1 files changed, 294 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_psmi.c b/drivers/gpu/drm/xe/xe_psmi.c
new file mode 100644
index 000000000000..45d142191d60
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_psmi.c
@@ -0,0 +1,294 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#include <linux/debugfs.h>
+
+#include "xe_bo.h"
+#include "xe_device.h"
+#include "xe_configfs.h"
+#include "xe_psmi.h"
+
+/*
+ * PSMI capture support
+ *
+ * Requirement for PSMI capture is to have a physically contiguous buffer.  The
+ * PSMI tool owns doing all necessary configuration (MMIO register writes are
+ * done from user-space). However, KMD needs to provide the PSMI tool with the
+ * required physical address of the base of PSMI buffer in case of VRAM.
+ *
+ * VRAM backed PSMI buffer:
+ * Buffer is allocated as GEM object and with XE_BO_CREATE_PINNED_BIT flag which
+ * creates a contiguous allocation. The physical address is returned from
+ * psmi_debugfs_capture_addr_show(). PSMI tool can mmap the buffer via the
+ * PCIBAR through sysfs.
+ *
+ * SYSTEM memory backed PSMI buffer:
+ * Interface here does not support allocating from SYSTEM memory region.  The
+ * PSMI tool needs to allocate memory themselves using hugetlbfs. In order to
+ * get the physical address, user-space can query /proc/[pid]/pagemap. As an
+ * alternative, CMA debugfs could also be used to allocate reserved CMA memory.
+ */
+
+static bool psmi_enabled(struct xe_device *xe)
+{
+	return xe_configfs_get_psmi_enabled(to_pci_dev(xe->drm.dev));
+}
+
+static void psmi_free_object(struct xe_bo *bo)
+{
+	xe_bo_lock(bo, NULL);
+	xe_bo_unpin(bo);
+	xe_bo_unlock(bo);
+	xe_bo_put(bo);
+}
+
+/*
+ * Free PSMI capture buffer objects.
+ */
+static void psmi_cleanup(struct xe_device *xe)
+{
+	unsigned long id, region_mask = xe->psmi.region_mask;
+	struct xe_bo *bo;
+
+	for_each_set_bit(id, &region_mask,
+			 ARRAY_SIZE(xe->psmi.capture_obj)) {
+		/* smem should never be set */
+		xe_assert(xe, id);
+
+		bo = xe->psmi.capture_obj[id];
+		if (bo) {
+			psmi_free_object(bo);
+			xe->psmi.capture_obj[id] = NULL;
+		}
+	}
+}
+
+static struct xe_bo *psmi_alloc_object(struct xe_device *xe,
+				       unsigned int id, size_t bo_size)
+{
+	struct xe_tile *tile;
+
+	if (!id || !bo_size)
+		return NULL;
+
+	tile = &xe->tiles[id - 1];
+
+	/* VRAM: Allocate GEM object for the capture buffer */
+	return xe_bo_create_pin_range_novm(xe, tile, bo_size, 0, ~0ull,
+					   ttm_bo_type_kernel,
+					   XE_BO_FLAG_VRAM_IF_DGFX(tile) |
+					   XE_BO_FLAG_PINNED |
+					   XE_BO_FLAG_PINNED_LATE_RESTORE |
+					   XE_BO_FLAG_NEEDS_CPU_ACCESS);
+}
+
+/*
+ * Allocate PSMI capture buffer objects (via debugfs set function), based on
+ * which regions the user has selected in region_mask.  @size: size in bytes
+ * (should be power of 2)
+ *
+ * Always release/free the current buffer objects before attempting to allocate
+ * new ones.  Size == 0 will free all current buffers.
+ *
+ * Note, we don't write any registers as the capture tool is already configuring
+ * all PSMI registers itself via mmio space.
+ */
+static int psmi_resize_object(struct xe_device *xe, size_t size)
+{
+	unsigned long id, region_mask = xe->psmi.region_mask;
+	struct xe_bo *bo = NULL;
+	int err = 0;
+
+	/* if resizing, free currently allocated buffers first */
+	psmi_cleanup(xe);
+
+	/* can set size to 0, in which case, now done */
+	if (!size)
+		return 0;
+
+	for_each_set_bit(id, &region_mask,
+			 ARRAY_SIZE(xe->psmi.capture_obj)) {
+		/* smem should never be set */
+		xe_assert(xe, id);
+
+		bo = psmi_alloc_object(xe, id, size);
+		if (IS_ERR(bo)) {
+			err = PTR_ERR(bo);
+			break;
+		}
+		xe->psmi.capture_obj[id] = bo;
+
+		drm_info(&xe->drm,
+			 "PSMI capture size requested: %zu bytes, allocated: %lu:%zu\n",
+			 size, id, bo ? xe_bo_size(bo) : 0);
+	}
+
+	/* on error, reverse what was allocated */
+	if (err)
+		psmi_cleanup(xe);
+
+	return err;
+}
+
+/*
+ * Returns an address for the capture tool to use to find start of capture
+ * buffer. Capture tool requires the capability to have a buffer allocated per
+ * each tile (VRAM region), thus we return an address for each region.
+ */
+static int psmi_debugfs_capture_addr_show(struct seq_file *m, void *data)
+{
+	struct xe_device *xe = m->private;
+	unsigned long id, region_mask;
+	struct xe_bo *bo;
+	u64 val;
+
+	region_mask = xe->psmi.region_mask;
+	for_each_set_bit(id, &region_mask,
+			 ARRAY_SIZE(xe->psmi.capture_obj)) {
+		/* smem should never be set */
+		xe_assert(xe, id);
+
+		/* VRAM region */
+		bo = xe->psmi.capture_obj[id];
+		if (!bo)
+			continue;
+
+		/* pinned, so don't need bo_lock */
+		val = __xe_bo_addr(bo, 0, PAGE_SIZE);
+		seq_printf(m, "%ld: 0x%llx\n", id, val);
+	}
+
+	return 0;
+}
+
+/*
+ * Return capture buffer size, using the size from first allocated object that
+ * is found. This works because all objects must be of the same size.
+ */
+static int psmi_debugfs_capture_size_get(void *data, u64 *val)
+{
+	unsigned long id, region_mask;
+	struct xe_device *xe = data;
+	struct xe_bo *bo;
+
+	region_mask = xe->psmi.region_mask;
+	for_each_set_bit(id, &region_mask,
+			 ARRAY_SIZE(xe->psmi.capture_obj)) {
+		/* smem should never be set */
+		xe_assert(xe, id);
+
+		bo = xe->psmi.capture_obj[id];
+		if (bo) {
+			*val = xe_bo_size(bo);
+			return 0;
+		}
+	}
+
+	/* no capture objects are allocated */
+	*val = 0;
+
+	return 0;
+}
+
+/*
+ * Set size of PSMI capture buffer. This triggers the allocation of capture
+ * buffer in each memory region as specified with prior write to
+ * psmi_capture_region_mask.
+ */
+static int psmi_debugfs_capture_size_set(void *data, u64 val)
+{
+	struct xe_device *xe = data;
+
+	/* user must have specified at least one region */
+	if (!xe->psmi.region_mask)
+		return -EINVAL;
+
+	return psmi_resize_object(xe, val);
+}
+
+static int psmi_debugfs_capture_region_mask_get(void *data, u64 *val)
+{
+	struct xe_device *xe = data;
+
+	*val = xe->psmi.region_mask;
+
+	return 0;
+}
+
+/*
+ * Select VRAM regions for multi-tile devices, only allowed when buffer is not
+ * currently allocated.
+ */
+static int psmi_debugfs_capture_region_mask_set(void *data, u64 region_mask)
+{
+	struct xe_device *xe = data;
+	u64 size = 0;
+
+	/* SMEM is not supported (see comments at top of file) */
+	if (region_mask & 0x1)
+		return -EOPNOTSUPP;
+
+	/* input bitmask should contain only valid TTM regions */
+	if (!region_mask || region_mask & ~xe->info.mem_region_mask)
+		return -EINVAL;
+
+	/* only allow setting mask if buffer is not yet allocated */
+	psmi_debugfs_capture_size_get(xe, &size);
+	if (size)
+		return -EBUSY;
+
+	xe->psmi.region_mask = region_mask;
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(psmi_debugfs_capture_addr);
+
+DEFINE_DEBUGFS_ATTRIBUTE(psmi_debugfs_capture_region_mask_fops,
+			 psmi_debugfs_capture_region_mask_get,
+			 psmi_debugfs_capture_region_mask_set,
+			 "0x%llx\n");
+
+DEFINE_DEBUGFS_ATTRIBUTE(psmi_debugfs_capture_size_fops,
+			 psmi_debugfs_capture_size_get,
+			 psmi_debugfs_capture_size_set,
+			 "%lld\n");
+
+void xe_psmi_debugfs_register(struct xe_device *xe)
+{
+	struct drm_minor *minor;
+
+	if (!psmi_enabled(xe))
+		return;
+
+	minor = xe->drm.primary;
+	if (!minor->debugfs_root)
+		return;
+
+	debugfs_create_file("psmi_capture_addr",
+			    0400, minor->debugfs_root, xe,
+			    &psmi_debugfs_capture_addr_fops);
+
+	debugfs_create_file("psmi_capture_region_mask",
+			    0600, minor->debugfs_root, xe,
+			    &psmi_debugfs_capture_region_mask_fops);
+
+	debugfs_create_file("psmi_capture_size",
+			    0600, minor->debugfs_root, xe,
+			    &psmi_debugfs_capture_size_fops);
+}
+
+static void psmi_fini(void *arg)
+{
+	psmi_cleanup(arg);
+}
+
+int xe_psmi_init(struct xe_device *xe)
+{
+	if (!psmi_enabled(xe))
+		return 0;
+
+	return devm_add_action(xe->drm.dev, psmi_fini, xe);
+}