Commit 9731dd4c authored by Daniel Phillips's avatar Daniel Phillips Committed by Alex Deucher
Browse files

drm/amdkfd: Add available memory ioctl 

Add a new KFD ioctl to return the largest possible memory size that
can be allocated as a buffer object using
kfd_ioctl_alloc_memory_of_gpu. It attempts to use exactly the same
accept/reject criteria as that function so that allocating a new
buffer object of the size returned by this new ioctl is guaranteed to
succeed, barring races with other allocating tasks.

This IOCTL will be used by libhsakmt:
https://www.mail-archive.com/amd-gfx@lists.freedesktop.org/msg75743.html



Signed-off-by: default avatarDaniel Phillips <Daniel.Phillips@amd.com>
Signed-off-by: default avatarDavid Yat Sin <David.YatSin@amd.com>
Reviewed-by: default avatarFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 1a65327a

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h

+1 −0
Original line number Diff line number Diff line
@@ -268,6 +268,7 @@ int amdgpu_amdkfd_gpuvm_acquire_process_vm(struct amdgpu_device *adev, 
void amdgpu_amdkfd_gpuvm_release_process_vm(struct amdgpu_device *adev,

					void *drm_priv);

uint64_t amdgpu_amdkfd_gpuvm_get_process_page_dir(void *drm_priv);

size_t amdgpu_amdkfd_get_available_memory(struct amdgpu_device *adev);

int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(

		struct amdgpu_device *adev, uint64_t va, uint64_t size,

		void *drm_priv, struct kgd_mem **mem,

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c

+34 −4
Original line number Diff line number Diff line
@@ -38,6 +38,12 @@ 
 */

#define AMDGPU_USERPTR_RESTORE_DELAY_MS 1



/*

 * Align VRAM allocations to 2MB to avoid fragmentation caused by 4K allocations in the tail 2MB

 * BO chunk

 */

#define VRAM_ALLOCATION_ALIGN (1 << 21)



/* Impose limit on how much memory KFD can use */

static struct {

	uint64_t max_system_mem_limit;
@@ -108,7 +114,7 @@ void amdgpu_amdkfd_reserve_system_mem(uint64_t size) 
 * compromise that should work in most cases without reserving too

 * much memory for page tables unnecessarily (factor 16K, >> 14).

 */

#define ESTIMATE_PT_SIZE(mem_size) ((mem_size) >> 14)

#define ESTIMATE_PT_SIZE(mem_size) max(((mem_size) >> 14), AMDGPU_VM_RESERVED_VRAM)



static size_t amdgpu_amdkfd_acc_size(uint64_t size)

{
@@ -148,7 +154,13 @@ static int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev, 
	} else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_VRAM) {

		system_mem_needed = acc_size;

		ttm_mem_needed = acc_size;

		vram_needed = size;



		/*

		 * Conservatively round up the allocation requirement to 2 MB

		 * to avoid fragmentation caused by 4K allocations in the tail

		 * 2M BO chunk.

		 */

		vram_needed = ALIGN(size, VRAM_ALLOCATION_ALIGN);

	} else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) {

		system_mem_needed = acc_size + size;

		ttm_mem_needed = acc_size;
@@ -173,7 +185,9 @@ static int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev, 
	    (kfd_mem_limit.ttm_mem_used + ttm_mem_needed >

	     kfd_mem_limit.max_ttm_mem_limit) ||

	    (adev->kfd.vram_used + vram_needed >

	     adev->gmc.real_vram_size - reserved_for_pt)) {

	     adev->gmc.real_vram_size -

	     atomic64_read(&adev->vram_pin_size) -

	     reserved_for_pt)) {

		ret = -ENOMEM;

		goto release;

	}
@@ -205,7 +219,7 @@ static void unreserve_mem_limit(struct amdgpu_device *adev, 
	} else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_VRAM) {

		kfd_mem_limit.system_mem_used -= acc_size;

		kfd_mem_limit.ttm_mem_used -= acc_size;

		adev->kfd.vram_used -= size;

		adev->kfd.vram_used -= ALIGN(size, VRAM_ALLOCATION_ALIGN);

	} else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) {

		kfd_mem_limit.system_mem_used -= (acc_size + size);

		kfd_mem_limit.ttm_mem_used -= acc_size;
@@ -1633,6 +1647,22 @@ int amdgpu_amdkfd_criu_resume(void *p) 
	return ret;

}



size_t amdgpu_amdkfd_get_available_memory(struct amdgpu_device *adev)

{

	uint64_t reserved_for_pt =

		ESTIMATE_PT_SIZE(amdgpu_amdkfd_total_mem_size);

	size_t available;



	spin_lock(&kfd_mem_limit.mem_limit_lock);

	available = adev->gmc.real_vram_size

		- adev->kfd.vram_used

		- atomic64_read(&adev->vram_pin_size)

		- reserved_for_pt;

	spin_unlock(&kfd_mem_limit.mem_limit_lock);



	return ALIGN_DOWN(available, VRAM_ALLOCATION_ALIGN);

}



int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(

		struct amdgpu_device *adev, uint64_t va, uint64_t size,

		void *drm_priv, struct kgd_mem **mem,

drivers/gpu/drm/amd/amdkfd/kfd_chardev.c

+34 −0
Original line number Diff line number Diff line
@@ -65,6 +65,25 @@ static int kfd_char_dev_major = -1; 
static struct class *kfd_class;

struct device *kfd_device;



static inline struct kfd_process_device *kfd_lock_pdd_by_id(struct kfd_process *p, __u32 gpu_id)

{

	struct kfd_process_device *pdd;



	mutex_lock(&p->mutex);

	pdd = kfd_process_device_data_by_id(p, gpu_id);



	if (pdd)

		return pdd;



	mutex_unlock(&p->mutex);

	return NULL;

}



static inline void kfd_unlock_pdd(struct kfd_process_device *pdd)

{

	mutex_unlock(&pdd->process->mutex);

}



int kfd_chardev_init(void)

{

	int err = 0;
@@ -958,6 +977,19 @@ bool kfd_dev_is_large_bar(struct kfd_dev *dev) 
	return false;

}



static int kfd_ioctl_get_available_memory(struct file *filep,

					  struct kfd_process *p, void *data)

{

	struct kfd_ioctl_get_available_memory_args *args = data;

	struct kfd_process_device *pdd = kfd_lock_pdd_by_id(p, args->gpu_id);



	if (!pdd)

		return -EINVAL;

	args->available = amdgpu_amdkfd_get_available_memory(pdd->dev->adev);

	kfd_unlock_pdd(pdd);

	return 0;

}



static int kfd_ioctl_alloc_memory_of_gpu(struct file *filep,

					struct kfd_process *p, void *data)

{
@@ -2648,6 +2680,8 @@ static const struct amdkfd_ioctl_desc amdkfd_ioctls[] = { 
	AMDKFD_IOCTL_DEF(AMDKFD_IOC_CRIU_OP,

			kfd_ioctl_criu, KFD_IOC_FLAG_CHECKPOINT_RESTORE),



	AMDKFD_IOCTL_DEF(AMDKFD_IOC_AVAILABLE_MEMORY,

			kfd_ioctl_get_available_memory, 0),

};



#define AMDKFD_CORE_IOCTL_COUNT	ARRAY_SIZE(amdkfd_ioctls)

include/uapi/linux/kfd_ioctl.h

+12 −2
Original line number Diff line number Diff line
@@ -34,9 +34,10 @@ 
 * - 1.6 - Query clear flags in SVM get_attr API

 * - 1.7 - Checkpoint Restore (CRIU) API

 * - 1.8 - CRIU - Support for SDMA transfers with GTT BOs

 * - 1.9 - Add available memory ioctl

 */

#define KFD_IOCTL_MAJOR_VERSION 1

#define KFD_IOCTL_MINOR_VERSION 8

#define KFD_IOCTL_MINOR_VERSION 9



struct kfd_ioctl_get_version_args {

	__u32 major_version;	/* from KFD */
@@ -100,6 +101,12 @@ struct kfd_ioctl_get_queue_wave_state_args { 
	__u32 pad;

};



struct kfd_ioctl_get_available_memory_args {

	__u64 available;	/* from KFD */

	__u32 gpu_id;		/* to KFD */

	__u32 pad;

};



/* For kfd_ioctl_set_memory_policy_args.default_policy and alternate_policy */

#define KFD_IOC_CACHE_POLICY_COHERENT 0

#define KFD_IOC_CACHE_POLICY_NONCOHERENT 1
@@ -826,7 +833,10 @@ struct kfd_ioctl_set_xnack_mode_args { 
#define AMDKFD_IOC_CRIU_OP			\

		AMDKFD_IOWR(0x22, struct kfd_ioctl_criu_args)



#define AMDKFD_IOC_AVAILABLE_MEMORY		\

		AMDKFD_IOWR(0x23, struct kfd_ioctl_get_available_memory_args)



#define AMDKFD_COMMAND_START		0x01

#define AMDKFD_COMMAND_END		0x23

#define AMDKFD_COMMAND_END		0x24



#endif