This adds a library for shmem backed GEM objects with the necessary drm_driver callbacks. Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx> --- Changes since version 1: - Fix missing argument in docs (kbuild test robot) - Fix: sparse: expression using sizeof(void) (kbuild test robot) - Rebasing gave a new checkpatch warning, so I changed to bitfields: CHECK: Avoid using bool structure members because of possible alignment issues - see: https://lkml.org/lkml/2017/11/21/384 #834: FILE: include/drm/drm_gem_shmem_helper.h:84: + bool pages_mark_dirty_on_put; #841: FILE: include/drm/drm_gem_shmem_helper.h:91: + bool pages_mark_accessed_on_put; Documentation/gpu/drm-kms-helpers.rst | 12 + drivers/gpu/drm/Kconfig | 6 + drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/drm_gem_shmem_helper.c | 676 +++++++++++++++++++++++++++++++++ include/drm/drm_gem_shmem_helper.h | 198 ++++++++++ 5 files changed, 893 insertions(+) create mode 100644 drivers/gpu/drm/drm_gem_shmem_helper.c create mode 100644 include/drm/drm_gem_shmem_helper.h diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst index f9cfcdcdf024..bc24b1b5216a 100644 --- a/Documentation/gpu/drm-kms-helpers.rst +++ b/Documentation/gpu/drm-kms-helpers.rst @@ -326,3 +326,15 @@ Legacy CRTC/Modeset Helper Functions Reference .. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c :export: + +SHMEM GEM Helper Reference +========================== + +.. kernel-doc:: drivers/gpu/drm/drm_gem_shmem_helper.c + :doc: overview + +.. kernel-doc:: include/drm/drm_gem_shmem_helper.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_gem_shmem_helper.c + :export: diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index cb88528e7b10..db588ae44bcc 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -157,6 +157,12 @@ config DRM_KMS_CMA_HELPER help Choose this if you need the KMS CMA helper functions +config DRM_GEM_SHMEM_HELPER + bool + depends on DRM + help + Choose this if you need the GEM shmem helper functions + config DRM_VM bool depends on DRM && MMU diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index a6771cef85e2..c6798590799f 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -24,6 +24,7 @@ drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o drm-$(CONFIG_DRM_VM) += drm_vm.o drm-$(CONFIG_COMPAT) += drm_ioc32.o drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o +drm-$(CONFIG_DRM_GEM_SHMEM_HELPER) += drm_gem_shmem_helper.o drm-$(CONFIG_PCI) += ati_pcigart.o drm-$(CONFIG_DRM_PANEL) += drm_panel.o drm-$(CONFIG_OF) += drm_of.o diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c new file mode 100644 index 000000000000..53181bb0e1cf --- /dev/null +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -0,0 +1,676 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2018 Noralf Trønnes + */ + +#include <linux/dma-buf.h> +#include <linux/export.h> +#include <linux/mutex.h> +#include <linux/shmem_fs.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> + +#include <drm/drm_device.h> +#include <drm/drm_drv.h> +#include <drm/drm_gem_shmem_helper.h> +#include <drm/drm_prime.h> +#include <drm/drm_print.h> + +/** + * DOC: overview + * + * This library provides helpers for GEM objects backed by shmem buffers + * allocated using anonymous pageable memory. + */ + +/** + * drm_gem_shmem_create - Allocate an object with the given size + * @dev: DRM device + * @size: Size of the object to allocate + * + * This function creates a shmem GEM object. The default cache mode is + * DRM_GEM_SHMEM_BO_CACHED. The &drm_driver->gem_create_object callback can be + * used override this. + * + * Returns: + * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative + * error code on failure. + */ +struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size) +{ + struct drm_gem_shmem_object *shmem; + struct drm_gem_object *obj; + int ret; + + size = PAGE_ALIGN(size); + + if (dev->driver->gem_create_object) + obj = dev->driver->gem_create_object(dev, size); + else + obj = kzalloc(sizeof(*shmem), GFP_KERNEL); + if (!obj) + return ERR_PTR(-ENOMEM); + + shmem = to_drm_gem_shmem_obj(obj); + + if (!dev->driver->gem_create_object) + shmem->cache_mode = DRM_GEM_SHMEM_BO_CACHED; + + ret = drm_gem_object_init(dev, obj, size); + if (ret) + goto err_free; + + ret = drm_gem_create_mmap_offset(obj); + if (ret) + goto err_release; + + mutex_init(&shmem->pages_lock); + mutex_init(&shmem->vmap_lock); + + return shmem; + +err_release: + drm_gem_object_release(obj); +err_free: + kfree(shmem); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_create); + +/** + * drm_gem_shmem_free_object - Free resources associated with a shmem GEM object + * @obj: GEM object to free + * + * This function cleans up the GEM object state and frees the memory used to + * store the object itself. Drivers using the shmem helpers should set this as + * their &drm_driver.gem_free_object_unlocked callback. + */ +void drm_gem_shmem_free_object(struct drm_gem_object *obj) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + WARN_ON(shmem->vmap_use_count); + + if (obj->import_attach) { + shmem->pages_use_count--; + drm_prime_gem_destroy(obj, shmem->sgt); + kvfree(shmem->pages); + } + + WARN_ON(shmem->pages_use_count); + + drm_gem_object_release(obj); + mutex_destroy(&shmem->pages_lock); + mutex_destroy(&shmem->vmap_lock); + kfree(shmem); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_free_object); + +static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem) +{ + struct drm_gem_object *obj = &shmem->base; + struct page **pages; + + if (shmem->pages_use_count++ > 0) + return 0; + + pages = drm_gem_get_pages(obj); + if (IS_ERR(pages)) { + DRM_DEBUG_KMS("Failed to get pages (%ld)\n", PTR_ERR(pages)); + shmem->pages_use_count = 0; + return PTR_ERR(pages); + } + + shmem->pages = pages; + + return 0; +} + +/* + * drm_gem_shmem_get_pages - Allocate backing pages for a shmem GEM object + * @shmem: shmem GEM object + * + * This function makes sure that backing pages exists for the shmem GEM object + * and increases the use count. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) +{ + int ret; + + ret = mutex_lock_interruptible(&shmem->pages_lock); + if (ret) + return ret; + ret = drm_gem_shmem_get_pages_locked(shmem); + mutex_unlock(&shmem->pages_lock); + + return ret; +} +EXPORT_SYMBOL(drm_gem_shmem_get_pages); + +static void drm_gem_shmem_put_pages_unlocked(struct drm_gem_shmem_object *shmem) +{ + struct drm_gem_object *obj = &shmem->base; + + if (WARN_ON_ONCE(!shmem->pages_use_count)) + return; + + if (--shmem->pages_use_count > 0) + return; + + drm_gem_put_pages(obj, shmem->pages, + shmem->pages_mark_dirty_on_put, + shmem->pages_mark_accessed_on_put); + shmem->pages = NULL; +} + +/* + * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object + * @shmem: shmem GEM object + * + * This function decreases the use count and puts the backing pages when use drops to zero. + */ +void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem) +{ + mutex_lock(&shmem->pages_lock); + drm_gem_shmem_put_pages_unlocked(shmem); + mutex_unlock(&shmem->pages_lock); +} +EXPORT_SYMBOL(drm_gem_shmem_put_pages); + +static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem) +{ + struct drm_gem_object *obj = &shmem->base; + int ret; + + if (shmem->vmap_use_count++ > 0) + return 0; + + ret = drm_gem_shmem_get_pages(shmem); + if (ret) + goto err_zero_use; + + if (obj->import_attach) { + shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf); + } else { + pgprot_t prot; + + switch (shmem->cache_mode) { + case DRM_GEM_SHMEM_BO_UNKNOWN: + ret = -EINVAL; + goto err_put_pages; + + case DRM_GEM_SHMEM_BO_WRITECOMBINED: + prot = pgprot_writecombine(PAGE_KERNEL); + break; + + case DRM_GEM_SHMEM_BO_UNCACHED: + prot = pgprot_noncached(PAGE_KERNEL); + break; + + case DRM_GEM_SHMEM_BO_CACHED: + prot = PAGE_KERNEL; + break; + } + + shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, VM_MAP, prot); + } + + if (!shmem->vaddr) { + DRM_DEBUG_KMS("Failed to vmap pages\n"); + ret = -ENOMEM; + goto err_put_pages; + } + + return 0; + +err_put_pages: + drm_gem_shmem_put_pages(shmem); +err_zero_use: + shmem->vmap_use_count = 0; + + return ret; +} + +/* + * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object + * @shmem: shmem GEM object + * + * This function makes sure that a virtual address exists for the buffer backing + * the shmem GEM object. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem) +{ + int ret; + + ret = mutex_lock_interruptible(&shmem->vmap_lock); + if (ret) + return ret; + ret = drm_gem_shmem_vmap_locked(shmem); + mutex_unlock(&shmem->vmap_lock); + + return ret; +} +EXPORT_SYMBOL(drm_gem_shmem_vmap); + +static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem) +{ + struct drm_gem_object *obj = &shmem->base; + + if (WARN_ON_ONCE(!shmem->vmap_use_count)) + return; + + if (--shmem->vmap_use_count > 0) + return; + + if (obj->import_attach) + dma_buf_vunmap(obj->import_attach->dmabuf, shmem->vaddr); + else + vunmap(shmem->vaddr); + + shmem->vaddr = NULL; + drm_gem_shmem_put_pages(shmem); +} + +/* + * drm_gem_shmem_vunmap - Unmap a virtual mapping fo a shmem GEM object + * @shmem: shmem GEM object + * + * This function removes the virtual address when use count drops to zero. + */ +void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem) +{ + mutex_lock(&shmem->vmap_lock); + drm_gem_shmem_vunmap_locked(shmem); + mutex_unlock(&shmem->vmap_lock); +} +EXPORT_SYMBOL(drm_gem_shmem_vunmap); + +static struct drm_gem_shmem_object * +drm_gem_shmem_create_with_handle(struct drm_file *file_priv, + struct drm_device *dev, size_t size, + uint32_t *handle) +{ + struct drm_gem_shmem_object *shmem; + int ret; + + shmem = drm_gem_shmem_create(dev, size); + if (IS_ERR(shmem)) + return shmem; + + /* + * Allocate an id of idr table where the obj is registered + * and handle has the id what user can see. + */ + ret = drm_gem_handle_create(file_priv, &shmem->base, handle); + /* drop reference from allocate - handle holds it now. */ + drm_gem_object_put_unlocked(&shmem->base); + if (ret) + return ERR_PTR(ret); + + return shmem; +} + +/** + * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object + * @file: DRM file structure to create the dumb buffer for + * @dev: DRM device + * @args: IOCTL data + * + * This function computes the pitch of the dumb buffer and rounds it up to an + * integer number of bytes per pixel. Drivers for hardware that doesn't have + * any additional restrictions on the pitch can directly use this function as + * their &drm_driver.dumb_create callback. + * + * For hardware with additional restrictions, drivers can adjust the fields + * set up by userspace before calling into this function. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, + struct drm_mode_create_dumb *args) +{ + u32 min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8); + struct drm_gem_shmem_object *shmem; + + if (!args->pitch || !args->size) { + args->pitch = min_pitch; + args->size = args->pitch * args->height; + } else { + /* ensure sane minimum values */ + if (args->pitch < min_pitch) + args->pitch = min_pitch; + if (args->size < args->pitch * args->height) + args->size = args->pitch * args->height; + } + + shmem = drm_gem_shmem_create_with_handle(file, dev, args->size, &args->handle); + + return PTR_ERR_OR_ZERO(shmem); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create); + +static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + struct drm_gem_object *obj = vma->vm_private_data; + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + /* We don't use vmf->pgoff since that has the fake offset: */ + pgoff_t pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT; + loff_t num_pages = obj->size >> PAGE_SHIFT; + struct page *page; + + if (pgoff > num_pages || WARN_ON_ONCE(!shmem->pages)) + return VM_FAULT_SIGBUS; + + page = shmem->pages[pgoff]; + + return vmf_insert_page(vma, vmf->address, page); +} + +static void drm_gem_shmem_vm_close(struct vm_area_struct *vma) +{ + struct drm_gem_object *obj = vma->vm_private_data; + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + drm_gem_shmem_put_pages(shmem); + drm_gem_vm_close(vma); +} + +const struct vm_operations_struct drm_gem_shmem_vm_ops = { + .fault = drm_gem_shmem_fault, + .open = drm_gem_vm_open, + .close = drm_gem_shmem_vm_close, +}; +EXPORT_SYMBOL_GPL(drm_gem_shmem_vm_ops); + +static int drm_gem_shmem_mmap_obj(struct drm_gem_shmem_object *shmem, + struct vm_area_struct *vma) +{ + int ret; + + ret = drm_gem_shmem_get_pages(shmem); + if (ret) + goto err_close; + + /* VM_PFNMAP was set by drm_gem_mmap() */ + vma->vm_flags &= ~VM_PFNMAP; + vma->vm_flags |= VM_MIXEDMAP; + + switch (shmem->cache_mode) { + case DRM_GEM_SHMEM_BO_UNKNOWN: + ret = -EINVAL; + goto err_put_pages; + + case DRM_GEM_SHMEM_BO_WRITECOMBINED: + vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); + break; + + case DRM_GEM_SHMEM_BO_UNCACHED: + vma->vm_page_prot = pgprot_noncached(vm_get_page_prot(vma->vm_flags)); + break; + + case DRM_GEM_SHMEM_BO_CACHED: + /* + * Shunt off cached objs to shmem file so they have their own + * address_space (so unmap_mapping_range does what we want, + * in particular in the case of mmap'd dmabufs) + */ + fput(vma->vm_file); + get_file(shmem->base.filp); + vma->vm_pgoff = 0; + vma->vm_file = shmem->base.filp; + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); + break; + } + + return 0; + +err_put_pages: + drm_gem_shmem_put_pages(shmem); +err_close: + drm_gem_vm_close(vma); + + return ret; +} + +/** + * drm_gem_shmem_mmap - Memory-map a shmem GEM object + * @filp: File object + * @vma: VMA for the area to be mapped + * + * This function implements an augmented version of the GEM DRM file mmap + * operation for shmem objects. Drivers which employ the shmem helpers should + * use this function as their &file_operations.mmap handler in the DRM device file's + * file_operations structure. + * + * Instead of directly referencing this function, drivers should use the + * DEFINE_DRM_GEM_SHMEM_FOPS() macro. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma) +{ + struct drm_gem_shmem_object *shmem; + int ret; + + ret = drm_gem_mmap(filp, vma); + if (ret) + return ret; + + shmem = to_drm_gem_shmem_obj(vma->vm_private_data); + + return drm_gem_shmem_mmap_obj(shmem, vma); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap); + +static const char * const cache_mode_str[] = { + [DRM_GEM_SHMEM_BO_UNKNOWN] = "unknown", + [DRM_GEM_SHMEM_BO_UNCACHED] = "uncached", + [DRM_GEM_SHMEM_BO_CACHED] = "cached", + [DRM_GEM_SHMEM_BO_WRITECOMBINED] = "writecombined", +}; + +/** + * drm_gem_shmem_print_info() - Print &drm_gem_cma_object info for debugfs + * @p: DRM printer + * @indent: Tab indentation level + * @obj: GEM object + * + * This function can be used as the &drm_driver->gem_print_info callback. + */ +void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent, + const struct drm_gem_object *obj) +{ + const struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + drm_printf_indent(p, indent, "cachemode=%s\n", cache_mode_str[shmem->cache_mode]); + drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count); + drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr); + drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count); +} +EXPORT_SYMBOL(drm_gem_shmem_print_info); + +/** + * drm_gem_shmem_prime_pin - Pin backing pages for a shmem GEM object + * @obj: GEM object + * + * This function makes sure the backing pages are pinned in memory while the + * buffer is exported. Drivers using the shmem helpers should set this as their + * DRM driver's &drm_driver.gem_prime_pin callback. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_gem_shmem_prime_pin(struct drm_gem_object *obj) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + return drm_gem_shmem_get_pages(shmem); +} +EXPORT_SYMBOL(drm_gem_shmem_prime_pin); + +/** + * drm_gem_shmem_prime_unpin - Unpin backing pages for a shmem GEM object + * @obj: GEM object + * + * This function removes the requirement that the backing pages are pinned in + * memory. Drivers using the shmem helpers should set this as their DRM driver's + * &drm_driver.gem_prime_unpin callback. + */ +void drm_gem_shmem_prime_unpin(struct drm_gem_object *obj) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + drm_gem_shmem_put_pages(shmem); +} +EXPORT_SYMBOL(drm_gem_shmem_prime_unpin); + +/** + * drm_gem_shmem_prime_get_sg_table - Provide a scatter/gather table of pinned + * pages for a shmem GEM object + * @obj: GEM object + * + * This function exports a scatter/gather table suitable for PRIME usage by + * calling the standard DMA mapping API. Drivers using the shmem helpers should + * set this as their &drm_driver.gem_prime_get_sg_table callback. + * + * Returns: + * A pointer to the scatter/gather table of pinned pages or NULL on failure. + */ +struct sg_table *drm_gem_shmem_prime_get_sg_table(struct drm_gem_object *obj) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + return drm_prime_pages_to_sg(shmem->pages, obj->size >> PAGE_SHIFT); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_get_sg_table); + +/** + * drm_gem_shmem_prime_import_sg_table - Produce a shmem GEM object from + * another driver's scatter/gather table of pinned pages + * @dev: Device to import into + * @attach: DMA-BUF attachment + * @sgt: Scatter/gather table of pinned pages + * + * This function imports a scatter/gather table exported via DMA-BUF by + * another driver. Drivers that use the shmem helpers should set this as their + * &drm_driver.gem_prime_import_sg_table callback. + * + * Returns: + * A pointer to a newly created GEM object or an ERR_PTR-encoded negative + * error code on failure. + */ +struct drm_gem_object * +drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, + struct dma_buf_attachment *attach, + struct sg_table *sgt) +{ + size_t size = PAGE_ALIGN(attach->dmabuf->size); + size_t npages = size >> PAGE_SHIFT; + struct drm_gem_shmem_object *shmem; + int ret; + + shmem = drm_gem_shmem_create(dev, size); + if (IS_ERR(shmem)) + return ERR_CAST(shmem); + + shmem->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); + if (!shmem->pages) { + ret = -ENOMEM; + goto err_free_gem; + } + + ret = drm_prime_sg_to_page_addr_arrays(sgt, shmem->pages, NULL, npages); + if (ret < 0) + goto err_free_array; + + shmem->sgt = sgt; + shmem->cache_mode = DRM_GEM_SHMEM_BO_UNKNOWN; + shmem->pages_use_count = 1; /* Permanently pinned from our point of view */ + + DRM_DEBUG_PRIME("size = %zu\n", size); + + return &shmem->base; + +err_free_array: + kvfree(shmem->pages); +err_free_gem: + drm_gem_object_put_unlocked(&shmem->base); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table); + +/** + * drm_gem_shmem_prime_mmap - Memory-map an exported shmem GEM object + * @obj: GEM object + * @vma: VMA for the area to be mapped + * + * This function maps a buffer imported via DRM PRIME into a userspace + * process's address space. Drivers that use the shmem helpers should set this + * as their &drm_driver.gem_prime_mmap callback. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_gem_shmem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + int ret; + + ret = drm_gem_mmap_obj(obj, obj->size, vma); + if (ret) + return ret; + + return drm_gem_shmem_mmap_obj(shmem, vma); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_mmap); + +/** + * drm_gem_shmem_prime_vmap - Map a shmem GEM object into the kernel's virtual + * address space + * @obj: GEM object + * + * This function maps a buffer exported via DRM PRIME into the kernel's + * virtual address space. Drivers using the shmem helpers should set this as + * their DRM driver's &drm_driver.gem_prime_vmap callback. + * + * Returns: + * The kernel virtual address of the shmem GEM object's backing store or NULL on error. + */ +void *drm_gem_shmem_prime_vmap(struct drm_gem_object *obj) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + drm_gem_shmem_vmap(shmem); + + return shmem->vaddr; +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_vmap); + +/** + * drm_gem_shmem_prime_vunmap - Unmap a shmem GEM object from the kernel's + * virtual address space + * @obj: GEM object + * @vaddr: kernel virtual address where the shmem GEM object was mapped + * + * This function removes a buffer exported via DRM PRIME from the kernel's + * virtual address space. Drivers using the shmem helpers should set this as + * their &drm_driver.gem_prime_vunmap callback. + */ +void drm_gem_shmem_prime_vunmap(struct drm_gem_object *obj, void *vaddr) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + drm_gem_shmem_vunmap(shmem); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_vunmap); diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h new file mode 100644 index 000000000000..8dfcb2c3d667 --- /dev/null +++ b/include/drm/drm_gem_shmem_helper.h @@ -0,0 +1,198 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __DRM_GEM_SHMEM_HELPER_H__ +#define __DRM_GEM_SHMEM_HELPER_H__ + +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/mutex.h> + +#include <drm/drm_file.h> +#include <drm/drm_gem.h> +#include <drm/drm_ioctl.h> +#include <drm/drm_prime.h> + +struct dma_buf_attachment; +struct drm_mode_create_dumb; +struct drm_printer; +struct sg_table; + +/** + * enum drm_gem_shmem_cache_mode - shmem buffer cache mode + */ +enum drm_gem_shmem_cache_mode { + /** + * @DRM_GEM_SHMEM_BO_UNKNOWN: + * + * Cache mode is not known. This is the case when importing a buffer. + */ + DRM_GEM_SHMEM_BO_UNKNOWN = 0, + + /** + * @DRM_GEM_SHMEM_BO_UNCACHED: Buffer is uncached. + */ + DRM_GEM_SHMEM_BO_UNCACHED, + + /** + * @DRM_GEM_SHMEM_BO_CACHED: Buffer is cached. + */ + DRM_GEM_SHMEM_BO_CACHED, + + /** + * @DRM_GEM_SHMEM_BO_WRITECOMBINED: Buffer is uncached with writes combined. + */ + DRM_GEM_SHMEM_BO_WRITECOMBINED, +}; + +/** + * struct drm_gem_shmem_object - GEM object backed by shmem + */ +struct drm_gem_shmem_object { + /** + * @base: Base GEM object + */ + struct drm_gem_object base; + + /** + * @cache_mode: Cache mode + */ + enum drm_gem_shmem_cache_mode cache_mode; + + /** + * @pages_lock: Protects the page table and use count + */ + struct mutex pages_lock; + + /** + * @pages: Page table + */ + struct page **pages; + + /** + * @pages_use_count: + * + * Reference count on the pages table. + * The pages are put when the count reaches zero. + */ + unsigned int pages_use_count; + + /** + * @pages_mark_dirty_on_put: + * + * Mark pages as dirty when they are put. + */ + unsigned int pages_mark_dirty_on_put : 1; + + /** + * @pages_mark_accessed_on_put: + * + * Mark pages as accessed when they are put. + */ + unsigned int pages_mark_accessed_on_put : 1; + + /** + * @sgt: Scatter/gather table for imported PRIME buffers + */ + struct sg_table *sgt; + + /** + * @vmap_lock: Protects the vmap address and use count + */ + struct mutex vmap_lock; + + /** + * @vaddr: Kernel virtual address of the backing memory + */ + void *vaddr; + + /** + * @vmap_use_count: + * + * Reference count on the virtual address. + * The address are un-mapped when the count reaches zero. + */ + unsigned int vmap_use_count; +}; + +#define to_drm_gem_shmem_obj(obj) \ + container_of(obj, struct drm_gem_shmem_object, base) + +/** + * DEFINE_DRM_GEM_SHMEM_FOPS() - Macro to generate file operations for shmem drivers + * @name: name for the generated structure + * + * This macro autogenerates a suitable &struct file_operations for shmem based + * drivers, which can be assigned to &drm_driver.fops. Note that this structure + * cannot be shared between drivers, because it contains a reference to the + * current module using THIS_MODULE. + * + * Note that the declaration is already marked as static - if you need a + * non-static version of this you're probably doing it wrong and will break the + * THIS_MODULE reference by accident. + */ +#define DEFINE_DRM_GEM_SHMEM_FOPS(name) \ + static const struct file_operations name = {\ + .owner = THIS_MODULE,\ + .open = drm_open,\ + .release = drm_release,\ + .unlocked_ioctl = drm_ioctl,\ + .compat_ioctl = drm_compat_ioctl,\ + .poll = drm_poll,\ + .read = drm_read,\ + .llseek = noop_llseek,\ + .mmap = drm_gem_shmem_mmap, \ + } + +struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size); +void drm_gem_shmem_free_object(struct drm_gem_object *obj); + +int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem); +void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem); +int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem); +void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem); + +int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, + struct drm_mode_create_dumb *args); + +int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma); + +extern const struct vm_operations_struct drm_gem_shmem_vm_ops; + +void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent, + const struct drm_gem_object *obj); + +int drm_gem_shmem_prime_pin(struct drm_gem_object *obj); +void drm_gem_shmem_prime_unpin(struct drm_gem_object *obj); +struct sg_table *drm_gem_shmem_prime_get_sg_table(struct drm_gem_object *obj); +struct drm_gem_object * +drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, + struct dma_buf_attachment *attach, + struct sg_table *sgt); +int drm_gem_shmem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma); +void *drm_gem_shmem_prime_vmap(struct drm_gem_object *obj); +void drm_gem_shmem_prime_vunmap(struct drm_gem_object *obj, void *vaddr); + +/** + * DRM_GEM_SHMEM_DRIVER_OPS - Default shmem GEM operations + * + * This macro provides a shortcut for setting the shmem GEM operations in + * the &drm_driver structure. + */ +#define DRM_GEM_SHMEM_DRIVER_OPS \ + .gem_free_object_unlocked = drm_gem_shmem_free_object, \ + .gem_print_info = drm_gem_shmem_print_info, \ + .gem_vm_ops = &drm_gem_shmem_vm_ops, \ + .prime_handle_to_fd = drm_gem_prime_handle_to_fd, \ + .prime_fd_to_handle = drm_gem_prime_fd_to_handle, \ + .gem_prime_pin = drm_gem_shmem_prime_pin, \ + .gem_prime_unpin = drm_gem_shmem_prime_unpin, \ + .gem_prime_import = drm_gem_prime_import, \ + .gem_prime_export = drm_gem_prime_export, \ + .gem_prime_get_sg_table = drm_gem_shmem_prime_get_sg_table, \ + .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, \ + .gem_prime_vmap = drm_gem_shmem_prime_vmap, \ + .gem_prime_vunmap = drm_gem_shmem_prime_vunmap, \ + .gem_prime_mmap = drm_gem_shmem_prime_mmap, \ + .dumb_create = drm_gem_shmem_dumb_create + +#endif /* __DRM_GEM_SHMEM_HELPER_H__ */ -- 2.15.1 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
