[PATCH 1/4] iommu/tegra-smmu: Add debugfs support

[PATCH 1/4] iommu/tegra-smmu: Add debugfs support

[Thierry Reding]

From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

Provide clients and swgroups files in debugfs. These files show for
which clients IOMMU translation is enabled and which ASID is associated
with each SWGROUP.

Cc: Hiroshi Doyu <hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 drivers/iommu/tegra-smmu.c | 109 +++++++++++++++++++++++++++++++++++++++++++++
 include/soc/tegra/mc.h     |   5 +++
 2 files changed, 114 insertions(+)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 6e134c7c227f..fff45b3d3e57 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -6,6 +6,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/debugfs.h>
 #include <linux/err.h>
 #include <linux/iommu.h>
 #include <linux/kernel.h>
@@ -28,6 +29,8 @@ struct tegra_smmu {
 	struct mutex lock;
 
 	struct list_head list;
+
+	struct dentry *debugfs;
 };
 
 struct tegra_smmu_as {
@@ -662,6 +665,103 @@ static void tegra_smmu_ahb_enable(void)
 	}
 }
 
+static int tegra_smmu_swgroups_show(struct seq_file *s, void *data)
+{
+	struct tegra_smmu *smmu = s->private;
+	unsigned int i;
+	u32 value;
+
+	seq_printf(s, "swgroup    enabled  ASID\n");
+	seq_printf(s, "------------------------\n");
+
+	for (i = 0; i < smmu->soc->num_swgroups; i++) {
+		const struct tegra_smmu_swgroup *group = &smmu->soc->swgroups[i];
+		const char *status;
+		unsigned int asid;
+
+		value = smmu_readl(smmu, group->reg);
+
+		if (value & SMMU_ASID_ENABLE)
+			status = "yes";
+		else
+			status = "no";
+
+		asid = value & SMMU_ASID_MASK;
+
+		seq_printf(s, "%-9s  %-7s  %#04x\n", group->name, status,
+			   asid);
+	}
+
+	return 0;
+}
+
+static int tegra_smmu_swgroups_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, tegra_smmu_swgroups_show, inode->i_private);
+}
+
+static const struct file_operations tegra_smmu_swgroups_fops = {
+	.open = tegra_smmu_swgroups_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int tegra_smmu_clients_show(struct seq_file *s, void *data)
+{
+	struct tegra_smmu *smmu = s->private;
+	unsigned int i;
+	u32 value;
+
+	seq_printf(s, "client       enabled\n");
+	seq_printf(s, "--------------------\n");
+
+	for (i = 0; i < smmu->soc->num_clients; i++) {
+		const struct tegra_mc_client *client = &smmu->soc->clients[i];
+		const char *status;
+
+		value = smmu_readl(smmu, client->smmu.reg);
+
+		if (value & BIT(client->smmu.bit))
+			status = "yes";
+		else
+			status = "no";
+
+		seq_printf(s, "%-12s %s\n", client->name, status);
+	}
+
+	return 0;
+}
+
+static int tegra_smmu_clients_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, tegra_smmu_clients_show, inode->i_private);
+}
+
+static const struct file_operations tegra_smmu_clients_fops = {
+	.open = tegra_smmu_clients_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static void tegra_smmu_debugfs_init(struct tegra_smmu *smmu)
+{
+	smmu->debugfs = debugfs_create_dir("smmu", NULL);
+	if (!smmu->debugfs)
+		return;
+
+	debugfs_create_file("swgroups", S_IRUGO, smmu->debugfs, smmu,
+			    &tegra_smmu_swgroups_fops);
+	debugfs_create_file("clients", S_IRUGO, smmu->debugfs, smmu,
+			    &tegra_smmu_clients_fops);
+}
+
+static void tegra_smmu_debugfs_exit(struct tegra_smmu *smmu)
+{
+	debugfs_remove_recursive(smmu->debugfs);
+}
+
 struct tegra_smmu *tegra_smmu_probe(struct device *dev,
 				    const struct tegra_smmu_soc *soc,
 				    struct tegra_mc *mc)
@@ -728,5 +828,14 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev,
 	if (err < 0)
 		return ERR_PTR(err);
 
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		tegra_smmu_debugfs_init(smmu);
+
 	return smmu;
 }
+
+void tegra_smmu_remove(struct tegra_smmu *smmu)
+{
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		tegra_smmu_debugfs_exit(smmu);
+}
diff --git a/include/soc/tegra/mc.h b/include/soc/tegra/mc.h
index 63deb8d9f82a..09a3dabf2ea7 100644
--- a/include/soc/tegra/mc.h
+++ b/include/soc/tegra/mc.h
@@ -71,6 +71,7 @@ struct tegra_smmu;
 struct tegra_smmu *tegra_smmu_probe(struct device *dev,
 				    const struct tegra_smmu_soc *soc,
 				    struct tegra_mc *mc);
+void tegra_smmu_remove(struct tegra_smmu *smmu);
 #else
 static inline struct tegra_smmu *
 tegra_smmu_probe(struct device *dev, const struct tegra_smmu_soc *soc,
@@ -78,6 +79,10 @@ tegra_smmu_probe(struct device *dev, const struct tegra_smmu_soc *soc,
 {
 	return NULL;
 }
+
+static inline void tegra_smmu_remove(struct tegra_smmu *smmu)
+{
+}
 #endif
 
 struct tegra_mc_soc {
-- 
2.3.2

[PATCH 2/4] iommu/tegra: Setup aperture

[Thierry Reding]

From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

Each address space in the Tegra SMMU provides 4 GiB worth of addresses.

Cc: Hiroshi Doyu <hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 drivers/iommu/tegra-smmu.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index fff45b3d3e57..7b36760ae087 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -269,6 +269,11 @@ static int tegra_smmu_domain_init(struct iommu_domain *domain)
 
 	domain->priv = as;
 
+	/* setup aperture */
+	domain->geometry.aperture_start = 0;
+	domain->geometry.aperture_end = 0xffffffff;
+	domain->geometry.force_aperture = true;
+
 	return 0;
 }
 
-- 
2.3.2

Re: [PATCH 2/4] iommu/tegra: Setup aperture

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 1199 bytes --]

On Fri, Mar 27, 2015 at 11:07:25AM +0100, Thierry Reding wrote:
> From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> 
> Each address space in the Tegra SMMU provides 4 GiB worth of addresses.
> 
> Cc: Hiroshi Doyu <hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> ---
>  drivers/iommu/tegra-smmu.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> index fff45b3d3e57..7b36760ae087 100644
> --- a/drivers/iommu/tegra-smmu.c
> +++ b/drivers/iommu/tegra-smmu.c
> @@ -269,6 +269,11 @@ static int tegra_smmu_domain_init(struct iommu_domain *domain)
>  
>  	domain->priv = as;
>  
> +	/* setup aperture */
> +	domain->geometry.aperture_start = 0;
> +	domain->geometry.aperture_end = 0xffffffff;
> +	domain->geometry.force_aperture = true;
> +
>  	return 0;
>  }

I also just realized that this hunk conflicts with the IOMMU domain
alloc/free series that you sent out yesterday. Were you planning on
merging that series for 4.1? If so I can regenerate these patches on
top of your series.

Thierry

[-- Attachment #2: Type: application/pgp-signature, Size: 819 bytes --]

Re: [PATCH 2/4] iommu/tegra: Setup aperture

[Joerg Roedel]

On Fri, Mar 27, 2015 at 11:19:36AM +0100, Thierry Reding wrote:
> I also just realized that this hunk conflicts with the IOMMU domain
> alloc/free series that you sent out yesterday. Were you planning on
> merging that series for 4.1? If so I can regenerate these patches on
> top of your series.

Yes, I just merged the series. But please just base these patches on
plain v4.0-rc6, so I can put them into a seperate branch. I'll try to
solve the conflict then by myself.


	Joerg

[PATCH 3/4] iommu/tegra: gart: Set aperture at domain initialization time

[Thierry Reding]

From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

The aperture of the domain should always be available, otherwise drivers
need to attach first before they can use the aperture geometry.

Cc: Hiroshi Doyu <hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 drivers/iommu/tegra-gart.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index c48da057dbb1..5f3b68c26b83 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c
@@ -156,20 +156,10 @@ static inline bool gart_iova_range_valid(struct gart_device *gart,
 static int gart_iommu_attach_dev(struct iommu_domain *domain,
 				 struct device *dev)
 {
-	struct gart_device *gart;
+	struct gart_device *gart = domain->priv;
 	struct gart_client *client, *c;
 	int err = 0;
 
-	gart = gart_handle;
-	if (!gart)
-		return -EINVAL;
-	domain->priv = gart;
-
-	domain->geometry.aperture_start = gart->iovmm_base;
-	domain->geometry.aperture_end   = gart->iovmm_base +
-					gart->page_count * GART_PAGE_SIZE - 1;
-	domain->geometry.force_aperture = true;
-
 	client = devm_kzalloc(gart->dev, sizeof(*c), GFP_KERNEL);
 	if (!client)
 		return -ENOMEM;
@@ -218,6 +208,19 @@ out:
 
 static int gart_iommu_domain_init(struct iommu_domain *domain)
 {
+	struct gart_device *gart;
+
+	gart = gart_handle;
+	if (!gart)
+		return -EINVAL;
+
+	domain->priv = gart;
+
+	domain->geometry.aperture_start = gart->iovmm_base;
+	domain->geometry.aperture_end = gart->iovmm_base +
+					gart->page_count * GART_PAGE_SIZE - 1;
+	domain->geometry.force_aperture = true;
+
 	return 0;
 }
 
-- 
2.3.2

[PATCH 4/4] iommu/tegra: smmu: Compute PFN mask at runtime

[Thierry Reding]

From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

The SMMU on Tegra30 and Tegra114 supports addressing up to 4 GiB of
physical memory. On Tegra124 the addressable physical memory was
extended to 16 GiB. The page frame number stored in PTEs therefore
requires 20 or 22 bits, depending on SoC generation.

In order to cope with this, compute the proper value at runtime.

Reported-by: Joseph Lo <josephl-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Cc: Hiroshi Doyu <hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 drivers/iommu/tegra-smmu.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 7b36760ae087..f0496e34ada3 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -6,6 +6,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/bitops.h>
 #include <linux/debugfs.h>
 #include <linux/err.h>
 #include <linux/iommu.h>
@@ -25,6 +26,8 @@ struct tegra_smmu {
 	struct tegra_mc *mc;
 	const struct tegra_smmu_soc *soc;
 
+	unsigned long pfn_mask;
+
 	unsigned long *asids;
 	struct mutex lock;
 
@@ -108,8 +111,6 @@ static inline u32 smmu_readl(struct tegra_smmu *smmu, unsigned long offset)
 #define SMMU_PDE_SHIFT 22
 #define SMMU_PTE_SHIFT 12
 
-#define SMMU_PFN_MASK 0x000fffff
-
 #define SMMU_PD_READABLE	(1 << 31)
 #define SMMU_PD_WRITABLE	(1 << 30)
 #define SMMU_PD_NONSECURE	(1 << 29)
@@ -489,7 +490,7 @@ static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
 		smmu_flush_tlb_section(smmu, as->id, iova);
 		smmu_flush(smmu);
 	} else {
-		page = pfn_to_page(pd[pde] & SMMU_PFN_MASK);
+		page = pfn_to_page(pd[pde] & smmu->pfn_mask);
 		pt = page_address(page);
 	}
 
@@ -511,7 +512,7 @@ static void as_put_pte(struct tegra_smmu_as *as, dma_addr_t iova)
 	u32 *pd = page_address(as->pd), *pt;
 	struct page *page;
 
-	page = pfn_to_page(pd[pde] & SMMU_PFN_MASK);
+	page = pfn_to_page(pd[pde] & as->smmu->pfn_mask);
 	pt = page_address(page);
 
 	/*
@@ -586,7 +587,7 @@ static phys_addr_t tegra_smmu_iova_to_phys(struct iommu_domain *domain,
 	u32 *pte;
 
 	pte = as_get_pte(as, iova, &page);
-	pfn = *pte & SMMU_PFN_MASK;
+	pfn = *pte & as->smmu->pfn_mask;
 
 	return PFN_PHYS(pfn);
 }
@@ -807,6 +808,10 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev,
 	smmu->dev = dev;
 	smmu->mc = mc;
 
+	smmu->pfn_mask = BIT_MASK(mc->soc->num_address_bits - PAGE_SHIFT) - 1;
+	dev_dbg(dev, "address bits: %u, PFN mask: %#lx\n",
+		mc->soc->num_address_bits, smmu->pfn_mask);
+
 	value = SMMU_PTC_CONFIG_ENABLE | SMMU_PTC_CONFIG_INDEX_MAP(0x3f);
 
 	if (soc->supports_request_limit)
-- 
2.3.2

Re: [PATCH 1/4] iommu/tegra-smmu: Add debugfs support

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 1686 bytes --]

On Fri, Mar 27, 2015 at 11:07:24AM +0100, Thierry Reding wrote:
> From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> 
> Provide clients and swgroups files in debugfs. These files show for
> which clients IOMMU translation is enabled and which ASID is associated
> with each SWGROUP.
> 
> Cc: Hiroshi Doyu <hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> ---
>  drivers/iommu/tegra-smmu.c | 109 +++++++++++++++++++++++++++++++++++++++++++++
>  include/soc/tegra/mc.h     |   5 +++
>  2 files changed, 114 insertions(+)

Hi Joerg,

I forgot to mention that this patch depends on another patch that I plan
to take through the Tegra tree. That patch adds the group names that are
used by the debugfs support introduced here.

There are a couple of ways to solve this: omit this patch for v4.1 and
merge it for v4.2, at which point the dependency will have been merged.
That's obviously the simplest one and given that this is debugfs support
it isn't very critical, just nice to have.

Another possibility would be for you to ack this patch so that I can
take it into the same branch as the dependency. The remainder of this
series doesn't depend on either of the two patches, so they should be
fine for you to take into your tree.

Yet another alternative would be for me to provide a stable branch that
can be merged into the Tegra and IOMMU trees, but quite frankly I don't
think it's worth jumping through hoops like that for this particular
patch. I'd prefer either the first or second alternative, whichever
suits you best.

Thanks,
Thierry

[-- Attachment #2: Type: application/pgp-signature, Size: 819 bytes --]

Re: [PATCH 1/4] iommu/tegra-smmu: Add debugfs support

[Joerg Roedel]

Hi Thierry,

On Fri, Mar 27, 2015 at 11:15:41AM +0100, Thierry Reding wrote:
> Another possibility would be for you to ack this patch so that I can
> take it into the same branch as the dependency. The remainder of this
> series doesn't depend on either of the two patches, so they should be
> fine for you to take into your tree.

This solution sounds like the best one. You have my

	Acked-by: Joerg Roedel <jroedel-l3A5Bk7waGM@public.gmane.org>

on the first patch. I merged patches 2-4 into the arm/tegra branch. As
you noticed there were conflict merging the branch into next. Please
have a look into my solution for that when I pushed it out later today
and let me know if it looks good and still works.


	Joerg

Re: [PATCH 1/4] iommu/tegra-smmu: Add debugfs support

[Thierry Reding]

[-- Attachment #1.1: Type: text/plain, Size: 969 bytes --]

On Tue, Mar 31, 2015 at 05:02:14PM +0200, Joerg Roedel wrote:
> Hi Thierry,
> 
> On Fri, Mar 27, 2015 at 11:15:41AM +0100, Thierry Reding wrote:
> > Another possibility would be for you to ack this patch so that I can
> > take it into the same branch as the dependency. The remainder of this
> > series doesn't depend on either of the two patches, so they should be
> > fine for you to take into your tree.
> 
> This solution sounds like the best one. You have my
> 
> 	Acked-by: Joerg Roedel <jroedel-l3A5Bk7waGM@public.gmane.org>
> 
> on the first patch.

Thanks.

> I merged patches 2-4 into the arm/tegra branch. As
> you noticed there were conflict merging the branch into next. Please
> have a look into my solution for that when I pushed it out later today
> and let me know if it looks good and still works.

Yes, the resolution looks correct and I've been running linux-next
without issues for a couple of days now.

Thanks,
Thierry

[-- Attachment #1.2: Type: application/pgp-signature, Size: 819 bytes --]

[-- Attachment #2: Type: text/plain, Size: 0 bytes --]