Re: [Intel-gfx] [PATCH v7 4/4] drm/i915: cache number of MOCS entries

2019-01-07 Thread Tvrtko Ursulin 


On 04/01/2019 23:47, Lucas De Marchi wrote:

On Fri, Dec 21, 2018 at 11:56:43AM +, Tvrtko Ursulin wrote:


On 14/12/2018 18:20, Lucas De Marchi wrote:

Instead of checking the gen number every time we need to know the max
number of entries, just save it into the table struct so we don't need
extra branches throughout the code.

Suggested-by: Tvrtko Ursulin 
Signed-off-by: Lucas De Marchi 
---
   drivers/gpu/drm/i915/intel_mocs.c | 31 ++-
   1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_mocs.c 
b/drivers/gpu/drm/i915/intel_mocs.c
index dfc4edea020f..22c5f576a3c2 100644
--- a/drivers/gpu/drm/i915/intel_mocs.c
+++ b/drivers/gpu/drm/i915/intel_mocs.c
@@ -32,6 +32,7 @@ struct drm_i915_mocs_entry {
   struct drm_i915_mocs_table {
u32 size;
+   u32 n_entries;


While at it I'd convert both counts to normal unsigned int.

Another nitpick: I'd also suggest some more descriptive names since I read
n_entries and size completely opposite than what they are in the code. Maybe
just s/n_entries/max_entries/ to keep the diff small, or even consider
changing s/size/used_entries/ or something?


size = ARRAY_SIZE() -- we use that to track accesses to the table so we
don't access beyond the array size.

n_entries = GEN[X]_NUM_ENTRIES -- we use that to track the number of
entries we will program.

So IMO the names look reasonable to me.


It was a minor comment so feel free to keep the naming. I was only 
commenting that for me as a reader it wasn't immediately obvious from 
the name to what the count refers, is it the table object in memory, or 
the table as supported by the underlying platform.





const struct drm_i915_mocs_entry *table;
   };
@@ -56,9 +57,6 @@ struct drm_i915_mocs_table {
   #define GEN9_NUM_MOCS_ENTRIES62  /* 62 out of 64 - 63 & 64 are 
reserved. */
   #define GEN11_NUM_MOCS_ENTRIES   64  /* 63-64 are reserved, but 
configured. */
-#define NUM_MOCS_ENTRIES(i915) \
-   (INTEL_GEN(i915) < 11 ? GEN9_NUM_MOCS_ENTRIES : GEN11_NUM_MOCS_ENTRIES)
-


Do you want to go through patch 3 adds this, patch 4 removes it, or why not
just squash it into one?


I considered doing that, but then thought the split approach would be
more logical since this patch is about caching the number of entries.
Squashing on the previous patch creates more noise on that patch and
additional headache since I'm not the original author. Not having this
macro in the previous patch basically means squashing this entire patch
there.

So in the end I decided to do it on top. Is that ok to you?


Yes that's okay.

Regards,

Tvrtko







   /* (e)LLC caching options */
   #define LE_0_PAGETABLE   _LE_CACHEABILITY(0)
   #define LE_1_UC  _LE_CACHEABILITY(1)
@@ -283,14 +281,17 @@ static bool get_mocs_settings(struct drm_i915_private 
*dev_priv,
if (IS_ICELAKE(dev_priv)) {
table->size  = ARRAY_SIZE(icelake_mocs_table);
+   table->n_entries = GEN11_NUM_MOCS_ENTRIES;
table->table = icelake_mocs_table;
result = true;
} else if (IS_GEN9_BC(dev_priv) || IS_CANNONLAKE(dev_priv)) {
table->size  = ARRAY_SIZE(skylake_mocs_table);
+   table->n_entries = GEN9_NUM_MOCS_ENTRIES;
table->table = skylake_mocs_table;
result = true;
} else if (IS_GEN9_LP(dev_priv)) {
table->size  = ARRAY_SIZE(broxton_mocs_table);
+   table->n_entries = GEN9_NUM_MOCS_ENTRIES;
table->table = broxton_mocs_table;
result = true;
} else {
@@ -348,8 +349,6 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
if (!get_mocs_settings(dev_priv, ))
return;
-   GEM_BUG_ON(table.size > NUM_MOCS_ENTRIES(dev_priv));
-
for (index = 0; index < table.size; index++)
I915_WRITE(mocs_register(engine->id, index),
   table.table[index].control_value);
@@ -362,7 +361,7 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
 * Entry 0 in the table is uncached - so we are just writing
 * that value to all the used entries.
 */
-   for (; index < NUM_MOCS_ENTRIES(dev_priv); index++)
+   for (; index < table.n_entries; index++)
I915_WRITE(mocs_register(engine->id, index),
   table.table[0].control_value);
   }
@@ -380,19 +379,18 @@ void intel_mocs_init_engine(struct intel_engine_cs 
*engine)
   static int emit_mocs_control_table(struct i915_request *rq,
   const struct drm_i915_mocs_table *table)
   {
-   struct drm_i915_private *i915 = rq->i915;
enum intel_engine_id engine = rq->engine->id;
unsigned int index;
u32 *cs;
-   if (WARN_ON(table->size > NUM_MOCS_ENTRIES(i915)))
+   if (GEM_WARN_ON(table->size > table->n_entries))

Re: [Intel-gfx] [PATCH v7 4/4] drm/i915: cache number of MOCS entries

2019-01-04 Thread Lucas De Marchi 
On Fri, Dec 21, 2018 at 11:56:43AM +, Tvrtko Ursulin wrote:
> 
> On 14/12/2018 18:20, Lucas De Marchi wrote:
> > Instead of checking the gen number every time we need to know the max
> > number of entries, just save it into the table struct so we don't need
> > extra branches throughout the code.
> > 
> > Suggested-by: Tvrtko Ursulin 
> > Signed-off-by: Lucas De Marchi 
> > ---
> >   drivers/gpu/drm/i915/intel_mocs.c | 31 ++-
> >   1 file changed, 14 insertions(+), 17 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_mocs.c 
> > b/drivers/gpu/drm/i915/intel_mocs.c
> > index dfc4edea020f..22c5f576a3c2 100644
> > --- a/drivers/gpu/drm/i915/intel_mocs.c
> > +++ b/drivers/gpu/drm/i915/intel_mocs.c
> > @@ -32,6 +32,7 @@ struct drm_i915_mocs_entry {
> >   struct drm_i915_mocs_table {
> > u32 size;
> > +   u32 n_entries;
> 
> While at it I'd convert both counts to normal unsigned int.
> 
> Another nitpick: I'd also suggest some more descriptive names since I read
> n_entries and size completely opposite than what they are in the code. Maybe
> just s/n_entries/max_entries/ to keep the diff small, or even consider
> changing s/size/used_entries/ or something?

size = ARRAY_SIZE() -- we use that to track accesses to the table so we
don't access beyond the array size.

n_entries = GEN[X]_NUM_ENTRIES -- we use that to track the number of
entries we will program.

So IMO the names look reasonable to me.

> 
> > const struct drm_i915_mocs_entry *table;
> >   };
> > @@ -56,9 +57,6 @@ struct drm_i915_mocs_table {
> >   #define GEN9_NUM_MOCS_ENTRIES 62  /* 62 out of 64 - 63 & 64 are 
> > reserved. */
> >   #define GEN11_NUM_MOCS_ENTRIES64  /* 63-64 are reserved, but 
> > configured. */
> > -#define NUM_MOCS_ENTRIES(i915) \
> > -   (INTEL_GEN(i915) < 11 ? GEN9_NUM_MOCS_ENTRIES : GEN11_NUM_MOCS_ENTRIES)
> > -
> 
> Do you want to go through patch 3 adds this, patch 4 removes it, or why not
> just squash it into one?

I considered doing that, but then thought the split approach would be
more logical since this patch is about caching the number of entries.
Squashing on the previous patch creates more noise on that patch and
additional headache since I'm not the original author. Not having this
macro in the previous patch basically means squashing this entire patch
there.

So in the end I decided to do it on top. Is that ok to you?


> 
> >   /* (e)LLC caching options */
> >   #define LE_0_PAGETABLE_LE_CACHEABILITY(0)
> >   #define LE_1_UC   _LE_CACHEABILITY(1)
> > @@ -283,14 +281,17 @@ static bool get_mocs_settings(struct drm_i915_private 
> > *dev_priv,
> > if (IS_ICELAKE(dev_priv)) {
> > table->size  = ARRAY_SIZE(icelake_mocs_table);
> > +   table->n_entries = GEN11_NUM_MOCS_ENTRIES;
> > table->table = icelake_mocs_table;
> > result = true;
> > } else if (IS_GEN9_BC(dev_priv) || IS_CANNONLAKE(dev_priv)) {
> > table->size  = ARRAY_SIZE(skylake_mocs_table);
> > +   table->n_entries = GEN9_NUM_MOCS_ENTRIES;
> > table->table = skylake_mocs_table;
> > result = true;
> > } else if (IS_GEN9_LP(dev_priv)) {
> > table->size  = ARRAY_SIZE(broxton_mocs_table);
> > +   table->n_entries = GEN9_NUM_MOCS_ENTRIES;
> > table->table = broxton_mocs_table;
> > result = true;
> > } else {
> > @@ -348,8 +349,6 @@ void intel_mocs_init_engine(struct intel_engine_cs 
> > *engine)
> > if (!get_mocs_settings(dev_priv, ))
> > return;
> > -   GEM_BUG_ON(table.size > NUM_MOCS_ENTRIES(dev_priv));
> > -
> > for (index = 0; index < table.size; index++)
> > I915_WRITE(mocs_register(engine->id, index),
> >table.table[index].control_value);
> > @@ -362,7 +361,7 @@ void intel_mocs_init_engine(struct intel_engine_cs 
> > *engine)
> >  * Entry 0 in the table is uncached - so we are just writing
> >  * that value to all the used entries.
> >  */
> > -   for (; index < NUM_MOCS_ENTRIES(dev_priv); index++)
> > +   for (; index < table.n_entries; index++)
> > I915_WRITE(mocs_register(engine->id, index),
> >table.table[0].control_value);
> >   }
> > @@ -380,19 +379,18 @@ void intel_mocs_init_engine(struct intel_engine_cs 
> > *engine)
> >   static int emit_mocs_control_table(struct i915_request *rq,
> >const struct drm_i915_mocs_table *table)
> >   {
> > -   struct drm_i915_private *i915 = rq->i915;
> > enum intel_engine_id engine = rq->engine->id;
> > unsigned int index;
> > u32 *cs;
> > -   if (WARN_ON(table->size > NUM_MOCS_ENTRIES(i915)))
> > +   if (GEM_WARN_ON(table->size > table->n_entries))
> > return -ENODEV;
> 
> This (and another below) could go to get_mocs_settings which is now the
> authority to set things up correctly. So fire a warn from there and say no
> mocs for

Re: [Intel-gfx] [PATCH v7 4/4] drm/i915: cache number of MOCS entries

2018-12-21 Thread Tvrtko Ursulin 


On 14/12/2018 18:20, Lucas De Marchi wrote:

Instead of checking the gen number every time we need to know the max
number of entries, just save it into the table struct so we don't need
extra branches throughout the code.

Suggested-by: Tvrtko Ursulin 
Signed-off-by: Lucas De Marchi 
---
  drivers/gpu/drm/i915/intel_mocs.c | 31 ++-
  1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_mocs.c 
b/drivers/gpu/drm/i915/intel_mocs.c
index dfc4edea020f..22c5f576a3c2 100644
--- a/drivers/gpu/drm/i915/intel_mocs.c
+++ b/drivers/gpu/drm/i915/intel_mocs.c
@@ -32,6 +32,7 @@ struct drm_i915_mocs_entry {
  
  struct drm_i915_mocs_table {

u32 size;
+   u32 n_entries;


While at it I'd convert both counts to normal unsigned int.

Another nitpick: I'd also suggest some more descriptive names since I 
read n_entries and size completely opposite than what they are in the 
code. Maybe just s/n_entries/max_entries/ to keep the diff small, or 
even consider changing s/size/used_entries/ or something?



const struct drm_i915_mocs_entry *table;
  };
  
@@ -56,9 +57,6 @@ struct drm_i915_mocs_table {

  #define GEN9_NUM_MOCS_ENTRIES 62  /* 62 out of 64 - 63 & 64 are reserved. */
  #define GEN11_NUM_MOCS_ENTRIES64  /* 63-64 are reserved, but 
configured. */
  
-#define NUM_MOCS_ENTRIES(i915) \

-   (INTEL_GEN(i915) < 11 ? GEN9_NUM_MOCS_ENTRIES : GEN11_NUM_MOCS_ENTRIES)
-


Do you want to go through patch 3 adds this, patch 4 removes it, or why 
not just squash it into one?



  /* (e)LLC caching options */
  #define LE_0_PAGETABLE_LE_CACHEABILITY(0)
  #define LE_1_UC   _LE_CACHEABILITY(1)
@@ -283,14 +281,17 @@ static bool get_mocs_settings(struct drm_i915_private 
*dev_priv,
  
  	if (IS_ICELAKE(dev_priv)) {

table->size  = ARRAY_SIZE(icelake_mocs_table);
+   table->n_entries = GEN11_NUM_MOCS_ENTRIES;
table->table = icelake_mocs_table;
result = true;
} else if (IS_GEN9_BC(dev_priv) || IS_CANNONLAKE(dev_priv)) {
table->size  = ARRAY_SIZE(skylake_mocs_table);
+   table->n_entries = GEN9_NUM_MOCS_ENTRIES;
table->table = skylake_mocs_table;
result = true;
} else if (IS_GEN9_LP(dev_priv)) {
table->size  = ARRAY_SIZE(broxton_mocs_table);
+   table->n_entries = GEN9_NUM_MOCS_ENTRIES;
table->table = broxton_mocs_table;
result = true;
} else {
@@ -348,8 +349,6 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
if (!get_mocs_settings(dev_priv, ))
return;
  
-	GEM_BUG_ON(table.size > NUM_MOCS_ENTRIES(dev_priv));

-
for (index = 0; index < table.size; index++)
I915_WRITE(mocs_register(engine->id, index),
   table.table[index].control_value);
@@ -362,7 +361,7 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
 * Entry 0 in the table is uncached - so we are just writing
 * that value to all the used entries.
 */
-   for (; index < NUM_MOCS_ENTRIES(dev_priv); index++)
+   for (; index < table.n_entries; index++)
I915_WRITE(mocs_register(engine->id, index),
   table.table[0].control_value);
  }
@@ -380,19 +379,18 @@ void intel_mocs_init_engine(struct intel_engine_cs 
*engine)
  static int emit_mocs_control_table(struct i915_request *rq,
   const struct drm_i915_mocs_table *table)
  {
-   struct drm_i915_private *i915 = rq->i915;
enum intel_engine_id engine = rq->engine->id;
unsigned int index;
u32 *cs;
  
-	if (WARN_ON(table->size > NUM_MOCS_ENTRIES(i915)))

+   if (GEM_WARN_ON(table->size > table->n_entries))
return -ENODEV;


This (and another below) could go to get_mocs_settings which is now the 
authority to set things up correctly. So fire a warn from there and say 
no mocs for you.


  
-	cs = intel_ring_begin(rq, 2 + 2 * NUM_MOCS_ENTRIES(i915));

+   cs = intel_ring_begin(rq, 2 + 2 * table->n_entries);
if (IS_ERR(cs))
return PTR_ERR(cs);
  
-	*cs++ = MI_LOAD_REGISTER_IMM(NUM_MOCS_ENTRIES(i915));

+   *cs++ = MI_LOAD_REGISTER_IMM(table->n_entries);
  
  	for (index = 0; index < table->size; index++) {

*cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
@@ -407,7 +405,7 @@ static int emit_mocs_control_table(struct i915_request *rq,
 * Entry 0 in the table is uncached - so we are just writing
 * that value to all the used entries.
 */
-   for (; index < NUM_MOCS_ENTRIES(i915); index++) {
+   for (; index < table->n_entries; index++) {
*cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
*cs++ = table->table[0].control_value;
}
@@

[Intel-gfx] [PATCH v7 4/4] drm/i915: cache number of MOCS entries

2018-12-14 Thread Lucas De Marchi 
Instead of checking the gen number every time we need to know the max
number of entries, just save it into the table struct so we don't need
extra branches throughout the code.

Suggested-by: Tvrtko Ursulin 
Signed-off-by: Lucas De Marchi 
---
 drivers/gpu/drm/i915/intel_mocs.c | 31 ++-
 1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_mocs.c 
b/drivers/gpu/drm/i915/intel_mocs.c
index dfc4edea020f..22c5f576a3c2 100644
--- a/drivers/gpu/drm/i915/intel_mocs.c
+++ b/drivers/gpu/drm/i915/intel_mocs.c
@@ -32,6 +32,7 @@ struct drm_i915_mocs_entry {
 
 struct drm_i915_mocs_table {
u32 size;
+   u32 n_entries;
const struct drm_i915_mocs_entry *table;
 };
 
@@ -56,9 +57,6 @@ struct drm_i915_mocs_table {
 #define GEN9_NUM_MOCS_ENTRIES  62  /* 62 out of 64 - 63 & 64 are reserved. */
 #define GEN11_NUM_MOCS_ENTRIES 64  /* 63-64 are reserved, but configured. */
 
-#define NUM_MOCS_ENTRIES(i915) \
-   (INTEL_GEN(i915) < 11 ? GEN9_NUM_MOCS_ENTRIES : GEN11_NUM_MOCS_ENTRIES)
-
 /* (e)LLC caching options */
 #define LE_0_PAGETABLE _LE_CACHEABILITY(0)
 #define LE_1_UC_LE_CACHEABILITY(1)
@@ -283,14 +281,17 @@ static bool get_mocs_settings(struct drm_i915_private 
*dev_priv,
 
if (IS_ICELAKE(dev_priv)) {
table->size  = ARRAY_SIZE(icelake_mocs_table);
+   table->n_entries = GEN11_NUM_MOCS_ENTRIES;
table->table = icelake_mocs_table;
result = true;
} else if (IS_GEN9_BC(dev_priv) || IS_CANNONLAKE(dev_priv)) {
table->size  = ARRAY_SIZE(skylake_mocs_table);
+   table->n_entries = GEN9_NUM_MOCS_ENTRIES;
table->table = skylake_mocs_table;
result = true;
} else if (IS_GEN9_LP(dev_priv)) {
table->size  = ARRAY_SIZE(broxton_mocs_table);
+   table->n_entries = GEN9_NUM_MOCS_ENTRIES;
table->table = broxton_mocs_table;
result = true;
} else {
@@ -348,8 +349,6 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
if (!get_mocs_settings(dev_priv, ))
return;
 
-   GEM_BUG_ON(table.size > NUM_MOCS_ENTRIES(dev_priv));
-
for (index = 0; index < table.size; index++)
I915_WRITE(mocs_register(engine->id, index),
   table.table[index].control_value);
@@ -362,7 +361,7 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
 * Entry 0 in the table is uncached - so we are just writing
 * that value to all the used entries.
 */
-   for (; index < NUM_MOCS_ENTRIES(dev_priv); index++)
+   for (; index < table.n_entries; index++)
I915_WRITE(mocs_register(engine->id, index),
   table.table[0].control_value);
 }
@@ -380,19 +379,18 @@ void intel_mocs_init_engine(struct intel_engine_cs 
*engine)
 static int emit_mocs_control_table(struct i915_request *rq,
   const struct drm_i915_mocs_table *table)
 {
-   struct drm_i915_private *i915 = rq->i915;
enum intel_engine_id engine = rq->engine->id;
unsigned int index;
u32 *cs;
 
-   if (WARN_ON(table->size > NUM_MOCS_ENTRIES(i915)))
+   if (GEM_WARN_ON(table->size > table->n_entries))
return -ENODEV;
 
-   cs = intel_ring_begin(rq, 2 + 2 * NUM_MOCS_ENTRIES(i915));
+   cs = intel_ring_begin(rq, 2 + 2 * table->n_entries);
if (IS_ERR(cs))
return PTR_ERR(cs);
 
-   *cs++ = MI_LOAD_REGISTER_IMM(NUM_MOCS_ENTRIES(i915));
+   *cs++ = MI_LOAD_REGISTER_IMM(table->n_entries);
 
for (index = 0; index < table->size; index++) {
*cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
@@ -407,7 +405,7 @@ static int emit_mocs_control_table(struct i915_request *rq,
 * Entry 0 in the table is uncached - so we are just writing
 * that value to all the used entries.
 */
-   for (; index < NUM_MOCS_ENTRIES(i915); index++) {
+   for (; index < table->n_entries; index++) {
*cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
*cs++ = table->table[0].control_value;
}
@@ -440,18 +438,17 @@ static inline u32 l3cc_combine(const struct 
drm_i915_mocs_table *table,
 static int emit_mocs_l3cc_table(struct i915_request *rq,
const struct drm_i915_mocs_table *table)
 {
-   struct drm_i915_private *i915 = rq->i915;
unsigned int i;
u32 *cs;
 
-   if (WARN_ON(table->size > NUM_MOCS_ENTRIES(i915)))
+   if (GEM_WARN_ON(table->size > table->n_entries))
return -ENODEV;
 
-   cs = intel_ring_begin(rq, 2 + NUM_MOCS_ENTRIES(i915));
+   cs = intel_ring_begin(rq, 2 + table->n_entries);
if (IS_ERR(cs))
return PTR_ERR(cs);
 
-   *cs++