drivers/gpu/drm/i915/gt/intel_region_lmem.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/i915/gt/intel_region_lmem.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/i915/gt/intel_region_lmem.c
Extension
.c
Size
7052 bytes
Lines
277
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

static void i915_resize_lmem_bar(struct drm_i915_private *i915, resource_size_t lmem_size) {}
#endif

static int
region_lmem_release(struct intel_memory_region *mem)
{
	int ret;

	ret = intel_region_ttm_fini(mem);
	io_mapping_fini(&mem->iomap);

	return ret;
}

static int
region_lmem_init(struct intel_memory_region *mem)
{
	int ret;

	if (!io_mapping_init_wc(&mem->iomap,
				mem->io.start,
				resource_size(&mem->io)))
		return -EIO;

	ret = intel_region_ttm_init(mem);
	if (ret)
		goto out_no_buddy;

	return 0;

out_no_buddy:
	io_mapping_fini(&mem->iomap);

	return ret;
}

static const struct intel_memory_region_ops intel_region_lmem_ops = {
	.init = region_lmem_init,
	.release = region_lmem_release,
	.init_object = __i915_gem_ttm_object_init,
};

static bool get_legacy_lowmem_region(struct intel_uncore *uncore,
				     u64 *start, u32 *size)
{
	if (!IS_DG1(uncore->i915))
		return false;

	*start = 0;
	*size = SZ_1M;

	drm_dbg(&uncore->i915->drm, "LMEM: reserved legacy low-memory [0x%llx-0x%llx]\n",
		*start, *start + *size);

	return true;
}

static int reserve_lowmem_region(struct intel_uncore *uncore,
				 struct intel_memory_region *mem)
{
	u64 reserve_start;
	u32 reserve_size;
	int ret;

	if (!get_legacy_lowmem_region(uncore, &reserve_start, &reserve_size))
		return 0;

	ret = intel_memory_region_reserve(mem, reserve_start, reserve_size);
	if (ret)
		drm_err(&uncore->i915->drm, "LMEM: reserving low memory region failed\n");

	return ret;
}

static struct intel_memory_region *setup_lmem(struct intel_gt *gt)
{
	struct drm_i915_private *i915 = gt->i915;
	struct intel_uncore *uncore = gt->uncore;
	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
	struct intel_memory_region *mem;
	resource_size_t min_page_size;
	resource_size_t io_start;
	resource_size_t io_size;
	resource_size_t lmem_size;
	int err;

	if (!IS_DGFX(i915))
		return ERR_PTR(-ENODEV);

	if (!i915_pci_resource_valid(pdev, GEN12_LMEM_BAR))

Annotation

Implementation Notes