| Message ID | 20240131191732.3247996-2-cleech@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | UIO_MEM_DMA_COHERENT for cnic/bnx2/bnx2x | expand |
Hi, On Wed, Jan 31, 2024 at 11:17:31AM -0800, Chris Leech wrote: > Add a UIO memtype specifically for sharing dma_alloc_coherent > memory with userspace, backed by dma_mmap_coherent. > > This is mainly for the bnx2/bnx2x/bnx2i "cnic" interface, although there > are a few other uio drivers which map dma_alloc_coherent memory and > could be converted to use dma_mmap_coherent as well. > > Signed-off-by: Nilesh Javali <njavali@marvell.com> > Signed-off-by: Chris Leech <cleech@redhat.com> > --- > drivers/uio/uio.c | 40 ++++++++++++++++++++++++++++++++++++++ > include/linux/uio_driver.h | 3 +++ > 2 files changed, 43 insertions(+) > > diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c > index 2d572f6c8ec83..dde3f49855233 100644 > --- a/drivers/uio/uio.c > +++ b/drivers/uio/uio.c > @@ -24,6 +24,7 @@ [..] > +static int uio_mmap_dma_coherent(struct vm_area_struct *vma) > +{ > + struct uio_device *idev = vma->vm_private_data; > + struct uio_mem *mem; > + void *addr; > + int ret = 0; > + int mi; > + > + mi = uio_find_mem_index(vma); > + if (mi < 0) > + return -EINVAL; > + > + mem = idev->info->mem + mi; > + > + if (mem->dma_addr & ~PAGE_MASK) > + return -ENODEV; > + if (vma->vm_end - vma->vm_start > mem->size) > + return -EINVAL; > + > + /* > + * UIO uses offset to index into the maps for a device. > + * We need to clear vm_pgoff for dma_mmap_coherent. > + */ > + vma->vm_pgoff = 0; > + > + addr = (void *)mem->addr; This cast introduces a build error when building with sizeof(void *) != sizeof(phys_addr_t). For example on i386 with PHYS_ADDR_T_64BIT. (Enabled through allmodconfig) drivers/uio/uio.c: In function 'uio_mmap_dma_coherent': drivers/uio/uio.c:795:16: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast] 795 | addr = (void *)mem->addr; | ^ drivers/uio/uio_pruss.c: In function 'pruss_probe': drivers/uio/uio_pruss.c:194:34: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast] 194 | p->mem[2].addr = (phys_addr_t) gdev->ddr_vaddr; | ^ drivers/uio/uio_dmem_genirq.c: In function 'uio_dmem_genirq_open': drivers/uio/uio_dmem_genirq.c:63:39: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast] 63 | uiomem->addr = addr ? (phys_addr_t) addr : DMEM_MAP_ERROR; | ^ drivers/uio/uio_dmem_genirq.c: In function 'uio_dmem_genirq_release': drivers/uio/uio_dmem_genirq.c:92:43: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast] 92 | (void *) uiomem->addr, As you can see some other files are also affected, which seem to be triggered by other but related patches. This is on next-20240312. > + ret = dma_mmap_coherent(mem->dma_device, > + vma, > + addr, > + mem->dma_addr, > + vma->vm_end - vma->vm_start); > + vma->vm_pgoff = mi; > + > + return ret; > +} > + [..] Thomas
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 2d572f6c8ec83..dde3f49855233 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -24,6 +24,7 @@ #include <linux/kobject.h> #include <linux/cdev.h> #include <linux/uio_driver.h> +#include <linux/dma-mapping.h> #define UIO_MAX_DEVICES (1U << MINORBITS) @@ -759,6 +760,42 @@ static int uio_mmap_physical(struct vm_area_struct *vma) vma->vm_page_prot); } +static int uio_mmap_dma_coherent(struct vm_area_struct *vma) +{ + struct uio_device *idev = vma->vm_private_data; + struct uio_mem *mem; + void *addr; + int ret = 0; + int mi; + + mi = uio_find_mem_index(vma); + if (mi < 0) + return -EINVAL; + + mem = idev->info->mem + mi; + + if (mem->dma_addr & ~PAGE_MASK) + return -ENODEV; + if (vma->vm_end - vma->vm_start > mem->size) + return -EINVAL; + + /* + * UIO uses offset to index into the maps for a device. + * We need to clear vm_pgoff for dma_mmap_coherent. + */ + vma->vm_pgoff = 0; + + addr = (void *)mem->addr; + ret = dma_mmap_coherent(mem->dma_device, + vma, + addr, + mem->dma_addr, + vma->vm_end - vma->vm_start); + vma->vm_pgoff = mi; + + return ret; +} + static int uio_mmap(struct file *filep, struct vm_area_struct *vma) { struct uio_listener *listener = filep->private_data; @@ -806,6 +843,9 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma) case UIO_MEM_VIRTUAL: ret = uio_mmap_logical(vma); break; + case UIO_MEM_DMA_COHERENT: + ret = uio_mmap_dma_coherent(vma); + break; default: ret = -EINVAL; } diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h index 47c5962b876b0..14d9dd2a07e85 100644 --- a/include/linux/uio_driver.h +++ b/include/linux/uio_driver.h @@ -37,10 +37,12 @@ struct uio_map; struct uio_mem { const char *name; phys_addr_t addr; + dma_addr_t dma_addr; unsigned long offs; resource_size_t size; int memtype; void __iomem *internal_addr; + struct device *dma_device; struct uio_map *map; }; @@ -158,6 +160,7 @@ extern int __must_check #define UIO_MEM_LOGICAL 2 #define UIO_MEM_VIRTUAL 3 #define UIO_MEM_IOVA 4 +#define UIO_MEM_DMA_COHERENT 5 /* defines for uio_port->porttype */ #define UIO_PORT_NONE 0