1 files changed, 506 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_lmtt.c b/drivers/gpu/drm/xe/xe_lmtt.c
new file mode 100644
index 000000000000..0d7c5514e092
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_lmtt.c
@@ -0,0 +1,506 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include <linux/align.h>
+
+#include <drm/drm_managed.h>
+
+#include "regs/xe_sriov_regs.h"
+
+#include "xe_assert.h"
+#include "xe_bo.h"
+#include "xe_lmtt.h"
+#include "xe_map.h"
+#include "xe_mmio.h"
+#include "xe_res_cursor.h"
+#include "xe_sriov.h"
+#include "xe_sriov_printk.h"
+
+/**
+ * DOC: Local Memory Translation Table
+ *
+ * The Local Memory Translation Table (LMTT) provides additional abstraction
+ * when Virtual Function (VF) is accessing device Local Memory (VRAM).
+ *
+ * The Root LMTT Page Directory contains one entry for each VF. Entries are
+ * indexed by the function number (1-based, index 0 is unused).
+ *
+ * See `Two-Level LMTT Structure`_ and `Multi-Level LMTT Structure`_.
+ */
+
+#define lmtt_assert(lmtt, condition)	xe_tile_assert(lmtt_to_tile(lmtt), condition)
+#define lmtt_debug(lmtt, msg...)	xe_sriov_dbg_verbose(lmtt_to_xe(lmtt), "LMTT: " msg)
+
+static bool xe_has_multi_level_lmtt(struct xe_device *xe)
+{
+	return xe->info.platform == XE_PVC;
+}
+
+static struct xe_tile *lmtt_to_tile(struct xe_lmtt *lmtt)
+{
+	return container_of(lmtt, struct xe_tile, sriov.pf.lmtt);
+}
+
+static struct xe_device *lmtt_to_xe(struct xe_lmtt *lmtt)
+{
+	return tile_to_xe(lmtt_to_tile(lmtt));
+}
+
+static u64 lmtt_page_size(struct xe_lmtt *lmtt)
+{
+	return BIT_ULL(lmtt->ops->lmtt_pte_shift(0));
+}
+
+static struct xe_lmtt_pt *lmtt_pt_alloc(struct xe_lmtt *lmtt, unsigned int level)
+{
+	unsigned int num_entries = level ? lmtt->ops->lmtt_pte_num(level) : 0;
+	struct xe_lmtt_pt *pt;
+	struct xe_bo *bo;
+	int err;
+
+	pt = kzalloc(struct_size(pt, entries, num_entries), GFP_KERNEL);
+	if (!pt) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	bo = xe_bo_create_pin_map(lmtt_to_xe(lmtt), lmtt_to_tile(lmtt), NULL,
+				  PAGE_ALIGN(lmtt->ops->lmtt_pte_size(level) *
+					     lmtt->ops->lmtt_pte_num(level)),
+				  ttm_bo_type_kernel,
+				  XE_BO_CREATE_VRAM_IF_DGFX(lmtt_to_tile(lmtt)) |
+				  XE_BO_CREATE_PINNED_BIT);
+	if (IS_ERR(bo)) {
+		err = PTR_ERR(bo);
+		goto out_free_pt;
+	}
+
+	lmtt_assert(lmtt, xe_bo_is_vram(bo));
+
+	pt->level = level;
+	pt->bo = bo;
+	return pt;
+
+out_free_pt:
+	kfree(pt);
+out:
+	return ERR_PTR(err);
+}
+
+static void lmtt_pt_free(struct xe_lmtt_pt *pt)
+{
+	xe_bo_unpin_map_no_vm(pt->bo);
+	kfree(pt);
+}
+
+static int lmtt_init_pd(struct xe_lmtt *lmtt)
+{
+	struct xe_lmtt_pt *pd;
+
+	lmtt_assert(lmtt, !lmtt->pd);
+	lmtt_assert(lmtt, lmtt->ops->lmtt_root_pd_level());
+
+	pd = lmtt_pt_alloc(lmtt, lmtt->ops->lmtt_root_pd_level());
+	if (IS_ERR(pd))
+		return PTR_ERR(pd);
+
+	lmtt->pd = pd;
+	return 0;
+}
+
+static void lmtt_fini_pd(struct xe_lmtt *lmtt)
+{
+	struct xe_lmtt_pt *pd = lmtt->pd;
+	unsigned int num_entries = lmtt->ops->lmtt_pte_num(pd->level);
+	unsigned int n = 0;
+
+	/* make sure we don't leak */
+	for (n = 0; n < num_entries; n++)
+		lmtt_assert(lmtt, !pd->entries[n]);
+
+	lmtt->pd = NULL;
+	lmtt_pt_free(pd);
+}
+
+static void fini_lmtt(struct drm_device *drm, void *arg)
+{
+	struct xe_lmtt *lmtt = arg;
+
+	lmtt_assert(lmtt, !(!!lmtt->ops ^ !!lmtt->pd));
+
+	if (!lmtt->pd)
+		return;
+
+	lmtt_fini_pd(lmtt);
+	lmtt->ops = NULL;
+}
+
+/**
+ * xe_lmtt_init - LMTT software initialization.
+ * @lmtt: the &xe_lmtt to initialize
+ *
+ * The LMTT initialization requires two steps.
+ *
+ * The xe_lmtt_init() checks if LMTT is required on current device and selects
+ * and initialize proper variant of the LMTT Root Directory. Currently supported
+ * variants are `Two-Level LMTT Structure`_ and `Multi-Level LMTT Structure`_.
+ *
+ * In next step xe_lmtt_init_hw() will register this directory on the hardware.
+ *
+ * Notes:
+ * The LMTT allocations are managed and will be implicitly released on driver unload.
+ * This function shall be called only once and only when running as a PF driver.
+ * Any LMTT initialization failure should block VFs enabling.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int xe_lmtt_init(struct xe_lmtt *lmtt)
+{
+	struct xe_device *xe = lmtt_to_xe(lmtt);
+	int err;
+
+	lmtt_assert(lmtt, IS_SRIOV_PF(xe));
+	lmtt_assert(lmtt, !lmtt->ops);
+
+	if (!IS_DGFX(xe))
+		return 0;
+
+	if (xe_has_multi_level_lmtt(xe))
+		lmtt->ops = &lmtt_ml_ops;
+	else
+		lmtt->ops = &lmtt_2l_ops;
+
+	err = lmtt_init_pd(lmtt);
+	if (unlikely(err))
+		goto fail;
+
+	return drmm_add_action_or_reset(&xe->drm, fini_lmtt, lmtt);
+
+fail:
+	lmtt->ops = NULL;
+	return err;
+}
+
+static void lmtt_setup_dir_ptr(struct xe_lmtt *lmtt)
+{
+	struct xe_tile *tile = lmtt_to_tile(lmtt);
+	struct xe_device *xe = tile_to_xe(tile);
+	dma_addr_t offset = xe_bo_main_addr(lmtt->pd->bo, XE_PAGE_SIZE);
+
+	lmtt_debug(lmtt, "DIR offset %pad\n", &offset);
+	lmtt_assert(lmtt, xe_bo_is_vram(lmtt->pd->bo));
+	lmtt_assert(lmtt, IS_ALIGNED(offset, SZ_64K));
+
+	xe_mmio_write32(tile->primary_gt,
+			GRAPHICS_VER(xe) >= 20 ? XE2_LMEM_CFG : LMEM_CFG,
+			LMEM_EN | REG_FIELD_PREP(LMTT_DIR_PTR, offset / SZ_64K));
+}
+
+/**
+ * xe_lmtt_init_hw - Perform LMTT hardware initialization.
+ * @lmtt: the &xe_lmtt to initialize
+ *
+ * This function is a second step of the LMTT initialization.
+ * This function registers LMTT Root Directory prepared in xe_lmtt_init().
+ *
+ * This function shall be called after every hardware reset.
+ * This function shall be called only when running as a PF driver.
+ */
+void xe_lmtt_init_hw(struct xe_lmtt *lmtt)
+{
+	if (!lmtt->pd)
+		return;
+
+	lmtt_setup_dir_ptr(lmtt);
+}
+
+static void lmtt_write_pte(struct xe_lmtt *lmtt, struct xe_lmtt_pt *pt,
+			   u64 pte, unsigned int idx)
+{
+	unsigned int level = pt->level;
+
+	lmtt_assert(lmtt, idx <= lmtt->ops->lmtt_pte_num(level));
+	lmtt_debug(lmtt, "WRITE level=%u index=%u pte=%#llx\n", level, idx, pte);
+
+	switch (lmtt->ops->lmtt_pte_size(level)) {
+	case sizeof(u32):
+		xe_map_wr(lmtt_to_xe(lmtt), &pt->bo->vmap, idx * sizeof(u32), u32, pte);
+		break;
+	case sizeof(u64):
+		xe_map_wr(lmtt_to_xe(lmtt), &pt->bo->vmap, idx * sizeof(u64), u64, pte);
+		break;
+	default:
+		lmtt_assert(lmtt, !!!"invalid pte size");
+	}
+}
+
+static void lmtt_destroy_pt(struct xe_lmtt *lmtt, struct xe_lmtt_pt *pd)
+{
+	unsigned int num_entries = pd->level ? lmtt->ops->lmtt_pte_num(pd->level) : 0;
+	struct xe_lmtt_pt *pt;
+	unsigned int i;
+
+	for (i = 0; i < num_entries; i++) {
+		pt = pd->entries[i];
+		pd->entries[i] = NULL;
+		if (!pt)
+			continue;
+
+		lmtt_destroy_pt(lmtt, pt);
+	}
+
+	lmtt_pt_free(pd);
+}
+
+static void lmtt_drop_pages(struct xe_lmtt *lmtt, unsigned int vfid)
+{
+	struct xe_lmtt_pt *pd = lmtt->pd;
+	struct xe_lmtt_pt *pt;
+
+	pt = pd->entries[vfid];
+	pd->entries[vfid] = NULL;
+	if (!pt)
+		return;
+
+	lmtt_write_pte(lmtt, pd, LMTT_PTE_INVALID, vfid);
+
+	lmtt_assert(lmtt, pd->level > 0);
+	lmtt_assert(lmtt, pt->level == pd->level - 1);
+	lmtt_destroy_pt(lmtt, pt);
+}
+
+static int __lmtt_alloc_range(struct xe_lmtt *lmtt, struct xe_lmtt_pt *pd,
+			      u64 start, u64 end)
+{
+	u64 pte_addr_shift = BIT_ULL(lmtt->ops->lmtt_pte_shift(pd->level));
+	u64 offset;
+	int err;
+
+	lmtt_assert(lmtt, pd->level > 0);
+
+	offset = start;
+	while (offset < end) {
+		struct xe_lmtt_pt *pt;
+		u64 next, pde, pt_addr;
+		unsigned int idx;
+
+		pt = lmtt_pt_alloc(lmtt, pd->level - 1);
+		if (IS_ERR(pt))
+			return PTR_ERR(pt);
+
+		pt_addr = xe_bo_main_addr(pt->bo, XE_PAGE_SIZE);
+
+		idx = lmtt->ops->lmtt_pte_index(offset, pd->level);
+		pde = lmtt->ops->lmtt_pte_encode(pt_addr, pd->level);
+
+		lmtt_write_pte(lmtt, pd, pde, idx);
+
+		pd->entries[idx] = pt;
+
+		next = min(end, round_up(offset + 1, pte_addr_shift));
+
+		if (pt->level != 0) {
+			err = __lmtt_alloc_range(lmtt, pt, offset, next);
+			if (err)
+				return err;
+		}
+
+		offset = next;
+	}
+
+	return 0;
+}
+
+static int lmtt_alloc_range(struct xe_lmtt *lmtt, unsigned int vfid, u64 start, u64 end)
+{
+	struct xe_lmtt_pt *pd = lmtt->pd;
+	struct xe_lmtt_pt *pt;
+	u64 pt_addr;
+	u64 pde;
+	int err;
+
+	lmtt_assert(lmtt, pd->level > 0);
+	lmtt_assert(lmtt, vfid <= lmtt->ops->lmtt_pte_num(pd->level));
+	lmtt_assert(lmtt, IS_ALIGNED(start, lmtt_page_size(lmtt)));
+	lmtt_assert(lmtt, IS_ALIGNED(end, lmtt_page_size(lmtt)));
+
+	if (pd->entries[vfid])
+		return -ENOTEMPTY;
+
+	pt = lmtt_pt_alloc(lmtt, pd->level - 1);
+	if (IS_ERR(pt))
+		return PTR_ERR(pt);
+
+	pt_addr = xe_bo_main_addr(pt->bo, XE_PAGE_SIZE);
+
+	pde = lmtt->ops->lmtt_pte_encode(pt_addr, pd->level);
+
+	lmtt_write_pte(lmtt, pd, pde, vfid);
+
+	pd->entries[vfid] = pt;
+
+	if (pt->level != 0) {
+		err = __lmtt_alloc_range(lmtt, pt, start, end);
+		if (err)
+			goto out_free_pt;
+	}
+
+	return 0;
+
+out_free_pt:
+	lmtt_pt_free(pt);
+	return err;
+}
+
+static struct xe_lmtt_pt *lmtt_leaf_pt(struct xe_lmtt *lmtt, unsigned int vfid, u64 addr)
+{
+	struct xe_lmtt_pt *pd = lmtt->pd;
+	struct xe_lmtt_pt *pt;
+
+	lmtt_assert(lmtt, vfid <= lmtt->ops->lmtt_pte_num(pd->level));
+	pt = pd->entries[vfid];
+
+	while (pt->level) {
+		lmtt_assert(lmtt, lmtt->ops->lmtt_pte_index(addr, pt->level) <=
+			    lmtt->ops->lmtt_pte_num(pt->level));
+
+		pt = pt->entries[lmtt->ops->lmtt_pte_index(addr, pt->level)];
+
+		addr >>= lmtt->ops->lmtt_pte_shift(pt->level);
+	}
+
+	lmtt_assert(lmtt, lmtt->ops->lmtt_pte_index(addr, pt->level) <=
+		    lmtt->ops->lmtt_pte_num(pt->level));
+	lmtt_assert(lmtt, pt->level != pd->level);
+	lmtt_assert(lmtt, pt->level == 0);
+	return pt;
+}
+
+static void lmtt_insert_bo(struct xe_lmtt *lmtt, unsigned int vfid, struct xe_bo *bo, u64 start)
+{
+	u64 page_size = lmtt_page_size(lmtt);
+	struct xe_res_cursor cur;
+	struct xe_lmtt_pt *pt;
+	u64 addr, vram_offset;
+
+	lmtt_assert(lmtt, IS_ALIGNED(start, page_size));
+	lmtt_assert(lmtt, IS_ALIGNED(bo->size, page_size));
+	lmtt_assert(lmtt, xe_bo_is_vram(bo));
+
+	vram_offset = vram_region_gpu_offset(bo->ttm.resource);
+	xe_res_first(bo->ttm.resource, 0, bo->size, &cur);
+	while (cur.remaining) {
+		addr = xe_res_dma(&cur);
+		addr += vram_offset; /* XXX */
+
+		pt = lmtt_leaf_pt(lmtt, vfid, start);
+
+		lmtt_write_pte(lmtt, pt, lmtt->ops->lmtt_pte_encode(addr, 0),
+					 lmtt->ops->lmtt_pte_index(start, 0));
+
+		xe_res_next(&cur, page_size);
+		start += page_size;
+	}
+}
+
+/**
+ * xe_lmtt_prepare_pages - Create VF's LMTT Page Tables.
+ * @lmtt: the &xe_lmtt to update
+ * @vfid: the VF identifier (1-based)
+ * @range: top range of LMEM offset to be supported
+ *
+ * This function creates empty LMTT page tables for given VF to support
+ * up to maximum #range LMEM offset. The LMTT page tables created by this
+ * function must be released using xe_lmtt_drop_pages() function.
+ *
+ * Notes:
+ * This function shall be called only after successful LMTT initialization.
+ * See xe_lmtt_init().
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int xe_lmtt_prepare_pages(struct xe_lmtt *lmtt, unsigned int vfid, u64 range)
+{
+	lmtt_assert(lmtt, lmtt->pd);
+	lmtt_assert(lmtt, vfid);
+
+	return lmtt_alloc_range(lmtt, vfid, 0, range);
+}
+
+/**
+ * xe_lmtt_populate_pages - Update VF's LMTT Page Table Entries.
+ * @lmtt: the &xe_lmtt to update
+ * @vfid: the VF identifier (1-based)
+ * @bo: the buffer object with LMEM allocation to be mapped
+ * @offset: the offset at which #bo should be mapped
+ *
+ * This function updates VF's LMTT entries to use given buffer object as a backstore.
+ *
+ * Notes:
+ * This function shall be called only after successful preparation of the
+ * VF's LMTT Page Tables. See xe_lmtt_prepare().
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int xe_lmtt_populate_pages(struct xe_lmtt *lmtt, unsigned int vfid, struct xe_bo *bo, u64 offset)
+{
+	lmtt_assert(lmtt, lmtt->pd);
+	lmtt_assert(lmtt, vfid);
+
+	lmtt_insert_bo(lmtt, vfid, bo, offset);
+	return 0;
+}
+
+/**
+ * xe_lmtt_drop_pages - Remove VF's LMTT Pages.
+ * @lmtt: the &xe_lmtt to update
+ * @vfid: the VF identifier (1-based)
+ *
+ * This function removes all LMTT Page Tables prepared by xe_lmtt_prepare_pages().
+ *
+ * This function shall be called only after successful LMTT initialization.
+ * See xe_lmtt_init().
+ */
+void xe_lmtt_drop_pages(struct xe_lmtt *lmtt, unsigned int vfid)
+{
+	lmtt_assert(lmtt, lmtt->pd);
+	lmtt_assert(lmtt, vfid);
+
+	lmtt_drop_pages(lmtt, vfid);
+}
+
+/**
+ * xe_lmtt_estimate_pt_size - Estimate size of LMTT PT allocations.
+ * @lmtt: the &xe_lmtt
+ * @size: the size of the LMEM to be mapped over LMTT (including any offset)
+ *
+ * This function shall be called only by PF.
+ *
+ * Return: size of the PT allocation(s) needed to support given LMEM size.
+ */
+u64 xe_lmtt_estimate_pt_size(struct xe_lmtt *lmtt, u64 size)
+{
+	unsigned int level = 0;
+	u64 pt_size;
+
+	lmtt_assert(lmtt, IS_SRIOV_PF(lmtt_to_xe(lmtt)));
+	lmtt_assert(lmtt, IS_DGFX(lmtt_to_xe(lmtt)));
+	lmtt_assert(lmtt, lmtt->ops);
+
+	pt_size = PAGE_ALIGN(lmtt->ops->lmtt_pte_size(level) *
+			     lmtt->ops->lmtt_pte_num(level));
+
+	while (++level < lmtt->ops->lmtt_root_pd_level()) {
+		pt_size *= lmtt->ops->lmtt_pte_index(size, level) + 1;
+		pt_size += PAGE_ALIGN(lmtt->ops->lmtt_pte_size(level) *
+				      lmtt->ops->lmtt_pte_num(level));
+	}
+
+	return pt_size;
+}
+
+#if IS_BUILTIN(CONFIG_DRM_XE_KUNIT_TEST)
+#include "tests/xe_lmtt_test.c"
+#endif