[PATCH i-g-t v5 6/7] lib/amdgpu: add amdgpu support to igt_dmem_driver

This allows dmem cgroups tests to run on top of amdgpu driver, adding
support to allocate and release VRAM memory.

This does this by allocating a BO from VRAM domain, which will try to
place BOs on VRAM, but may fallback to GTT.

Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
---
 lib/amdgpu/amd_dmem.c | 99 +++++++++++++++++++++++++++++++++++++++++++
 lib/igt_dmem_driver.h |  1 +
 lib/meson.build       |  1 +
 3 files changed, 101 insertions(+)
 create mode 100644 lib/amdgpu/amd_dmem.c

diff --git a/lib/amdgpu/amd_dmem.c b/lib/amdgpu/amd_dmem.c
new file mode 100644
index 000000000000..5ff6437dc78a
--- /dev/null
+++ b/lib/amdgpu/amd_dmem.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright 2026 Valve Corporation
+ * Authors:
+ *  Thadeu Lima de Souza Cascardo <[email protected]>
+ */
+
+#include <errno.h>
+
+#include "igt.h"
+#include "igt_cgroup.h"
+#include "igt_dmem_driver.h"
+#include "lib/amdgpu/amd_memory.h"
+
+struct amdgpu_dmem_ctx {
+	int fd;
+	amdgpu_device_handle device;
+	amdgpu_bo_handle *handles;
+	int max_bo;
+};
+
+static int amdgpu_dmem_init(void **ctx, int fd, int max_bo)
+{
+	struct amdgpu_dmem_ctx *actx;
+	uint32_t major, minor;
+	int err = -ENOMEM;
+
+	actx = malloc(sizeof(*actx));
+	if (!actx)
+		return -ENOMEM;
+
+	actx->handles = calloc(max_bo, sizeof(actx->handles[0]));
+	if (!actx->handles)
+		goto out;
+
+	actx->max_bo = max_bo;
+
+	err = amdgpu_device_initialize(fd, &major, &minor, &actx->device);
+	if (err)
+		goto out;
+
+	*ctx = actx;
+
+	return 0;
+
+out:
+	if (actx->handles)
+		free(actx->handles);
+	free(actx);
+
+	return err;
+}
+
+static void amdgpu_dmem_deinit(void *ctx)
+{
+	struct amdgpu_dmem_ctx *actx = ctx;
+
+	amdgpu_device_deinitialize(actx->device);
+	free(actx->handles);
+	free(actx);
+}
+
+static int amdgpu_dmem_allocate_vram(void *ctx, int n_bo, size_t len)
+{
+	struct amdgpu_dmem_ctx *actx = ctx;
+	amdgpu_bo_handle handle;
+	int err;
+
+	if (n_bo >= actx->max_bo)
+		return -ENOMEM;
+
+	err = amdgpu_bo_alloc_wrap(actx->device, len, 4096,
+				   AMDGPU_GEM_DOMAIN_VRAM, 0, &handle);
+	if (err)
+		return err;
+
+	actx->handles[n_bo] = handle;
+
+	return 0;
+}
+
+static void amdgpu_dmem_free_vram(void *ctx, int n_bo)
+{
+	struct amdgpu_dmem_ctx *actx = ctx;
+	if (n_bo >= actx->max_bo)
+		return;
+	if (actx->handles[n_bo])
+		amdgpu_bo_free(actx->handles[n_bo]);
+	actx->handles[n_bo] = 0;
+}
+
+const struct igt_dmem_driver amdgpu_dmem_driver = {
+	.name = "amdgpu",
+	.get_region_name = amdgpu_cgroup_region_name,
+	.init = amdgpu_dmem_init,
+	.deinit = amdgpu_dmem_deinit,
+	.allocate_vram = amdgpu_dmem_allocate_vram,
+	.free_vram = amdgpu_dmem_free_vram,
+};
diff --git a/lib/igt_dmem_driver.h b/lib/igt_dmem_driver.h
index 2f4a4673ab16..d34c839740a5 100644
--- a/lib/igt_dmem_driver.h
+++ b/lib/igt_dmem_driver.h
@@ -20,5 +20,6 @@ struct igt_dmem_driver {
 };
 
 extern const struct igt_dmem_driver xe_dmem_driver;
+extern const struct igt_dmem_driver amdgpu_dmem_driver;
 
 #endif
diff --git a/lib/meson.build b/lib/meson.build
index 012802475de0..27177f385ae6 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -199,6 +199,7 @@ if libdrm_amdgpu.found()
 		'amdgpu/amd_mmd_shared.c',
 		'amdgpu/amd_jpeg_shared.c',
 		'amdgpu/amd_utils.c',
+		'amdgpu/amd_dmem.c',
 		'amdgpu/amd_vcn_shared.c'
 	]
 	if libdrm_amdgpu.version().version_compare('> 2.4.99')
-- 
2.47.3