs */
@@ -180,9 +183,9 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
lis r5,grackle_wake_up@ha
addi r5,r5,grackle_wake_up@l
tophys(r5,r5)
- stw r5,SL_PC(r1)
+ stw r5,SL_PC(r11)
lis r4,KERNELBASE@h
- tophys(r5,r1)
+ tophys(r5,r11)
addi r5,r5,SL_PC
lis r6,MAGIC@ha
addi r6,r6,MAGIC@l
@@ -194,12 +197,6 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
tophys(r3,r3)
stw r3,0x80(r4)
stw r5,0x84(r4)
- /* Store a pointer to our backup storage into
- * a kernel global
- */
- lis r3,sleep_storage@ha
- addi r3,r3,sleep_storage@l
- stw r5,0(r3)
.globl low_cpu_offline_self
low_cpu_offline_self:
@@ -279,7 +276,7 @@ _GLOBAL(core99_wake_up)
lis r3,sleep_storage@ha
addi r3,r3,sleep_storage@l
tophys(r3,r3)
- lwz r1,0(r3)
+ addi r1,r3,SL_PC
/* Pass thru to older resume code ... */
_ASM_NOKPROBE_SYMBOL(core99_wake_up)
@@ -399,13 +396,6 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
blt 1b
sync
- /* restore the MSR and turn on the MMU */
- lwz r3,SL_MSR(r1)
- bl turn_on_mmu
-
- /* get back the stack pointer */
- tovirt(r1,r1)
-
/* Restore TB */
li r3,0
mttbl r3
@@ -419,28 +409,24 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
mtcr r0
lwz r2,SL_R2(r1)
lmw r12,SL_R12(r1)
- addi r1,r1,SL_SIZE
- lwz r0,4(r1)
- mtlr r0
- blr
-_ASM_NOKPROBE_SYMBOL(grackle_wake_up)
-turn_on_mmu:
- mflr r4
- tovirt(r4,r4)
+ /* restore the MSR and SP and turn on the MMU and return */
+ lwz r3,SL_MSR(r1)
+ lwz r4,SL_LR(r1)
+ lwz r1,SL_SP(r1)
mtsrr0 r4
mtsrr1 r3
sync
isync
rfi
-_ASM_NOKPROBE_SYMBOL(turn_on_mmu)
+_ASM_NOKPROBE_SYMBOL(grackle_wake_up)
#endif /* defined(CONFIG_PM) || defined(CONFIG_CPU_FREQ) */
.section .data
.balign L1_CACHE_BYTES
sleep_storage:
- .long 0
+ .space SL_SIZE
.balign L1_CACHE_BYTES, 0
#endif /* CONFIG_PPC_BOOK3S_32 */
--
2.25.0
^ permalink raw reply related
* [powerpc:next-test 192/220] arch/powerpc/kernel/rtas.c:938:21: error: no member named 'rtas_args_reentrant' in 'struct paca_struct'
From: kernel test robot @ 2020-12-04 20:05 UTC (permalink / raw)
To: Nathan Lynch; +Cc: clang-built-linux, kbuild-all, linuxppc-dev
[-- Attachment #1: Type: text/plain, Size: 5568 bytes --]
tree: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next-test
head: 4e4ed87981c764498942c52004c620bb8f104eac
commit: e2f67efc6c8654d7aed885e943499f00a29eecdc [192/220] powerpc/rtas: move rtas_call_reentrant() out of pseries guards
config: powerpc-randconfig-r016-20201204 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 32c501dd88b62787d3a5ffda7aabcf4650dbe3cd)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install powerpc cross compiling tool for clang build
# apt-get install binutils-powerpc-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id=e2f67efc6c8654d7aed885e943499f00a29eecdc
git remote add powerpc https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git
git fetch --no-tags powerpc next-test
git checkout e2f67efc6c8654d7aed885e943499f00a29eecdc
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
>> arch/powerpc/kernel/rtas.c:938:21: error: no member named 'rtas_args_reentrant' in 'struct paca_struct'
args = local_paca->rtas_args_reentrant;
~~~~~~~~~~ ^
1 error generated.
vim +938 arch/powerpc/kernel/rtas.c
b664db8e3f976d Leonardo Bras 2020-05-18 906
b664db8e3f976d Leonardo Bras 2020-05-18 907 /**
b664db8e3f976d Leonardo Bras 2020-05-18 908 * rtas_call_reentrant() - Used for reentrant rtas calls
b664db8e3f976d Leonardo Bras 2020-05-18 909 * @token: Token for desired reentrant RTAS call
b664db8e3f976d Leonardo Bras 2020-05-18 910 * @nargs: Number of Input Parameters
b664db8e3f976d Leonardo Bras 2020-05-18 911 * @nret: Number of Output Parameters
b664db8e3f976d Leonardo Bras 2020-05-18 912 * @outputs: Array of outputs
b664db8e3f976d Leonardo Bras 2020-05-18 913 * @...: Inputs for desired RTAS call
b664db8e3f976d Leonardo Bras 2020-05-18 914 *
b664db8e3f976d Leonardo Bras 2020-05-18 915 * According to LoPAR documentation, only "ibm,int-on", "ibm,int-off",
b664db8e3f976d Leonardo Bras 2020-05-18 916 * "ibm,get-xive" and "ibm,set-xive" are currently reentrant.
b664db8e3f976d Leonardo Bras 2020-05-18 917 * Reentrant calls need their own rtas_args buffer, so not using rtas.args, but
b664db8e3f976d Leonardo Bras 2020-05-18 918 * PACA one instead.
b664db8e3f976d Leonardo Bras 2020-05-18 919 *
b664db8e3f976d Leonardo Bras 2020-05-18 920 * Return: -1 on error,
b664db8e3f976d Leonardo Bras 2020-05-18 921 * First output value of RTAS call if (nret > 0),
b664db8e3f976d Leonardo Bras 2020-05-18 922 * 0 otherwise,
b664db8e3f976d Leonardo Bras 2020-05-18 923 */
b664db8e3f976d Leonardo Bras 2020-05-18 924 int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...)
b664db8e3f976d Leonardo Bras 2020-05-18 925 {
b664db8e3f976d Leonardo Bras 2020-05-18 926 va_list list;
b664db8e3f976d Leonardo Bras 2020-05-18 927 struct rtas_args *args;
b664db8e3f976d Leonardo Bras 2020-05-18 928 unsigned long flags;
b664db8e3f976d Leonardo Bras 2020-05-18 929 int i, ret = 0;
b664db8e3f976d Leonardo Bras 2020-05-18 930
b664db8e3f976d Leonardo Bras 2020-05-18 931 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
b664db8e3f976d Leonardo Bras 2020-05-18 932 return -1;
b664db8e3f976d Leonardo Bras 2020-05-18 933
b664db8e3f976d Leonardo Bras 2020-05-18 934 local_irq_save(flags);
b664db8e3f976d Leonardo Bras 2020-05-18 935 preempt_disable();
b664db8e3f976d Leonardo Bras 2020-05-18 936
b664db8e3f976d Leonardo Bras 2020-05-18 937 /* We use the per-cpu (PACA) rtas args buffer */
b664db8e3f976d Leonardo Bras 2020-05-18 @938 args = local_paca->rtas_args_reentrant;
b664db8e3f976d Leonardo Bras 2020-05-18 939
b664db8e3f976d Leonardo Bras 2020-05-18 940 va_start(list, outputs);
b664db8e3f976d Leonardo Bras 2020-05-18 941 va_rtas_call_unlocked(args, token, nargs, nret, list);
b664db8e3f976d Leonardo Bras 2020-05-18 942 va_end(list);
b664db8e3f976d Leonardo Bras 2020-05-18 943
b664db8e3f976d Leonardo Bras 2020-05-18 944 if (nret > 1 && outputs)
b664db8e3f976d Leonardo Bras 2020-05-18 945 for (i = 0; i < nret - 1; ++i)
b664db8e3f976d Leonardo Bras 2020-05-18 946 outputs[i] = be32_to_cpu(args->rets[i + 1]);
b664db8e3f976d Leonardo Bras 2020-05-18 947
b664db8e3f976d Leonardo Bras 2020-05-18 948 if (nret > 0)
b664db8e3f976d Leonardo Bras 2020-05-18 949 ret = be32_to_cpu(args->rets[0]);
b664db8e3f976d Leonardo Bras 2020-05-18 950
b664db8e3f976d Leonardo Bras 2020-05-18 951 local_irq_restore(flags);
b664db8e3f976d Leonardo Bras 2020-05-18 952 preempt_enable();
b664db8e3f976d Leonardo Bras 2020-05-18 953
b664db8e3f976d Leonardo Bras 2020-05-18 954 return ret;
b664db8e3f976d Leonardo Bras 2020-05-18 955 }
b664db8e3f976d Leonardo Bras 2020-05-18 956
:::::: The code at line 938 was first introduced by commit
:::::: b664db8e3f976d9233cc9ea5e3f8a8c0bcabeb48 powerpc/rtas: Implement reentrant rtas call
:::::: TO: Leonardo Bras <leobras.c@gmail.com>
:::::: CC: Michael Ellerman <mpe@ellerman.id.au>
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 21980 bytes --]
^ permalink raw reply
* Re: powerpc 5.10-rcN boot failures with RCU_SCALE_TEST=m
From: Uladzislau Rezki @ 2020-12-04 20:23 UTC (permalink / raw)
To: Michael Ellerman, Paul E . McKenney; +Cc: rcu, linuxppc-dev, Daniel Axtens
In-Reply-To: <20201203143445.GA22204@pc636>
On Thu, Dec 03, 2020 at 03:34:45PM +0100, Uladzislau Rezki wrote:
> On Thu, Dec 03, 2020 at 05:22:20PM +1100, Michael Ellerman wrote:
> > Uladzislau Rezki <urezki@gmail.com> writes:
> > > On Thu, Dec 03, 2020 at 01:03:32AM +1100, Michael Ellerman wrote:
> > ...
> > >>
> > >> The SMP bringup stalls because _cpu_up() is blocked trying to take
> > >> cpu_hotplug_lock for writing:
> > >>
> > >> [ 401.403132][ T0] task:swapper/0 state:D stack:12512 pid: 1 ppid: 0 flags:0x00000800
> > >> [ 401.403502][ T0] Call Trace:
> > >> [ 401.403907][ T0] [c0000000062c37d0] [c0000000062c3830] 0xc0000000062c3830 (unreliable)
> > >> [ 401.404068][ T0] [c0000000062c39b0] [c000000000019d70] __switch_to+0x2e0/0x4a0
> > >> [ 401.404189][ T0] [c0000000062c3a10] [c000000000b87228] __schedule+0x288/0x9b0
> > >> [ 401.404257][ T0] [c0000000062c3ad0] [c000000000b879b8] schedule+0x68/0x120
> > >> [ 401.404324][ T0] [c0000000062c3b00] [c000000000184ad4] percpu_down_write+0x164/0x170
> > >> [ 401.404390][ T0] [c0000000062c3b50] [c000000000116b68] _cpu_up+0x68/0x280
> > >> [ 401.404475][ T0] [c0000000062c3bb0] [c000000000116e70] cpu_up+0xf0/0x140
> > >> [ 401.404546][ T0] [c0000000062c3c30] [c00000000011776c] bringup_nonboot_cpus+0xac/0xf0
> > >> [ 401.404643][ T0] [c0000000062c3c80] [c000000000eea1b8] smp_init+0x40/0xcc
> > >> [ 401.404727][ T0] [c0000000062c3ce0] [c000000000ec43dc] kernel_init_freeable+0x1e0/0x3a0
> > >> [ 401.404799][ T0] [c0000000062c3db0] [c000000000011ec4] kernel_init+0x24/0x150
> > >> [ 401.404958][ T0] [c0000000062c3e20] [c00000000000daf0] ret_from_kernel_thread+0x5c/0x6c
> > >>
> > >> It can't get it because kprobe_optimizer() has taken it for read and is now
> > >> blocked waiting for synchronize_rcu_tasks():
> > >>
> > >> [ 401.418808][ T0] task:kworker/0:1 state:D stack:13392 pid: 12 ppid: 2 flags:0x00000800
> > >> [ 401.418951][ T0] Workqueue: events kprobe_optimizer
> > >> [ 401.419078][ T0] Call Trace:
> > >> [ 401.419121][ T0] [c0000000062ef650] [c0000000062ef710] 0xc0000000062ef710 (unreliable)
> > >> [ 401.419213][ T0] [c0000000062ef830] [c000000000019d70] __switch_to+0x2e0/0x4a0
> > >> [ 401.419281][ T0] [c0000000062ef890] [c000000000b87228] __schedule+0x288/0x9b0
> > >> [ 401.419347][ T0] [c0000000062ef950] [c000000000b879b8] schedule+0x68/0x120
> > >> [ 401.419415][ T0] [c0000000062ef980] [c000000000b8e664] schedule_timeout+0x2a4/0x340
> > >> [ 401.419484][ T0] [c0000000062efa80] [c000000000b894ec] wait_for_completion+0x9c/0x170
> > >> [ 401.419552][ T0] [c0000000062efae0] [c0000000001ac85c] __wait_rcu_gp+0x19c/0x210
> > >> [ 401.419619][ T0] [c0000000062efb40] [c0000000001ac90c] synchronize_rcu_tasks_generic+0x3c/0x70
> > >> [ 401.419690][ T0] [c0000000062efbe0] [c00000000022a3dc] kprobe_optimizer+0x1dc/0x470
> > >> [ 401.419757][ T0] [c0000000062efc60] [c000000000136684] process_one_work+0x2f4/0x530
> > >> [ 401.419823][ T0] [c0000000062efd20] [c000000000138d28] worker_thread+0x78/0x570
> > >> [ 401.419891][ T0] [c0000000062efdb0] [c000000000142424] kthread+0x194/0x1a0
> > >> [ 401.419976][ T0] [c0000000062efe20] [c00000000000daf0] ret_from_kernel_thread+0x5c/0x6c
> > >>
> > >> But why is the synchronize_rcu_tasks() not completing?
OK. Seems i have understood why the synchronize_rcu_tasks() is not doing progress
waiting on complition. Actually the GP kthreads are not spawned by the time when
early_initcall callbacks gets invoked.
It means that callbacks will not be processed because GP kthreads do not exist,
so wakeme_after_rcu() is not invoked, thus does not signal about that a grace
period has elapsed.
<snip>
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 35bdcfd84d42..c5422bba7fe7 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -241,7 +241,7 @@ static int __noreturn rcu_tasks_kthread(void *arg)
}
}
-/* Spawn RCU-tasks grace-period kthread, e.g., at core_initcall() time. */
+/* Spawn RCU-tasks grace-period kthread at early_initcall() time. */
static void __init rcu_spawn_tasks_kthread_generic(struct rcu_tasks *rtp)
{
struct task_struct *t;
@@ -564,7 +564,7 @@ static int __init rcu_spawn_tasks_kthread(void)
rcu_spawn_tasks_kthread_generic(&rcu_tasks);
return 0;
}
-core_initcall(rcu_spawn_tasks_kthread);
+early_initcall(rcu_spawn_tasks_kthread);
#if !defined(CONFIG_TINY_RCU)
void show_rcu_tasks_classic_gp_kthread(void)
@@ -692,7 +692,7 @@ static int __init rcu_spawn_tasks_rude_kthread(void)
rcu_spawn_tasks_kthread_generic(&rcu_tasks_rude);
return 0;
}
-core_initcall(rcu_spawn_tasks_rude_kthread);
+early_initcall(rcu_spawn_tasks_rude_kthread);
#if !defined(CONFIG_TINY_RCU)
void show_rcu_tasks_rude_gp_kthread(void)
@@ -1193,7 +1193,7 @@ static int __init rcu_spawn_tasks_trace_kthread(void)
rcu_spawn_tasks_kthread_generic(&rcu_tasks_trace);
return 0;
}
-core_initcall(rcu_spawn_tasks_trace_kthread);
+early_initcall(rcu_spawn_tasks_trace_kthread);
#if !defined(CONFIG_TINY_RCU)
void show_rcu_tasks_trace_gp_kthread(void)
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 39334d2d2b37..a251fc705abd 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -133,7 +133,7 @@ EXPORT_SYMBOL(rcu_read_lock_sched_held);
* that if the user specifies both rcu_expedited and rcu_normal, then
* rcu_normal wins. (Except during the time period during boot from
* when the first task is spawned until the rcu_set_runtime_mode()
- * core_initcall() is invoked, at which point everything is expedited.)
+ * early_initcall() is invoked, at which point everything is expedited.)
*/
ol rcu_gp_is_normal(void)
{
@@ -235,7 +235,7 @@ static int __init rcu_set_runtime_mode(void)
rcu_test_sync_prims();
return 0;
}
-core_initcall(rcu_set_runtime_mode);
+early_initcall(rcu_set_runtime_mode);
#endif /* #if !defined(CONFIG_TINY_RCU) || defined(CONFIG_SRCU) */
<snip>
Appreciate if you can test on your setup above patch!
--
Vlad Rezki
^ permalink raw reply related
* Re: [RFC v2 1/2] [NEEDS HELP] x86/mm: Handle unlazying membarrier core sync in the arch code
From: Mathieu Desnoyers @ 2020-12-04 20:24 UTC (permalink / raw)
To: Andy Lutomirski, Peter Zijlstra
Cc: linux-arch, Nadav Amit, Arnd Bergmann, riel, Will Deacon, x86,
Dave Hansen, linux-kernel, Nicholas Piggin, linux-mm,
Catalin Marinas, Jann Horn, linuxppc-dev
In-Reply-To: <203d39d11562575fd8bd6a094d97a3a332d8b265.1607059162.git.luto@kernel.org>
----- On Dec 4, 2020, at 12:26 AM, Andy Lutomirski luto@kernel.org wrote:
> The core scheduler isn't a great place for
> membarrier_mm_sync_core_before_usermode() -- the core scheduler doesn't
> actually know whether we are lazy. With the old code, if a CPU is
> running a membarrier-registered task, goes idle, gets unlazied via a TLB
> shootdown IPI, and switches back to the membarrier-registered task, it
> will do an unnecessary core sync.
>
> Conveniently, x86 is the only architecture that does anything in this
> hook, so we can just move the code.
>
> XXX: there are some comments in swich_mm_irqs_off() that seem to be
> trying to document what barriers are expected, and it's not clear to me
> that these barriers are actually present in all paths through the
> code. So I think this change makes the code more comprehensible and
> has no effect on the code's correctness, but I'm not at all convinced
> that the code is correct.
>
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> ---
> arch/x86/mm/tlb.c | 17 ++++++++++++++++-
> kernel/sched/core.c | 14 +++++++-------
> 2 files changed, 23 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
> index 3338a1feccf9..23df035b80e8 100644
> --- a/arch/x86/mm/tlb.c
> +++ b/arch/x86/mm/tlb.c
> @@ -8,6 +8,7 @@
> #include <linux/export.h>
> #include <linux/cpu.h>
> #include <linux/debugfs.h>
> +#include <linux/sched/mm.h>
>
> #include <asm/tlbflush.h>
> #include <asm/mmu_context.h>
> @@ -496,6 +497,8 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct
> mm_struct *next,
> * from one thread in a process to another thread in the same
> * process. No TLB flush required.
> */
> +
> + // XXX: why is this okay wrt membarrier?
> if (!was_lazy)
> return;
As I recall, when the scheduler switches between threads which belong to
the same mm, it does not have to provide explicit memory barriers for
membarrier because it does not change the "rq->curr->mm" value which is
used as condition in the membarrier loop to send the IPI.
>
> @@ -508,12 +511,24 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct
> mm_struct *next,
> smp_mb();
> next_tlb_gen = atomic64_read(&next->context.tlb_gen);
> if (this_cpu_read(cpu_tlbstate.ctxs[prev_asid].tlb_gen) ==
> - next_tlb_gen)
> + next_tlb_gen) {
> + /*
> + * We're reactivating an mm, and membarrier might
> + * need to serialize. Tell membarrier.
> + */
> +
> + // XXX: I can't understand the logic in
> + // membarrier_mm_sync_core_before_usermode(). What's
> + // the mm check for?
> + membarrier_mm_sync_core_before_usermode(next);
I think you mean the:
if (current->mm != mm)
return;
check at the beginning.
We have to look at it from the scheduler context from which this function is called
(yeah, I know, it's not so great to mix up scheduler and mm states like this).
in finish_task_switch() we have:
struct mm_struct *mm = rq->prev_mm;
[...]
if (mm) {
membarrier_mm_sync_core_before_usermode(mm);
mmdrop(mm);
}
I recall that this current->mm vs rq->prev_mm check is just there to
figure out whether we are in lazy tlb mode, and don't sync core in lazy
tlb mode. Hopefully I'm not stating anything stupid here, maybe Peter
could enlighten us. And you should definitely be careful when calling this
helper from other contexts, as it was originally crafted only for that
single use in the scheduler.
> return;
> + }
>
> /*
> * TLB contents went out of date while we were in lazy
> * mode. Fall through to the TLB switching code below.
> + * No need for an explicit membarrier invocation -- the CR3
> + * write will serialize.
> */
> new_asid = prev_asid;
> need_flush = true;
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 2d95dc3f4644..6c4b76147166 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -3619,22 +3619,22 @@ static struct rq *finish_task_switch(struct task_struct
> *prev)
> kcov_finish_switch(current);
>
> fire_sched_in_preempt_notifiers(current);
> +
> /*
> * When switching through a kernel thread, the loop in
> * membarrier_{private,global}_expedited() may have observed that
> * kernel thread and not issued an IPI. It is therefore possible to
> * schedule between user->kernel->user threads without passing though
> * switch_mm(). Membarrier requires a barrier after storing to
> - * rq->curr, before returning to userspace, so provide them here:
> + * rq->curr, before returning to userspace, and mmdrop() provides
> + * this barrier.
> *
> - * - a full memory barrier for {PRIVATE,GLOBAL}_EXPEDITED, implicitly
> - * provided by mmdrop(),
> - * - a sync_core for SYNC_CORE.
> + * XXX: I don't think mmdrop() actually does this. There's no
> + * smp_mb__before/after_atomic() in there.
I recall mmdrop providing a memory barrier. It looks like I event went though the
trouble of documenting it myself. ;-)
static inline void mmdrop(struct mm_struct *mm)
{
/*
* The implicit full barrier implied by atomic_dec_and_test() is
* required by the membarrier system call before returning to
* user-space, after storing to rq->curr.
*/
if (unlikely(atomic_dec_and_test(&mm->mm_count)))
__mmdrop(mm);
}
> */
> - if (mm) {
> - membarrier_mm_sync_core_before_usermode(mm);
OK so here is the meat. The current code is using the (possibly incomplete)
lazy TLB state known by the scheduler to sync core, and it appears it may be
a bit more heavy that what is strictly needed.
Your change instead rely on the internal knowledge of lazy TLB within x86
switch_mm_irqs_off to achieve this, which overall seems like an improvement.
I agree with Nick's comment that it should go on top of his exit_lazy_mm
patches.
Thanks,
Mathieu
> + if (mm)
> mmdrop(mm);
> - }
> +
> if (unlikely(prev_state == TASK_DEAD)) {
> if (prev->sched_class->task_dead)
> prev->sched_class->task_dead(prev);
> --
> 2.28.0
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
^ permalink raw reply
* Re: [RFC v2 1/2] [NEEDS HELP] x86/mm: Handle unlazying membarrier core sync in the arch code
From: Mathieu Desnoyers @ 2020-12-04 20:39 UTC (permalink / raw)
To: Nadav Amit, Peter Zijlstra
Cc: linux-arch, Arnd Bergmann, riel, Will Deacon, x86, Dave Hansen,
linux-kernel, Nicholas Piggin, linux-mm, Andy Lutomirski,
Catalin Marinas, Jann Horn, linuxppc-dev
In-Reply-To: <A61977A7-F0B2-4492-AB6D-06E24417FA59@gmail.com>
----- On Dec 4, 2020, at 3:17 AM, Nadav Amit nadav.amit@gmail.com wrote:
> I am not very familiar with membarrier, but here are my 2 cents while trying
> to answer your questions.
>
>> On Dec 3, 2020, at 9:26 PM, Andy Lutomirski <luto@kernel.org> wrote:
>> @@ -496,6 +497,8 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct
>> mm_struct *next,
>> * from one thread in a process to another thread in the same
>> * process. No TLB flush required.
>> */
>> +
>> + // XXX: why is this okay wrt membarrier?
>> if (!was_lazy)
>> return;
>
> I am confused.
>
> On one hand, it seems that membarrier_private_expedited() would issue an IPI
> to that core, as it would find that this core’s cpu_rq(cpu)->curr->mm is the
> same as the one that the membarrier applies to.
If the scheduler switches from one thread to another which both have the same mm,
it means cpu_rq(cpu)->curr->mm is invariant, even though ->curr changes. So there
is no need to issue a memory barrier or sync core for membarrier in this case,
because there is no way the IPI can be missed.
> But… (see below)
>
>
>> @@ -508,12 +511,24 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct
>> mm_struct *next,
>> smp_mb();
>> next_tlb_gen = atomic64_read(&next->context.tlb_gen);
>> if (this_cpu_read(cpu_tlbstate.ctxs[prev_asid].tlb_gen) ==
>> - next_tlb_gen)
>> + next_tlb_gen) {
>> + /*
>> + * We're reactivating an mm, and membarrier might
>> + * need to serialize. Tell membarrier.
>> + */
>> +
>> + // XXX: I can't understand the logic in
>> + // membarrier_mm_sync_core_before_usermode(). What's
>> + // the mm check for?
>> + membarrier_mm_sync_core_before_usermode(next);
>
> On the other hand the reason for this mm check that you mention contradicts
> my previous understanding as the git log says:
>
> commit 2840cf02fae627860156737e83326df354ee4ec6
> Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Date: Thu Sep 19 13:37:01 2019 -0400
>
> sched/membarrier: Call sync_core only before usermode for same mm
>
> When the prev and next task's mm change, switch_mm() provides the core
> serializing guarantees before returning to usermode. The only case
> where an explicit core serialization is needed is when the scheduler
> keeps the same mm for prev and next.
Hrm, so your point here is that if the scheduler keeps the same mm for
prev and next, it means membarrier will have observed the same rq->curr->mm,
and therefore the IPI won't be missed. I wonder if that
membarrier_mm_sync_core_before_usermode is needed at all then or if we
have just been too careful and did not consider that all the scenarios which
need to be core-sync'd are indeed taken care of ?
I see here that my prior commit message indeed discusses prev and next task's
mm, but in reality, we are comparing current->mm with rq->prev_mm. So from
a lazy TLB perspective, this probably matters, and we may still need a core sync
in some lazy TLB scenarios.
>
>> /*
>> * When switching through a kernel thread, the loop in
>> * membarrier_{private,global}_expedited() may have observed that
>> * kernel thread and not issued an IPI. It is therefore possible to
>> * schedule between user->kernel->user threads without passing though
>> * switch_mm(). Membarrier requires a barrier after storing to
>> - * rq->curr, before returning to userspace, so provide them here:
>> + * rq->curr, before returning to userspace, and mmdrop() provides
>> + * this barrier.
>> *
>> - * - a full memory barrier for {PRIVATE,GLOBAL}_EXPEDITED, implicitly
>> - * provided by mmdrop(),
>> - * - a sync_core for SYNC_CORE.
>> + * XXX: I don't think mmdrop() actually does this. There's no
>> + * smp_mb__before/after_atomic() in there.
>
> I presume that since x86 is the only one that needs
> membarrier_mm_sync_core_before_usermode(), nobody noticed the missing
> smp_mb__before/after_atomic(). These are anyhow a compiler barrier in x86,
> and such a barrier would take place before the return to userspace.
mmdrop already provides the memory barriers for membarrer, as I documented within the
function.
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
^ permalink raw reply
* Re: [PATCH 01/29] powerpc/rtas: move rtas_call_reentrant() out of pseries guards
From: Nathan Lynch @ 2020-12-04 20:37 UTC (permalink / raw)
To: linuxppc-dev; +Cc: tyreld, ajd, mmc, cforno12, drt, brking
In-Reply-To: <20201030011805.1224603-2-nathanl@linux.ibm.com>
Nathan Lynch <nathanl@linux.ibm.com> writes:
> rtas_call_reentrant() isn't platform-dependent; move it out of
> CONFIG_PPC_PSERIES-guarded code.
As reported by the 0-day CI, this is mistaken, and it breaks non-pseries
builds:
>> arch/powerpc/kernel/rtas.c:938:21: error: no member named 'rtas_args_reentrant' in 'struct paca_struct'
args = local_paca->rtas_args_reentrant;
~~~~~~~~~~ ^
1 error generated.
https://lore.kernel.org/linuxppc-dev/202012050432.SFbbjWMw-lkp@intel.com/
I'll drop this and reroll the series.
^ permalink raw reply
* Re: [PATCH kernel v2] powerpc/kuap: Restore AMR after replaying soft interrupts
From: kernel test robot @ 2020-12-04 21:02 UTC (permalink / raw)
To: Alexey Kardashevskiy, linuxppc-dev
Cc: Alexey Kardashevskiy, clang-built-linux, kbuild-all,
Nicholas Piggin
In-Reply-To: <20201203054724.44838-1-aik@ozlabs.ru>
[-- Attachment #1: Type: text/plain, Size: 7629 bytes --]
Hi Alexey,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v5.10-rc6 next-20201204]
[cannot apply to powerpc/next scottwood/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Alexey-Kardashevskiy/powerpc-kuap-Restore-AMR-after-replaying-soft-interrupts/20201203-135010
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 34816d20f173a90389c8a7e641166d8ea9dce70a
config: powerpc64-randconfig-r023-20201204 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 32c501dd88b62787d3a5ffda7aabcf4650dbe3cd)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install powerpc64 cross compiling tool for clang build
# apt-get install binutils-powerpc64-linux-gnu
# https://github.com/0day-ci/linux/commit/d2a99260ef6d241abe6fb961ee3ed84bbc5db7f5
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Alexey-Kardashevskiy/powerpc-kuap-Restore-AMR-after-replaying-soft-interrupts/20201203-135010
git checkout d2a99260ef6d241abe6fb961ee3ed84bbc5db7f5
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from arch/powerpc/kernel/asm-offsets.c:14:
In file included from include/linux/compat.h:17:
In file included from include/linux/fs.h:33:
In file included from include/linux/percpu-rwsem.h:7:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:9:
In file included from include/linux/sched/task.h:11:
In file included from include/linux/uaccess.h:11:
In file included from arch/powerpc/include/asm/uaccess.h:9:
>> arch/powerpc/include/asm/kup.h:71:29: error: redefinition of 'get_kuap'
static inline unsigned long get_kuap(void)
^
arch/powerpc/include/asm/book3s/64/kup-radix.h:152:29: note: previous definition is here
static inline unsigned long get_kuap(void)
^
In file included from arch/powerpc/kernel/asm-offsets.c:14:
In file included from include/linux/compat.h:17:
In file included from include/linux/fs.h:33:
In file included from include/linux/percpu-rwsem.h:7:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:9:
In file included from include/linux/sched/task.h:11:
In file included from include/linux/uaccess.h:11:
In file included from arch/powerpc/include/asm/uaccess.h:9:
>> arch/powerpc/include/asm/kup.h:76:20: error: redefinition of 'set_kuap'
static inline void set_kuap(unsigned long value) { }
^
arch/powerpc/include/asm/book3s/64/kup-radix.h:157:20: note: previous definition is here
static inline void set_kuap(unsigned long value) { }
^
In file included from arch/powerpc/kernel/asm-offsets.c:21:
include/linux/mman.h:155:9: warning: division by zero is undefined [-Wdivision-by-zero]
_calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/mman.h:133:21: note: expanded from macro '_calc_vm_trans'
: ((x) & (bit1)) / ((bit1) / (bit2))))
^ ~~~~~~~~~~~~~~~~~
include/linux/mman.h:156:9: warning: division by zero is undefined [-Wdivision-by-zero]
_calc_vm_trans(flags, MAP_SYNC, VM_SYNC ) |
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/mman.h:133:21: note: expanded from macro '_calc_vm_trans'
: ((x) & (bit1)) / ((bit1) / (bit2))))
^ ~~~~~~~~~~~~~~~~~
2 warnings and 2 errors generated.
--
In file included from arch/powerpc/kernel/asm-offsets.c:14:
In file included from include/linux/compat.h:17:
In file included from include/linux/fs.h:33:
In file included from include/linux/percpu-rwsem.h:7:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:9:
In file included from include/linux/sched/task.h:11:
In file included from include/linux/uaccess.h:11:
In file included from arch/powerpc/include/asm/uaccess.h:9:
>> arch/powerpc/include/asm/kup.h:71:29: error: redefinition of 'get_kuap'
static inline unsigned long get_kuap(void)
^
arch/powerpc/include/asm/book3s/64/kup-radix.h:152:29: note: previous definition is here
static inline unsigned long get_kuap(void)
^
In file included from arch/powerpc/kernel/asm-offsets.c:14:
In file included from include/linux/compat.h:17:
In file included from include/linux/fs.h:33:
In file included from include/linux/percpu-rwsem.h:7:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:9:
In file included from include/linux/sched/task.h:11:
In file included from include/linux/uaccess.h:11:
In file included from arch/powerpc/include/asm/uaccess.h:9:
>> arch/powerpc/include/asm/kup.h:76:20: error: redefinition of 'set_kuap'
static inline void set_kuap(unsigned long value) { }
^
arch/powerpc/include/asm/book3s/64/kup-radix.h:157:20: note: previous definition is here
static inline void set_kuap(unsigned long value) { }
^
In file included from arch/powerpc/kernel/asm-offsets.c:21:
include/linux/mman.h:155:9: warning: division by zero is undefined [-Wdivision-by-zero]
_calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/mman.h:133:21: note: expanded from macro '_calc_vm_trans'
: ((x) & (bit1)) / ((bit1) / (bit2))))
^ ~~~~~~~~~~~~~~~~~
include/linux/mman.h:156:9: warning: division by zero is undefined [-Wdivision-by-zero]
_calc_vm_trans(flags, MAP_SYNC, VM_SYNC ) |
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/mman.h:133:21: note: expanded from macro '_calc_vm_trans'
: ((x) & (bit1)) / ((bit1) / (bit2))))
^ ~~~~~~~~~~~~~~~~~
2 warnings and 2 errors generated.
make[2]: *** [scripts/Makefile.build:117: arch/powerpc/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [Makefile:1198: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:185: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.
vim +/get_kuap +71 arch/powerpc/include/asm/kup.h
69
70 static inline void kuap_check_amr(void) { }
> 71 static inline unsigned long get_kuap(void)
72 {
73 return AMR_KUAP_BLOCKED;
74 }
75
> 76 static inline void set_kuap(unsigned long value) { }
77
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 41007 bytes --]
^ permalink raw reply
* Re: [PATCH v3 15/18] ibmvfc: send Cancel MAD down each hw scsi channel
From: Brian King @ 2020-12-04 21:26 UTC (permalink / raw)
To: Tyrel Datwyler, james.bottomley
Cc: brking, linuxppc-dev, linux-scsi, martin.petersen, linux-kernel
In-Reply-To: <20201203020806.14747-16-tyreld@linux.ibm.com>
On 12/2/20 8:08 PM, Tyrel Datwyler wrote:
> In general the client needs to send Cancel MADs and task management
> commands down the same channel as the command(s) intended to cancel or
> abort. The client assigns cancel keys per LUN and thus must send a
> Cancel down each channel commands were submitted for that LUN. Further,
> the client then must wait for those cancel completions prior to
> submitting a LUN RESET or ABORT TASK SET.
>
> Add a cancel event pointer and cancel rsp iu storage to the
> ibmvfc_sub_queue struct such that the cancel routine can assign a cancel
> event to each applicable queue. When in legacy CRQ mode we fake treating
> it as a subqueue by using a subqueue struct allocated on the stack. Wait
> for completion of each submitted cancel.
>
> Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
> ---
> drivers/scsi/ibmvscsi/ibmvfc.c | 104 ++++++++++++++++++++++-----------
> drivers/scsi/ibmvscsi/ibmvfc.h | 38 ++++++------
> 2 files changed, 90 insertions(+), 52 deletions(-)
>
> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
> index ec3db5a6baf3..e353b9e88104 100644
> --- a/drivers/scsi/ibmvscsi/ibmvfc.c
> +++ b/drivers/scsi/ibmvscsi/ibmvfc.c
> @@ -2339,67 +2339,103 @@ static int ibmvfc_cancel_all(struct scsi_device *sdev, int type)
> {
> struct ibmvfc_host *vhost = shost_priv(sdev->host);
> struct ibmvfc_event *evt, *found_evt;
> - union ibmvfc_iu rsp;
> - int rsp_rc = -EBUSY;
> + struct ibmvfc_sub_queue *scrqs;
> + struct ibmvfc_sub_queue legacy_crq;
> + int rsp_rc = 0;
> unsigned long flags;
> u16 status;
> + int cancel_cnt = 0;
> + int num_hwq;
> + int ret = 0;
> + int i;
>
> ENTER;
> spin_lock_irqsave(vhost->host->host_lock, flags);
> - found_evt = NULL;
> - list_for_each_entry(evt, &vhost->sent, queue) {
> - if (evt->cmnd && evt->cmnd->device == sdev) {
> - found_evt = evt;
> + if (vhost->using_channels && vhost->scsi_scrqs.active_queues) {
> + num_hwq = vhost->scsi_scrqs.active_queues;
> + scrqs = vhost->scsi_scrqs.scrqs;
> + } else {
> + /* Use ibmvfc_sub_queue on the stack to fake legacy CRQ as a subqueue */
> + num_hwq = 1;
> + scrqs = &legacy_crq;
> + }
> +
> + for (i = 0; i < num_hwq; i++) {
> + scrqs[i].cancel_event = NULL;
> + found_evt = NULL;
> + list_for_each_entry(evt, &vhost->sent, queue) {
> + if (evt->cmnd && evt->cmnd->device == sdev && evt->hwq == i) {
> + found_evt = evt;
> + cancel_cnt++;
> + break;
> + }
> + }
> +
> + if (!found_evt)
> + continue;
> +
> + if (vhost->logged_in) {
> + scrqs[i].cancel_event = ibmvfc_init_tmf(vhost, sdev, type);
> + scrqs[i].cancel_event->hwq = i;
> + scrqs[i].cancel_event->sync_iu = &scrqs[i].cancel_rsp;
> + rsp_rc = ibmvfc_send_event(scrqs[i].cancel_event, vhost, default_timeout);
> + if (rsp_rc)
> + break;
It looks like if you have two outstanding commands, on two different hwqs, and you succeed
in sending a cancel for the first hwq but fail sending it for the second hwq due to
something happening like a xport event of some sort, then you would end up falling down
into free_events where you'd call ibmvfc_free_event which will do a list_add_tail to add
the event to the free list without having even pulled the event off the sent list, which
will result in list corruption as now the free list and sent list will be intermingled.
It would probably be better to only free the events if you never sent them or if you
are sure they completed. So, you might need to have to wait for the completion of
the cancel events that did get sent, which would likely be completed via purge_all.
> + } else {
> + rsp_rc = -EBUSY;
> break;
> }
> }
>
> - if (!found_evt) {
> + spin_unlock_irqrestore(vhost->host->host_lock, flags);
> +
> + if (!cancel_cnt) {
> if (vhost->log_level > IBMVFC_DEFAULT_LOG_LEVEL)
> sdev_printk(KERN_INFO, sdev, "No events found to cancel\n");
> - spin_unlock_irqrestore(vhost->host->host_lock, flags);
> return 0;
> }
>
> - if (vhost->logged_in) {
> - evt = ibmvfc_init_tmf(vhost, sdev, type);
> - evt->sync_iu = &rsp;
> - rsp_rc = ibmvfc_send_event(evt, vhost, default_timeout);
> - }
> -
> - spin_unlock_irqrestore(vhost->host->host_lock, flags);
> -
> if (rsp_rc != 0) {
> sdev_printk(KERN_ERR, sdev, "Failed to send cancel event. rc=%d\n", rsp_rc);
> /* If failure is received, the host adapter is most likely going
> through reset, return success so the caller will wait for the command
> being cancelled to get returned */
> - return 0;
> + goto free_events;
> }
>
> sdev_printk(KERN_INFO, sdev, "Cancelling outstanding commands.\n");
>
> - wait_for_completion(&evt->comp);
> - status = be16_to_cpu(rsp.mad_common.status);
> - spin_lock_irqsave(vhost->host->host_lock, flags);
> - ibmvfc_free_event(evt);
> - spin_unlock_irqrestore(vhost->host->host_lock, flags);
> + for (i = 0; i < num_hwq; i++) {
> + if (!scrqs[i].cancel_event)
> + continue;
>
> - if (status != IBMVFC_MAD_SUCCESS) {
> - sdev_printk(KERN_WARNING, sdev, "Cancel failed with rc=%x\n", status);
> - switch (status) {
> - case IBMVFC_MAD_DRIVER_FAILED:
> - case IBMVFC_MAD_CRQ_ERROR:
> - /* Host adapter most likely going through reset, return success to
> - the caller will wait for the command being cancelled to get returned */
> - return 0;
> - default:
> - return -EIO;
> - };
> + wait_for_completion(&scrqs[i].cancel_event->comp);
> + status = be16_to_cpu(scrqs[i].cancel_rsp.mad_common.status);
> +
> + if (status != IBMVFC_MAD_SUCCESS) {
> + sdev_printk(KERN_WARNING, sdev, "Cancel failed with rc=%x\n", status);
> + switch (status) {
> + case IBMVFC_MAD_DRIVER_FAILED:
> + case IBMVFC_MAD_CRQ_ERROR:
> + /* Host adapter most likely going through reset, return success to
> + the caller will wait for the command being cancelled to get returned */
> + goto free_events;
Similar comment here... What about the rest of the outstanding cancel commands? Do you need
to wait for those to complete before freeing them?
> + default:
> + ret = -EIO;
> + goto free_events;
> + };
> + }
> }
>
> sdev_printk(KERN_INFO, sdev, "Successfully cancelled outstanding commands\n");
> - return 0;
> +free_events:
> + spin_lock_irqsave(vhost->host->host_lock, flags);
> + for (i = 0; i < num_hwq; i++)
> + if (scrqs[i].cancel_event)
> + ibmvfc_free_event(scrqs[i].cancel_event);
> + spin_unlock_irqrestore(vhost->host->host_lock, flags);
> +
> + return ret;
> }
>
> /**
--
Brian King
Power Linux I/O
IBM Linux Technology Center
^ permalink raw reply
* Re: [PATCH v3 17/18] ibmvfc: provide modules parameters for MQ settings
From: Brian King @ 2020-12-04 21:28 UTC (permalink / raw)
To: Tyrel Datwyler, james.bottomley
Cc: brking, linuxppc-dev, linux-scsi, martin.petersen, linux-kernel
In-Reply-To: <20201203020806.14747-18-tyreld@linux.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
--
Brian King
Power Linux I/O
IBM Linux Technology Center
^ permalink raw reply
* Re: [PATCH v3 18/18] ibmvfc: drop host lock when completing commands in CRQ
From: Brian King @ 2020-12-04 21:35 UTC (permalink / raw)
To: Tyrel Datwyler, james.bottomley
Cc: brking, linuxppc-dev, linux-scsi, martin.petersen, linux-kernel
In-Reply-To: <20201203020806.14747-19-tyreld@linux.ibm.com>
On 12/2/20 8:08 PM, Tyrel Datwyler wrote:
> The legacy CRQ holds the host lock the even while completing commands.
> This presents a problem when in legacy single queue mode and
> nr_hw_queues is greater than one since calling scsi_done() introduces
> the potential for deadlock.
>
> If nr_hw_queues is greater than one drop the hostlock in the legacy CRQ
> path when completing a command.
>
> Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
> ---
> drivers/scsi/ibmvscsi/ibmvfc.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
> index e499599662ec..e2200bdff2be 100644
> --- a/drivers/scsi/ibmvscsi/ibmvfc.c
> +++ b/drivers/scsi/ibmvscsi/ibmvfc.c
> @@ -2969,6 +2969,7 @@ static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, struct ibmvfc_host *vhost)
> {
> long rc;
> struct ibmvfc_event *evt = (struct ibmvfc_event *)be64_to_cpu(crq->ioba);
> + unsigned long flags;
>
> switch (crq->valid) {
> case IBMVFC_CRQ_INIT_RSP:
> @@ -3039,7 +3040,12 @@ static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, struct ibmvfc_host *vhost)
> del_timer(&evt->timer);
> list_del(&evt->queue);
> ibmvfc_trc_end(evt);
> - evt->done(evt);
> + if (nr_scsi_hw_queues > 1) {
> + spin_unlock_irqrestore(vhost->host->host_lock, flags);
> + evt->done(evt);
> + spin_lock_irqsave(vhost->host->host_lock, flags);
> + } else
> + evt->done(evt);
Similar comment here as previously. The flags parameter is an output for
spin_lock_irqsave but an input for spin_unlock_irqrestore. You'll need
to rethink the locking here. You could just do a spin_unlock_irq / spin_lock_irq
here and that would probably be OK, but probably isn't the best.
> }
>
> /**
>
--
Brian King
Power Linux I/O
IBM Linux Technology Center
^ permalink raw reply
* [powerpc:next] BUILD SUCCESS c9344769e2b46ba28b947bec7a8a8f0a091ecd57
From: kernel test robot @ 2020-12-04 22:26 UTC (permalink / raw)
To: Michael Ellerman; +Cc: linuxppc-dev
tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
branch HEAD: c9344769e2b46ba28b947bec7a8a8f0a091ecd57 selftests/powerpc: Fix uninitialized variable warning
elapsed time: 1926m
configs tested: 161
configs skipped: 4
The following configs have been built successfully.
More configs may be tested in the coming days.
gcc tested configs:
arm defconfig
arm64 allyesconfig
arm64 defconfig
arm allyesconfig
arm allmodconfig
arm shannon_defconfig
mips decstation_defconfig
mips mpc30x_defconfig
mips ci20_defconfig
nios2 alldefconfig
arc vdk_hs38_defconfig
powerpc cm5200_defconfig
arm tango4_defconfig
mips decstation_r4k_defconfig
mips mtx1_defconfig
mips qi_lb60_defconfig
arm omap1_defconfig
arm h5000_defconfig
m68k amiga_defconfig
sh r7785rp_defconfig
sh microdev_defconfig
m68k m5275evb_defconfig
nds32 alldefconfig
mips fuloong2e_defconfig
sh se7724_defconfig
powerpc obs600_defconfig
arm pcm027_defconfig
arm dove_defconfig
mips tb0219_defconfig
m68k m5475evb_defconfig
powerpc ep8248e_defconfig
powerpc mpc512x_defconfig
arm orion5x_defconfig
arm shmobile_defconfig
arm u8500_defconfig
powerpc ppc6xx_defconfig
arm vf610m4_defconfig
sh se7750_defconfig
powerpc mgcoge_defconfig
ia64 tiger_defconfig
mips jmr3927_defconfig
xtensa iss_defconfig
arm ixp4xx_defconfig
powerpc motionpro_defconfig
nds32 defconfig
mips jazz_defconfig
powerpc cell_defconfig
ia64 alldefconfig
powerpc tqm5200_defconfig
arc haps_hs_defconfig
arm spitz_defconfig
arm exynos_defconfig
powerpc asp8347_defconfig
arm nhk8815_defconfig
arm colibri_pxa300_defconfig
powerpc chrp32_defconfig
sh urquell_defconfig
arm netwinder_defconfig
mips gpr_defconfig
powerpc skiroot_defconfig
arm aspeed_g4_defconfig
arm hackkit_defconfig
sparc sparc64_defconfig
powerpc wii_defconfig
arm versatile_defconfig
arc nsimosci_hs_defconfig
mips maltasmvp_eva_defconfig
arm trizeps4_defconfig
arm spear3xx_defconfig
powerpc redwood_defconfig
m68k m5208evb_defconfig
arm stm32_defconfig
powerpc pseries_defconfig
arm prima2_defconfig
sh titan_defconfig
powerpc eiger_defconfig
sh lboxre2_defconfig
mips ip32_defconfig
arm s3c2410_defconfig
xtensa defconfig
c6x evmc6474_defconfig
powerpc amigaone_defconfig
powerpc mpc834x_itxgp_defconfig
arm vt8500_v6_v7_defconfig
parisc defconfig
arm keystone_defconfig
sh se7343_defconfig
powerpc tqm8540_defconfig
arm pxa_defconfig
arm omap2plus_defconfig
powerpc socrates_defconfig
xtensa smp_lx200_defconfig
c6x evmc6472_defconfig
ia64 allmodconfig
ia64 defconfig
ia64 allyesconfig
m68k allmodconfig
m68k defconfig
m68k allyesconfig
nios2 defconfig
arc allyesconfig
nds32 allnoconfig
c6x allyesconfig
nios2 allyesconfig
csky defconfig
alpha defconfig
alpha allyesconfig
xtensa allyesconfig
h8300 allyesconfig
arc defconfig
sh allmodconfig
s390 allyesconfig
parisc allyesconfig
s390 defconfig
i386 allyesconfig
sparc allyesconfig
sparc defconfig
i386 tinyconfig
i386 defconfig
mips allyesconfig
mips allmodconfig
powerpc allyesconfig
powerpc allmodconfig
powerpc allnoconfig
x86_64 randconfig-a004-20201204
x86_64 randconfig-a006-20201204
x86_64 randconfig-a002-20201204
x86_64 randconfig-a001-20201204
x86_64 randconfig-a005-20201204
x86_64 randconfig-a003-20201204
i386 randconfig-a005-20201204
i386 randconfig-a004-20201204
i386 randconfig-a001-20201204
i386 randconfig-a002-20201204
i386 randconfig-a006-20201204
i386 randconfig-a003-20201204
i386 randconfig-a014-20201204
i386 randconfig-a013-20201204
i386 randconfig-a011-20201204
i386 randconfig-a015-20201204
i386 randconfig-a012-20201204
i386 randconfig-a016-20201204
riscv nommu_k210_defconfig
riscv allyesconfig
riscv nommu_virt_defconfig
riscv allnoconfig
riscv defconfig
riscv rv32_defconfig
riscv allmodconfig
x86_64 rhel
x86_64 allyesconfig
x86_64 rhel-7.6-kselftests
x86_64 defconfig
x86_64 kexec
x86_64 rhel-8.3
clang tested configs:
x86_64 randconfig-a016-20201204
x86_64 randconfig-a012-20201204
x86_64 randconfig-a014-20201204
x86_64 randconfig-a013-20201204
x86_64 randconfig-a015-20201204
x86_64 randconfig-a011-20201204
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
^ permalink raw reply
* [PATCH] powerpc: Stop exporting __clear_user which is now inlined.
From: Michal Suchanek @ 2020-12-04 23:28 UTC (permalink / raw)
To: stable; +Cc: linux-kernel, Paul Mackerras, Michal Suchanek, linuxppc-dev
Stable commit 452e2a83ea23 ("powerpc: Fix __clear_user() with KUAP
enabled") redefines __clear_user as inline function but does not remove
the export.
Fixes: 452e2a83ea23 ("powerpc: Fix __clear_user() with KUAP enabled")
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/lib/ppc_ksyms.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/lib/ppc_ksyms.c b/arch/powerpc/lib/ppc_ksyms.c
index c7f8e9586316..4b81fd96aa3e 100644
--- a/arch/powerpc/lib/ppc_ksyms.c
+++ b/arch/powerpc/lib/ppc_ksyms.c
@@ -24,7 +24,6 @@ EXPORT_SYMBOL(csum_tcpudp_magic);
#endif
EXPORT_SYMBOL(__copy_tofrom_user);
-EXPORT_SYMBOL(__clear_user);
EXPORT_SYMBOL(copy_page);
#ifdef CONFIG_PPC64
--
2.26.2
^ permalink raw reply related
* Re: [PATCH] ASoC: fsl_aud2htx: mark PM functions as __maybe_unused
From: Mark Brown @ 2020-12-04 23:30 UTC (permalink / raw)
To: Arnd Bergmann, Nicolin Chen, Shengjiu Wang, Liam Girdwood,
Timur Tabi, Takashi Iwai, Xiubo Li, Jaroslav Kysela
Cc: alsa-devel, Arnd Bergmann, linuxppc-dev, linux-kernel,
Fabio Estevam, Shengjiu Wang
In-Reply-To: <20201203222900.1042578-1-arnd@kernel.org>
On Thu, 3 Dec 2020 23:28:47 +0100, Arnd Bergmann wrote:
> When CONFIG_PM is disabled, we get a warning for unused functions:
>
> sound/soc/fsl/fsl_aud2htx.c:261:12: error: unused function 'fsl_aud2htx_runtime_suspend' [-Werror,-Wunused-function]
> static int fsl_aud2htx_runtime_suspend(struct device *dev)
> sound/soc/fsl/fsl_aud2htx.c:271:12: error: unused function 'fsl_aud2htx_runtime_resume' [-Werror,-Wunused-function]
> static int fsl_aud2htx_runtime_resume(struct device *dev)
>
> [...]
Applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next
Thanks!
[1/1] ASoC: fsl_aud2htx: mark PM functions as __maybe_unused
commit: 7b153760513cee875515398f4a9ba329a8d426e2
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
Thanks,
Mark
^ permalink raw reply
* Re: [PATCH v3 04/18] ibmvfc: add alloc/dealloc routines for SCSI Sub-CRQ Channels
From: Tyrel Datwyler @ 2020-12-05 0:15 UTC (permalink / raw)
To: Brian King, james.bottomley
Cc: brking, linuxppc-dev, linux-scsi, martin.petersen, linux-kernel
In-Reply-To: <b372b257-49d8-16ae-2390-9617222e4cd9@linux.vnet.ibm.com>
On 12/4/20 6:47 AM, Brian King wrote:
> On 12/2/20 8:07 PM, Tyrel Datwyler wrote:
>> @@ -4983,6 +4993,118 @@ static int ibmvfc_init_crq(struct ibmvfc_host *vhost)
>> return retrc;
>> }
>>
>> +static int ibmvfc_register_scsi_channel(struct ibmvfc_host *vhost,
>> + int index)
>> +{
>> + struct device *dev = vhost->dev;
>> + struct vio_dev *vdev = to_vio_dev(dev);
>> + struct ibmvfc_sub_queue *scrq = &vhost->scsi_scrqs.scrqs[index];
>> + int rc = -ENOMEM;
>> +
>> + ENTER;
>> +
>> + scrq->msgs = (struct ibmvfc_sub_crq *)get_zeroed_page(GFP_KERNEL);
>> + if (!scrq->msgs)
>> + return rc;
>> +
>> + scrq->size = PAGE_SIZE / sizeof(*scrq->msgs);
>> + scrq->msg_token = dma_map_single(dev, scrq->msgs, PAGE_SIZE,
>> + DMA_BIDIRECTIONAL);
>> +
>> + if (dma_mapping_error(dev, scrq->msg_token))
>> + goto dma_map_failed;
>> +
>> + rc = h_reg_sub_crq(vdev->unit_address, scrq->msg_token, PAGE_SIZE,
>> + &scrq->cookie, &scrq->hw_irq);
>> +
>> + if (rc) {
>> + dev_warn(dev, "Error registering sub-crq: %d\n", rc);
>> + if (rc == H_PARAMETER)
>> + dev_warn_once(dev, "Firmware may not support MQ\n");
>> + goto reg_failed;
>> + }
>> +
>> + scrq->hwq_id = index;
>> + scrq->vhost = vhost;
>> +
>> + LEAVE;
>> + return 0;
>> +
>> +reg_failed:
>> + dma_unmap_single(dev, scrq->msg_token, PAGE_SIZE, DMA_BIDIRECTIONAL);
>> +dma_map_failed:
>> + free_page((unsigned long)scrq->msgs);
>> + LEAVE;
>> + return rc;
>> +}
>> +
>> +static void ibmvfc_deregister_scsi_channel(struct ibmvfc_host *vhost, int index)
>> +{
>> + struct device *dev = vhost->dev;
>> + struct vio_dev *vdev = to_vio_dev(dev);
>> + struct ibmvfc_sub_queue *scrq = &vhost->scsi_scrqs.scrqs[index];
>> + long rc;
>> +
>> + ENTER;
>> +
>> + do {
>> + rc = plpar_hcall_norets(H_FREE_SUB_CRQ, vdev->unit_address,
>> + scrq->cookie);
>> + } while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
>> +
>> + if (rc)
>> + dev_err(dev, "Failed to free sub-crq[%d]: rc=%ld\n", index, rc);
>> +
>> + dma_unmap_single(dev, scrq->msg_token, PAGE_SIZE, DMA_BIDIRECTIONAL);
>> + free_page((unsigned long)scrq->msgs);
>> + LEAVE;
>> +}
>> +
>> +static int ibmvfc_init_sub_crqs(struct ibmvfc_host *vhost)
>> +{
>> + int i, j;
>> +
>> + ENTER;
>> +
>> + vhost->scsi_scrqs.scrqs = kcalloc(IBMVFC_SCSI_HW_QUEUES,
>> + sizeof(*vhost->scsi_scrqs.scrqs),
>> + GFP_KERNEL);
>> + if (!vhost->scsi_scrqs.scrqs)
>> + return -1;
>> +
>> + for (i = 0; i < IBMVFC_SCSI_HW_QUEUES; i++) {
>> + if (ibmvfc_register_scsi_channel(vhost, i)) {
>> + for (j = i; j > 0; j--)
>> + ibmvfc_deregister_scsi_channel(vhost, j - 1);
>> + kfree(vhost->scsi_scrqs.scrqs);
>> + vhost->scsi_scrqs.scrqs = NULL;
>> + vhost->scsi_scrqs.active_queues = 0;
>> + LEAVE;
>> + return -1;
>> + }
>> + }
>> +
>> + LEAVE;
>> + return 0;
>> +}
>> +
>> +static void ibmvfc_release_sub_crqs(struct ibmvfc_host *vhost)
>> +{
>> + int i;
>> +
>> + ENTER;
>> + if (!vhost->scsi_scrqs.scrqs)
>> + return;
>> +
>> + for (i = 0; i < IBMVFC_SCSI_HW_QUEUES; i++)
>> + ibmvfc_deregister_scsi_channel(vhost, i);
>> +
>> + kfree(vhost->scsi_scrqs.scrqs);
>> + vhost->scsi_scrqs.scrqs = NULL;
>> + vhost->scsi_scrqs.active_queues = 0;
>> + LEAVE;
>> +}
>> +
>> /**
>> * ibmvfc_free_mem - Free memory for vhost
>> * @vhost: ibmvfc host struct
>> @@ -5239,6 +5361,12 @@ static int ibmvfc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
>> goto remove_shost;
>> }
>>
>> + if (vhost->mq_enabled) {
>> + rc = ibmvfc_init_sub_crqs(vhost);
>> + if (rc)
>> + dev_warn(dev, "Failed to allocate Sub-CRQs. rc=%d\n", rc);
>
> So, I think if you end up down this path, you will have:
>
> vhost->scsi_scrqs.scrqs == NULL
> vhost->scsi_scrqs.active_queues == 0
>
> And you proceed with discovery. You will proceed with enquiry and channel setup.
> Then, I think you could end up in queuecommand doing this
>
> evt->hwq = hwq % vhost->scsi_scrqs.active_queues;
>
> And that is a divide by zero...
Actually, we would bite the dust earlier than that but it requires the sub-crq
allocation to fail for a reason other than lack of firmware support. In the no
firmware support case the VIOS doesn't report channel support and we skip the
enquiry and setup steps. However, in the case where there is support and
allocation fails we would dereference a NULL pointer trying to write the channel
sub-crq handles into the channel_setup MAD.
>
> I wonder if it would be better in this scenario where registering the sub crqs fails,
> if you just did:
>
> vhost->do_enquiry = 0;
> vhost->mq_enabled = 0;
> vhost->using_channels = 0;
>
> It looks like you only try to allocate the subcrqs in probe, so if that fails, we'd
> never end up using mq, so just disabling in this case seems reasonable.
This breaks migration from legacy to a target with channel support. It appears
that migration for that case is already broken anyways. Need to rethink sub-crq
setup. Maybe best to actually do it during the negoation steps instead of in probe.
-Tyrel
>
> Thanks,
>
> Brian
>
^ permalink raw reply
* Re: [PATCH v3 06/18] ibmvfc: add handlers to drain and complete Sub-CRQ responses
From: Tyrel Datwyler @ 2020-12-05 0:16 UTC (permalink / raw)
To: Brian King, james.bottomley
Cc: brking, linuxppc-dev, linux-scsi, martin.petersen, linux-kernel
In-Reply-To: <3fe8683a-47f6-8713-762a-02c57c2e4ec2@linux.vnet.ibm.com>
On 12/4/20 6:51 AM, Brian King wrote:
> On 12/2/20 8:07 PM, Tyrel Datwyler wrote:
>> The logic for iterating over the Sub-CRQ responses is similiar to that
>> of the primary CRQ. Add the necessary handlers for processing those
>> responses.
>>
>> Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
>> ---
>> drivers/scsi/ibmvscsi/ibmvfc.c | 80 ++++++++++++++++++++++++++++++++++
>> 1 file changed, 80 insertions(+)
>>
>> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
>> index e082935f56cf..b61ae1df21e5 100644
>> --- a/drivers/scsi/ibmvscsi/ibmvfc.c
>> +++ b/drivers/scsi/ibmvscsi/ibmvfc.c
>> @@ -3381,6 +3381,86 @@ static int ibmvfc_toggle_scrq_irq(struct ibmvfc_sub_queue *scrq, int enable)
>> return rc;
>> }
>>
>> +static void ibmvfc_handle_scrq(struct ibmvfc_crq *crq, struct ibmvfc_host *vhost)
>> +{
>> + struct ibmvfc_event *evt = (struct ibmvfc_event *)be64_to_cpu(crq->ioba);
>> + unsigned long flags;
>> +
>> + switch (crq->valid) {
>> + case IBMVFC_CRQ_CMD_RSP:
>> + break;
>> + case IBMVFC_CRQ_XPORT_EVENT:
>> + return;
>> + default:
>> + dev_err(vhost->dev, "Got and invalid message type 0x%02x\n", crq->valid);
>> + return;
>> + }
>> +
>> + /* The only kind of payload CRQs we should get are responses to
>> + * things we send. Make sure this response is to something we
>> + * actually sent
>> + */
>> + if (unlikely(!ibmvfc_valid_event(&vhost->pool, evt))) {
>> + dev_err(vhost->dev, "Returned correlation_token 0x%08llx is invalid!\n",
>> + crq->ioba);
>> + return;
>> + }
>> +
>> + if (unlikely(atomic_read(&evt->free))) {
>> + dev_err(vhost->dev, "Received duplicate correlation_token 0x%08llx!\n",
>> + crq->ioba);
>> + return;
>> + }
>> +
>> + del_timer(&evt->timer);
>> + list_del(&evt->queue);
>> + ibmvfc_trc_end(evt);> + spin_unlock_irqrestore(vhost->host->host_lock, flags);
>
> You can't do this here... You are grabbing the host lock in ibmvfc_drain_sub_crq
> and saving the irqflags to a local in that function, then doing a spin_unlock_irqrestore
> and restoring irqflags using an uninitialized local in this function...
>
> I'm assuming this will get sorted out with the locking changes we've been discussing off-list...
Correct, moving to per-queue locks and flags stored in the queue struct.
-Tyrel
>
>
>> + evt->done(evt);
>> + spin_lock_irqsave(vhost->host->host_lock, flags);
>> +}
>> +
>> +static struct ibmvfc_crq *ibmvfc_next_scrq(struct ibmvfc_sub_queue *scrq)
>> +{
>> + struct ibmvfc_crq *crq;
>> +
>> + crq = &scrq->msgs[scrq->cur].crq;
>> + if (crq->valid & 0x80) {
>> + if (++scrq->cur == scrq->size)
>> + scrq->cur = 0;
>> + rmb();
>> + } else
>> + crq = NULL;
>> +
>> + return crq;
>> +}
>> +
>> +static void ibmvfc_drain_sub_crq(struct ibmvfc_sub_queue *scrq)
>> +{
>> + struct ibmvfc_crq *crq;
>> + unsigned long flags;
>> + int done = 0;
>> +
>> + spin_lock_irqsave(scrq->vhost->host->host_lock, flags);
>> + while (!done) {
>> + while ((crq = ibmvfc_next_scrq(scrq)) != NULL) {
>> + ibmvfc_handle_scrq(crq, scrq->vhost);
>> + crq->valid = 0;
>> + wmb();
>> + }
>> +
>> + ibmvfc_toggle_scrq_irq(scrq, 1);
>> + if ((crq = ibmvfc_next_scrq(scrq)) != NULL) {
>> + ibmvfc_toggle_scrq_irq(scrq, 0);
>> + ibmvfc_handle_scrq(crq, scrq->vhost);
>> + crq->valid = 0;
>> + wmb();
>> + } else
>> + done = 1;
>> + }
>> + spin_unlock_irqrestore(scrq->vhost->host->host_lock, flags);
>> +}
>> +
>> /**
>> * ibmvfc_init_tgt - Set the next init job step for the target
>> * @tgt: ibmvfc target struct
>>
>
>
^ permalink raw reply
* Re: [PATCH v3 18/18] ibmvfc: drop host lock when completing commands in CRQ
From: Tyrel Datwyler @ 2020-12-05 0:20 UTC (permalink / raw)
To: Brian King, james.bottomley
Cc: brking, linuxppc-dev, linux-scsi, martin.petersen, linux-kernel
In-Reply-To: <b048ede5-e673-4ba9-3c28-df077aa4467a@linux.vnet.ibm.com>
On 12/4/20 1:35 PM, Brian King wrote:
> On 12/2/20 8:08 PM, Tyrel Datwyler wrote:
>> The legacy CRQ holds the host lock the even while completing commands.
>> This presents a problem when in legacy single queue mode and
>> nr_hw_queues is greater than one since calling scsi_done() introduces
>> the potential for deadlock.
>>
>> If nr_hw_queues is greater than one drop the hostlock in the legacy CRQ
>> path when completing a command.
>>
>> Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
>> ---
>> drivers/scsi/ibmvscsi/ibmvfc.c | 8 +++++++-
>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
>> index e499599662ec..e2200bdff2be 100644
>> --- a/drivers/scsi/ibmvscsi/ibmvfc.c
>> +++ b/drivers/scsi/ibmvscsi/ibmvfc.c
>> @@ -2969,6 +2969,7 @@ static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, struct ibmvfc_host *vhost)
>> {
>> long rc;
>> struct ibmvfc_event *evt = (struct ibmvfc_event *)be64_to_cpu(crq->ioba);
>> + unsigned long flags;
>>
>> switch (crq->valid) {
>> case IBMVFC_CRQ_INIT_RSP:
>> @@ -3039,7 +3040,12 @@ static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, struct ibmvfc_host *vhost)
>> del_timer(&evt->timer);
>> list_del(&evt->queue);
>> ibmvfc_trc_end(evt);
>> - evt->done(evt);
>> + if (nr_scsi_hw_queues > 1) {
>> + spin_unlock_irqrestore(vhost->host->host_lock, flags);
>> + evt->done(evt);
>> + spin_lock_irqsave(vhost->host->host_lock, flags);
>> + } else
>> + evt->done(evt);
>
> Similar comment here as previously. The flags parameter is an output for
> spin_lock_irqsave but an input for spin_unlock_irqrestore. You'll need
> to rethink the locking here. You could just do a spin_unlock_irq / spin_lock_irq
> here and that would probably be OK, but probably isn't the best.
>
Yeah, this will also get its own lock and flags saved in the per-queue struct in
the next spin.
-Tyrel
>> }
>>
>> /**
>>
>
>
^ permalink raw reply
* [powerpc:next-test] BUILD REGRESSION 4e4ed87981c764498942c52004c620bb8f104eac
From: kernel test robot @ 2020-12-05 1:23 UTC (permalink / raw)
To: Michael Ellerman; +Cc: linuxppc-dev
tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next-test
branch HEAD: 4e4ed87981c764498942c52004c620bb8f104eac powerpc/pseries/mobility: refactor node lookup during DT update
Error/Warning reports:
https://lore.kernel.org/linuxppc-dev/202012042220.zO7hSFT2-lkp@intel.com
https://lore.kernel.org/linuxppc-dev/202012050432.SFbbjWMw-lkp@intel.com
Error/Warning in current branch:
arch/powerpc/kernel/rtas.c:938:21: error: no member named 'rtas_args_reentrant' in 'struct paca_struct'
arch/powerpc/kernel/vdso32/vgettimeofday.c:13:5: warning: no previous prototype for function '__c_kernel_clock_gettime64' [-Wmissing-prototypes]
arch/powerpc/kernel/vdso32/vgettimeofday.c:19:5: error: conflicting types for '__c_kernel_clock_getres'
arch/powerpc/kernel/vdso32/vgettimeofday.c:7:5: error: conflicting types for '__c_kernel_clock_gettime'
Error/Warning ids grouped by kconfigs:
clang_recent_errors
|-- powerpc-randconfig-r016-20201204
| `-- arch-powerpc-kernel-rtas.c:error:no-member-named-rtas_args_reentrant-in-struct-paca_struct
`-- powerpc64-randconfig-r011-20201204
|-- arch-powerpc-kernel-vdso32-vgettimeofday.c:error:conflicting-types-for-__c_kernel_clock_getres
|-- arch-powerpc-kernel-vdso32-vgettimeofday.c:error:conflicting-types-for-__c_kernel_clock_gettime
`-- arch-powerpc-kernel-vdso32-vgettimeofday.c:warning:no-previous-prototype-for-function-__c_kernel_clock_gettime64
elapsed time: 726m
configs tested: 101
configs skipped: 2
gcc tested configs:
arm defconfig
arm64 allyesconfig
arm64 defconfig
arm allyesconfig
arm allmodconfig
m68k amiga_defconfig
sh r7785rp_defconfig
sh microdev_defconfig
m68k m5275evb_defconfig
arm shmobile_defconfig
um x86_64_defconfig
ia64 tiger_defconfig
arm mv78xx0_defconfig
ia64 zx1_defconfig
nios2 allyesconfig
parisc generic-64bit_defconfig
powerpc sbc8548_defconfig
powerpc skiroot_defconfig
sh lboxre2_defconfig
powerpc motionpro_defconfig
mips jazz_defconfig
powerpc cell_defconfig
ia64 alldefconfig
mips maltasmvp_eva_defconfig
arm trizeps4_defconfig
arm spear3xx_defconfig
powerpc redwood_defconfig
m68k m5208evb_defconfig
arm stm32_defconfig
powerpc pseries_defconfig
powerpc amigaone_defconfig
powerpc mpc834x_itxgp_defconfig
ia64 allmodconfig
ia64 defconfig
ia64 allyesconfig
m68k allmodconfig
m68k defconfig
m68k allyesconfig
nios2 defconfig
arc allyesconfig
nds32 allnoconfig
c6x allyesconfig
nds32 defconfig
csky defconfig
alpha defconfig
alpha allyesconfig
xtensa allyesconfig
h8300 allyesconfig
arc defconfig
sh allmodconfig
parisc defconfig
s390 allyesconfig
parisc allyesconfig
s390 defconfig
i386 allyesconfig
sparc allyesconfig
sparc defconfig
i386 tinyconfig
i386 defconfig
mips allyesconfig
mips allmodconfig
powerpc allyesconfig
powerpc allmodconfig
powerpc allnoconfig
x86_64 randconfig-a004-20201204
x86_64 randconfig-a006-20201204
x86_64 randconfig-a002-20201204
x86_64 randconfig-a001-20201204
x86_64 randconfig-a005-20201204
x86_64 randconfig-a003-20201204
i386 randconfig-a005-20201204
i386 randconfig-a004-20201204
i386 randconfig-a001-20201204
i386 randconfig-a002-20201204
i386 randconfig-a006-20201204
i386 randconfig-a003-20201204
i386 randconfig-a014-20201204
i386 randconfig-a013-20201204
i386 randconfig-a011-20201204
i386 randconfig-a015-20201204
i386 randconfig-a012-20201204
i386 randconfig-a016-20201204
riscv nommu_k210_defconfig
riscv allyesconfig
riscv nommu_virt_defconfig
riscv allnoconfig
riscv defconfig
riscv rv32_defconfig
riscv allmodconfig
x86_64 rhel
x86_64 allyesconfig
x86_64 rhel-7.6-kselftests
x86_64 defconfig
x86_64 rhel-8.3
x86_64 kexec
clang tested configs:
x86_64 randconfig-a016-20201204
x86_64 randconfig-a012-20201204
x86_64 randconfig-a014-20201204
x86_64 randconfig-a013-20201204
x86_64 randconfig-a015-20201204
x86_64 randconfig-a011-20201204
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
^ permalink raw reply
* [powerpc:merge] BUILD SUCCESS 466556ab940c1dfc7aee8db02a8329f1f3efed3d
From: kernel test robot @ 2020-12-05 1:23 UTC (permalink / raw)
To: Michael Ellerman; +Cc: linuxppc-dev
tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git merge
branch HEAD: 466556ab940c1dfc7aee8db02a8329f1f3efed3d Automatic merge of 'next' into merge (2020-12-05 00:01)
elapsed time: 727m
configs tested: 115
configs skipped: 3
The following configs have been built successfully.
More configs may be tested in the coming days.
gcc tested configs:
arm defconfig
arm64 allyesconfig
arm64 defconfig
arm allyesconfig
arm allmodconfig
m68k amiga_defconfig
sh r7785rp_defconfig
sh microdev_defconfig
m68k m5275evb_defconfig
arm shmobile_defconfig
um x86_64_defconfig
ia64 tiger_defconfig
arm mv78xx0_defconfig
ia64 zx1_defconfig
arm lpc18xx_defconfig
sh titan_defconfig
mips tb0226_defconfig
nios2 allyesconfig
parisc generic-64bit_defconfig
powerpc sbc8548_defconfig
powerpc skiroot_defconfig
sh lboxre2_defconfig
powerpc motionpro_defconfig
mips jazz_defconfig
powerpc cell_defconfig
ia64 alldefconfig
powerpc tqm5200_defconfig
arc haps_hs_defconfig
arm spitz_defconfig
arm exynos_defconfig
arm aspeed_g4_defconfig
arm hackkit_defconfig
sparc sparc64_defconfig
powerpc wii_defconfig
arm versatile_defconfig
arc nsimosci_hs_defconfig
mips maltasmvp_eva_defconfig
arm trizeps4_defconfig
arm spear3xx_defconfig
nds32 alldefconfig
powerpc fsp2_defconfig
arm ep93xx_defconfig
xtensa audio_kc705_defconfig
sh hp6xx_defconfig
powerpc amigaone_defconfig
powerpc mpc834x_itxgp_defconfig
ia64 allmodconfig
ia64 defconfig
ia64 allyesconfig
m68k allmodconfig
m68k defconfig
m68k allyesconfig
nios2 defconfig
arc allyesconfig
nds32 allnoconfig
c6x allyesconfig
nds32 defconfig
csky defconfig
alpha defconfig
alpha allyesconfig
h8300 allyesconfig
arc defconfig
sh allmodconfig
xtensa allyesconfig
parisc defconfig
s390 allyesconfig
parisc allyesconfig
s390 defconfig
i386 allyesconfig
sparc allyesconfig
sparc defconfig
i386 tinyconfig
i386 defconfig
mips allyesconfig
mips allmodconfig
powerpc allyesconfig
powerpc allmodconfig
powerpc allnoconfig
x86_64 randconfig-a004-20201204
x86_64 randconfig-a006-20201204
x86_64 randconfig-a002-20201204
x86_64 randconfig-a001-20201204
x86_64 randconfig-a005-20201204
x86_64 randconfig-a003-20201204
i386 randconfig-a005-20201204
i386 randconfig-a004-20201204
i386 randconfig-a001-20201204
i386 randconfig-a002-20201204
i386 randconfig-a006-20201204
i386 randconfig-a003-20201204
i386 randconfig-a014-20201204
i386 randconfig-a013-20201204
i386 randconfig-a011-20201204
i386 randconfig-a015-20201204
i386 randconfig-a012-20201204
i386 randconfig-a016-20201204
riscv nommu_k210_defconfig
riscv allyesconfig
riscv nommu_virt_defconfig
riscv allnoconfig
riscv defconfig
riscv rv32_defconfig
riscv allmodconfig
x86_64 rhel
x86_64 allyesconfig
x86_64 rhel-7.6-kselftests
x86_64 defconfig
x86_64 rhel-8.3
x86_64 kexec
clang tested configs:
x86_64 randconfig-a016-20201204
x86_64 randconfig-a012-20201204
x86_64 randconfig-a014-20201204
x86_64 randconfig-a013-20201204
x86_64 randconfig-a015-20201204
x86_64 randconfig-a011-20201204
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
^ permalink raw reply
* Re: [PATCH] macintosh/adb-iop: Always wait for reply message from IOP
From: Finn Thain @ 2020-12-05 3:09 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: linuxppc-dev, Linux Kernel Mailing List, Joshua Thompson
In-Reply-To: <CAMuHMdX5yUaCWYsM7WgatYSDLZMcSckugOQxBBnBZOB_eJm=1g@mail.gmail.com>
On Fri, 4 Dec 2020, Geert Uytterhoeven wrote:
> Hi Finn,
>
> On Fri, Nov 20, 2020 at 5:54 AM Finn Thain <fthain@telegraphics.com.au> wrote:
> > A recent patch incorrectly altered the adb-iop state machine behaviour
> > and introduced a regression that can appear intermittently as a
> > malfunctioning ADB input device. This seems to be caused when reply
> > packets from different ADB commands become mixed up, especially during
> > the adb bus scan. Fix this by unconditionally entering the awaiting_reply
> > state after sending an explicit command, even when the ADB command won't
> > generate a reply from the ADB device.
> >
> > Cc: Joshua Thompson <funaho@jurai.org>
> > Fixes: e2954e5f727f ("macintosh/adb-iop: Implement sending -> idle state transition")
> > Tested-by: Stan Johnson <userm57@yahoo.com>
> > Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
>
> Thanks for your patch!
>
> > --- a/drivers/macintosh/adb-iop.c
> > +++ b/drivers/macintosh/adb-iop.c
> > @@ -84,10 +84,7 @@ static void adb_iop_complete(struct iop_msg *msg)
> >
> > local_irq_save(flags);
> >
> > - if (current_req->reply_expected)
> > - adb_iop_state = awaiting_reply;
> > - else
> > - adb_iop_done();
> > + adb_iop_state = awaiting_reply;
> >
> > local_irq_restore(flags);
> > }
> > @@ -95,8 +92,9 @@ static void adb_iop_complete(struct iop_msg *msg)
> > /*
> > * Listen for ADB messages from the IOP.
> > *
> > - * This will be called when unsolicited messages (usually replies to TALK
> > - * commands or autopoll packets) are received.
> > + * This will be called when unsolicited IOP messages are received.
> > + * These IOP messages can carry ADB autopoll responses and also occur
> > + * after explicit ADB commands.
> > */
> >
> > static void adb_iop_listen(struct iop_msg *msg)
> > @@ -123,8 +121,10 @@ static void adb_iop_listen(struct iop_msg *msg)
> > if (adb_iop_state == awaiting_reply) {
> > struct adb_request *req = current_req;
> >
> > - req->reply_len = amsg->count + 1;
> > - memcpy(req->reply, &amsg->cmd, req->reply_len);
> > + if (req->reply_expected) {
> > + req->reply_len = amsg->count + 1;
> > + memcpy(req->reply, &amsg->cmd, req->reply_len);
> > + }
>
> So if we're not expecting a reply. It's ignored.
> Just wondering: what kind of messages are being dropped?
I believe they were empty, with flags == ADB_IOP_EXPLICIT|ADB_IOP_TIMEOUT.
> If reply packets from different ADB commands become mixed up, they are
> still (expected?) replies to messages we sent before. Why shouldn't we
> depend on receiving the replies?
>
It turns out that the IOP always generates reply messages, even when the
ADB command does not produce a reply packet (e.g. ADB Listen command).
The commit being fixed got that wrong.
So it's not really the ADB reply packets that are being mixed up, it's the
IOP messages that enclose them. The bug goes like this:
1. CPU sends a message to the IOP, expecting no response because this
message contains an ADB Listen command. The ADB command is now considered
complete.
2. CPU sends a second message to the IOP, this time expecting a response
because this message contains an ADB Talk command. This ADB command needs
a reply before it can be completed.
3. adb-iop driver receives an IOP message and assumes that it relates to
the Talk command. It's actually for the previous command. The Talk command
is now considered complete but it gets the wrong reply data.
4. adb-iop driver gets another IOP response message, which contains the
actual reply data for the Talk command, but this is dropped (the driver is
no longer in awaiting_reply state).
Please go ahead and add this analysis to the commit log if you think it
would help.
> >
> > req_done = true;
> > }
>
> Gr{oetje,eeting}s,
>
> Geert
>
>
^ permalink raw reply
* Re: [PATCH] macintosh/adb-iop: Send correct poll command
From: Finn Thain @ 2020-12-05 3:10 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: linuxppc-dev, Linux Kernel Mailing List, Joshua Thompson
In-Reply-To: <CAMuHMdVYf83+y1aUR6HqCgr-CLfWYvbuynpfogLrt3cXA-9_aA@mail.gmail.com>
On Fri, 4 Dec 2020, Geert Uytterhoeven wrote:
> Hi Finn,
>
> On Fri, Nov 20, 2020 at 5:54 AM Finn Thain <fthain@telegraphics.com.au> wrote:
> > The behaviour of the IOP firmware is not well documented but we do know
> > that IOP message reply data can be used to issue new ADB commands.
> > Use the message reply to better control autopoll behaviour by sending
> > a Talk Register 0 command after every ADB response, not unlike the
> > algorithm in the via-macii driver. This poll command is addressed to
> > that device which last received a Talk command (explicit or otherwise).
> >
> > Cc: Joshua Thompson <funaho@jurai.org>
> > Fixes: fa3b5a9929fc ("macintosh/adb-iop: Implement idle -> sending state transition")
>
> WARNING: Unknown commit id 'fa3b5a9929fc', maybe rebased or not pulled?
>
> 32226e817043?
>
Yes, that's the one. I accidentally gave a commit id from one of my
backport branches.
> > Tested-by: Stan Johnson <userm57@yahoo.com>
> > Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
>
> Thanks, will queue in the m68k for-v5.11 branch.
>
Thanks.
> Gr{oetje,eeting}s,
>
> Geert
>
>
^ permalink raw reply
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