[PATCH v3 23/30] drm/xe: Add Xe SVM populate_devmem_pfn GPU SVM vfunc

[Matthew Brost]

Get device pfns from BO's buddy blocks. Used in migrate_* core MM
functions called in GPU SVM to migrate between device and system memory.

v2:
 - Use new drm_gpusvm_devmem_ops
v3:
 - Better commit message (Thomas)

Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathap...@intel.com>
Signed-off-by: Oak Zeng <oak.z...@intel.com>
Signed-off-by: Matthew Brost <matthew.br...@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellst...@linux.intel.com>
---
 drivers/gpu/drm/xe/xe_svm.c | 40 +++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
index dcd99520a6d9..16d526b2d19a 100644
--- a/drivers/gpu/drm/xe/xe_svm.c
+++ b/drivers/gpu/drm/xe/xe_svm.c
@@ -7,6 +7,7 @@
 #include "xe_migrate.h"
 #include "xe_pt.h"
 #include "xe_svm.h"
+#include "xe_ttm_vram_mgr.h"
 #include "xe_vm.h"
 #include "xe_vm_types.h"
 
@@ -454,8 +455,47 @@ static int xe_svm_copy_to_ram(struct page **pages, 
dma_addr_t *dma_addr,
        return xe_svm_copy(pages, dma_addr, npages, XE_SVM_COPY_TO_SRAM);
 }
 
+static struct xe_bo *to_xe_bo(struct drm_gpusvm_devmem *devmem_allocation)
+{
+       return container_of(devmem_allocation, struct xe_bo, devmem_allocation);
+}
+
+static u64 block_offset_to_pfn(struct xe_mem_region *mr, u64 offset)
+{
+       return PHYS_PFN(offset + mr->hpa_base);
+}
+
+static struct drm_buddy *tile_to_buddy(struct xe_tile *tile)
+{
+       return &tile->mem.vram_mgr->mm;
+}
+
+static int xe_svm_populate_devmem_pfn(struct drm_gpusvm_devmem 
*devmem_allocation,
+                                     unsigned long npages, unsigned long *pfn)
+{
+       struct xe_bo *bo = to_xe_bo(devmem_allocation);
+       struct ttm_resource *res = bo->ttm.resource;
+       struct list_head *blocks = &to_xe_ttm_vram_mgr_resource(res)->blocks;
+       struct drm_buddy_block *block;
+       int j = 0;
+
+       list_for_each_entry(block, blocks, link) {
+               struct xe_mem_region *mr = block->private;
+               struct xe_tile *tile = mr_to_tile(mr);
+               struct drm_buddy *buddy = tile_to_buddy(tile);
+               u64 block_pfn = block_offset_to_pfn(mr, 
drm_buddy_block_offset(block));
+               int i;
+
+               for (i = 0; i < drm_buddy_block_size(buddy, block) >> 
PAGE_SHIFT; ++i)
+                       pfn[j++] = block_pfn + i;
+       }
+
+       return 0;
+}
+
 __maybe_unused
 static const struct drm_gpusvm_devmem_ops gpusvm_devmem_ops = {
+       .populate_devmem_pfn = xe_svm_populate_devmem_pfn,
        .copy_to_devmem = xe_svm_copy_to_devmem,
        .copy_to_ram = xe_svm_copy_to_ram,
 };
-- 
2.34.1