drm: Add |struct drm_gem_vram_object| and helpers (85438a8d) · Commits · 戴 / test

Documentation/gpu/drm-mm.rst

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		@@ -380,6 +380,21 @@ GEM CMA Helper Functions Reference
		.. kernel-doc:: drivers/gpu/drm/drm_gem_cma_helper.c
		:export:

		VRAM Helper Function Reference
		==============================

		GEM VRAM Helper Functions Reference
		-----------------------------------

		.. kernel-doc:: drivers/gpu/drm/drm_gem_vram_helper.c
		:doc: overview

		.. kernel-doc:: include/drm/drm_gem_vram_helper.h
		:internal:

		.. kernel-doc:: drivers/gpu/drm/drm_gem_vram_helper.c
		:export:

		VMA Offset Manager
		==================

drivers/gpu/drm/Kconfig

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		@@ -160,6 +160,13 @@ config DRM_TTM
		GPU memory types. Will be enabled automatically if a device driver
		uses it.

		config DRM_VRAM_HELPER
		tristate
		depends on DRM
		select DRM_TTM
		help
		Helpers for VRAM memory management

		config DRM_GEM_CMA_HELPER
		bool
		depends on DRM

drivers/gpu/drm/Makefile

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		@@ -32,6 +32,10 @@ drm-$(CONFIG_AGP) += drm_agpsupport.o
		drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
		drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o

		drm_vram_helper-y := drm_gem_vram_helper.o \
		drm_vram_helper_common.o
		obj-$(CONFIG_DRM_VRAM_HELPER) += drm_vram_helper.o

		drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper.o \
		drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \
		drm_kms_helper_common.o drm_dp_dual_mode_helper.o \

drivers/gpu/drm/drm_gem_vram_helper.c

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		// SPDX-License-Identifier: GPL-2.0-or-later

		#include <drm/drm_gem_vram_helper.h>
		#include <drm/ttm/ttm_page_alloc.h>

		/**
		* DOC: overview
		*
		* This library provides a GEM buffer object that is backed by video RAM
		* (VRAM). It can be used for framebuffer devices with dedicated memory.
		*/

		/*
		* Buffer-objects helpers
		*/

		static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo)
		{
		/* We got here via ttm_bo_put(), which means that the
		* TTM buffer object in 'bo' has already been cleaned
		* up; only release the GEM object.
		*/
		drm_gem_object_release(&gbo->gem);
		}

		static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo)
		{
		drm_gem_vram_cleanup(gbo);
		kfree(gbo);
		}

		static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo)
		{
		struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);

		drm_gem_vram_destroy(gbo);
		}

		static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo,
		unsigned long pl_flag)
		{
		unsigned int i;
		unsigned int c = 0;

		gbo->placement.placement = gbo->placements;
		gbo->placement.busy_placement = gbo->placements;

		if (pl_flag & TTM_PL_FLAG_VRAM)
		gbo->placements[c++].flags = TTM_PL_FLAG_WC \|
		TTM_PL_FLAG_UNCACHED \|
		TTM_PL_FLAG_VRAM;

		if (pl_flag & TTM_PL_FLAG_SYSTEM)
		gbo->placements[c++].flags = TTM_PL_MASK_CACHING \|
		TTM_PL_FLAG_SYSTEM;

		if (!c)
		gbo->placements[c++].flags = TTM_PL_MASK_CACHING \|
		TTM_PL_FLAG_SYSTEM;

		gbo->placement.num_placement = c;
		gbo->placement.num_busy_placement = c;

		for (i = 0; i < c; ++i) {
		gbo->placements[i].fpfn = 0;
		gbo->placements[i].lpfn = 0;
		}
		}

		static int drm_gem_vram_init(struct drm_device *dev,
		struct ttm_bo_device *bdev,
		struct drm_gem_vram_object *gbo,
		size_t size, unsigned long pg_align,
		bool interruptible)
		{
		int ret;
		size_t acc_size;

		ret = drm_gem_object_init(dev, &gbo->gem, size);
		if (ret)
		return ret;

		acc_size = ttm_bo_dma_acc_size(bdev, size, sizeof(*gbo));

		gbo->bo.bdev = bdev;
		drm_gem_vram_placement(gbo, TTM_PL_FLAG_VRAM \| TTM_PL_FLAG_SYSTEM);

		ret = ttm_bo_init(bdev, &gbo->bo, size, ttm_bo_type_device,
		&gbo->placement, pg_align, interruptible, acc_size,
		NULL, NULL, ttm_buffer_object_destroy);
		if (ret)
		goto err_drm_gem_object_release;

		return 0;

		err_drm_gem_object_release:
		drm_gem_object_release(&gbo->gem);
		return ret;
		}

		/**
		* drm_gem_vram_create() - Creates a VRAM-backed GEM object
		* @dev: the DRM device
		* @bdev: the TTM BO device backing the object
		* @size: the buffer size in bytes
		* @pg_align: the buffer's alignment in multiples of the page size
		* @interruptible: sleep interruptible if waiting for memory
		*
		* Returns:
		* A new instance of &struct drm_gem_vram_object on success, or
		* an ERR_PTR()-encoded error code otherwise.
		*/
		struct drm_gem_vram_object drm_gem_vram_create(struct drm_device dev,
		struct ttm_bo_device *bdev,
		size_t size,
		unsigned long pg_align,
		bool interruptible)
		{
		struct drm_gem_vram_object *gbo;
		int ret;

		gbo = kzalloc(sizeof(*gbo), GFP_KERNEL);
		if (!gbo)
		return ERR_PTR(-ENOMEM);

		ret = drm_gem_vram_init(dev, bdev, gbo, size, pg_align, interruptible);
		if (ret < 0)
		goto err_kfree;

		return gbo;

		err_kfree:
		kfree(gbo);
		return ERR_PTR(ret);
		}
		EXPORT_SYMBOL(drm_gem_vram_create);

		/**
		* drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object
		* @gbo: the GEM VRAM object
		*
		* See ttm_bo_put() for more information.
		*/
		void drm_gem_vram_put(struct drm_gem_vram_object *gbo)
		{
		ttm_bo_put(&gbo->bo);
		}
		EXPORT_SYMBOL(drm_gem_vram_put);

		/**
		* drm_gem_vram_reserve() - Reserves a VRAM-backed GEM object
		* @gbo: the GEM VRAM object
		* @no_wait: don't wait for buffer object to become available
		*
		* See ttm_bo_reserve() for more information.
		*
		* Returns:
		* 0 on success, or
		* a negative error code otherwise
		*/
		int drm_gem_vram_reserve(struct drm_gem_vram_object *gbo, bool no_wait)
		{
		return ttm_bo_reserve(&gbo->bo, true, no_wait, NULL);
		}
		EXPORT_SYMBOL(drm_gem_vram_reserve);

		/**
		* drm_gem_vram_unreserve() - \
		Release a reservation acquired by drm_gem_vram_reserve()
		* @gbo: the GEM VRAM object
		*
		* See ttm_bo_unreserve() for more information.
		*/
		void drm_gem_vram_unreserve(struct drm_gem_vram_object *gbo)
		{
		ttm_bo_unreserve(&gbo->bo);
		}
		EXPORT_SYMBOL(drm_gem_vram_unreserve);

		/**
		* drm_gem_vram_mmap_offset() - Returns a GEM VRAM object's mmap offset
		* @gbo: the GEM VRAM object
		*
		* See drm_vma_node_offset_addr() for more information.
		*
		* Returns:
		* The buffer object's offset for userspace mappings on success, or
		* 0 if no offset is allocated.
		*/
		u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo)
		{
		return drm_vma_node_offset_addr(&gbo->bo.vma_node);
		}
		EXPORT_SYMBOL(drm_gem_vram_mmap_offset);

		/**
		* drm_gem_vram_offset() - \
		Returns a GEM VRAM object's offset in video memory
		* @gbo: the GEM VRAM object
		*
		* This function returns the buffer object's offset in the device's video
		* memory. The buffer object has to be pinned to %TTM_PL_VRAM.
		*
		* Returns:
		* The buffer object's offset in video memory on success, or
		* a negative errno code otherwise.
		*/
		s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo)
		{
		if (WARN_ON_ONCE(!gbo->pin_count))
		return (s64)-ENODEV;
		return gbo->bo.offset;
		}
		EXPORT_SYMBOL(drm_gem_vram_offset);

		/**
		* drm_gem_vram_pin() - Pins a GEM VRAM object in a region.
		* @gbo: the GEM VRAM object
		* @pl_flag: a bitmask of possible memory regions
		*
		* Pinning a buffer object ensures that it is not evicted from
		* a memory region. A pinned buffer object has to be unpinned before
		* it can be pinned to another region.
		*
		* Returns:
		* 0 on success, or
		* a negative error code otherwise.
		*/
		int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag)
		{
		int i, ret;
		struct ttm_operation_ctx ctx = { false, false };

		if (gbo->pin_count) {
		++gbo->pin_count;
		return 0;
		}

		drm_gem_vram_placement(gbo, pl_flag);
		for (i = 0; i < gbo->placement.num_placement; ++i)
		gbo->placements[i].flags \|= TTM_PL_FLAG_NO_EVICT;

		ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
		if (ret < 0)
		return ret;

		gbo->pin_count = 1;

		return 0;
		}
		EXPORT_SYMBOL(drm_gem_vram_pin);

		/**
		* drm_gem_vram_unpin() - Unpins a GEM VRAM object
		* @gbo: the GEM VRAM object
		*
		* Returns:
		* 0 on success, or
		* a negative error code otherwise.
		*/
		int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
		{
		int i, ret;
		struct ttm_operation_ctx ctx = { false, false };

		if (WARN_ON_ONCE(!gbo->pin_count))
		return 0;

		--gbo->pin_count;
		if (gbo->pin_count)
		return 0;

		for (i = 0; i < gbo->placement.num_placement ; ++i)
		gbo->placements[i].flags &= ~TTM_PL_FLAG_NO_EVICT;

		ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
		if (ret < 0)
		return ret;

		return 0;
		}
		EXPORT_SYMBOL(drm_gem_vram_unpin);

		/**
		* drm_gem_vram_push_to_system() - \
		Unpins a GEM VRAM object and moves it to system memory
		* @gbo: the GEM VRAM object
		*
		* This operation only works if the caller holds the final pin on the
		* buffer object.
		*
		* Returns:
		* 0 on success, or
		* a negative error code otherwise.
		*/
		int drm_gem_vram_push_to_system(struct drm_gem_vram_object *gbo)
		{
		int i, ret;
		struct ttm_operation_ctx ctx = { false, false };

		if (WARN_ON_ONCE(!gbo->pin_count))
		return 0;

		--gbo->pin_count;
		if (gbo->pin_count)
		return 0;

		if (gbo->kmap.virtual)
		ttm_bo_kunmap(&gbo->kmap);

		drm_gem_vram_placement(gbo, TTM_PL_FLAG_SYSTEM);
		for (i = 0; i < gbo->placement.num_placement ; ++i)
		gbo->placements[i].flags \|= TTM_PL_FLAG_NO_EVICT;

		ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
		if (ret)
		return ret;

		return 0;
		}
		EXPORT_SYMBOL(drm_gem_vram_push_to_system);

		/**
		* drm_gem_vram_kmap_at() - Maps a GEM VRAM object into kernel address space
		* @gbo: the GEM VRAM object
		* @map: establish a mapping if necessary
		* @is_iomem: returns true if the mapped memory is I/O memory, or false \
		otherwise; can be NULL
		* @kmap: the mapping's kmap object
		*
		* This function maps the buffer object into the kernel's address space
		* or returns the current mapping. If the parameter map is false, the
		* function only queries the current mapping, but does not establish a
		* new one.
		*
		* Returns:
		* The buffers virtual address if mapped, or
		* NULL if not mapped, or
		* an ERR_PTR()-encoded error code otherwise.
		*/
		void drm_gem_vram_kmap_at(struct drm_gem_vram_object gbo, bool map,
		bool is_iomem, struct ttm_bo_kmap_obj kmap)
		{
		int ret;

		if (kmap->virtual \|\| !map)
		goto out;

		ret = ttm_bo_kmap(&gbo->bo, 0, gbo->bo.num_pages, kmap);
		if (ret)
		return ERR_PTR(ret);

		out:
		if (!is_iomem)
		return kmap->virtual;
		if (!kmap->virtual) {
		*is_iomem = false;
		return NULL;
		}
		return ttm_kmap_obj_virtual(kmap, is_iomem);
		}
		EXPORT_SYMBOL(drm_gem_vram_kmap_at);

		/**
		* drm_gem_vram_kmap() - Maps a GEM VRAM object into kernel address space
		* @gbo: the GEM VRAM object
		* @map: establish a mapping if necessary
		* @is_iomem: returns true if the mapped memory is I/O memory, or false \
		otherwise; can be NULL
		*
		* This function maps the buffer object into the kernel's address space
		* or returns the current mapping. If the parameter map is false, the
		* function only queries the current mapping, but does not establish a
		* new one.
		*
		* Returns:
		* The buffers virtual address if mapped, or
		* NULL if not mapped, or
		* an ERR_PTR()-encoded error code otherwise.
		*/
		void drm_gem_vram_kmap(struct drm_gem_vram_object gbo, bool map,
		bool *is_iomem)
		{
		return drm_gem_vram_kmap_at(gbo, map, is_iomem, &gbo->kmap);
		}
		EXPORT_SYMBOL(drm_gem_vram_kmap);

		/**
		* drm_gem_vram_kunmap_at() - Unmaps a GEM VRAM object
		* @gbo: the GEM VRAM object
		* @kmap: the mapping's kmap object
		*/
		void drm_gem_vram_kunmap_at(struct drm_gem_vram_object *gbo,
		struct ttm_bo_kmap_obj *kmap)
		{
		if (!kmap->virtual)
		return;

		ttm_bo_kunmap(kmap);
		kmap->virtual = NULL;
		}
		EXPORT_SYMBOL(drm_gem_vram_kunmap_at);

		/**
		* drm_gem_vram_kunmap() - Unmaps a GEM VRAM object
		* @gbo: the GEM VRAM object
		*/
		void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo)
		{
		drm_gem_vram_kunmap_at(gbo, &gbo->kmap);
		}
		EXPORT_SYMBOL(drm_gem_vram_kunmap);

drivers/gpu/drm/drm_vram_helper_common.c

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		// SPDX-License-Identifier: GPL-2.0-or-later

		#include <linux/module.h>

		MODULE_DESCRIPTION("DRM VRAM memory-management helpers");
		MODULE_LICENSE("GPL");

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