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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/media/v4l2-core/videobuf-dma-sg.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/media/v4l2-core/videobuf-dma-sg.c')
-rw-r--r-- | drivers/media/v4l2-core/videobuf-dma-sg.c | 686 |
1 files changed, 686 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/videobuf-dma-sg.c b/drivers/media/v4l2-core/videobuf-dma-sg.c new file mode 100644 index 000000000..8dd0562de --- /dev/null +++ b/drivers/media/v4l2-core/videobuf-dma-sg.c @@ -0,0 +1,686 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * helper functions for SG DMA video4linux capture buffers + * + * The functions expect the hardware being able to scatter gather + * (i.e. the buffers are not linear in physical memory, but fragmented + * into PAGE_SIZE chunks). They also assume the driver does not need + * to touch the video data. + * + * (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org> + * + * Highly based on video-buf written originally by: + * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> + * (c) 2006 Mauro Carvalho Chehab, <mchehab@kernel.org> + * (c) 2006 Ted Walther and John Sokol + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/sched/mm.h> +#include <linux/slab.h> +#include <linux/interrupt.h> +#include <linux/pgtable.h> + +#include <linux/dma-mapping.h> +#include <linux/vmalloc.h> +#include <linux/pagemap.h> +#include <linux/scatterlist.h> +#include <asm/page.h> + +#include <media/videobuf-dma-sg.h> + +#define MAGIC_DMABUF 0x19721112 +#define MAGIC_SG_MEM 0x17890714 + +#define MAGIC_CHECK(is, should) \ + if (unlikely((is) != (should))) { \ + printk(KERN_ERR "magic mismatch: %x (expected %x)\n", \ + is, should); \ + BUG(); \ + } + +static int debug; +module_param(debug, int, 0644); + +MODULE_DESCRIPTION("helper module to manage video4linux dma sg buffers"); +MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@kernel.org>"); +MODULE_LICENSE("GPL"); + +#define dprintk(level, fmt, arg...) \ + if (debug >= level) \ + printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg) + +/* --------------------------------------------------------------------- */ + +/* + * Return a scatterlist for some page-aligned vmalloc()'ed memory + * block (NULL on errors). Memory for the scatterlist is allocated + * using kmalloc. The caller must free the memory. + */ +static struct scatterlist *videobuf_vmalloc_to_sg(unsigned char *virt, + int nr_pages) +{ + struct scatterlist *sglist; + struct page *pg; + int i; + + sglist = vzalloc(array_size(nr_pages, sizeof(*sglist))); + if (NULL == sglist) + return NULL; + sg_init_table(sglist, nr_pages); + for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) { + pg = vmalloc_to_page(virt); + if (NULL == pg) + goto err; + BUG_ON(PageHighMem(pg)); + sg_set_page(&sglist[i], pg, PAGE_SIZE, 0); + } + return sglist; + +err: + vfree(sglist); + return NULL; +} + +/* + * Return a scatterlist for a an array of userpages (NULL on errors). + * Memory for the scatterlist is allocated using kmalloc. The caller + * must free the memory. + */ +static struct scatterlist *videobuf_pages_to_sg(struct page **pages, + int nr_pages, int offset, size_t size) +{ + struct scatterlist *sglist; + int i; + + if (NULL == pages[0]) + return NULL; + sglist = vmalloc(array_size(nr_pages, sizeof(*sglist))); + if (NULL == sglist) + return NULL; + sg_init_table(sglist, nr_pages); + + if (PageHighMem(pages[0])) + /* DMA to highmem pages might not work */ + goto highmem; + sg_set_page(&sglist[0], pages[0], + min_t(size_t, PAGE_SIZE - offset, size), offset); + size -= min_t(size_t, PAGE_SIZE - offset, size); + for (i = 1; i < nr_pages; i++) { + if (NULL == pages[i]) + goto nopage; + if (PageHighMem(pages[i])) + goto highmem; + sg_set_page(&sglist[i], pages[i], min_t(size_t, PAGE_SIZE, size), 0); + size -= min_t(size_t, PAGE_SIZE, size); + } + return sglist; + +nopage: + dprintk(2, "sgl: oops - no page\n"); + vfree(sglist); + return NULL; + +highmem: + dprintk(2, "sgl: oops - highmem page\n"); + vfree(sglist); + return NULL; +} + +/* --------------------------------------------------------------------- */ + +struct videobuf_dmabuf *videobuf_to_dma(struct videobuf_buffer *buf) +{ + struct videobuf_dma_sg_memory *mem = buf->priv; + BUG_ON(!mem); + + MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); + + return &mem->dma; +} +EXPORT_SYMBOL_GPL(videobuf_to_dma); + +static void videobuf_dma_init(struct videobuf_dmabuf *dma) +{ + memset(dma, 0, sizeof(*dma)); + dma->magic = MAGIC_DMABUF; +} + +static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma, + int direction, unsigned long data, unsigned long size) +{ + unsigned long first, last; + int err, rw = 0; + unsigned int flags = FOLL_FORCE; + + dma->direction = direction; + switch (dma->direction) { + case DMA_FROM_DEVICE: + rw = READ; + break; + case DMA_TO_DEVICE: + rw = WRITE; + break; + default: + BUG(); + } + + first = (data & PAGE_MASK) >> PAGE_SHIFT; + last = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT; + dma->offset = data & ~PAGE_MASK; + dma->size = size; + dma->nr_pages = last-first+1; + dma->pages = kmalloc_array(dma->nr_pages, sizeof(struct page *), + GFP_KERNEL); + if (NULL == dma->pages) + return -ENOMEM; + + if (rw == READ) + flags |= FOLL_WRITE; + + dprintk(1, "init user [0x%lx+0x%lx => %lu pages]\n", + data, size, dma->nr_pages); + + err = pin_user_pages(data & PAGE_MASK, dma->nr_pages, + flags | FOLL_LONGTERM, dma->pages, NULL); + + if (err != dma->nr_pages) { + dma->nr_pages = (err >= 0) ? err : 0; + dprintk(1, "pin_user_pages: err=%d [%lu]\n", err, + dma->nr_pages); + return err < 0 ? err : -EINVAL; + } + return 0; +} + +static int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction, + unsigned long data, unsigned long size) +{ + int ret; + + mmap_read_lock(current->mm); + ret = videobuf_dma_init_user_locked(dma, direction, data, size); + mmap_read_unlock(current->mm); + + return ret; +} + +static int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction, + unsigned long nr_pages) +{ + int i; + + dprintk(1, "init kernel [%lu pages]\n", nr_pages); + + dma->direction = direction; + dma->vaddr_pages = kcalloc(nr_pages, sizeof(*dma->vaddr_pages), + GFP_KERNEL); + if (!dma->vaddr_pages) + return -ENOMEM; + + dma->dma_addr = kcalloc(nr_pages, sizeof(*dma->dma_addr), GFP_KERNEL); + if (!dma->dma_addr) { + kfree(dma->vaddr_pages); + return -ENOMEM; + } + for (i = 0; i < nr_pages; i++) { + void *addr; + + addr = dma_alloc_coherent(dma->dev, PAGE_SIZE, + &(dma->dma_addr[i]), GFP_KERNEL); + if (addr == NULL) + goto out_free_pages; + + dma->vaddr_pages[i] = virt_to_page(addr); + } + dma->vaddr = vmap(dma->vaddr_pages, nr_pages, VM_MAP | VM_IOREMAP, + PAGE_KERNEL); + if (NULL == dma->vaddr) { + dprintk(1, "vmalloc_32(%lu pages) failed\n", nr_pages); + goto out_free_pages; + } + + dprintk(1, "vmalloc is at addr %p, size=%lu\n", + dma->vaddr, nr_pages << PAGE_SHIFT); + + memset(dma->vaddr, 0, nr_pages << PAGE_SHIFT); + dma->nr_pages = nr_pages; + + return 0; +out_free_pages: + while (i > 0) { + void *addr; + + i--; + addr = page_address(dma->vaddr_pages[i]); + dma_free_coherent(dma->dev, PAGE_SIZE, addr, dma->dma_addr[i]); + } + kfree(dma->dma_addr); + dma->dma_addr = NULL; + kfree(dma->vaddr_pages); + dma->vaddr_pages = NULL; + + return -ENOMEM; + +} + +static int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction, + dma_addr_t addr, unsigned long nr_pages) +{ + dprintk(1, "init overlay [%lu pages @ bus 0x%lx]\n", + nr_pages, (unsigned long)addr); + dma->direction = direction; + + if (0 == addr) + return -EINVAL; + + dma->bus_addr = addr; + dma->nr_pages = nr_pages; + + return 0; +} + +static int videobuf_dma_map(struct device *dev, struct videobuf_dmabuf *dma) +{ + MAGIC_CHECK(dma->magic, MAGIC_DMABUF); + BUG_ON(0 == dma->nr_pages); + + if (dma->pages) { + dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages, + dma->offset, dma->size); + } + if (dma->vaddr) { + dma->sglist = videobuf_vmalloc_to_sg(dma->vaddr, + dma->nr_pages); + } + if (dma->bus_addr) { + dma->sglist = vmalloc(sizeof(*dma->sglist)); + if (NULL != dma->sglist) { + dma->sglen = 1; + sg_dma_address(&dma->sglist[0]) = dma->bus_addr + & PAGE_MASK; + dma->sglist[0].offset = dma->bus_addr & ~PAGE_MASK; + sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE; + } + } + if (NULL == dma->sglist) { + dprintk(1, "scatterlist is NULL\n"); + return -ENOMEM; + } + if (!dma->bus_addr) { + dma->sglen = dma_map_sg(dev, dma->sglist, + dma->nr_pages, dma->direction); + if (0 == dma->sglen) { + printk(KERN_WARNING + "%s: videobuf_map_sg failed\n", __func__); + vfree(dma->sglist); + dma->sglist = NULL; + dma->sglen = 0; + return -ENOMEM; + } + } + + return 0; +} + +int videobuf_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma) +{ + MAGIC_CHECK(dma->magic, MAGIC_DMABUF); + + if (!dma->sglen) + return 0; + + dma_unmap_sg(dev, dma->sglist, dma->nr_pages, dma->direction); + + vfree(dma->sglist); + dma->sglist = NULL; + dma->sglen = 0; + + return 0; +} +EXPORT_SYMBOL_GPL(videobuf_dma_unmap); + +int videobuf_dma_free(struct videobuf_dmabuf *dma) +{ + int i; + MAGIC_CHECK(dma->magic, MAGIC_DMABUF); + BUG_ON(dma->sglen); + + if (dma->pages) { + unpin_user_pages_dirty_lock(dma->pages, dma->nr_pages, + dma->direction == DMA_FROM_DEVICE); + kfree(dma->pages); + dma->pages = NULL; + } + + if (dma->dma_addr) { + for (i = 0; i < dma->nr_pages; i++) { + void *addr; + + addr = page_address(dma->vaddr_pages[i]); + dma_free_coherent(dma->dev, PAGE_SIZE, addr, + dma->dma_addr[i]); + } + kfree(dma->dma_addr); + dma->dma_addr = NULL; + kfree(dma->vaddr_pages); + dma->vaddr_pages = NULL; + vunmap(dma->vaddr); + dma->vaddr = NULL; + } + + if (dma->bus_addr) + dma->bus_addr = 0; + dma->direction = DMA_NONE; + + return 0; +} +EXPORT_SYMBOL_GPL(videobuf_dma_free); + +/* --------------------------------------------------------------------- */ + +static void videobuf_vm_open(struct vm_area_struct *vma) +{ + struct videobuf_mapping *map = vma->vm_private_data; + + dprintk(2, "vm_open %p [count=%d,vma=%08lx-%08lx]\n", map, + map->count, vma->vm_start, vma->vm_end); + + map->count++; +} + +static void videobuf_vm_close(struct vm_area_struct *vma) +{ + struct videobuf_mapping *map = vma->vm_private_data; + struct videobuf_queue *q = map->q; + struct videobuf_dma_sg_memory *mem; + int i; + + dprintk(2, "vm_close %p [count=%d,vma=%08lx-%08lx]\n", map, + map->count, vma->vm_start, vma->vm_end); + + map->count--; + if (0 == map->count) { + dprintk(1, "munmap %p q=%p\n", map, q); + videobuf_queue_lock(q); + for (i = 0; i < VIDEO_MAX_FRAME; i++) { + if (NULL == q->bufs[i]) + continue; + mem = q->bufs[i]->priv; + if (!mem) + continue; + + MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); + + if (q->bufs[i]->map != map) + continue; + q->bufs[i]->map = NULL; + q->bufs[i]->baddr = 0; + q->ops->buf_release(q, q->bufs[i]); + } + videobuf_queue_unlock(q); + kfree(map); + } + return; +} + +/* + * Get a anonymous page for the mapping. Make sure we can DMA to that + * memory location with 32bit PCI devices (i.e. don't use highmem for + * now ...). Bounce buffers don't work very well for the data rates + * video capture has. + */ +static vm_fault_t videobuf_vm_fault(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + struct page *page; + + dprintk(3, "fault: fault @ %08lx [vma %08lx-%08lx]\n", + vmf->address, vma->vm_start, vma->vm_end); + + page = alloc_page(GFP_USER | __GFP_DMA32); + if (!page) + return VM_FAULT_OOM; + clear_user_highpage(page, vmf->address); + vmf->page = page; + + return 0; +} + +static const struct vm_operations_struct videobuf_vm_ops = { + .open = videobuf_vm_open, + .close = videobuf_vm_close, + .fault = videobuf_vm_fault, +}; + +/* --------------------------------------------------------------------- + * SG handlers for the generic methods + */ + +/* Allocated area consists on 3 parts: + struct video_buffer + struct <driver>_buffer (cx88_buffer, saa7134_buf, ...) + struct videobuf_dma_sg_memory + */ + +static struct videobuf_buffer *__videobuf_alloc_vb(size_t size) +{ + struct videobuf_dma_sg_memory *mem; + struct videobuf_buffer *vb; + + vb = kzalloc(size + sizeof(*mem), GFP_KERNEL); + if (!vb) + return vb; + + mem = vb->priv = ((char *)vb) + size; + mem->magic = MAGIC_SG_MEM; + + videobuf_dma_init(&mem->dma); + + dprintk(1, "%s: allocated at %p(%ld+%ld) & %p(%ld)\n", + __func__, vb, (long)sizeof(*vb), (long)size - sizeof(*vb), + mem, (long)sizeof(*mem)); + + return vb; +} + +static void *__videobuf_to_vaddr(struct videobuf_buffer *buf) +{ + struct videobuf_dma_sg_memory *mem = buf->priv; + BUG_ON(!mem); + + MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); + + return mem->dma.vaddr; +} + +static int __videobuf_iolock(struct videobuf_queue *q, + struct videobuf_buffer *vb, + struct v4l2_framebuffer *fbuf) +{ + struct videobuf_dma_sg_memory *mem = vb->priv; + unsigned long pages; + dma_addr_t bus; + int err; + + BUG_ON(!mem); + + MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); + + if (!mem->dma.dev) + mem->dma.dev = q->dev; + else + WARN_ON(mem->dma.dev != q->dev); + + switch (vb->memory) { + case V4L2_MEMORY_MMAP: + case V4L2_MEMORY_USERPTR: + if (0 == vb->baddr) { + /* no userspace addr -- kernel bounce buffer */ + pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT; + err = videobuf_dma_init_kernel(&mem->dma, + DMA_FROM_DEVICE, + pages); + if (0 != err) + return err; + } else if (vb->memory == V4L2_MEMORY_USERPTR) { + /* dma directly to userspace */ + err = videobuf_dma_init_user(&mem->dma, + DMA_FROM_DEVICE, + vb->baddr, vb->bsize); + if (0 != err) + return err; + } else { + /* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP + buffers can only be called from videobuf_qbuf + we take current->mm->mmap_lock there, to prevent + locking inversion, so don't take it here */ + + err = videobuf_dma_init_user_locked(&mem->dma, + DMA_FROM_DEVICE, + vb->baddr, vb->bsize); + if (0 != err) + return err; + } + break; + case V4L2_MEMORY_OVERLAY: + if (NULL == fbuf) + return -EINVAL; + /* FIXME: need sanity checks for vb->boff */ + /* + * Using a double cast to avoid compiler warnings when + * building for PAE. Compiler doesn't like direct casting + * of a 32 bit ptr to 64 bit integer. + */ + bus = (dma_addr_t)(unsigned long)fbuf->base + vb->boff; + pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT; + err = videobuf_dma_init_overlay(&mem->dma, DMA_FROM_DEVICE, + bus, pages); + if (0 != err) + return err; + break; + default: + BUG(); + } + err = videobuf_dma_map(q->dev, &mem->dma); + if (0 != err) + return err; + + return 0; +} + +static int __videobuf_sync(struct videobuf_queue *q, + struct videobuf_buffer *buf) +{ + struct videobuf_dma_sg_memory *mem = buf->priv; + BUG_ON(!mem || !mem->dma.sglen); + + MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); + MAGIC_CHECK(mem->dma.magic, MAGIC_DMABUF); + + dma_sync_sg_for_cpu(q->dev, mem->dma.sglist, + mem->dma.nr_pages, mem->dma.direction); + + return 0; +} + +static int __videobuf_mmap_mapper(struct videobuf_queue *q, + struct videobuf_buffer *buf, + struct vm_area_struct *vma) +{ + struct videobuf_dma_sg_memory *mem = buf->priv; + struct videobuf_mapping *map; + unsigned int first, last, size = 0, i; + int retval; + + retval = -EINVAL; + + BUG_ON(!mem); + MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); + + /* look for first buffer to map */ + for (first = 0; first < VIDEO_MAX_FRAME; first++) { + if (buf == q->bufs[first]) { + size = PAGE_ALIGN(q->bufs[first]->bsize); + break; + } + } + + /* paranoia, should never happen since buf is always valid. */ + if (!size) { + dprintk(1, "mmap app bug: offset invalid [offset=0x%lx]\n", + (vma->vm_pgoff << PAGE_SHIFT)); + goto done; + } + + last = first; + + /* create mapping + update buffer list */ + retval = -ENOMEM; + map = kmalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); + if (NULL == map) + goto done; + + size = 0; + for (i = first; i <= last; i++) { + if (NULL == q->bufs[i]) + continue; + q->bufs[i]->map = map; + q->bufs[i]->baddr = vma->vm_start + size; + size += PAGE_ALIGN(q->bufs[i]->bsize); + } + + map->count = 1; + map->q = q; + vma->vm_ops = &videobuf_vm_ops; + vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; + vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */ + vma->vm_private_data = map; + dprintk(1, "mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n", + map, q, vma->vm_start, vma->vm_end, vma->vm_pgoff, first, last); + retval = 0; + +done: + return retval; +} + +static struct videobuf_qtype_ops sg_ops = { + .magic = MAGIC_QTYPE_OPS, + + .alloc_vb = __videobuf_alloc_vb, + .iolock = __videobuf_iolock, + .sync = __videobuf_sync, + .mmap_mapper = __videobuf_mmap_mapper, + .vaddr = __videobuf_to_vaddr, +}; + +void *videobuf_sg_alloc(size_t size) +{ + struct videobuf_queue q; + + /* Required to make generic handler to call __videobuf_alloc */ + q.int_ops = &sg_ops; + + q.msize = size; + + return videobuf_alloc_vb(&q); +} +EXPORT_SYMBOL_GPL(videobuf_sg_alloc); + +void videobuf_queue_sg_init(struct videobuf_queue *q, + const struct videobuf_queue_ops *ops, + struct device *dev, + spinlock_t *irqlock, + enum v4l2_buf_type type, + enum v4l2_field field, + unsigned int msize, + void *priv, + struct mutex *ext_lock) +{ + videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, + priv, &sg_ops, ext_lock); +} +EXPORT_SYMBOL_GPL(videobuf_queue_sg_init); + |