[Intel-gfx] [PATCH v3 7/8] drm/i915/migrate: add acceleration support for DG2

Matthew Auld
2021-12-06T13:32:52Z

This is all kinds of awkward since we now have to contend with using 64K
GTT pages when mapping anything in LMEM(including the page-tables
themselves).

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Ramalingam C <ramalingam.c@intel.com>
---
drivers/gpu/drm/i915/gt/intel_migrate.c | 189 +++++++++++++++++++-----
1 file changed, 150 insertions(+), 39 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_migrate.c b/drivers/gpu/drm/i915/gt/intel_migrate.c
index 0192b61ab541..fb658ae70a8d 100644
--- a/drivers/gpu/drm/i915/gt/intel_migrate.c
+++ b/drivers/gpu/drm/i915/gt/intel_migrate.c
@@ -33,6 +33,38 @@ static bool engine_supports_migration(struct intel_engine_cs *engine)
return true;
}

+static void xehpsdv_toggle_pdes(struct i915_address_space *vm,
+ struct i915_page_table *pt,
+ void *data)
+{
+ struct insert_pte_data *d = data;
+
+ /*
+ * Insert a dummy PTE into every PT that will map to LMEM to ensure
+ * we have a correctly setup PDE structure for later use.
+ */
+ vm->insert_page(vm, 0, d->offset, I915_CACHE_NONE, PTE_LM);
+ GEM_BUG_ON(!pt->is_compact);
+ d->offset += SZ_2M;
+}
+
+static void xehpsdv_insert_pte(struct i915_address_space *vm,
+ struct i915_page_table *pt,
+ void *data)
+{
+ struct insert_pte_data *d = data;
+
+ /*
+ * We are playing tricks here, since the actual pt, from the hw
+ * pov, is only 256bytes with 32 entries, or 4096bytes with 512
+ * entries, but we are still guaranteed that the physical
+ * alignment is 64K underneath for the pt, and we are careful
+ * not to access the space in the void.
+ */
+ vm->insert_page(vm, px_dma(pt), d->offset, I915_CACHE_NONE, PTE_LM);
+ d->offset += SZ_64K;
+}
+
static void insert_pte(struct i915_address_space *vm,
struct i915_page_table *pt,
void *data)
@@ -75,7 +107,12 @@ static struct i915_address_space *migrate_vm(struct intel_gt *gt)
* i.e. within the same non-preemptible window so that we do not switch
* to another migration context that overwrites the PTE.
*
- * TODO: Add support for huge LMEM PTEs
+ * On platforms with HAS_64K_PAGES support we have three windows, and
+ * dedicate two windows just for mapping lmem pages(smem <-> smem is not
+ * a thing), since we are forced to use 64K GTT pages underneath which
+ * requires also modifying the PDE. An alternative might be to instead
+ * map the PD into the GTT, and then on the fly toggle the 4K/64K mode
+ * in the PDE from the same batch that also modifies the PTEs.
*/

vm = i915_ppgtt_create(gt, I915_BO_ALLOC_PM_EARLY);
@@ -87,6 +124,9 @@ static struct i915_address_space *migrate_vm(struct intel_gt *gt)
goto err_vm;
}

+ if (HAS_64K_PAGES(gt->i915))
+ stash.pt_sz = I915_GTT_PAGE_SIZE_64K;
+
/*
* Each engine instance is assigned its own chunk in the VM, so
* that we can run multiple instances concurrently
@@ -106,14 +146,20 @@ static struct i915_address_space *migrate_vm(struct intel_gt *gt)
* We copy in 8MiB chunks. Each PDE covers 2MiB, so we need
* 4x2 page directories for source/destination.
*/
- sz = 2 * CHUNK_SZ;
+ if (HAS_64K_PAGES(gt->i915))
+ sz = 3 * CHUNK_SZ;
+ else
+ sz = 2 * CHUNK_SZ;
d.offset = base + sz;

/*
* We need another page directory setup so that we can write
* the 8x512 PTE in each chunk.
*/
- sz += (sz >> 12) * sizeof(u64);
+ if (HAS_64K_PAGES(gt->i915))
+ sz += (sz / SZ_2M) * SZ_64K;
+ else
+ sz += (sz >> 12) * sizeof(u64);

err = i915_vm_alloc_pt_stash(&vm->vm, &stash, sz);
if (err)
@@ -134,7 +180,18 @@ static struct i915_address_space *migrate_vm(struct intel_gt *gt)
goto err_vm;

/* Now allow the GPU to rewrite the PTE via its own ppGTT */
- vm->vm.foreach(&vm->vm, base, d.offset - base, insert_pte, &d);
+ if (HAS_64K_PAGES(gt->i915)) {
+ vm->vm.foreach(&vm->vm, base, d.offset - base,
+ xehpsdv_insert_pte, &d);
+ d.offset = base + CHUNK_SZ;
+ vm->vm.foreach(&vm->vm,
+ d.offset,
+ 2 * CHUNK_SZ,
+ xehpsdv_toggle_pdes, &d);
+ } else {
+ vm->vm.foreach(&vm->vm, base, d.offset - base,
+ insert_pte, &d);
+ }
}

return &vm->vm;
@@ -272,19 +329,38 @@ static int emit_pte(struct i915_request *rq,
u64 offset,
int length)
{
+ bool has_64K_pages = HAS_64K_PAGES(rq->engine->i915);
const u64 encode = rq->context->vm->pte_encode(0, cache_level,
is_lmem ? PTE_LM : 0);
struct intel_ring *ring = rq->ring;
- int total = 0;
+ int pkt, dword_length;
+ u32 total = 0;
+ u32 page_size;
u32 *hdr, *cs;
- int pkt;

GEM_BUG_ON(GRAPHICS_VER(rq->engine->i915) < 8);

+ page_size = I915_GTT_PAGE_SIZE;
+ dword_length = 0x400;
+
/* Compute the page directory offset for the target address range */
- offset >>= 12;
- offset *= sizeof(u64);
- offset += 2 * CHUNK_SZ;
+ if (has_64K_pages) {
+ GEM_BUG_ON(!IS_ALIGNED(offset, SZ_2M));
+
+ offset /= SZ_2M;
+ offset *= SZ_64K;
+ offset += 3 * CHUNK_SZ;
+
+ if (is_lmem) {
+ page_size = I915_GTT_PAGE_SIZE_64K;
+ dword_length = 0x40;
+ }
+ } else {
+ offset >>= 12;
+ offset *= sizeof(u64);
+ offset += 2 * CHUNK_SZ;
+ }
+
offset += (u64)rq->engine->instance << 32;

cs = intel_ring_begin(rq, 6);
@@ -292,7 +368,7 @@ static int emit_pte(struct i915_request *rq,
return PTR_ERR(cs);

/* Pack as many PTE updates as possible into a single MI command */
- pkt = min_t(int, 0x400, ring->space / sizeof(u32) + 5);
+ pkt = min_t(int, dword_length, ring->space / sizeof(u32) + 5);
pkt = min_t(int, pkt, (ring->size - ring->emit) / sizeof(u32) + 5);

hdr = cs;
@@ -302,6 +378,8 @@ static int emit_pte(struct i915_request *rq,

do {
if (cs - hdr >= pkt) {
+ int dword_rem;
+
*hdr += cs - hdr - 2;
*cs++ = MI_NOOP;

@@ -313,7 +391,18 @@ static int emit_pte(struct i915_request *rq,
if (IS_ERR(cs))
return PTR_ERR(cs);

- pkt = min_t(int, 0x400, ring->space / sizeof(u32) + 5);
+ dword_rem = dword_length;
+ if (has_64K_pages) {
+ if (IS_ALIGNED(total, SZ_2M)) {
+ offset = round_up(offset, SZ_64K);
+ } else {
+ dword_rem = SZ_2M - (total & (SZ_2M - 1));
+ dword_rem /= page_size;
+ dword_rem *= 2;
+ }
+ }
+
+ pkt = min_t(int, dword_rem, ring->space / sizeof(u32) + 5);
pkt = min_t(int, pkt, (ring->size - ring->emit) / sizeof(u32) + 5);

hdr = cs;
@@ -322,13 +411,15 @@ static int emit_pte(struct i915_request *rq,
*cs++ = upper_32_bits(offset);
}

+ GEM_BUG_ON(!IS_ALIGNED(it->dma, page_size));
+
*cs++ = lower_32_bits(encode | it->dma);
*cs++ = upper_32_bits(encode | it->dma);

offset += 8;
- total += I915_GTT_PAGE_SIZE;
+ total += page_size;

- it->dma += I915_GTT_PAGE_SIZE;
+ it->dma += page_size;
if (it->dma >= it->max) {
it->sg = __sg_next(it->sg);
if (!it->sg || sg_dma_len(it->sg) == 0)
@@ -359,7 +450,8 @@ static bool wa_1209644611_applies(int ver, u32 size)
return height % 4 == 3 && height <= 8;
}

-static int emit_copy(struct i915_request *rq, int size)
+static int emit_copy(struct i915_request *rq,
+ u32 dst_offset, u32 src_offset, int size)
{
const int ver = GRAPHICS_VER(rq->engine->i915);
u32 instance = rq->engine->instance;
@@ -374,31 +466,31 @@ static int emit_copy(struct i915_request *rq, int size)
*cs++ = BLT_DEPTH_32 | PAGE_SIZE;
*cs++ = 0;
*cs++ = size >> PAGE_SHIFT << 16 | PAGE_SIZE / 4;
- *cs++ = CHUNK_SZ; /* dst offset */
+ *cs++ = dst_offset;
*cs++ = instance;
*cs++ = 0;
*cs++ = PAGE_SIZE;
- *cs++ = 0; /* src offset */
+ *cs++ = src_offset;
*cs++ = instance;
} else if (ver >= 8) {
*cs++ = XY_SRC_COPY_BLT_CMD | BLT_WRITE_RGBA | (10 - 2);
*cs++ = BLT_DEPTH_32 | BLT_ROP_SRC_COPY | PAGE_SIZE;
*cs++ = 0;
*cs++ = size >> PAGE_SHIFT << 16 | PAGE_SIZE / 4;
- *cs++ = CHUNK_SZ; /* dst offset */
+ *cs++ = dst_offset;
*cs++ = instance;
*cs++ = 0;
*cs++ = PAGE_SIZE;
- *cs++ = 0; /* src offset */
+ *cs++ = src_offset;
*cs++ = instance;
} else {
GEM_BUG_ON(instance);
*cs++ = SRC_COPY_BLT_CMD | BLT_WRITE_RGBA | (6 - 2);
*cs++ = BLT_DEPTH_32 | BLT_ROP_SRC_COPY | PAGE_SIZE;
*cs++ = size >> PAGE_SHIFT << 16 | PAGE_SIZE;
- *cs++ = CHUNK_SZ; /* dst offset */
+ *cs++ = dst_offset;
*cs++ = PAGE_SIZE;
- *cs++ = 0; /* src offset */
+ *cs++ = src_offset;
}

intel_ring_advance(rq, cs);
@@ -426,6 +518,7 @@ intel_context_migrate_copy(struct intel_context *ce,
GEM_BUG_ON(ce->ring->size < SZ_64K);

do {
+ u32 src_offset, dst_offset;
int len;

rq = i915_request_create(ce);
@@ -453,15 +546,28 @@ intel_context_migrate_copy(struct intel_context *ce,
if (err)
goto out_rq;

- len = emit_pte(rq, &it_src, src_cache_level, src_is_lmem, 0,
- CHUNK_SZ);
+ src_offset = 0;
+ dst_offset = CHUNK_SZ;
+ if (HAS_64K_PAGES(ce->engine->i915)) {
+ GEM_BUG_ON(!src_is_lmem && !dst_is_lmem);
+
+ src_offset = 0;
+ dst_offset = 0;
+ if (src_is_lmem)
+ src_offset = CHUNK_SZ;
+ if (dst_is_lmem)
+ dst_offset = 2 * CHUNK_SZ;
+ }
+
+ len = emit_pte(rq, &it_src, src_cache_level, src_is_lmem,
+ src_offset, CHUNK_SZ);
if (len <= 0) {
err = len;
goto out_rq;
}

err = emit_pte(rq, &it_dst, dst_cache_level, dst_is_lmem,
- CHUNK_SZ, len);
+ dst_offset, len);
if (err < 0)
goto out_rq;
if (err < len) {
@@ -473,7 +579,7 @@ intel_context_migrate_copy(struct intel_context *ce,
if (err)
goto out_rq;

- err = emit_copy(rq, len);
+ err = emit_copy(rq, dst_offset, src_offset, len);

/* Arbitration is re-enabled between requests. */
out_rq:
@@ -571,18 +677,20 @@ static u32 *_i915_ctrl_surf_copy_blt(u32 *cmd, u64 src_addr, u64 dst_addr,
}

static int emit_clear(struct i915_request *rq,
+ u64 offset,
int size,
u32 value,
bool is_lmem)
{
- const int ver = GRAPHICS_VER(rq->engine->i915);
- u32 instance = rq->engine->instance;
- u32 *cs;
struct drm_i915_private *i915 = rq->engine->i915;
+ const int ver = GRAPHICS_VER(rq->engine->i915);
u32 num_ccs_blks, ccs_ring_size;
+ u32 *cs;

GEM_BUG_ON(size >> PAGE_SHIFT > S16_MAX);

+ offset += (u64)rq->engine->instance << 32;
+
/* Clear flat css only when value is 0 */
ccs_ring_size = (is_lmem && !value) ?
calc_ctrl_surf_instr_size(i915, size)
@@ -597,17 +705,17 @@ static int emit_clear(struct i915_request *rq,
*cs++ = BLT_DEPTH_32 | BLT_ROP_COLOR_COPY | PAGE_SIZE;
*cs++ = 0;
*cs++ = size >> PAGE_SHIFT << 16 | PAGE_SIZE / 4;
- *cs++ = 0; /* offset */
- *cs++ = instance;
+ *cs++ = lower_32_bits(offset);
+ *cs++ = upper_32_bits(offset);
*cs++ = value;
*cs++ = MI_NOOP;
} else {
- GEM_BUG_ON(instance);
+ GEM_BUG_ON(upper_32_bits(offset));
*cs++ = XY_COLOR_BLT_CMD | BLT_WRITE_RGBA | (6 - 2);
*cs++ = BLT_DEPTH_32 | BLT_ROP_COLOR_COPY | PAGE_SIZE;
*cs++ = 0;
*cs++ = size >> PAGE_SHIFT << 16 | PAGE_SIZE / 4;
- *cs++ = 0;
+ *cs++ = lower_32_bits(offset);
*cs++ = value;
}

@@ -623,17 +731,15 @@ static int emit_clear(struct i915_request *rq,
* and use it as a source.
*/

- cs = i915_flush_dw(cs, (u64)instance << 32,
- MI_FLUSH_LLC | MI_FLUSH_CCS);
+ cs = i915_flush_dw(cs, offset, MI_FLUSH_LLC | MI_FLUSH_CCS);
cs = _i915_ctrl_surf_copy_blt(cs,
- (u64)instance << 32,
- (u64)instance << 32,
+ offset,
+ offset,
DIRECT_ACCESS,
INDIRECT_ACCESS,
1, 1,
num_ccs_blks);
- cs = i915_flush_dw(cs, (u64)instance << 32,
- MI_FLUSH_LLC | MI_FLUSH_CCS);
+ cs = i915_flush_dw(cs, offset, MI_FLUSH_LLC | MI_FLUSH_CCS);
}
intel_ring_advance(rq, cs);
return 0;
@@ -658,6 +764,7 @@ intel_context_migrate_clear(struct intel_context *ce,
GEM_BUG_ON(ce->ring->size < SZ_64K);

do {
+ u32 offset;
int len;

rq = i915_request_create(ce);
@@ -685,7 +792,11 @@ intel_context_migrate_clear(struct intel_context *ce,
if (err)
goto out_rq;

- len = emit_pte(rq, &it, cache_level, is_lmem, 0, CHUNK_SZ);
+ offset = 0;
+ if (HAS_64K_PAGES(ce->engine->i915) && is_lmem)
+ offset = CHUNK_SZ;
+
+ len = emit_pte(rq, &it, cache_level, is_lmem, offset, CHUNK_SZ);
if (len <= 0) {
err = len;
goto out_rq;
@@ -695,7 +806,7 @@ intel_context_migrate_clear(struct intel_context *ce,
if (err)
goto out_rq;

- err = emit_clear(rq, len, value, is_lmem);
+ err = emit_clear(rq, offset, len, value, is_lmem);

/* Arbitration is re-enabled between requests. */
out_rq:
--
2.31.1