Subject: [PATCH v4 04/13] drm/amdkfd: add SPM support for SVM

When CPU is connected throug XGMI, it has coherent
access to VRAM resource. In this case that resource
is taken from a table in the device gmc aperture base.
This resource is used along with the device type, which could
be DEVICE_PRIVATE or DEVICE_GENERIC to create the device
page map region.

Signed-off-by: Alex Sierra <[email protected]>
Reviewed-by: Felix Kuehling <[email protected]>
---
drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
index 21b86c35a4f2..3e9315354ce4 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
@@ -916,6 +916,7 @@ int svm_migrate_init(struct amdgpu_device *adev)
struct resource *res;
unsigned long size;
void *r;
+ bool xgmi_connected_to_cpu = adev->gmc.xgmi.connected_to_cpu;

/* Page migration works on Vega10 or newer */
if (kfddev->device_info->asic_family < CHIP_VEGA10)
@@ -928,17 +929,22 @@ int svm_migrate_init(struct amdgpu_device *adev)
* should remove reserved size
*/
size = ALIGN(adev->gmc.real_vram_size, 2ULL << 20);
- res = devm_request_free_mem_region(adev->dev, &iomem_resource, size);
+ if (xgmi_connected_to_cpu)
+ res = lookup_resource(&iomem_resource, adev->gmc.aper_base);
+ else
+ res = devm_request_free_mem_region(adev->dev, &iomem_resource, size);
+
if (IS_ERR(res))
return -ENOMEM;

- pgmap->type = MEMORY_DEVICE_PRIVATE;
pgmap->nr_range = 1;
pgmap->range.start = res->start;
pgmap->range.end = res->end;
+ pgmap->type = xgmi_connected_to_cpu ?
+ MEMORY_DEVICE_GENERIC : MEMORY_DEVICE_PRIVATE;
pgmap->ops = &svm_migrate_pgmap_ops;
pgmap->owner = SVM_ADEV_PGMAP_OWNER(adev);
- pgmap->flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
+ pgmap->flags = 0;
r = devm_memremap_pages(adev->dev, pgmap);
if (IS_ERR(r)) {
pr_err("failed to register HMM device memory\n");
@@ -962,6 +968,7 @@ void svm_migrate_fini(struct amdgpu_device *adev)
struct dev_pagemap *pgmap = &adev->kfd.dev->pgmap;

devm_memunmap_pages(adev->dev, pgmap);
- devm_release_mem_region(adev->dev, pgmap->range.start,
- pgmap->range.end - pgmap->range.start + 1);
+ if (pgmap->type == MEMORY_DEVICE_PRIVATE)
+ devm_release_mem_region(adev->dev, pgmap->range.start,
+ pgmap->range.end - pgmap->range.start + 1);
}
--
2.32.0