blob: d88f4230c22195a626070cca0e657a4a538cf3da [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2018 Noralf Tr√łnnes
*/
#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.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.
*/
static const struct drm_gem_object_funcs drm_gem_shmem_funcs = {
.free = drm_gem_shmem_free_object,
.print_info = drm_gem_shmem_print_info,
.pin = drm_gem_shmem_pin,
.unpin = drm_gem_shmem_unpin,
.get_sg_table = drm_gem_shmem_get_sg_table,
.vmap = drm_gem_shmem_vmap,
.vunmap = drm_gem_shmem_vunmap,
.vm_ops = &drm_gem_shmem_vm_ops,
};
/**
* 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)
{
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);
if (!obj->funcs)
obj->funcs = &drm_gem_shmem_funcs;
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;
shmem = to_drm_gem_shmem_obj(obj);
mutex_init(&shmem->pages_lock);
mutex_init(&shmem->vmap_lock);
INIT_LIST_HEAD(&shmem->madv_list);
/*
* Our buffers are kept pinned, so allocating them
* from the MOVABLE zone is a really bad idea, and
* conflicts with CMA. See comments above new_inode()
* why this is required _and_ expected if you're
* going to pin these pages.
*/
mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER |
__GFP_RETRY_MAYFAIL | __GFP_NOWARN);
return shmem;
err_release:
drm_gem_object_release(obj);
err_free:
kfree(obj);
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.
*/
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);
} else {
if (shmem->sgt) {
dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
shmem->sgt->nents, DMA_BIDIRECTIONAL);
sg_free_table(shmem->sgt);
kfree(shmem->sgt);
}
if (shmem->pages)
drm_gem_shmem_put_pages(shmem);
}
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_locked(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_locked(shmem);
mutex_unlock(&shmem->pages_lock);
}
EXPORT_SYMBOL(drm_gem_shmem_put_pages);
/**
* drm_gem_shmem_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.
*
* Returns:
* 0 on success or a negative error code on failure.
*/
int drm_gem_shmem_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_pin);
/**
* drm_gem_shmem_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.
*/
void drm_gem_shmem_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_unpin);
static void *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 shmem->vaddr;
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
shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT,
VM_MAP, pgprot_writecombine(PAGE_KERNEL));
if (!shmem->vaddr) {
DRM_DEBUG_KMS("Failed to vmap pages\n");
ret = -ENOMEM;
goto err_put_pages;
}
return shmem->vaddr;
err_put_pages:
drm_gem_shmem_put_pages(shmem);
err_zero_use:
shmem->vmap_use_count = 0;
return ERR_PTR(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.
*/
void *drm_gem_shmem_vmap(struct drm_gem_object *obj)
{
struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
void *vaddr;
int ret;
ret = mutex_lock_interruptible(&shmem->vmap_lock);
if (ret)
return ERR_PTR(ret);
vaddr = drm_gem_shmem_vmap_locked(shmem);
mutex_unlock(&shmem->vmap_lock);
return vaddr;
}
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_object *obj, void *vaddr)
{
struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
mutex_lock(&shmem->vmap_lock);
drm_gem_shmem_vunmap_locked(shmem);
mutex_unlock(&shmem->vmap_lock);
}
EXPORT_SYMBOL(drm_gem_shmem_vunmap);
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;
}
EXPORT_SYMBOL(drm_gem_shmem_create_with_handle);
/* Update madvise status, returns true if not purged, else
* false or -errno.
*/
int drm_gem_shmem_madvise(struct drm_gem_object *obj, int madv)
{
struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
mutex_lock(&shmem->pages_lock);
if (shmem->madv >= 0)
shmem->madv = madv;
madv = shmem->madv;
mutex_unlock(&shmem->pages_lock);
return (madv >= 0);
}
EXPORT_SYMBOL(drm_gem_shmem_madvise);
void drm_gem_shmem_purge_locked(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
WARN_ON(!drm_gem_shmem_is_purgeable(shmem));
dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
shmem->sgt->nents, DMA_BIDIRECTIONAL);
sg_free_table(shmem->sgt);
kfree(shmem->sgt);
shmem->sgt = NULL;
drm_gem_shmem_put_pages_locked(shmem);
shmem->madv = -1;
drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
drm_gem_free_mmap_offset(obj);
/* Our goal here is to return as much of the memory as
* is possible back to the system as we are called from OOM.
* To do this we must instruct the shmfs to drop all of its
* backing pages, *now*.
*/
shmem_truncate_range(file_inode(obj->filp), 0, (loff_t)-1);
invalidate_mapping_pages(file_inode(obj->filp)->i_mapping,
0, (loff_t)-1);
}
EXPORT_SYMBOL(drm_gem_shmem_purge_locked);
bool drm_gem_shmem_purge(struct drm_gem_object *obj)
{
struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
if (!mutex_trylock(&shmem->pages_lock))
return false;
drm_gem_shmem_purge_locked(obj);
mutex_unlock(&shmem->pages_lock);
return true;
}
EXPORT_SYMBOL(drm_gem_shmem_purge);
/**
* 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);
loff_t num_pages = obj->size >> PAGE_SHIFT;
vm_fault_t ret;
struct page *page;
pgoff_t page_offset;
/* We don't use vmf->pgoff since that has the fake offset */
page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
mutex_lock(&shmem->pages_lock);
if (page_offset >= num_pages ||
WARN_ON_ONCE(!shmem->pages) ||
shmem->madv < 0) {
ret = VM_FAULT_SIGBUS;
} else {
page = shmem->pages[page_offset];
ret = vmf_insert_page(vma, vmf->address, page);
}
mutex_unlock(&shmem->pages_lock);
return ret;
}
static void drm_gem_shmem_vm_open(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);
int ret;
ret = drm_gem_shmem_get_pages(shmem);
WARN_ON_ONCE(ret != 0);
drm_gem_vm_open(vma);
}
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_shmem_vm_open,
.close = drm_gem_shmem_vm_close,
};
EXPORT_SYMBOL_GPL(drm_gem_shmem_vm_ops);
/**
* 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);
ret = drm_gem_shmem_get_pages(shmem);
if (ret) {
drm_gem_vm_close(vma);
return ret;
}
/* VM_PFNMAP was set by drm_gem_mmap() */
vma->vm_flags &= ~VM_PFNMAP;
vma->vm_flags |= VM_MIXEDMAP;
return 0;
}
EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap);
/**
* drm_gem_shmem_print_info() - Print &drm_gem_shmem_object info for debugfs
* @p: DRM printer
* @indent: Tab indentation level
* @obj: GEM object
*/
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, "pages_use_count=%u\n", shmem->pages_use_count);
drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count);
drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr);
}
EXPORT_SYMBOL(drm_gem_shmem_print_info);
/**
* drm_gem_shmem_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.
*
* Returns:
* A pointer to the scatter/gather table of pinned pages or NULL on failure.
*/
struct sg_table *drm_gem_shmem_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_get_sg_table);
/**
* drm_gem_shmem_get_pages_sgt - Pin pages, dma map them, and return a
* scatter/gather table for a shmem GEM object.
* @obj: 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.
*
* 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_object *obj)
{
int ret;
struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
struct sg_table *sgt;
if (shmem->sgt)
return shmem->sgt;
WARN_ON(obj->import_attach);
ret = drm_gem_shmem_get_pages(shmem);
if (ret)
return ERR_PTR(ret);
sgt = drm_gem_shmem_get_sg_table(&shmem->base);
if (IS_ERR(sgt)) {
ret = PTR_ERR(sgt);
goto err_put_pages;
}
/* Map the pages for use by the h/w. */
dma_map_sg(obj->dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
shmem->sgt = sgt;
return sgt;
err_put_pages:
drm_gem_shmem_put_pages(shmem);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(drm_gem_shmem_get_pages_sgt);
/**
* 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->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);