Add migrate layer functions to access VRAM and update
xe_ttm_access_memory to use for non-visible access and large (more tahn
16k) BO access.
v4:
- Fix non-page aligned accesses
- Add support for small / unaligned access
- Update commit message indicating migrate used for large accesses (Auld)
- Fix warning in xe_res_cursor for non-zero offset
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
---
drivers/gpu/drm/xe/xe_bo.c | 15 +-
drivers/gpu/drm/xe/xe_migrate.c | 325 ++++++++++++++++++++++++++++++++
drivers/gpu/drm/xe/xe_migrate.h | 4 +
3 files changed, 340 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 04bc042f3bc7..4e1f54aad5bc 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -1127,6 +1127,7 @@ static int xe_ttm_access_memory(struct ttm_buffer_object *ttm_bo,
struct xe_res_cursor cursor;
struct xe_mem_region *vram;
int bytes_left = len;
+ int err = 0;
xe_bo_assert_held(bo);
xe_device_assert_mem_access(xe);
@@ -1134,9 +1135,14 @@ static int xe_ttm_access_memory(struct ttm_buffer_object *ttm_bo,
if (!mem_type_is_vram(ttm_bo->resource->mem_type))
return -EIO;
- /* FIXME: Use GPU for non-visible VRAM */
- if (!xe_ttm_resource_visible(ttm_bo->resource))
- return -EIO;
+ if (!xe_ttm_resource_visible(ttm_bo->resource) || len >= SZ_16K) {
+ struct xe_migrate *migrate =
+ mem_type_to_migrate(xe, ttm_bo->resource->mem_type);
+
+ err = xe_migrate_access_memory(migrate, bo, offset, buf, len,
+ write);
+ goto out;
+ }
vram = res_to_mem_region(ttm_bo->resource);
xe_res_first(ttm_bo->resource, offset & PAGE_MASK,
@@ -1160,7 +1166,8 @@ static int xe_ttm_access_memory(struct ttm_buffer_object *ttm_bo,
xe_res_next(&cursor, PAGE_SIZE);
} while (bytes_left);
- return len;
+out:
+ return err ?: len;
}
const struct ttm_device_funcs xe_ttm_funcs = {
diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
index cfd31ae49cc1..c658b94a35af 100644
--- a/drivers/gpu/drm/xe/xe_migrate.c
+++ b/drivers/gpu/drm/xe/xe_migrate.c
@@ -669,6 +669,7 @@ static void emit_copy(struct xe_gt *gt, struct xe_bb *bb,
u32 mocs = 0;
u32 tile_y = 0;
+ xe_gt_assert(gt, !(pitch & 3));
xe_gt_assert(gt, size / pitch <= S16_MAX);
xe_gt_assert(gt, pitch / 4 <= S16_MAX);
xe_gt_assert(gt, pitch <= U16_MAX);
@@ -1542,6 +1543,330 @@ void xe_migrate_wait(struct xe_migrate *m)
dma_fence_wait(m->fence, false);
}
+static u32 pte_update_cmd_size(u64 size)
+{
+ u32 dword;
+ u64 entries = DIV_ROUND_UP(size, XE_PAGE_SIZE);
+
+ XE_WARN_ON(size > MAX_PREEMPTDISABLE_TRANSFER);
+ /*
+ * MI_STORE_DATA_IMM command is used to update page table. Each
+ * instruction can update maximumly 0x1ff pte entries. To update
+ * n (n <= 0x1ff) pte entries, we need:
+ * 1 dword for the MI_STORE_DATA_IMM command header (opcode etc)
+ * 2 dword for the page table's physical location
+ * 2*n dword for value of pte to fill (each pte entry is 2 dwords)
+ */
+ dword = (1 + 2) * DIV_ROUND_UP(entries, 0x1ff);
+ dword += entries * 2;
+
+ return dword;
+}
+
+static void build_pt_update_batch_sram(struct xe_migrate *m,
+ struct xe_bb *bb, u32 pt_offset,
+ dma_addr_t *sram_addr, u32 size)
+{
+ u16 pat_index = tile_to_xe(m->tile)->pat.idx[XE_CACHE_WB];
+ u32 ptes;
+ int i = 0;
+
+ ptes = DIV_ROUND_UP(size, XE_PAGE_SIZE);
+ while (ptes) {
+ u32 chunk = min(0x1ffU, ptes);
+
+ bb->cs[bb->len++] = MI_STORE_DATA_IMM | MI_SDI_NUM_QW(chunk);
+ bb->cs[bb->len++] = pt_offset;
+ bb->cs[bb->len++] = 0;
+
+ pt_offset += chunk * 8;
+ ptes -= chunk;
+
+ while (chunk--) {
+ u64 addr = sram_addr[i++] & PAGE_MASK;
+
+ xe_tile_assert(m->tile, addr);
+ addr = m->q->vm->pt_ops->pte_encode_addr(m->tile->xe,
+ addr, pat_index,
+ 0, false, 0);
+ bb->cs[bb->len++] = lower_32_bits(addr);
+ bb->cs[bb->len++] = upper_32_bits(addr);
+ }
+ }
+}
+
+enum xe_migrate_copy_dir {
+ XE_MIGRATE_COPY_TO_VRAM,
+ XE_MIGRATE_COPY_TO_SRAM,
+};
+
+#define CACHELINE_BYTES 64ull
+#define CACHELINE_MASK (CACHELINE_BYTES - 1)
+
+static struct dma_fence *xe_migrate_vram(struct xe_migrate *m,
+ unsigned long len,
+ unsigned long sram_offset,
+ dma_addr_t *sram_addr, u64 vram_addr,
+ const enum xe_migrate_copy_dir dir)
+{
+ struct xe_gt *gt = m->tile->primary_gt;
+ struct xe_device *xe = gt_to_xe(gt);
+ struct dma_fence *fence = NULL;
+ u32 batch_size = 2;
+ u64 src_L0_ofs, dst_L0_ofs;
+ struct xe_sched_job *job;
+ struct xe_bb *bb;
+ u32 update_idx, pt_slot = 0;
+ unsigned long npages = DIV_ROUND_UP(len + sram_offset, PAGE_SIZE);
+ unsigned int pitch = len >= PAGE_SIZE && !(len & ~PAGE_MASK) ?
+ PAGE_SIZE : 4;
+ int err;
+
+ if (drm_WARN_ON(&xe->drm, (len & CACHELINE_MASK) ||
+ (sram_offset | vram_addr) & CACHELINE_MASK))
+ return ERR_PTR(-EOPNOTSUPP);
+
+ xe_assert(xe, npages * PAGE_SIZE <= MAX_PREEMPTDISABLE_TRANSFER);
+
+ batch_size += pte_update_cmd_size(len);
+ batch_size += EMIT_COPY_DW;
+
+ bb = xe_bb_new(gt, batch_size, true);
+ if (IS_ERR(bb)) {
+ err = PTR_ERR(bb);
+ return ERR_PTR(err);
+ }
+
+ build_pt_update_batch_sram(m, bb, pt_slot * XE_PAGE_SIZE,
+ sram_addr, len + sram_offset);
+
+ if (dir == XE_MIGRATE_COPY_TO_VRAM) {
+ src_L0_ofs = xe_migrate_vm_addr(pt_slot, 0) + sram_offset;
+ dst_L0_ofs = xe_migrate_vram_ofs(xe, vram_addr, false);
+
+ } else {
+ src_L0_ofs = xe_migrate_vram_ofs(xe, vram_addr, false);
+ dst_L0_ofs = xe_migrate_vm_addr(pt_slot, 0) + sram_offset;
+ }
+
+ bb->cs[bb->len++] = MI_BATCH_BUFFER_END;
+ update_idx = bb->len;
+
+ emit_copy(gt, bb, src_L0_ofs, dst_L0_ofs, len, pitch);
+
+ job = xe_bb_create_migration_job(m->q, bb,
+ xe_migrate_batch_base(m, true),
+ update_idx);
+ if (IS_ERR(job)) {
+ err = PTR_ERR(job);
+ goto err;
+ }
+
+ xe_sched_job_add_migrate_flush(job, 0);
+
+ mutex_lock(&m->job_mutex);
+ xe_sched_job_arm(job);
+ fence = dma_fence_get(&job->drm.s_fence->finished);
+ xe_sched_job_push(job);
+
+ dma_fence_put(m->fence);
+ m->fence = dma_fence_get(fence);
+ mutex_unlock(&m->job_mutex);
+
+ xe_bb_free(bb, fence);
+
+ return fence;
+
+err:
+ xe_bb_free(bb, NULL);
+
+ return ERR_PTR(err);
+}
+
+static void xe_migrate_dma_unmap(struct xe_device *xe, dma_addr_t *dma_addr,
+ int len, int write)
+{
+ unsigned long i, npages = DIV_ROUND_UP(len, PAGE_SIZE);
+
+ for (i = 0; i < npages; ++i) {
+ if (!dma_addr[i])
+ continue;
+
+ dma_unmap_page(xe->drm.dev, dma_addr[i], PAGE_SIZE,
+ write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+ }
+ kfree(dma_addr);
+}
+
+static dma_addr_t *xe_migrate_dma_map(struct xe_device *xe,
+ void *buf, int len, int write)
+{
+ dma_addr_t *dma_addr;
+ unsigned long i, npages = DIV_ROUND_UP(len, PAGE_SIZE);
+
+ dma_addr = kcalloc(npages, sizeof(*dma_addr), GFP_KERNEL);
+ if (!dma_addr)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < npages; ++i) {
+ dma_addr_t addr;
+ struct page *page;
+
+ if (is_vmalloc_addr(buf))
+ page = vmalloc_to_page(buf);
+ else
+ page = virt_to_page(buf);
+
+ addr = dma_map_page(xe->drm.dev,
+ page, 0, PAGE_SIZE,
+ write ? DMA_TO_DEVICE :
+ DMA_FROM_DEVICE);
+ if (dma_mapping_error(xe->drm.dev, addr))
+ goto err_fault;
+
+ dma_addr[i] = addr;
+ buf += PAGE_SIZE;
+ }
+
+ return dma_addr;
+
+err_fault:
+ xe_migrate_dma_unmap(xe, dma_addr, len, write);
+ return ERR_PTR(-EFAULT);
+}
+
+/**
+ * xe_migrate_access_memory - Access memory of a BO via GPU
+ *
+ * @m: The migration context.
+ * @bo: buffer object
+ * @offset: access offset into buffer object
+ * @buf: pointer to caller memory to read into or write from
+ * @len: length of access
+ * @write: write access
+ *
+ * Access memory of a BO via GPU either reading in or writing from a passed in
+ * pointer. Pointer is dma mapped for GPU access and GPU commands are issued to
+ * read to or write from pointer.
+ *
+ * Returns:
+ * 0 if successful, negative error code on failure.
+ */
+int xe_migrate_access_memory(struct xe_migrate *m, struct xe_bo *bo,
+ unsigned long offset, void *buf, int len,
+ int write)
+{
+ struct xe_tile *tile = m->tile;
+ struct xe_device *xe = tile_to_xe(tile);
+ struct xe_res_cursor cursor;
+ struct dma_fence *fence = NULL;
+ dma_addr_t *dma_addr;
+ unsigned long page_offset = (unsigned long)buf & ~PAGE_MASK;
+ int bytes_left = len, current_page = 0;
+ void *orig_buf = buf;
+
+ xe_bo_assert_held(bo);
+
+ /* Use bounce buffer for small access and unaligned access */
+ if (len & CACHELINE_MASK || ((u64)buf | offset) & CACHELINE_MASK) {
+ int buf_offset = 0;
+
+ /*
+ * Less than ideal for large unaligned access but this should be
+ * fairly rare, can fixup if this becomes common.
+ */
+ do {
+ u8 bounce[CACHELINE_BYTES];
+ void *ptr = (void *)bounce;
+ int err;
+ int copy_bytes = min_t(int, bytes_left,
+ CACHELINE_BYTES -
+ (offset & CACHELINE_MASK));
+ int ptr_offset = offset & CACHELINE_MASK;
+
+ err = xe_migrate_access_memory(m, bo,
+ offset & ~CACHELINE_MASK,
+ (void *)ptr,
+ sizeof(bounce), 0);
+ if (err)
+ return err;
+
+ if (!write) {
+ memcpy(buf + buf_offset, ptr + ptr_offset,
+ copy_bytes);
+ goto next;
+ }
+
+ memcpy(ptr + ptr_offset, buf + buf_offset, copy_bytes);
+ err = xe_migrate_access_memory(m, bo,
+ offset & ~CACHELINE_MASK,
+ (void *)ptr,
+ sizeof(bounce), 0);
+ if (err)
+ return err;
+
+next:
+ bytes_left -= copy_bytes;
+ buf_offset += copy_bytes;
+ offset += copy_bytes;
+ } while (bytes_left);
+
+ return 0;
+ }
+
+ dma_addr = xe_migrate_dma_map(xe, buf, len + page_offset, write);
+ if (IS_ERR(dma_addr))
+ return PTR_ERR(dma_addr);
+
+ xe_res_first(bo->ttm.resource, offset, bo->size - offset, &cursor);
+
+ do {
+ struct dma_fence *__fence;
+ u64 vram_addr = vram_region_gpu_offset(bo->ttm.resource) +
+ cursor.start;
+ int current_bytes;
+
+ if (cursor.size > MAX_PREEMPTDISABLE_TRANSFER)
+ current_bytes = min_t(int, bytes_left,
+ MAX_PREEMPTDISABLE_TRANSFER);
+ else
+ current_bytes = min_t(int, bytes_left, cursor.size);
+
+ if (fence)
+ dma_fence_put(fence);
+
+ __fence = xe_migrate_vram(m, current_bytes,
+ (unsigned long)buf & ~PAGE_MASK,
+ dma_addr + current_page,
+ vram_addr, write ?
+ XE_MIGRATE_COPY_TO_VRAM :
+ XE_MIGRATE_COPY_TO_SRAM);
+ if (IS_ERR(__fence)) {
+ if (fence)
+ dma_fence_wait(fence, false);
+ fence = __fence;
+ goto out_err;
+ }
+ fence = __fence;
+
+ buf += current_bytes;
+ offset += current_bytes;
+ current_page = (int)(buf - orig_buf) / PAGE_SIZE;
+ bytes_left -= current_bytes;
+ if (bytes_left)
+ xe_res_next(&cursor, current_bytes);
+ } while (bytes_left);
+
+ dma_fence_wait(fence, false);
+ xe_migrate_dma_unmap(xe, dma_addr, len + page_offset, write);
+
+ return 0;
+
+out_err:
+ xe_migrate_dma_unmap(xe, dma_addr, len + page_offset, write);
+ return PTR_ERR(fence);
+}
+
#if IS_ENABLED(CONFIG_DRM_XE_KUNIT_TEST)
#include "tests/xe_migrate.c"
#endif
diff --git a/drivers/gpu/drm/xe/xe_migrate.h b/drivers/gpu/drm/xe/xe_migrate.h
index 0109866e398a..94197d262178 100644
--- a/drivers/gpu/drm/xe/xe_migrate.h
+++ b/drivers/gpu/drm/xe/xe_migrate.h
@@ -102,6 +102,10 @@ struct dma_fence *xe_migrate_copy(struct xe_migrate *m,
struct ttm_resource *dst,
bool copy_only_ccs);
+int xe_migrate_access_memory(struct xe_migrate *m, struct xe_bo *bo,
+ unsigned long offset, void *buf, int len,
+ int write);
+
#define XE_MIGRATE_CLEAR_FLAG_BO_DATA BIT(0)
#define XE_MIGRATE_CLEAR_FLAG_CCS_DATA BIT(1)
#define XE_MIGRATE_CLEAR_FLAG_FULL (XE_MIGRATE_CLEAR_FLAG_BO_DATA | \
--
2.34.1
