1 files changed, 524 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_mmio.c b/drivers/gpu/drm/xe/xe_mmio.c
new file mode 100644
index 000000000000..c8c5d74b6e90
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_mmio.c
@@ -0,0 +1,524 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2021-2023 Intel Corporation
+ */
+
+#include <linux/minmax.h>
+
+#include "xe_mmio.h"
+
+#include <drm/drm_managed.h>
+#include <drm/xe_drm.h>
+
+#include "regs/xe_engine_regs.h"
+#include "regs/xe_gt_regs.h"
+#include "regs/xe_regs.h"
+#include "xe_bo.h"
+#include "xe_device.h"
+#include "xe_ggtt.h"
+#include "xe_gt.h"
+#include "xe_gt_mcr.h"
+#include "xe_macros.h"
+#include "xe_module.h"
+#include "xe_tile.h"
+
+#define XEHP_MTCFG_ADDR		XE_REG(0x101800)
+#define TILE_COUNT		REG_GENMASK(15, 8)
+
+#define BAR_SIZE_SHIFT 20
+
+static void
+_resize_bar(struct xe_device *xe, int resno, resource_size_t size)
+{
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+	int bar_size = pci_rebar_bytes_to_size(size);
+	int ret;
+
+	if (pci_resource_len(pdev, resno))
+		pci_release_resource(pdev, resno);
+
+	ret = pci_resize_resource(pdev, resno, bar_size);
+	if (ret) {
+		drm_info(&xe->drm, "Failed to resize BAR%d to %dM (%pe). Consider enabling 'Resizable BAR' support in your BIOS\n",
+			 resno, 1 << bar_size, ERR_PTR(ret));
+		return;
+	}
+
+	drm_info(&xe->drm, "BAR%d resized to %dM\n", resno, 1 << bar_size);
+}
+
+/*
+ * if force_vram_bar_size is set, attempt to set to the requested size
+ * else set to maximum possible size
+ */
+static void xe_resize_vram_bar(struct xe_device *xe)
+{
+	u64 force_vram_bar_size = xe_modparam.force_vram_bar_size;
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+	struct pci_bus *root = pdev->bus;
+	resource_size_t current_size;
+	resource_size_t rebar_size;
+	struct resource *root_res;
+	u32 bar_size_mask;
+	u32 pci_cmd;
+	int i;
+
+	/* gather some relevant info */
+	current_size = pci_resource_len(pdev, LMEM_BAR);
+	bar_size_mask = pci_rebar_get_possible_sizes(pdev, LMEM_BAR);
+
+	if (!bar_size_mask)
+		return;
+
+	/* set to a specific size? */
+	if (force_vram_bar_size) {
+		u32 bar_size_bit;
+
+		rebar_size = force_vram_bar_size * (resource_size_t)SZ_1M;
+
+		bar_size_bit = bar_size_mask & BIT(pci_rebar_bytes_to_size(rebar_size));
+
+		if (!bar_size_bit) {
+			drm_info(&xe->drm,
+				 "Requested size: %lluMiB is not supported by rebar sizes: 0x%x. Leaving default: %lluMiB\n",
+				 (u64)rebar_size >> 20, bar_size_mask, (u64)current_size >> 20);
+			return;
+		}
+
+		rebar_size = 1ULL << (__fls(bar_size_bit) + BAR_SIZE_SHIFT);
+
+		if (rebar_size == current_size)
+			return;
+	} else {
+		rebar_size = 1ULL << (__fls(bar_size_mask) + BAR_SIZE_SHIFT);
+
+		/* only resize if larger than current */
+		if (rebar_size <= current_size)
+			return;
+	}
+
+	drm_info(&xe->drm, "Attempting to resize bar from %lluMiB -> %lluMiB\n",
+		 (u64)current_size >> 20, (u64)rebar_size >> 20);
+
+	while (root->parent)
+		root = root->parent;
+
+	pci_bus_for_each_resource(root, root_res, i) {
+		if (root_res && root_res->flags & (IORESOURCE_MEM | IORESOURCE_MEM_64) &&
+		    root_res->start > 0x100000000ull)
+			break;
+	}
+
+	if (!root_res) {
+		drm_info(&xe->drm, "Can't resize VRAM BAR - platform support is missing. Consider enabling 'Resizable BAR' support in your BIOS\n");
+		return;
+	}
+
+	pci_read_config_dword(pdev, PCI_COMMAND, &pci_cmd);
+	pci_write_config_dword(pdev, PCI_COMMAND, pci_cmd & ~PCI_COMMAND_MEMORY);
+
+	_resize_bar(xe, LMEM_BAR, rebar_size);
+
+	pci_assign_unassigned_bus_resources(pdev->bus);
+	pci_write_config_dword(pdev, PCI_COMMAND, pci_cmd);
+}
+
+static bool xe_pci_resource_valid(struct pci_dev *pdev, int bar)
+{
+	if (!pci_resource_flags(pdev, bar))
+		return false;
+
+	if (pci_resource_flags(pdev, bar) & IORESOURCE_UNSET)
+		return false;
+
+	if (!pci_resource_len(pdev, bar))
+		return false;
+
+	return true;
+}
+
+static int xe_determine_lmem_bar_size(struct xe_device *xe)
+{
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+
+	if (!xe_pci_resource_valid(pdev, LMEM_BAR)) {
+		drm_err(&xe->drm, "pci resource is not valid\n");
+		return -ENXIO;
+	}
+
+	xe_resize_vram_bar(xe);
+
+	xe->mem.vram.io_start = pci_resource_start(pdev, LMEM_BAR);
+	xe->mem.vram.io_size = pci_resource_len(pdev, LMEM_BAR);
+	if (!xe->mem.vram.io_size)
+		return -EIO;
+
+	/* XXX: Need to change when xe link code is ready */
+	xe->mem.vram.dpa_base = 0;
+
+	/* set up a map to the total memory area. */
+	xe->mem.vram.mapping = ioremap_wc(xe->mem.vram.io_start, xe->mem.vram.io_size);
+
+	return 0;
+}
+
+/**
+ * xe_mmio_tile_vram_size() - Collect vram size and offset information
+ * @tile: tile to get info for
+ * @vram_size: available vram (size - device reserved portions)
+ * @tile_size: actual vram size
+ * @tile_offset: physical start point in the vram address space
+ *
+ * There are 4 places for size information:
+ * - io size (from pci_resource_len of LMEM bar) (only used for small bar and DG1)
+ * - TILEx size (actual vram size)
+ * - GSMBASE offset (TILEx - "stolen")
+ * - CSSBASE offset (TILEx - CSS space necessary)
+ *
+ * CSSBASE is always a lower/smaller offset then GSMBASE.
+ *
+ * The actual available size of memory is to the CCS or GSM base.
+ * NOTE: multi-tile bases will include the tile offset.
+ *
+ */
+static int xe_mmio_tile_vram_size(struct xe_tile *tile, u64 *vram_size,
+				  u64 *tile_size, u64 *tile_offset)
+{
+	struct xe_device *xe = tile_to_xe(tile);
+	struct xe_gt *gt = tile->primary_gt;
+	u64 offset;
+	int err;
+	u32 reg;
+
+	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
+	if (err)
+		return err;
+
+	/* actual size */
+	if (unlikely(xe->info.platform == XE_DG1)) {
+		*tile_size = pci_resource_len(to_pci_dev(xe->drm.dev), LMEM_BAR);
+		*tile_offset = 0;
+	} else {
+		reg = xe_gt_mcr_unicast_read_any(gt, XEHP_TILE_ADDR_RANGE(gt->info.id));
+		*tile_size = (u64)REG_FIELD_GET(GENMASK(14, 8), reg) * SZ_1G;
+		*tile_offset = (u64)REG_FIELD_GET(GENMASK(7, 1), reg) * SZ_1G;
+	}
+
+	/* minus device usage */
+	if (xe->info.has_flat_ccs) {
+		reg = xe_gt_mcr_unicast_read_any(gt, XEHP_FLAT_CCS_BASE_ADDR);
+		offset = (u64)REG_FIELD_GET(GENMASK(31, 8), reg) * SZ_64K;
+	} else {
+		offset = xe_mmio_read64_2x32(gt, GSMBASE);
+	}
+
+	/* remove the tile offset so we have just the available size */
+	*vram_size = offset - *tile_offset;
+
+	return xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
+}
+
+int xe_mmio_probe_vram(struct xe_device *xe)
+{
+	struct xe_tile *tile;
+	resource_size_t io_size;
+	u64 available_size = 0;
+	u64 total_size = 0;
+	u64 tile_offset;
+	u64 tile_size;
+	u64 vram_size;
+	int err;
+	u8 id;
+
+	if (!IS_DGFX(xe))
+		return 0;
+
+	/* Get the size of the root tile's vram for later accessibility comparison */
+	tile = xe_device_get_root_tile(xe);
+	err = xe_mmio_tile_vram_size(tile, &vram_size, &tile_size, &tile_offset);
+	if (err)
+		return err;
+
+	err = xe_determine_lmem_bar_size(xe);
+	if (err)
+		return err;
+
+	drm_info(&xe->drm, "VISIBLE VRAM: %pa, %pa\n", &xe->mem.vram.io_start,
+		 &xe->mem.vram.io_size);
+
+	io_size = xe->mem.vram.io_size;
+
+	/* tile specific ranges */
+	for_each_tile(tile, xe, id) {
+		err = xe_mmio_tile_vram_size(tile, &vram_size, &tile_size, &tile_offset);
+		if (err)
+			return err;
+
+		tile->mem.vram.actual_physical_size = tile_size;
+		tile->mem.vram.io_start = xe->mem.vram.io_start + tile_offset;
+		tile->mem.vram.io_size = min_t(u64, vram_size, io_size);
+
+		if (!tile->mem.vram.io_size) {
+			drm_err(&xe->drm, "Tile without any CPU visible VRAM. Aborting.\n");
+			return -ENODEV;
+		}
+
+		tile->mem.vram.dpa_base = xe->mem.vram.dpa_base + tile_offset;
+		tile->mem.vram.usable_size = vram_size;
+		tile->mem.vram.mapping = xe->mem.vram.mapping + tile_offset;
+
+		if (tile->mem.vram.io_size < tile->mem.vram.usable_size)
+			drm_info(&xe->drm, "Small BAR device\n");
+		drm_info(&xe->drm, "VRAM[%u, %u]: Actual physical size %pa, usable size exclude stolen %pa, CPU accessible size %pa\n", id,
+			 tile->id, &tile->mem.vram.actual_physical_size, &tile->mem.vram.usable_size, &tile->mem.vram.io_size);
+		drm_info(&xe->drm, "VRAM[%u, %u]: DPA range: [%pa-%llx], io range: [%pa-%llx]\n", id, tile->id,
+			 &tile->mem.vram.dpa_base, tile->mem.vram.dpa_base + tile->mem.vram.actual_physical_size,
+			 &tile->mem.vram.io_start, tile->mem.vram.io_start + tile->mem.vram.io_size);
+
+		/* calculate total size using tile size to get the correct HW sizing */
+		total_size += tile_size;
+		available_size += vram_size;
+
+		if (total_size > xe->mem.vram.io_size) {
+			drm_info(&xe->drm, "VRAM: %pa is larger than resource %pa\n",
+				 &total_size, &xe->mem.vram.io_size);
+		}
+
+		io_size -= min_t(u64, tile_size, io_size);
+	}
+
+	xe->mem.vram.actual_physical_size = total_size;
+
+	drm_info(&xe->drm, "Total VRAM: %pa, %pa\n", &xe->mem.vram.io_start,
+		 &xe->mem.vram.actual_physical_size);
+	drm_info(&xe->drm, "Available VRAM: %pa, %pa\n", &xe->mem.vram.io_start,
+		 &available_size);
+
+	return 0;
+}
+
+void xe_mmio_probe_tiles(struct xe_device *xe)
+{
+	size_t tile_mmio_size = SZ_16M, tile_mmio_ext_size = xe->info.tile_mmio_ext_size;
+	u8 id, tile_count = xe->info.tile_count;
+	struct xe_gt *gt = xe_root_mmio_gt(xe);
+	struct xe_tile *tile;
+	void __iomem *regs;
+	u32 mtcfg;
+
+	if (tile_count == 1)
+		goto add_mmio_ext;
+
+	if (!xe->info.skip_mtcfg) {
+		mtcfg = xe_mmio_read64_2x32(gt, XEHP_MTCFG_ADDR);
+		tile_count = REG_FIELD_GET(TILE_COUNT, mtcfg) + 1;
+		if (tile_count < xe->info.tile_count) {
+			drm_info(&xe->drm, "tile_count: %d, reduced_tile_count %d\n",
+					xe->info.tile_count, tile_count);
+			xe->info.tile_count = tile_count;
+
+			/*
+			 * FIXME: Needs some work for standalone media, but should be impossible
+			 * with multi-tile for now.
+			 */
+			xe->info.gt_count = xe->info.tile_count;
+		}
+	}
+
+	regs = xe->mmio.regs;
+	for_each_tile(tile, xe, id) {
+		tile->mmio.size = tile_mmio_size;
+		tile->mmio.regs = regs;
+		regs += tile_mmio_size;
+	}
+
+add_mmio_ext:
+	/*
+	 * By design, there's a contiguous multi-tile MMIO space (16MB hard coded per tile).
+	 * When supported, there could be an additional contiguous multi-tile MMIO extension
+	 * space ON TOP of it, and hence the necessity for distinguished MMIO spaces.
+	 */
+	if (xe->info.has_mmio_ext) {
+		regs = xe->mmio.regs + tile_mmio_size * tile_count;
+
+		for_each_tile(tile, xe, id) {
+			tile->mmio_ext.size = tile_mmio_ext_size;
+			tile->mmio_ext.regs = regs;
+
+			regs += tile_mmio_ext_size;
+		}
+	}
+}
+
+static void mmio_fini(struct drm_device *drm, void *arg)
+{
+	struct xe_device *xe = arg;
+
+	pci_iounmap(to_pci_dev(xe->drm.dev), xe->mmio.regs);
+	if (xe->mem.vram.mapping)
+		iounmap(xe->mem.vram.mapping);
+}
+
+static int xe_verify_lmem_ready(struct xe_device *xe)
+{
+	struct xe_gt *gt = xe_root_mmio_gt(xe);
+
+	/*
+	 * The boot firmware initializes local memory and assesses its health.
+	 * If memory training fails, the punit will have been instructed to
+	 * keep the GT powered down; we won't be able to communicate with it
+	 * and we should not continue with driver initialization.
+	 */
+	if (IS_DGFX(xe) && !(xe_mmio_read32(gt, GU_CNTL) & LMEM_INIT)) {
+		drm_err(&xe->drm, "VRAM not initialized by firmware\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+int xe_mmio_init(struct xe_device *xe)
+{
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+	const int mmio_bar = 0;
+
+	/*
+	 * Map the entire BAR.
+	 * The first 16MB of the BAR, belong to the root tile, and include:
+	 * registers (0-4MB), reserved space (4MB-8MB) and GGTT (8MB-16MB).
+	 */
+	xe->mmio.size = pci_resource_len(pdev, mmio_bar);
+	xe->mmio.regs = pci_iomap(pdev, mmio_bar, 0);
+	if (xe->mmio.regs == NULL) {
+		drm_err(&xe->drm, "failed to map registers\n");
+		return -EIO;
+	}
+
+	return drmm_add_action_or_reset(&xe->drm, mmio_fini, xe);
+}
+
+int xe_mmio_root_tile_init(struct xe_device *xe)
+{
+	struct xe_tile *root_tile = xe_device_get_root_tile(xe);
+	int err;
+
+	/* Setup first tile; other tiles (if present) will be setup later. */
+	root_tile->mmio.size = SZ_16M;
+	root_tile->mmio.regs = xe->mmio.regs;
+
+	err = xe_verify_lmem_ready(xe);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+/**
+ * xe_mmio_read64_2x32() - Read a 64-bit register as two 32-bit reads
+ * @gt: MMIO target GT
+ * @reg: register to read value from
+ *
+ * Although Intel GPUs have some 64-bit registers, the hardware officially
+ * only supports GTTMMADR register reads of 32 bits or smaller.  Even if
+ * a readq operation may return a reasonable value, that violation of the
+ * spec shouldn't be relied upon and all 64-bit register reads should be
+ * performed as two 32-bit reads of the upper and lower dwords.
+ *
+ * When reading registers that may be changing (such as
+ * counters), a rollover of the lower dword between the two 32-bit reads
+ * can be problematic.  This function attempts to ensure the upper dword has
+ * stabilized before returning the 64-bit value.
+ *
+ * Note that because this function may re-read the register multiple times
+ * while waiting for the value to stabilize it should not be used to read
+ * any registers where read operations have side effects.
+ *
+ * Returns the value of the 64-bit register.
+ */
+u64 xe_mmio_read64_2x32(struct xe_gt *gt, struct xe_reg reg)
+{
+	struct xe_reg reg_udw = { .addr = reg.addr + 0x4 };
+	u32 ldw, udw, oldudw, retries;
+
+	if (reg.addr < gt->mmio.adj_limit) {
+		reg.addr += gt->mmio.adj_offset;
+		reg_udw.addr += gt->mmio.adj_offset;
+	}
+
+	oldudw = xe_mmio_read32(gt, reg_udw);
+	for (retries = 5; retries; --retries) {
+		ldw = xe_mmio_read32(gt, reg);
+		udw = xe_mmio_read32(gt, reg_udw);
+
+		if (udw == oldudw)
+			break;
+
+		oldudw = udw;
+	}
+
+	xe_gt_WARN(gt, retries == 0,
+		   "64-bit read of %#x did not stabilize\n", reg.addr);
+
+	return (u64)udw << 32 | ldw;
+}
+
+/**
+ * xe_mmio_wait32() - Wait for a register to match the desired masked value
+ * @gt: MMIO target GT
+ * @reg: register to read value from
+ * @mask: mask to be applied to the value read from the register
+ * @val: desired value after applying the mask
+ * @timeout_us: time out after this period of time. Wait logic tries to be
+ * smart, applying an exponential backoff until @timeout_us is reached.
+ * @out_val: if not NULL, points where to store the last unmasked value
+ * @atomic: needs to be true if calling from an atomic context
+ *
+ * This function polls for the desired masked value and returns zero on success
+ * or -ETIMEDOUT if timed out.
+ *
+ * Note that @timeout_us represents the minimum amount of time to wait before
+ * giving up. The actual time taken by this function can be a little more than
+ * @timeout_us for different reasons, specially in non-atomic contexts. Thus,
+ * it is possible that this function succeeds even after @timeout_us has passed.
+ */
+int xe_mmio_wait32(struct xe_gt *gt, struct xe_reg reg, u32 mask, u32 val, u32 timeout_us,
+		   u32 *out_val, bool atomic)
+{
+	ktime_t cur = ktime_get_raw();
+	const ktime_t end = ktime_add_us(cur, timeout_us);
+	int ret = -ETIMEDOUT;
+	s64 wait = 10;
+	u32 read;
+
+	for (;;) {
+		read = xe_mmio_read32(gt, reg);
+		if ((read & mask) == val) {
+			ret = 0;
+			break;
+		}
+
+		cur = ktime_get_raw();
+		if (!ktime_before(cur, end))
+			break;
+
+		if (ktime_after(ktime_add_us(cur, wait), end))
+			wait = ktime_us_delta(end, cur);
+
+		if (atomic)
+			udelay(wait);
+		else
+			usleep_range(wait, wait << 1);
+		wait <<= 1;
+	}
+
+	if (ret != 0) {
+		read = xe_mmio_read32(gt, reg);
+		if ((read & mask) == val)
+			ret = 0;
+	}
+
+	if (out_val)
+		*out_val = read;
+
+	return ret;
+}