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iommu/tegra: smmu: debugfs for TLB/PTC statistics
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Add debugfs entries to collect TLB/PTC statistics.

  $ echo "reset" > /sys/kernel/debug/smmu/mc/{tlb,ptc}
  $ echo "on" > /sys/kernel/debug/smmu/mc/{tlb,ptc}
  $ echo "off" > /sys/kernel/debug/smmu/mc/{tlb,ptc}
  $ cat /sys/kernel/debug/smmu/mc/{tlb,ptc}
  hit:0014910c miss:00014d22

  The above format is:
  hit:<HIT count><SPC>miss:<MISS count><SPC><CR+LF>

  fscanf(fp, "hit:%lx miss:%lx", &hit, &miss);

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
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Hiroshi Doyu authored and Joerg Roedel committed Aug 3, 2012
1 parent 0d7614f commit 39abf8a
Showing 1 changed file with 190 additions and 12 deletions.
202 changes: 190 additions & 12 deletions drivers/iommu/tegra-smmu.c
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Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,8 @@
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_iommu.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>

#include <asm/page.h>
#include <asm/cacheflush.h>
Expand All @@ -47,16 +49,29 @@
#define SMMU_CONFIG_DISABLE 0
#define SMMU_CONFIG_ENABLE 1

#define SMMU_TLB_CONFIG 0x14
#define SMMU_TLB_CONFIG_STATS__MASK (1 << 31)
#define SMMU_TLB_CONFIG_STATS__ENABLE (1 << 31)
/* REVISIT: To support multiple MCs */
enum {
_MC = 0,
};

enum {
_TLB = 0,
_PTC,
};

#define SMMU_CACHE_CONFIG_BASE 0x14
#define __SMMU_CACHE_CONFIG(mc, cache) (SMMU_CACHE_CONFIG_BASE + 4 * cache)
#define SMMU_CACHE_CONFIG(cache) __SMMU_CACHE_CONFIG(_MC, cache)

#define SMMU_CACHE_CONFIG_STATS_SHIFT 31
#define SMMU_CACHE_CONFIG_STATS_ENABLE (1 << SMMU_CACHE_CONFIG_STATS_SHIFT)
#define SMMU_CACHE_CONFIG_STATS_TEST_SHIFT 30
#define SMMU_CACHE_CONFIG_STATS_TEST (1 << SMMU_CACHE_CONFIG_STATS_TEST_SHIFT)

#define SMMU_TLB_CONFIG_HIT_UNDER_MISS__ENABLE (1 << 29)
#define SMMU_TLB_CONFIG_ACTIVE_LINES__VALUE 0x10
#define SMMU_TLB_CONFIG_RESET_VAL 0x20000010

#define SMMU_PTC_CONFIG 0x18
#define SMMU_PTC_CONFIG_STATS__MASK (1 << 31)
#define SMMU_PTC_CONFIG_STATS__ENABLE (1 << 31)
#define SMMU_PTC_CONFIG_CACHE__ENABLE (1 << 29)
#define SMMU_PTC_CONFIG_INDEX_MAP__PATTERN 0x3f
#define SMMU_PTC_CONFIG_RESET_VAL 0x2000003f
Expand Down Expand Up @@ -86,10 +101,10 @@

#define SMMU_ASID_SECURITY 0x38

#define SMMU_STATS_TLB_HIT_COUNT 0x1f0
#define SMMU_STATS_TLB_MISS_COUNT 0x1f4
#define SMMU_STATS_PTC_HIT_COUNT 0x1f8
#define SMMU_STATS_PTC_MISS_COUNT 0x1fc
#define SMMU_STATS_CACHE_COUNT_BASE 0x1f0

#define SMMU_STATS_CACHE_COUNT(mc, cache, hitmiss) \
(SMMU_STATS_CACHE_COUNT_BASE + 8 * cache + 4 * hitmiss)

#define SMMU_TRANSLATION_ENABLE_0 0x228
#define SMMU_TRANSLATION_ENABLE_1 0x22c
Expand Down Expand Up @@ -251,6 +266,8 @@ struct smmu_device {
unsigned long translation_enable_2;
unsigned long asid_security;

struct dentry *debugfs_root;

struct device_node *ahb;

int num_as;
Expand Down Expand Up @@ -412,8 +429,8 @@ static int smmu_setup_regs(struct smmu_device *smmu)
smmu_write(smmu, smmu->translation_enable_1, SMMU_TRANSLATION_ENABLE_1);
smmu_write(smmu, smmu->translation_enable_2, SMMU_TRANSLATION_ENABLE_2);
smmu_write(smmu, smmu->asid_security, SMMU_ASID_SECURITY);
smmu_write(smmu, SMMU_TLB_CONFIG_RESET_VAL, SMMU_TLB_CONFIG);
smmu_write(smmu, SMMU_PTC_CONFIG_RESET_VAL, SMMU_PTC_CONFIG);
smmu_write(smmu, SMMU_TLB_CONFIG_RESET_VAL, SMMU_CACHE_CONFIG(_TLB));
smmu_write(smmu, SMMU_PTC_CONFIG_RESET_VAL, SMMU_CACHE_CONFIG(_PTC));

smmu_flush_regs(smmu, 1);

Expand Down Expand Up @@ -892,6 +909,164 @@ static struct iommu_ops smmu_iommu_ops = {
.pgsize_bitmap = SMMU_IOMMU_PGSIZES,
};

/* Should be in the order of enum */
static const char * const smmu_debugfs_mc[] = { "mc", };
static const char * const smmu_debugfs_cache[] = { "tlb", "ptc", };

static ssize_t smmu_debugfs_stats_write(struct file *file,
const char __user *buffer,
size_t count, loff_t *pos)
{
struct smmu_device *smmu;
struct dentry *dent;
int i, cache, mc;
enum {
_OFF = 0,
_ON,
_RESET,
};
const char * const command[] = {
[_OFF] = "off",
[_ON] = "on",
[_RESET] = "reset",
};
char str[] = "reset";
u32 val;
size_t offs;

count = min_t(size_t, count, sizeof(str));
if (copy_from_user(str, buffer, count))
return -EINVAL;

for (i = 0; i < ARRAY_SIZE(command); i++)
if (strncmp(str, command[i],
strlen(command[i])) == 0)
break;

if (i == ARRAY_SIZE(command))
return -EINVAL;

dent = file->f_dentry;
cache = (int)dent->d_inode->i_private;
mc = (int)dent->d_parent->d_inode->i_private;
smmu = dent->d_parent->d_parent->d_inode->i_private;

offs = SMMU_CACHE_CONFIG(cache);
val = smmu_read(smmu, offs);
switch (i) {
case _OFF:
val &= ~SMMU_CACHE_CONFIG_STATS_ENABLE;
val &= ~SMMU_CACHE_CONFIG_STATS_TEST;
smmu_write(smmu, val, offs);
break;
case _ON:
val |= SMMU_CACHE_CONFIG_STATS_ENABLE;
val &= ~SMMU_CACHE_CONFIG_STATS_TEST;
smmu_write(smmu, val, offs);
break;
case _RESET:
val |= SMMU_CACHE_CONFIG_STATS_TEST;
smmu_write(smmu, val, offs);
val &= ~SMMU_CACHE_CONFIG_STATS_TEST;
smmu_write(smmu, val, offs);
break;
default:
BUG();
break;
}

dev_dbg(smmu->dev, "%s() %08x, %08x @%08x\n", __func__,
val, smmu_read(smmu, offs), offs);

return count;
}

static int smmu_debugfs_stats_show(struct seq_file *s, void *v)
{
struct smmu_device *smmu;
struct dentry *dent;
int i, cache, mc;
const char * const stats[] = { "hit", "miss", };

dent = d_find_alias(s->private);
cache = (int)dent->d_inode->i_private;
mc = (int)dent->d_parent->d_inode->i_private;
smmu = dent->d_parent->d_parent->d_inode->i_private;

for (i = 0; i < ARRAY_SIZE(stats); i++) {
u32 val;
size_t offs;

offs = SMMU_STATS_CACHE_COUNT(mc, cache, i);
val = smmu_read(smmu, offs);
seq_printf(s, "%s:%08x ", stats[i], val);

dev_dbg(smmu->dev, "%s() %s %08x @%08x\n", __func__,
stats[i], val, offs);
}
seq_printf(s, "\n");

return 0;
}

static int smmu_debugfs_stats_open(struct inode *inode, struct file *file)
{
return single_open(file, smmu_debugfs_stats_show, inode);
}

static const struct file_operations smmu_debugfs_stats_fops = {
.open = smmu_debugfs_stats_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.write = smmu_debugfs_stats_write,
};

static void smmu_debugfs_delete(struct smmu_device *smmu)
{
debugfs_remove_recursive(smmu->debugfs_root);
}

static void smmu_debugfs_create(struct smmu_device *smmu)
{
int i;
struct dentry *root;

root = debugfs_create_file(dev_name(smmu->dev),
S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
NULL, smmu, NULL);
if (!root)
goto err_out;
smmu->debugfs_root = root;

for (i = 0; i < ARRAY_SIZE(smmu_debugfs_mc); i++) {
int j;
struct dentry *mc;

mc = debugfs_create_file(smmu_debugfs_mc[i],
S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
root, (void *)i, NULL);
if (!mc)
goto err_out;

for (j = 0; j < ARRAY_SIZE(smmu_debugfs_cache); j++) {
struct dentry *cache;

cache = debugfs_create_file(smmu_debugfs_cache[j],
S_IWUGO | S_IRUGO, mc,
(void *)j,
&smmu_debugfs_stats_fops);
if (!cache)
goto err_out;
}
}

return;

err_out:
smmu_debugfs_delete(smmu);
}

static int tegra_smmu_suspend(struct device *dev)
{
struct smmu_device *smmu = dev_get_drvdata(dev);
Expand Down Expand Up @@ -996,6 +1171,7 @@ static int tegra_smmu_probe(struct platform_device *pdev)
if (!smmu->avp_vector_page)
return -ENOMEM;

smmu_debugfs_create(smmu);
smmu_handle = smmu;
return 0;
}
Expand All @@ -1005,6 +1181,8 @@ static int tegra_smmu_remove(struct platform_device *pdev)
struct smmu_device *smmu = platform_get_drvdata(pdev);
int i;

smmu_debugfs_delete(smmu);

smmu_write(smmu, SMMU_CONFIG_DISABLE, SMMU_CONFIG);
for (i = 0; i < smmu->num_as; i++)
free_pdir(&smmu->as[i]);
Expand Down

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