[Intel-gfx] [PATCH 1/7] drm/i915: setup the LMEM region

[Matthew Auld]

On 26/01/2021 10:09, Tvrtko Ursulin wrote:
> 
> On 26/01/2021 09:46, Matthew Auld wrote:
>> Hook up the LMEM region. Addresses will start from zero, and for CPU
>> access we get LMEM_BAR which is just a 1:1 mapping of said region.
>>
>> Based on a patch from Michel Thierry.
>>
>> v2 by Jani:
>> - use intel_uncore_read/intel_uncore_write
>> - remove trailing blank line
>>
>> v3: s/drm_info/drm_dbg for info which in non-pertinent for the user
>>
>> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
>> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
>> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
>> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> ---
>>   drivers/gpu/drm/i915/gt/intel_region_lmem.c | 37 +++++++++++++++++++++
>>   drivers/gpu/drm/i915/gt/intel_region_lmem.h |  2 ++
>>   drivers/gpu/drm/i915/i915_reg.h             |  3 ++
>>   drivers/gpu/drm/i915/intel_memory_region.c  | 11 +++++-
>>   4 files changed, 52 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gt/intel_region_lmem.c 
>> b/drivers/gpu/drm/i915/gt/intel_region_lmem.c
>> index 28a1d5e1fb92..bdd38efe0811 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_region_lmem.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_region_lmem.c
>> @@ -136,3 +136,40 @@ intel_setup_fake_lmem(struct drm_i915_private *i915)
>>       return mem;
>>   }
>> +
>> +static struct intel_memory_region *
>> +setup_lmem(struct drm_i915_private *i915)
>> +{ > +    struct pci_dev *pdev = i915->drm.pdev;
>> +    struct intel_memory_region *mem;
>> +    resource_size_t io_start;
>> +    resource_size_t size;
>> +
>> +    /* Enables Local Memory functionality in GAM */
>> +    intel_uncore_write(&i915->uncore, GEN12_LMEM_CFG_ADDR,
>> +               intel_uncore_read(&i915->uncore, GEN12_LMEM_CFG_ADDR) 
>> | LMEM_ENABLE);
> 
> You could use intel_uncore_rmw as well for some minimal improvement in 
> readability. Just a passing by observation, no need to respin if it 
> doesn't fit the schedules.

On second thought, I think we can just drop this since it should be 
default enabled nowadays anyway.

> 
>> +
>> +    io_start = pci_resource_start(pdev, 2);
>> +    size = pci_resource_len(pdev, 2);
>> +
>> +    mem = intel_memory_region_create(i915,
>> +                     0,
>> +                     size,
>> +                     I915_GTT_PAGE_SIZE_4K,
>> +                     io_start,
>> +                     &intel_region_lmem_ops);
>> +    if (!IS_ERR(mem)) {
>> +        drm_dbg(&i915->drm, "Intel graphics LMEM: %pR\n", &mem->region);
>> +        drm_dbg(&i915->drm, "Intel graphics LMEM IO start: %pa\n",
>> +             &mem->io_start);
>> +        drm_info(&i915->drm, "Intel graphics LMEM size: %pa\n", &size);
>> +    }
>> +
>> +    return mem;
>> +}
>> +
>> +struct intel_memory_region *
>> +i915_gem_setup_lmem(struct drm_i915_private *i915)
>> +{
>> +    return setup_lmem(i915);
>> +}
> 
> Was it ever discussed if there was an easy way (and if it makes sense 
> actually) to move this from GEM to GT (in name and input parameter?

Yeah, makes sense, especially since this is now in gt/

So just:
intel_gt_setup_lmem(gt)

?

> 
> Regards,
> 
> Tvrtko
> 
>> diff --git a/drivers/gpu/drm/i915/gt/intel_region_lmem.h 
>> b/drivers/gpu/drm/i915/gt/intel_region_lmem.h
>> index 8ea43e538dab..b32222bd493c 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_region_lmem.h
>> +++ b/drivers/gpu/drm/i915/gt/intel_region_lmem.h
>> @@ -8,6 +8,8 @@
>>   struct drm_i915_private;
>> +struct intel_memory_region *i915_gem_setup_lmem(struct 
>> drm_i915_private *i915);
>> +
>>   struct intel_memory_region *
>>   intel_setup_fake_lmem(struct drm_i915_private *i915);
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h 
>> b/drivers/gpu/drm/i915/i915_reg.h
>> index e7e41a3c467e..28001b5a3cb5 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -12111,6 +12111,9 @@ enum skl_power_gate {
>>   #define GEN12_GLOBAL_MOCS(i)    _MMIO(0x4000 + (i) * 4) /* Global 
>> MOCS regs */
>> +#define GEN12_LMEM_CFG_ADDR        _MMIO(0xcf58)
>> +#define   LMEM_ENABLE            (1 << 31)
>> +
>>   /* gamt regs */
>>   #define GEN8_L3_LRA_1_GPGPU _MMIO(0x4dd4)
>>   #define   GEN8_L3_LRA_1_GPGPU_DEFAULT_VALUE_BDW  0x67F1427F /* 
>> max/min for LRA1/2 */
>> diff --git a/drivers/gpu/drm/i915/intel_memory_region.c 
>> b/drivers/gpu/drm/i915/intel_memory_region.c
>> index 1bfcdd89b241..9ce4a81c48b1 100644
>> --- a/drivers/gpu/drm/i915/intel_memory_region.c
>> +++ b/drivers/gpu/drm/i915/intel_memory_region.c
>> @@ -259,7 +259,16 @@ int intel_memory_regions_hw_probe(struct 
>> drm_i915_private *i915)
>>               mem = i915_gem_stolen_setup(i915);
>>               break;
>>           case INTEL_MEMORY_LOCAL:
>> -            mem = intel_setup_fake_lmem(i915);
>> +#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
>> +            if (IS_ENABLED(CONFIG_DRM_I915_UNSTABLE_FAKE_LMEM)) {
>> +                if (INTEL_GEN(i915) >= 9 && i915_selftest.live < 0 &&
>> +                    i915->params.fake_lmem_start)
>> +                    mem = intel_setup_fake_lmem(i915);
>> +            }
>> +#endif
>> +
>> +            if (IS_ERR(mem))
>> +                mem = i915_gem_setup_lmem(i915);
>>               break;
>>           }
>>