// SPDX-License-Identifier: GPL-2.0 /* * Copyright 2018 Noralf Trønnes */ #include <linux/dma-buf.h> #include <linux/export.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/shmem_fs.h> #include <linux/slab.h> #include <linux/vmalloc.h> #ifdef CONFIG_X86 #include <asm/set_memory.h> #endif #include <drm/drm.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> MODULE_IMPORT_NS(…); /** * DOC: overview * * This library provides helpers for GEM objects backed by shmem buffers * allocated using anonymous pageable memory. * * Functions that operate on the GEM object receive struct &drm_gem_shmem_object. * For GEM callback helpers in struct &drm_gem_object functions, see likewise * named functions with an _object_ infix (e.g., drm_gem_shmem_object_vmap() wraps * drm_gem_shmem_vmap()). These helpers perform the necessary type conversion. */ static const struct drm_gem_object_funcs drm_gem_shmem_funcs = …; static struct drm_gem_shmem_object * __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private) { … } /** * 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. * * 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) { … } EXPORT_SYMBOL_GPL(…); /** * drm_gem_shmem_free - Free resources associated with a shmem GEM object * @shmem: shmem GEM object to free * * This function cleans up the GEM object state and frees the memory used to * store the object itself. */ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem) { … } EXPORT_SYMBOL_GPL(…); static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) { … } /* * 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) { … } EXPORT_SYMBOL(…); int drm_gem_shmem_pin_locked(struct drm_gem_shmem_object *shmem) { … } EXPORT_SYMBOL(…); void drm_gem_shmem_unpin_locked(struct drm_gem_shmem_object *shmem) { … } EXPORT_SYMBOL(…); /** * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object * @shmem: shmem GEM object * * This function makes sure the backing pages are pinned in memory while the * buffer is exported. * * Returns: * 0 on success or a negative error code on failure. */ int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem) { … } EXPORT_SYMBOL(…); /** * drm_gem_shmem_unpin - Unpin backing pages for a shmem GEM object * @shmem: shmem GEM object * * This function removes the requirement that the backing pages are pinned in * memory. */ void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem) { … } EXPORT_SYMBOL(…); /* * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object * @shmem: shmem GEM object * @map: Returns the kernel virtual address of the SHMEM GEM object's backing * store. * * This function makes sure that a contiguous kernel virtual address mapping * exists for the buffer backing the shmem GEM object. It hides the differences * between dma-buf imported and natively allocated objects. * * Acquired mappings should be cleaned up by calling drm_gem_shmem_vunmap(). * * Returns: * 0 on success or a negative error code on failure. */ int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem, struct iosys_map *map) { … } EXPORT_SYMBOL(…); /* * drm_gem_shmem_vunmap - Unmap a virtual mapping for a shmem GEM object * @shmem: shmem GEM object * @map: Kernel virtual address where the SHMEM GEM object was mapped * * This function cleans up a kernel virtual address mapping acquired by * drm_gem_shmem_vmap(). The mapping is only removed when the use count drops to * zero. * * This function hides the differences between dma-buf imported and natively * allocated objects. */ void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem, struct iosys_map *map) { … } EXPORT_SYMBOL(…); static int drm_gem_shmem_create_with_handle(struct drm_file *file_priv, struct drm_device *dev, size_t size, uint32_t *handle) { … } /* Update madvise status, returns true if not purged, else * false or -errno. */ int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv) { … } EXPORT_SYMBOL(…); void drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) { … } static void drm_gem_shmem_vm_open(struct vm_area_struct *vma) { … } static void drm_gem_shmem_vm_close(struct vm_area_struct *vma) { … } const struct vm_operations_struct drm_gem_shmem_vm_ops = …; EXPORT_SYMBOL_GPL(…); /** * drm_gem_shmem_mmap - Memory-map a shmem GEM object * @shmem: shmem GEM 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. * * Returns: * 0 on success or a negative error code on failure. */ int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct *vma) { … } EXPORT_SYMBOL_GPL(…); /** * drm_gem_shmem_print_info() - Print &drm_gem_shmem_object info for debugfs * @shmem: shmem GEM object * @p: DRM printer * @indent: Tab indentation level */ void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem, struct drm_printer *p, unsigned int indent) { … } EXPORT_SYMBOL(…); /** * drm_gem_shmem_get_sg_table - Provide a scatter/gather table of pinned * pages for a shmem GEM object * @shmem: shmem GEM object * * This function exports a scatter/gather table suitable for PRIME usage by * calling the standard DMA mapping API. * * Drivers who need to acquire an scatter/gather table for objects need to call * drm_gem_shmem_get_pages_sgt() instead. * * Returns: * A pointer to the scatter/gather table of pinned pages or error pointer on failure. */ struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_shmem_object *shmem) { … } EXPORT_SYMBOL_GPL(…); static struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem) { … } /** * drm_gem_shmem_get_pages_sgt - Pin pages, dma map them, and return a * scatter/gather table for a shmem GEM object. * @shmem: shmem GEM object * * This function returns a scatter/gather table suitable for driver usage. If * the sg table doesn't exist, the pages are pinned, dma-mapped, and a sg * table created. * * This is the main function for drivers to get at backing storage, and it hides * and difference between dma-buf imported and natively allocated objects. * drm_gem_shmem_get_sg_table() should not be directly called by drivers. * * Returns: * A pointer to the scatter/gather table of pinned pages or errno on failure. */ struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); MODULE_DESCRIPTION(…) …; MODULE_IMPORT_NS(…); MODULE_LICENSE(…) …;
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