Since the source pages of the svm range can be physically none
contiguous, and the destination vram pages can also be none
contiguous, there is no easy way to migrate multiple pages per
blitter command. We do page by page migration for now.
Migration is best effort. Even if we fail to migrate some pages,
we will try to migrate the rest pages.
Signed-off-by: Oak Zeng <oak.zeng@xxxxxxxxx>
Co-developed-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@xxxxxxxxx>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@xxxxxxxxx>
Cc: Matthew Brost <matthew.brost@xxxxxxxxx>
Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxx>
Cc: Brian Welty <brian.welty@xxxxxxxxx>
---
drivers/gpu/drm/xe/xe_svm.c | 7 ++
drivers/gpu/drm/xe/xe_svm.h | 3 +
drivers/gpu/drm/xe/xe_svm_migrate.c | 114 ++++++++++++++++++++++++++++
3 files changed, 124 insertions(+)
diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
index 5772bfcf7da4..44d4f4216a93 100644
--- a/drivers/gpu/drm/xe/xe_svm.c
+++ b/drivers/gpu/drm/xe/xe_svm.c
@@ -5,12 +5,19 @@
#include <linux/mutex.h>
#include <linux/mm_types.h>
+#include <linux/interval_tree.h>
+#include <linux/container_of.h>
+#include <linux/types.h>
+#include <linux/migrate.h>
#include "xe_svm.h"
#include <linux/hmm.h>
#include <linux/scatterlist.h>
#include "xe_pt.h"
#include "xe_assert.h"
#include "xe_vm_types.h"
+#include "xe_gt.h"
+#include "xe_migrate.h"
+#include "xe_trace.h"
DEFINE_HASHTABLE(xe_svm_table, XE_MAX_SVM_PROCESS);
diff --git a/drivers/gpu/drm/xe/xe_svm.h b/drivers/gpu/drm/xe/xe_svm.h
index 5b3bd2c064f5..659bcb7927d6 100644
--- a/drivers/gpu/drm/xe/xe_svm.h
+++ b/drivers/gpu/drm/xe/xe_svm.h
@@ -80,6 +80,9 @@ struct xe_svm_range {
};
vm_fault_t xe_devm_migrate_to_ram(struct vm_fault *vmf);
+int svm_migrate_range_to_vram(struct xe_svm_range *range,
+ struct vm_area_struct *vma,
+ struct xe_tile *tile);
void xe_destroy_svm(struct xe_svm *svm);
struct xe_svm *xe_create_svm(struct xe_vm *vm);
struct xe_svm *xe_lookup_svm_by_mm(struct mm_struct *mm);
diff --git a/drivers/gpu/drm/xe/xe_svm_migrate.c b/drivers/gpu/drm/xe/xe_svm_migrate.c
index b4df411e04f3..3724ad6c7aea 100644
--- a/drivers/gpu/drm/xe/xe_svm_migrate.c
+++ b/drivers/gpu/drm/xe/xe_svm_migrate.c
@@ -229,3 +229,117 @@ vm_fault_t xe_devm_migrate_to_ram(struct vm_fault *vmf)
kvfree(buf);
return 0;
}
+
+
+/**
+ * svm_migrate_range_to_vram() - migrate backing store of a va range to vram
+ * Must be called with mmap_read_lock(mm) held.
+ * @range: the va range to migrate. Range should only belong to one vma.
+ * @vma: the vma that this range belongs to. @range can cover whole @vma
+ * or a sub-range of @vma.
+ * @tile: the destination tile which holds the new backing store of the range
+ *
+ * Returns: negative errno on faiure, 0 on success
+ */
+int svm_migrate_range_to_vram(struct xe_svm_range *range,
+ struct vm_area_struct *vma,
+ struct xe_tile *tile)
+{
+ struct mm_struct *mm = range->svm->mm;
+ unsigned long start = range->start;
+ unsigned long end = range->end;
+ unsigned long npages = (end - start) >> PAGE_SHIFT;
+ struct xe_mem_region *mr = &tile->mem.vram;
+ struct migrate_vma migrate = {
+ .vma = vma,
+ .start = start,
+ .end = end,
+ .pgmap_owner = tile->xe->drm.dev,
+ .flags = MIGRATE_VMA_SELECT_SYSTEM,
+ };
+ struct device *dev = tile->xe->drm.dev;
+ dma_addr_t *src_dma_addr;
+ struct dma_fence *fence;
+ struct page *src_page;
+ LIST_HEAD(blocks);
+ int ret = 0, i;
+ u64 dst_dpa;
+ void *buf;
+
+ mmap_assert_locked(mm);
+ xe_assert(tile->xe, xe_svm_range_belongs_to_vma(mm, range, vma));
+
+ buf = kvcalloc(npages, 2* sizeof(*migrate.src) + sizeof(*src_dma_addr),
+ GFP_KERNEL);
+ if(!buf)
+ return -ENOMEM;
+ migrate.src = buf;
+ migrate.dst = migrate.src + npages;
+ src_dma_addr = (dma_addr_t *) (migrate.dst + npages);
+ ret = xe_devm_alloc_pages(tile, npages, &blocks, migrate.dst);
+ if (ret)
+ goto kfree_buf;
+
+ ret = migrate_vma_setup(&migrate);
+ if (ret) {
+ drm_err(&tile->xe->drm, "vma setup returned %d for range [%lx - %lx]\n",
+ ret, start, end);
+ goto free_dst_pages;
+ }
+
+ trace_xe_svm_migrate_sram_to_vram(range);
+ /**FIXME: partial migration of a range
+ * print a warning for now. If this message
+ * is printed, we need to fall back to page by page
+ * migration: only migrate pages with MIGRATE_PFN_MIGRATE
+ */
+ if (migrate.cpages != npages)
+ drm_warn(&tile->xe->drm, "Partial migration for range [%lx - %lx], range is %ld pages, migrate only %ld pages\n",
+ start, end, npages, migrate.cpages);
+
+ /**Migrate page by page for now.
+ * Both source pages and destination pages can physically not contiguous,
+ * there is no good way to migrate multiple pages per blitter command.
+ */
+ for (i = 0; i < npages; i++) {
+ src_page = migrate_pfn_to_page(migrate.src[i]);
+ if (unlikely(!src_page || !(migrate.src[i] & MIGRATE_PFN_MIGRATE)))
+ goto free_dst_page;
+
+ xe_assert(tile->xe, !is_zone_device_page(src_page));
+ src_dma_addr[i] = dma_map_page(dev, src_page, 0, PAGE_SIZE, DMA_TO_DEVICE);
+ if (unlikely(dma_mapping_error(dev, src_dma_addr[i]))) {
+ drm_warn(&tile->xe->drm, "dma map error for host pfn %lx\n", migrate.src[i]);
+ goto free_dst_page;
+ }
+ dst_dpa = vram_pfn_to_dpa(mr, migrate.dst[i]);
+ fence = xe_migrate_svm(tile->migrate, src_dma_addr[i], false,
+ dst_dpa, true, PAGE_SIZE);
+ if (IS_ERR(fence)) {
+ drm_warn(&tile->xe->drm, "migrate host page (pfn: %lx) to vram failed\n",
+ migrate.src[i]);
+ /**Migration is best effort. Even we failed here, we continue*/
+ goto free_dst_page;
+ }
+ /**FIXME: Use the first migration's out fence as the second migration's input fence,
+ * and so on. Only wait the out fence of last migration?
+ */
+ dma_fence_wait(fence, false);
+ dma_fence_put(fence);
+free_dst_page:
+ xe_devm_page_free(pfn_to_page(migrate.dst[i]));
+ }
+
+ for (i = 0; i < npages; i++)
+ if (!(dma_mapping_error(dev, src_dma_addr[i])))
+ dma_unmap_page(dev, src_dma_addr[i], PAGE_SIZE, DMA_TO_DEVICE);
+
+ migrate_vma_pages(&migrate);
+ migrate_vma_finalize(&migrate);
+free_dst_pages:
+ if (ret)
+ xe_devm_free_blocks(&blocks);
+kfree_buf:
+ kfree(buf);
+ return ret;
+}
--
2.26.3
