Commit 01be2b62 authored by Ramesh Errabolu's avatar Ramesh Errabolu Committed by Alex Deucher
Browse files

drm/amdgpu: Surface svm_default_granularity, a RW module parameter 



Enables users to update SVM's default granularity, used in
buffer migration and handling of recoverable page faults.
Param value is set in terms of log(numPages(buffer)),
e.g. 9 for a 2 MIB buffer

Signed-off-by: default avatarRamesh Errabolu <Ramesh.Errabolu@amd.com>
Reviewed-by: default avatarPhilip Yang <Philip.Yang@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent e8397d32

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

+1 −0
Original line number Diff line number Diff line
@@ -237,6 +237,7 @@ extern int sched_policy; 
extern bool debug_evictions;

extern bool no_system_mem_limit;

extern int halt_if_hws_hang;

extern uint amdgpu_svm_default_granularity;

#else

static const int __maybe_unused sched_policy = KFD_SCHED_POLICY_HWS;

static const bool __maybe_unused debug_evictions; /* = false */

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

+17 −0
Original line number Diff line number Diff line
@@ -169,6 +169,16 @@ uint amdgpu_sdma_phase_quantum = 32; 
char *amdgpu_disable_cu;

char *amdgpu_virtual_display;

bool enforce_isolation;



/* Specifies the default granularity for SVM, used in buffer

 * migration and restoration of backing memory when handling

 * recoverable page faults.

 *

 * The value is given as log(numPages(buffer)); for a 2 MiB

 * buffer it computes to be 9

 */

uint amdgpu_svm_default_granularity = 9;



/*

 * OverDrive(bit 14) disabled by default

 * GFX DCS(bit 19) disabled by default
@@ -320,6 +330,13 @@ module_param_named(pcie_gen2, amdgpu_pcie_gen2, int, 0444); 
MODULE_PARM_DESC(msi, "MSI support (1 = enable, 0 = disable, -1 = auto)");

module_param_named(msi, amdgpu_msi, int, 0444);



/**

 * DOC: svm_default_granularity (uint)

 * Used in buffer migration and handling of recoverable page faults

 */

MODULE_PARM_DESC(svm_default_granularity, "SVM's default granularity in log(2^Pages), default 9 = 2^9 = 2 MiB");

module_param_named(svm_default_granularity, amdgpu_svm_default_granularity, uint, 0644);



/**

 * DOC: lockup_timeout (string)

 * Set GPU scheduler timeout value in ms.

drivers/gpu/drm/amd/amdkfd/kfd_priv.h

+6 −0
Original line number Diff line number Diff line
@@ -868,6 +868,12 @@ struct svm_range_list { 
	struct task_struct		*faulting_task;

	/* check point ts decides if page fault recovery need be dropped */

	uint64_t			checkpoint_ts[MAX_GPU_INSTANCE];



	/* Default granularity to use in buffer migration

	 * and restoration of backing memory while handling

	 * recoverable page faults

	 */

	uint8_t default_granularity;

};



/* Process data */

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

+15 −7
Original line number Diff line number Diff line
@@ -309,12 +309,13 @@ static void svm_range_free(struct svm_range *prange, bool do_unmap) 
}



static void

svm_range_set_default_attributes(int32_t *location, int32_t *prefetch_loc,

				 uint8_t *granularity, uint32_t *flags)

svm_range_set_default_attributes(struct svm_range_list *svms, int32_t *location,

				 int32_t *prefetch_loc, uint8_t *granularity,

				 uint32_t *flags)

{

	*location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;

	*prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;

	*granularity = 9;

	*granularity = svms->default_granularity;

	*flags =

		KFD_IOCTL_SVM_FLAG_HOST_ACCESS | KFD_IOCTL_SVM_FLAG_COHERENT;

}
@@ -358,7 +359,7 @@ svm_range *svm_range_new(struct svm_range_list *svms, uint64_t start, 
		bitmap_copy(prange->bitmap_access, svms->bitmap_supported,

			    MAX_GPU_INSTANCE);



	svm_range_set_default_attributes(&prange->preferred_loc,

	svm_range_set_default_attributes(svms, &prange->preferred_loc,

					 &prange->prefetch_loc,

					 &prange->granularity, &prange->flags);
@@ -2703,9 +2704,10 @@ svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr, 
	*is_heap_stack = vma_is_initial_heap(vma) || vma_is_initial_stack(vma);



	start_limit = max(vma->vm_start >> PAGE_SHIFT,

		      (unsigned long)ALIGN_DOWN(addr, 2UL << 8));

		      (unsigned long)ALIGN_DOWN(addr, 1UL << p->svms.default_granularity));

	end_limit = min(vma->vm_end >> PAGE_SHIFT,

		    (unsigned long)ALIGN(addr + 1, 2UL << 8));

		    (unsigned long)ALIGN(addr + 1, 1UL << p->svms.default_granularity));



	/* First range that starts after the fault address */

	node = interval_tree_iter_first(&p->svms.objects, addr + 1, ULONG_MAX);

	if (node) {
@@ -3249,6 +3251,12 @@ int svm_range_list_init(struct kfd_process *p) 
		if (KFD_IS_SVM_API_SUPPORTED(p->pdds[i]->dev->adev))

			bitmap_set(svms->bitmap_supported, i, 1);



	 /* Value of default granularity cannot exceed 0x1B, the

	  * number of pages supported by a 4-level paging table

	  */

	svms->default_granularity = min_t(u8, amdgpu_svm_default_granularity, 0x1B);

	pr_debug("Default SVM Granularity to use: %d\n", svms->default_granularity);



	return 0;

}
@@ -3776,7 +3784,7 @@ svm_range_get_attr(struct kfd_process *p, struct mm_struct *mm, 
	node = interval_tree_iter_first(&svms->objects, start, last);

	if (!node) {

		pr_debug("range attrs not found return default values\n");

		svm_range_set_default_attributes(&location, &prefetch_loc,

		svm_range_set_default_attributes(svms, &location, &prefetch_loc,

						 &granularity, &flags_and);

		flags_or = flags_and;

		if (p->xnack_enabled)