[PATCH v2] drm/amdgpu: Unify Device Aperture in amdgpu_info_ioctl for KGD/KFD

Christian König christian.koenig at amd.com
Tue Jul 1 14:11:29 UTC 2025


On 01.07.25 16:07, Alex Deucher wrote:
> On Tue, Jul 1, 2025 at 2:53 AM Srinivasan Shanmugam
> <srinivasan.shanmugam at amd.com> wrote:
>>
>> This commit refines the amdgpu_info_ioctl function to unify
>> the reporting of device apertures for both KGD and KFD
>> subsystems.
>>
>> v2:
>> - Use amdgpu_ip_version() instead of directly accessing
>>   adev->ip_versions. (Alex)
>> - Added AMDGPU_VM_ prefix to scratch and LDS base and limit macros.
>>   (Christian)
>> - Clarified in comments that the top 16 bits of the 64-bit address must
>>   not be 0x0000 or 0xffff to avoid sign extension problems. (Christian)
>>
>> Cc: David Yat Sin <David.YatSin at amd.com>
>> Cc: Christian König <christian.koenig at amd.com>
>> Cc: Alex Deucher <alexander.deucher at amd.com>
>> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam at amd.com>
> 
> Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

Reviewed-by: Christian König <christian.koenig at amd.com> as well.

> But don't commit this yet as we are still waiting on the userspace
> side to be complete.

Mhm, how do we want to do this with the ROCm?

I mean for Mesa we usually wait for the merge request these days.

For ROCm we just wait for it to end up in thunk or libdrm or what?

Regards,
Christian.

> 
> Alex
> 
>> ---
>>  drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c      | 25 +++++++++++
>>  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h       | 23 ++++++++++
>>  drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c | 45 ++++----------------
>>  include/uapi/drm/amdgpu_drm.h                |  6 +++
>>  4 files changed, 62 insertions(+), 37 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> index 4aab5e394ce2..76d902342271 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> @@ -46,6 +46,7 @@
>>  #include "amdgpu_reset.h"
>>  #include "amd_pcie.h"
>>  #include "amdgpu_userq.h"
>> +#include "amdgpu_vm.h"
>>
>>  void amdgpu_unregister_gpu_instance(struct amdgpu_device *adev)
>>  {
>> @@ -1031,6 +1032,30 @@ int amdgpu_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
>>
>>                 dev_info->userq_ip_mask = amdgpu_userq_get_supported_ip_mask(adev);
>>
>> +               /* Retrieve Device Apertures */
>> +               if (amdgpu_ip_version(adev, GC_HWIP, 0) >= IP_VERSION(9, 0, 0)) {
>> +                       dev_info->lds_base = AMDGPU_VM_MAKE_LDS_APP_BASE_V9();
>> +                       dev_info->scratch_base = AMDGPU_VM_MAKE_SCRATCH_APP_BASE_V9();
>> +
>> +                       dev_info->lds_limit = AMDGPU_VM_MAKE_LDS_APP_LIMIT(dev_info->lds_base);
>> +                       dev_info->scratch_limit =
>> +                               AMDGPU_VM_MAKE_SCRATCH_APP_LIMIT(dev_info->scratch_base);
>> +               } else {
>> +                       dev_info->lds_base = AMDGPU_VM_MAKE_LDS_APP_BASE_VI();
>> +                       dev_info->scratch_base = AMDGPU_VM_MAKE_SCRATCH_APP_BASE_VI();
>> +
>> +                       dev_info->lds_limit = AMDGPU_VM_MAKE_LDS_APP_LIMIT(dev_info->lds_base);
>> +                       dev_info->scratch_limit =
>> +                               AMDGPU_VM_MAKE_SCRATCH_APP_LIMIT(dev_info->scratch_base);
>> +               }
>> +
>> +               dev_dbg(adev->dev, "Node ID: %u\n", adev->dev->id);
>> +               dev_dbg(adev->dev, "GPU ID: %u\n", dev_info->device_id);
>> +               dev_dbg(adev->dev, "LDS Base: %llX\n", dev_info->lds_base);
>> +               dev_dbg(adev->dev, "LDS Limit: %llX\n", dev_info->lds_limit);
>> +               dev_dbg(adev->dev, "Scratch Base: %llX\n", dev_info->scratch_base);
>> +               dev_dbg(adev->dev, "Scratch Limit: %llX\n", dev_info->scratch_limit);
>> +
>>                 ret = copy_to_user(out, dev_info,
>>                                    min((size_t)size, sizeof(*dev_info))) ? -EFAULT : 0;
>>                 kfree(dev_info);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>> index f3ad687125ad..fd8f6da30096 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>> @@ -184,6 +184,29 @@ struct amdgpu_bo_vm;
>>  #define AMDGPU_VM_USE_CPU_FOR_GFX (1 << 0)
>>  #define AMDGPU_VM_USE_CPU_FOR_COMPUTE (1 << 1)
>>
>> +#define AMDGPU_VM_MAKE_SCRATCH_APP_BASE_VI() \
>> +       (((uint64_t)(0x1UL) << 61) + 0x100000000L)
>> +#define AMDGPU_VM_MAKE_SCRATCH_APP_LIMIT(base) \
>> +       (((uint64_t)(base) & 0xFFFFFFFF00000000UL) | 0xFFFFFFFF)
>> +
>> +#define AMDGPU_VM_MAKE_LDS_APP_BASE_VI() \
>> +       (((uint64_t)(0x1UL) << 61) + 0x0)
>> +#define AMDGPU_VM_MAKE_LDS_APP_LIMIT(base) \
>> +       (((uint64_t)(base) & 0xFFFFFFFF00000000UL) | 0xFFFFFFFF)
>> +
>> +/* On GFXv9 the LDS and scratch apertures are programmed independently
>> + * using the high 16 bits of the 64-bit virtual address. They must be
>> + * in the hole, which will be the case as long as the high 16 bits are
>> + * neither 0x0000 nor 0xffff to avoid sign extension issues.
>> + *
>> + * The aperture sizes are still 4GB implicitly.
>> + *
>> + * Note: While GPUVM apertures are generally not applicable on GFXv9,
>> + * there is at least one APU case where GFX9 has a limited GPUVM aperture.
>> + */
>> +#define AMDGPU_VM_MAKE_LDS_APP_BASE_V9() ((uint64_t)(0x1UL) << 48)
>> +#define AMDGPU_VM_MAKE_SCRATCH_APP_BASE_V9() ((uint64_t)(0x2UL) << 48)
>> +
>>  /* VMPT level enumerate, and the hiberachy is:
>>   * PDB2->PDB1->PDB0->PTB
>>   */
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c b/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c
>> index 1d170dc50df3..291b068aaf8a 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c
>> @@ -276,35 +276,6 @@
>>   * for FLAT_* / S_LOAD operations.
>>   */
>>
>> -#define MAKE_GPUVM_APP_BASE_VI(gpu_num) \
>> -       (((uint64_t)(gpu_num) << 61) + 0x1000000000000L)
>> -
>> -#define MAKE_GPUVM_APP_LIMIT(base, size) \
>> -       (((uint64_t)(base) & 0xFFFFFF0000000000UL) + (size) - 1)
>> -
>> -#define MAKE_SCRATCH_APP_BASE_VI() \
>> -       (((uint64_t)(0x1UL) << 61) + 0x100000000L)
>> -
>> -#define MAKE_SCRATCH_APP_LIMIT(base) \
>> -       (((uint64_t)base & 0xFFFFFFFF00000000UL) | 0xFFFFFFFF)
>> -
>> -#define MAKE_LDS_APP_BASE_VI() \
>> -       (((uint64_t)(0x1UL) << 61) + 0x0)
>> -#define MAKE_LDS_APP_LIMIT(base) \
>> -       (((uint64_t)(base) & 0xFFFFFFFF00000000UL) | 0xFFFFFFFF)
>> -
>> -/* On GFXv9 the LDS and scratch apertures are programmed independently
>> - * using the high 16 bits of the 64-bit virtual address. They must be
>> - * in the hole, which will be the case as long as the high 16 bits are
>> - * not 0.
>> - *
>> - * The aperture sizes are still 4GB implicitly.
>> - *
>> - * A GPUVM aperture is not applicable on GFXv9.
>> - */
>> -#define MAKE_LDS_APP_BASE_V9() ((uint64_t)(0x1UL) << 48)
>> -#define MAKE_SCRATCH_APP_BASE_V9() ((uint64_t)(0x2UL) << 48)
>> -
>>  /* User mode manages most of the SVM aperture address space. The low
>>   * 16MB are reserved for kernel use (CWSR trap handler and kernel IB
>>   * for now).
>> @@ -319,8 +290,8 @@ static void kfd_init_apertures_vi(struct kfd_process_device *pdd, uint8_t id)
>>          * node id couldn't be 0 - the three MSB bits of
>>          * aperture shouldn't be 0
>>          */
>> -       pdd->lds_base = MAKE_LDS_APP_BASE_VI();
>> -       pdd->lds_limit = MAKE_LDS_APP_LIMIT(pdd->lds_base);
>> +       pdd->lds_base = AMDGPU_VM_MAKE_LDS_APP_BASE_VI();
>> +       pdd->lds_limit = AMDGPU_VM_MAKE_LDS_APP_LIMIT(pdd->lds_base);
>>
>>         /* dGPUs: SVM aperture starting at 0
>>          * with small reserved space for kernel.
>> @@ -336,21 +307,21 @@ static void kfd_init_apertures_vi(struct kfd_process_device *pdd, uint8_t id)
>>         pdd->qpd.cwsr_base = SVM_CWSR_BASE;
>>         pdd->qpd.ib_base = SVM_IB_BASE;
>>
>> -       pdd->scratch_base = MAKE_SCRATCH_APP_BASE_VI();
>> -       pdd->scratch_limit = MAKE_SCRATCH_APP_LIMIT(pdd->scratch_base);
>> +       pdd->scratch_base = AMDGPU_VM_MAKE_SCRATCH_APP_BASE_VI();
>> +       pdd->scratch_limit = AMDGPU_VM_MAKE_SCRATCH_APP_LIMIT(pdd->scratch_base);
>>  }
>>
>>  static void kfd_init_apertures_v9(struct kfd_process_device *pdd, uint8_t id)
>>  {
>> -       pdd->lds_base = MAKE_LDS_APP_BASE_V9();
>> -       pdd->lds_limit = MAKE_LDS_APP_LIMIT(pdd->lds_base);
>> +       pdd->lds_base = AMDGPU_VM_MAKE_LDS_APP_BASE_V9();
>> +       pdd->lds_limit = AMDGPU_VM_MAKE_LDS_APP_LIMIT(pdd->lds_base);
>>
>>         pdd->gpuvm_base = AMDGPU_VA_RESERVED_BOTTOM;
>>         pdd->gpuvm_limit =
>>                 pdd->dev->kfd->shared_resources.gpuvm_size - 1;
>>
>> -       pdd->scratch_base = MAKE_SCRATCH_APP_BASE_V9();
>> -       pdd->scratch_limit = MAKE_SCRATCH_APP_LIMIT(pdd->scratch_base);
>> +       pdd->scratch_base = AMDGPU_VM_MAKE_SCRATCH_APP_BASE_V9();
>> +       pdd->scratch_limit = AMDGPU_VM_MAKE_SCRATCH_APP_LIMIT(pdd->scratch_base);
>>
>>         /*
>>          * Place TBA/TMA on opposite side of VM hole to prevent
>> diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
>> index 66c4a03ac9f9..f285e9325d06 100644
>> --- a/include/uapi/drm/amdgpu_drm.h
>> +++ b/include/uapi/drm/amdgpu_drm.h
>> @@ -1477,6 +1477,12 @@ struct drm_amdgpu_info_device {
>>         /* Userq IP mask (1 << AMDGPU_HW_IP_*) */
>>         __u32 userq_ip_mask;
>>         __u32 pad;
>> +
>> +       /* Additional fields for memory aperture information */
>> +       __u64 lds_base;          /* LDS base */
>> +       __u64 lds_limit;         /* LDS limit */
>> +       __u64 scratch_base;      /* Scratch base */
>> +       __u64 scratch_limit;     /* Scratch limit */
>>  };
>>
>>  struct drm_amdgpu_info_hw_ip {
>> --
>> 2.34.1
>>



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