1 files changed, 334 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
new file mode 100644
index 0000000000..e5d7d5e2be
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2021-2023 Intel Corporation
+ * Copyright (C) 2021-2002 Red Hat
+ */
+
+#include <drm/drm_managed.h>
+#include <drm/drm_mm.h>
+
+#include <drm/ttm/ttm_device.h>
+#include <drm/ttm/ttm_placement.h>
+#include <drm/ttm/ttm_range_manager.h>
+
+#include "generated/xe_wa_oob.h"
+#include "regs/xe_gt_regs.h"
+#include "regs/xe_regs.h"
+#include "xe_bo.h"
+#include "xe_device.h"
+#include "xe_gt.h"
+#include "xe_mmio.h"
+#include "xe_res_cursor.h"
+#include "xe_ttm_stolen_mgr.h"
+#include "xe_ttm_vram_mgr.h"
+#include "xe_wa.h"
+
+struct xe_ttm_stolen_mgr {
+	struct xe_ttm_vram_mgr base;
+
+	/* PCI base offset */
+	resource_size_t io_base;
+	/* GPU base offset */
+	resource_size_t stolen_base;
+
+	void __iomem *mapping;
+};
+
+static inline struct xe_ttm_stolen_mgr *
+to_stolen_mgr(struct ttm_resource_manager *man)
+{
+	return container_of(man, struct xe_ttm_stolen_mgr, base.manager);
+}
+
+/**
+ * xe_ttm_stolen_cpu_access_needs_ggtt() - If we can't directly CPU access
+ * stolen, can we then fallback to mapping through the GGTT.
+ * @xe: xe device
+ *
+ * Some older integrated platforms don't support reliable CPU access for stolen,
+ * however on such hardware we can always use the mappable part of the GGTT for
+ * CPU access. Check if that's the case for this device.
+ */
+bool xe_ttm_stolen_cpu_access_needs_ggtt(struct xe_device *xe)
+{
+	return GRAPHICS_VERx100(xe) < 1270 && !IS_DGFX(xe);
+}
+
+static s64 detect_bar2_dgfx(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
+{
+	struct xe_tile *tile = xe_device_get_root_tile(xe);
+	struct xe_gt *mmio = xe_root_mmio_gt(xe);
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+	u64 stolen_size;
+	u64 tile_offset;
+	u64 tile_size;
+
+	tile_offset = tile->mem.vram.io_start - xe->mem.vram.io_start;
+	tile_size = tile->mem.vram.actual_physical_size;
+
+	/* Use DSM base address instead for stolen memory */
+	mgr->stolen_base = (xe_mmio_read64_2x32(mmio, DSMBASE) & BDSM_MASK) - tile_offset;
+	if (drm_WARN_ON(&xe->drm, tile_size < mgr->stolen_base))
+		return 0;
+
+	stolen_size = tile_size - mgr->stolen_base;
+
+	/* Verify usage fits in the actual resource available */
+	if (mgr->stolen_base + stolen_size <= pci_resource_len(pdev, LMEM_BAR))
+		mgr->io_base = tile->mem.vram.io_start + mgr->stolen_base;
+
+	/*
+	 * There may be few KB of platform dependent reserved memory at the end
+	 * of vram which is not part of the DSM. Such reserved memory portion is
+	 * always less then DSM granularity so align down the stolen_size to DSM
+	 * granularity to accommodate such reserve vram portion.
+	 */
+	return ALIGN_DOWN(stolen_size, SZ_1M);
+}
+
+static u32 get_wopcm_size(struct xe_device *xe)
+{
+	u32 wopcm_size;
+	u64 val;
+
+	val = xe_mmio_read64_2x32(xe_root_mmio_gt(xe), STOLEN_RESERVED);
+	val = REG_FIELD_GET64(WOPCM_SIZE_MASK, val);
+
+	switch (val) {
+	case 0x5 ... 0x6:
+		val--;
+		fallthrough;
+	case 0x0 ... 0x3:
+		wopcm_size = (1U << val) * SZ_1M;
+		break;
+	default:
+		WARN(1, "Missing case wopcm_size=%llx\n", val);
+		wopcm_size = 0;
+	}
+
+	return wopcm_size;
+}
+
+static u32 detect_bar2_integrated(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
+{
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+	struct xe_gt *media_gt = xe_device_get_root_tile(xe)->media_gt;
+	u32 stolen_size, wopcm_size;
+	u32 ggc, gms;
+
+	ggc = xe_mmio_read32(xe_root_mmio_gt(xe), GGC);
+
+	/*
+	 * Check GGMS: it should be fixed 0x3 (8MB), which corresponds to the
+	 * GTT size
+	 */
+	if (drm_WARN_ON(&xe->drm, (ggc & GGMS_MASK) != GGMS_MASK))
+		return 0;
+
+	/*
+	 * Graphics >= 1270 uses the offset to the GSMBASE as address in the
+	 * PTEs, together with the DM flag being set. Previously there was no
+	 * such flag so the address was the io_base.
+	 *
+	 * DSMBASE = GSMBASE + 8MB
+	 */
+	mgr->stolen_base = SZ_8M;
+	mgr->io_base = pci_resource_start(pdev, 2) + mgr->stolen_base;
+
+	/* return valid GMS value, -EIO if invalid */
+	gms = REG_FIELD_GET(GMS_MASK, ggc);
+	switch (gms) {
+	case 0x0 ... 0x04:
+		stolen_size = gms * 32 * SZ_1M;
+		break;
+	case 0xf0 ... 0xfe:
+		stolen_size = (gms - 0xf0 + 1) * 4 * SZ_1M;
+		break;
+	default:
+		return 0;
+	}
+
+	/* Carve out the top of DSM as it contains the reserved WOPCM region */
+	wopcm_size = get_wopcm_size(xe);
+	if (drm_WARN_ON(&xe->drm, !wopcm_size))
+		return 0;
+
+	stolen_size -= wopcm_size;
+
+	if (media_gt && XE_WA(media_gt, 14019821291)) {
+		u64 gscpsmi_base = xe_mmio_read64_2x32(media_gt, GSCPSMI_BASE)
+			& ~GENMASK_ULL(5, 0);
+
+		/*
+		 * This workaround is primarily implemented by the BIOS.  We
+		 * just need to figure out whether the BIOS has applied the
+		 * workaround (meaning the programmed address falls within
+		 * the DSM) and, if so, reserve that part of the DSM to
+		 * prevent accidental reuse.  The DSM location should be just
+		 * below the WOPCM.
+		 */
+		if (gscpsmi_base >= mgr->io_base &&
+		    gscpsmi_base < mgr->io_base + stolen_size) {
+			xe_gt_dbg(media_gt,
+				  "Reserving %llu bytes of DSM for Wa_14019821291\n",
+				  mgr->io_base + stolen_size - gscpsmi_base);
+			stolen_size = gscpsmi_base - mgr->io_base;
+		}
+	}
+
+	if (drm_WARN_ON(&xe->drm, stolen_size + SZ_8M > pci_resource_len(pdev, 2)))
+		return 0;
+
+	return stolen_size;
+}
+
+extern struct resource intel_graphics_stolen_res;
+
+static u64 detect_stolen(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
+{
+#ifdef CONFIG_X86
+	/* Map into GGTT */
+	mgr->io_base = pci_resource_start(to_pci_dev(xe->drm.dev), 2);
+
+	/* Stolen memory is x86 only */
+	mgr->stolen_base = intel_graphics_stolen_res.start;
+	return resource_size(&intel_graphics_stolen_res);
+#else
+	return 0;
+#endif
+}
+
+void xe_ttm_stolen_mgr_init(struct xe_device *xe)
+{
+	struct xe_ttm_stolen_mgr *mgr = drmm_kzalloc(&xe->drm, sizeof(*mgr), GFP_KERNEL);
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+	u64 stolen_size, io_size, pgsize;
+	int err;
+
+	if (IS_DGFX(xe))
+		stolen_size = detect_bar2_dgfx(xe, mgr);
+	else if (GRAPHICS_VERx100(xe) >= 1270)
+		stolen_size = detect_bar2_integrated(xe, mgr);
+	else
+		stolen_size = detect_stolen(xe, mgr);
+
+	if (!stolen_size) {
+		drm_dbg_kms(&xe->drm, "No stolen memory support\n");
+		return;
+	}
+
+	pgsize = xe->info.vram_flags & XE_VRAM_FLAGS_NEED64K ? SZ_64K : SZ_4K;
+	if (pgsize < PAGE_SIZE)
+		pgsize = PAGE_SIZE;
+
+	/*
+	 * We don't try to attempt partial visible support for stolen vram,
+	 * since stolen is always at the end of vram, and the BAR size is pretty
+	 * much always 256M, with small-bar.
+	 */
+	io_size = 0;
+	if (mgr->io_base && !xe_ttm_stolen_cpu_access_needs_ggtt(xe))
+		io_size = stolen_size;
+
+	err = __xe_ttm_vram_mgr_init(xe, &mgr->base, XE_PL_STOLEN, stolen_size,
+				     io_size, pgsize);
+	if (err) {
+		drm_dbg_kms(&xe->drm, "Stolen mgr init failed: %i\n", err);
+		return;
+	}
+
+	drm_dbg_kms(&xe->drm, "Initialized stolen memory support with %llu bytes\n",
+		    stolen_size);
+
+	if (io_size)
+		mgr->mapping = devm_ioremap_wc(&pdev->dev, mgr->io_base, io_size);
+}
+
+u64 xe_ttm_stolen_io_offset(struct xe_bo *bo, u32 offset)
+{
+	struct xe_device *xe = xe_bo_device(bo);
+	struct ttm_resource_manager *ttm_mgr = ttm_manager_type(&xe->ttm, XE_PL_STOLEN);
+	struct xe_ttm_stolen_mgr *mgr = to_stolen_mgr(ttm_mgr);
+	struct xe_res_cursor cur;
+
+	XE_WARN_ON(!mgr->io_base);
+
+	if (xe_ttm_stolen_cpu_access_needs_ggtt(xe))
+		return mgr->io_base + xe_bo_ggtt_addr(bo) + offset;
+
+	xe_res_first(bo->ttm.resource, offset, 4096, &cur);
+	return mgr->io_base + cur.start;
+}
+
+static int __xe_ttm_stolen_io_mem_reserve_bar2(struct xe_device *xe,
+					       struct xe_ttm_stolen_mgr *mgr,
+					       struct ttm_resource *mem)
+{
+	struct xe_res_cursor cur;
+
+	if (!mgr->io_base)
+		return -EIO;
+
+	xe_res_first(mem, 0, 4096, &cur);
+	mem->bus.offset = cur.start;
+
+	drm_WARN_ON(&xe->drm, !(mem->placement & TTM_PL_FLAG_CONTIGUOUS));
+
+	if (mem->placement & TTM_PL_FLAG_CONTIGUOUS && mgr->mapping)
+		mem->bus.addr = (u8 __force *)mgr->mapping + mem->bus.offset;
+
+	mem->bus.offset += mgr->io_base;
+	mem->bus.is_iomem = true;
+	mem->bus.caching = ttm_write_combined;
+
+	return 0;
+}
+
+static int __xe_ttm_stolen_io_mem_reserve_stolen(struct xe_device *xe,
+						 struct xe_ttm_stolen_mgr *mgr,
+						 struct ttm_resource *mem)
+{
+#ifdef CONFIG_X86
+	struct xe_bo *bo = ttm_to_xe_bo(mem->bo);
+
+	XE_WARN_ON(IS_DGFX(xe));
+
+	/* XXX: Require BO to be mapped to GGTT? */
+	if (drm_WARN_ON(&xe->drm, !(bo->flags & XE_BO_CREATE_GGTT_BIT)))
+		return -EIO;
+
+	/* GGTT is always contiguously mapped */
+	mem->bus.offset = xe_bo_ggtt_addr(bo) + mgr->io_base;
+
+	mem->bus.is_iomem = true;
+	mem->bus.caching = ttm_write_combined;
+
+	return 0;
+#else
+	/* How is it even possible to get here without gen12 stolen? */
+	drm_WARN_ON(&xe->drm, 1);
+	return -EIO;
+#endif
+}
+
+int xe_ttm_stolen_io_mem_reserve(struct xe_device *xe, struct ttm_resource *mem)
+{
+	struct ttm_resource_manager *ttm_mgr = ttm_manager_type(&xe->ttm, XE_PL_STOLEN);
+	struct xe_ttm_stolen_mgr *mgr = ttm_mgr ? to_stolen_mgr(ttm_mgr) : NULL;
+
+	if (!mgr || !mgr->io_base)
+		return -EIO;
+
+	if (xe_ttm_stolen_cpu_access_needs_ggtt(xe))
+		return __xe_ttm_stolen_io_mem_reserve_stolen(xe, mgr, mem);
+	else
+		return __xe_ttm_stolen_io_mem_reserve_bar2(xe, mgr, mem);
+}
+
+u64 xe_ttm_stolen_gpu_offset(struct xe_device *xe)
+{
+	struct xe_ttm_stolen_mgr *mgr =
+		to_stolen_mgr(ttm_manager_type(&xe->ttm, XE_PL_STOLEN));
+
+	return mgr->stolen_base;
+}