// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Russell King
*/
#include <linux/dma-buf.h>
#include <linux/dma-mapping.h>
#include <linux/mman.h>
#include <linux/shmem_fs.h>
#include <drm/armada_drm.h>
#include <drm/drm_prime.h>
#include "armada_drm.h"
#include "armada_gem.h"
#include "armada_ioctlP.h"
MODULE_IMPORT_NS(DMA_BUF);
static vm_fault_t armada_gem_vm_fault(struct vm_fault *vmf)
{
struct drm_gem_object *gobj = vmf->vma->vm_private_data;
struct armada_gem_object *obj = drm_to_armada_gem(gobj);
unsigned long pfn = obj->phys_addr >> PAGE_SHIFT;
pfn += (vmf->address - vmf->vma->vm_start) >> PAGE_SHIFT;
return vmf_insert_pfn(vmf->vma, vmf->address, pfn);
}
static const struct vm_operations_struct armada_gem_vm_ops = {
.fault = armada_gem_vm_fault,
.open = drm_gem_vm_open,
.close = drm_gem_vm_close,
};
static size_t roundup_gem_size(size_t size)
{
return roundup(size, PAGE_SIZE);
}
void armada_gem_free_object(struct drm_gem_object *obj)
{
struct armada_gem_object *dobj = drm_to_armada_gem(obj);
struct armada_private *priv = drm_to_armada_dev(obj->dev);
DRM_DEBUG_DRIVER("release obj %p\n", dobj);
drm_gem_free_mmap_offset(&dobj->obj);
might_lock(&priv->linear_lock);
if (dobj->page) {
/* page backed memory */
unsigned int order = get_order(dobj->obj.size);
__free_pages(dobj->page, order);
} else if (dobj->linear) {
/* linear backed memory */
mutex_lock(&priv->linear_lock);
drm_mm_remove_node(dobj->linear);
mutex_unlock(&priv->linear_lock);
kfree(dobj->linear);
if (dobj->addr)
iounmap(dobj->addr);
}
if (dobj->obj.import_attach) {
/* We only ever display imported data */
if (dobj->sgt)
dma_buf_unmap_attachment_unlocked(dobj->obj.import_attach,
dobj->sgt, DMA_TO_DEVICE);
drm_prime_gem_destroy(&dobj->obj, NULL);
}
drm_gem_object_release(&dobj->obj);
kfree(dobj);
}
int
armada_gem_linear_back(struct drm_device *dev, struct armada_gem_object *obj)
{
struct armada_private *priv = drm_to_armada_dev(dev);
size_t size = obj->obj.size;
if (obj->page || obj->linear)
return 0;
/*
* If it is a small allocation (typically cursor, which will
* be 32x64 or 64x32 ARGB pixels) try to get it from the system.
* Framebuffers will never be this small (our minimum size for
* framebuffers is larger than this anyway.) Such objects are
* only accessed by the CPU so we don't need any special handing
* here.
*/
if (size <= 8192) {
unsigned int order = get_order(size);
struct page *p = alloc_pages(GFP_KERNEL, order);
if (p) {
obj->addr = page_address(p);
obj->phys_addr = page_to_phys(p);
obj->page = p;
memset(obj->addr, 0, PAGE_ALIGN(size));
}
}
/*
* We could grab something from DMA if it's enabled, but that
* involves building in a problem:
*
* GEM DMA helper interface uses dma_alloc_coherent(), which provides
* us with an CPU virtual address and a device address.
*
* The CPU virtual address may be either an address in the kernel
* direct mapped region (for example, as it would be on x86) or
* it may be remapped into another part of kernel memory space
* (eg, as it would be on ARM.) This means virt_to_phys() on the
* returned virtual address is invalid depending on the architecture
* implementation.
*
* The device address may also not be a physical address; it may
* be that there is some kind of remapping between the device and
* system RAM, which makes the use of the device address also
* unsafe to re-use as a physical address.
*
* This makes DRM usage of dma_alloc_coherent() in a generic way
* at best very questionable and unsafe.
*/
/* Otherwise, grab it from our linear allocation */
if (!obj->page) {
struct drm_mm_node *node;
unsigned align = min_t(unsigned, size, SZ_2M);
void __iomem *ptr;
int ret;
node = kzalloc(sizeof(*node), GFP_KERNEL);
if (!node)
return -ENOSPC;
mutex_lock(&priv->linear_lock);
ret = drm_mm_insert_node_generic(&priv->linear, node,
size, align, 0, 0);
mutex_unlock(&priv->linear_lock);
if (ret) {
kfree(node);
return ret;
}
obj->linear = node;
/* Ensure that the memory we're returning is cleared. */
ptr = ioremap_wc(obj->linear->start, size);
if (!ptr) {
mutex_lock(&priv->linear_lock);
drm_mm_remove_node(obj->linear);
mutex_unlock(&priv->linear_lock);
kfree(obj->linear);
obj->linear = NULL;
return -ENOMEM;
}
memset_io(ptr, 0, size);
iounmap(ptr);
obj->phys_addr = obj->linear->start;
obj->dev_addr = obj->linear->start;
obj->mapped = true;
}
DRM_DEBUG_DRIVER("obj %p phys %#llx dev %#llx\n", obj,
(unsigned long long)obj->phys_addr,
(unsigned long long)obj->dev_addr);
return 0;
}
void *
armada_gem_map_object(struct drm_device *dev, struct armada_gem_object *dobj)
{
/* only linear objects need to be ioremap'd */
if (!dobj->addr && dobj->linear)
dobj->addr = ioremap_wc(dobj->phys_addr, dobj->obj.size);
return dobj->addr;
}
static const struct drm_gem_object_funcs armada_gem_object_funcs = {
.free = armada_gem_free_object,
.export = armada_gem_prime_export,
.vm_ops = &armada_gem_vm_ops,
};
struct armada_gem_object *
armada_gem_alloc_private_object(struct drm_device *dev, size_t size)
{
struct armada_gem_object *obj;
size = roundup_gem_size(size);
obj = kzalloc(sizeof(*obj), GFP_KERNEL);
if (!obj)
return NULL;
obj->obj.funcs = &armada_gem_object_funcs;
drm_gem_private_object_init(dev, &obj->obj, size);
DRM_DEBUG_DRIVER("alloc private obj %p size %zu\n", obj, size);
return obj;
}
static struct armada_gem_object *armada_gem_alloc_object(struct drm_device *dev,
size_t size)
{
struct armada_gem_object *obj;
struct address_space *mapping;
size = roundup_gem_size(size);
obj = kzalloc(sizeof(*obj), GFP_KERNEL);
if (!obj)
return NULL;
obj->obj.funcs = &armada_gem_object_funcs;
if (drm_gem_object_init(dev, &obj->obj, size)) {
kfree(obj);
return NULL;
}
mapping = obj->obj.filp->f_mapping;
mapping_set_gfp_mask(mapping, GFP_HIGHUSER | __GFP_RECLAIMABLE);
DRM_DEBUG_DRIVER("alloc obj %p size %zu\n", obj, size);
return obj;
}
/* Dumb alloc support */
int armada_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
struct drm_mode_create_dumb *args)
{
struct armada_gem_object *dobj;
u32 handle;
size_t size;
int ret;
args->pitch = armada_pitch(args->width, args->bpp);
args->size = size = args->pitch * args->height;
dobj = armada_gem_alloc_private_object(dev, size);
if (dobj == NULL)
return -ENOMEM;
ret = armada_gem_linear_back(dev, dobj);
if (ret)
goto err;
ret = drm_gem_handle_create(file, &dobj->obj, &handle);
if (ret)
goto err;
args->handle = handle;
/* drop reference from allocate - handle holds it now */
DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
err:
drm_gem_object_put(&dobj->obj);
return ret;
}
/* Private driver gem ioctls */
int armada_gem_create_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_armada_gem_create *args = data;
struct armada_gem_object *dobj;
size_t size;
u32 handle;
int ret;
if (args->size == 0)
return -ENOMEM;
size = args->size;
dobj = armada_gem_alloc_object(dev, size);
if (dobj == NULL)
return -ENOMEM;
ret = drm_gem_handle_create(file, &dobj->obj, &handle);
if (ret)
goto err;
args->handle = handle;
/* drop reference from allocate - handle holds it now */
DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
err:
drm_gem_object_put(&dobj->obj);
return ret;
}
/* Map a shmem-backed object into process memory space */
int armada_gem_mmap_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_armada_gem_mmap *args = data;
struct armada_gem_object *dobj;
unsigned long addr;
dobj = armada_gem_object_lookup(file, args->handle);
if (dobj == NULL)
return -ENOENT;
if (!dobj->obj.filp) {
drm_gem_object_put(&dobj->obj);
return -EINVAL;
}
addr = vm_mmap(dobj->obj.filp, 0, args->size, PROT_READ | PROT_WRITE,
MAP_SHARED, args->offset);
drm_gem_object_put(&dobj->obj);
if (IS_ERR_VALUE(addr))
return addr;
args->addr = addr;
return 0;
}
int armada_gem_pwrite_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_armada_gem_pwrite *args = data;
struct armada_gem_object *dobj;
char __user *ptr;
int ret = 0;
DRM_DEBUG_DRIVER("handle %u off %u size %u ptr 0x%llx\n",
args->handle, args->offset, args->size, args->ptr);
if (args->size == 0)
return 0;
ptr = (char __user *)(uintptr_t)args->ptr;
if (!access_ok(ptr, args->size))
return -EFAULT;
if (fault_in_readable(ptr, args->size))
return -EFAULT;
dobj = armada_gem_object_lookup(file, args->handle);
if (dobj == NULL)
return -ENOENT;
/* Must be a kernel-mapped object */
if (!dobj->addr)
return -EINVAL;
if (args->offset > dobj->obj.size ||
args->size > dobj->obj.size - args->offset) {
DRM_ERROR("invalid size: object size %u\n", dobj->obj.size);
ret = -EINVAL;
goto unref;
}
if (copy_from_user(dobj->addr + args->offset, ptr, args->size)) {
ret = -EFAULT;
} else if (dobj->update) {
dobj->update(dobj->update_data);
ret = 0;
}
unref:
drm_gem_object_put(&dobj->obj);
return ret;
}
/* Prime support */
static struct sg_table *
armada_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
enum dma_data_direction dir)
{
struct drm_gem_object *obj = attach->dmabuf->priv;
struct armada_gem_object *dobj = drm_to_armada_gem(obj);
struct scatterlist *sg;
struct sg_table *sgt;
int i;
sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
if (!sgt)
return NULL;
if (dobj->obj.filp) {
struct address_space *mapping;
int count;
count = dobj->obj.size / PAGE_SIZE;
if (sg_alloc_table(sgt, count, GFP_KERNEL))
goto free_sgt;
mapping = dobj->obj.filp->f_mapping;
for_each_sgtable_sg(sgt, sg, i) {
struct page *page;
page = shmem_read_mapping_page(mapping, i);
if (IS_ERR(page))
goto release;
sg_set_page(sg, page, PAGE_SIZE, 0);
}
if (dma_map_sgtable(attach->dev, sgt, dir, 0))
goto release;
} else if (dobj->page) {
/* Single contiguous page */
if (sg_alloc_table(sgt, 1, GFP_KERNEL))
goto free_sgt;
sg_set_page(sgt->sgl, dobj->page, dobj->obj.size, 0);
if (dma_map_sgtable(attach->dev, sgt, dir, 0))
goto free_table;
} else if (dobj->linear) {
/* Single contiguous physical region - no struct page */
if (sg_alloc_table(sgt, 1, GFP_KERNEL))
goto free_sgt;
sg_dma_address(sgt->sgl) = dobj->dev_addr;
sg_dma_len(sgt->sgl) = dobj->obj.size;
} else {
goto free_sgt;
}
return sgt;
release:
for_each_sgtable_sg(sgt, sg, i)
if (sg_page(sg))
put_page(sg_page(sg));
free_table:
sg_free_table(sgt);
free_sgt:
kfree(sgt);
return NULL;
}
static void armada_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
struct sg_table *sgt, enum dma_data_direction dir)
{
struct drm_gem_object *obj = attach->dmabuf->priv;
struct armada_gem_object *dobj = drm_to_armada_gem(obj);
int i;
if (!dobj->linear)
dma_unmap_sgtable(attach->dev, sgt, dir, 0);
if (dobj->obj.filp) {
struct scatterlist *sg;
for_each_sgtable_sg(sgt, sg, i)
put_page(sg_page(sg));
}
sg_free_table(sgt);
kfree(sgt);
}
static int
armada_gem_dmabuf_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
{
return -EINVAL;
}
static const struct dma_buf_ops armada_gem_prime_dmabuf_ops = {
.map_dma_buf = armada_gem_prime_map_dma_buf,
.unmap_dma_buf = armada_gem_prime_unmap_dma_buf,
.release = drm_gem_dmabuf_release,
.mmap = armada_gem_dmabuf_mmap,
};
struct dma_buf *
armada_gem_prime_export(struct drm_gem_object *obj, int flags)
{
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
exp_info.ops = &armada_gem_prime_dmabuf_ops;
exp_info.size = obj->size;
exp_info.flags = O_RDWR;
exp_info.priv = obj;
return drm_gem_dmabuf_export(obj->dev, &exp_info);
}
struct drm_gem_object *
armada_gem_prime_import(struct drm_device *dev, struct dma_buf *buf)
{
struct dma_buf_attachment *attach;
struct armada_gem_object *dobj;
if (buf->ops == &armada_gem_prime_dmabuf_ops) {
struct drm_gem_object *obj = buf->priv;
if (obj->dev == dev) {
/*
* Importing our own dmabuf(s) increases the
* refcount on the gem object itself.
*/
drm_gem_object_get(obj);
return obj;
}
}
attach = dma_buf_attach(buf, dev->dev);
if (IS_ERR(attach))
return ERR_CAST(attach);
dobj = armada_gem_alloc_private_object(dev, buf->size);
if (!dobj) {
dma_buf_detach(buf, attach);
return ERR_PTR(-ENOMEM);
}
dobj->obj.import_attach = attach;
get_dma_buf(buf);
/*
* Don't call dma_buf_map_attachment() here - it maps the
* scatterlist immediately for DMA, and this is not always
* an appropriate thing to do.
*/
return &dobj->obj;
}
int armada_gem_map_import(struct armada_gem_object *dobj)
{
int ret;
dobj->sgt = dma_buf_map_attachment_unlocked(dobj->obj.import_attach,
DMA_TO_DEVICE);
if (IS_ERR(dobj->sgt)) {
ret = PTR_ERR(dobj->sgt);
dobj->sgt = NULL;
DRM_ERROR("dma_buf_map_attachment() error: %d\n", ret);
return ret;
}
if (dobj->sgt->nents > 1) {
DRM_ERROR("dma_buf_map_attachment() returned an (unsupported) scattered list\n");
return -EINVAL;
}
if (sg_dma_len(dobj->sgt->sgl) < dobj->obj.size) {
DRM_ERROR("dma_buf_map_attachment() returned a small buffer\n");
return -EINVAL;
}
dobj->dev_addr = sg_dma_address(dobj->sgt->sgl);
dobj->mapped = true;
return 0;
}
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