diff options
authorKai Jiang <Kai.Jiang@freescale.com>2011-10-17 20:50:20 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-10-18 11:18:57 -0700
commit27a90700a4275c5178b883b65927affdafa5185c (patch)
parentc4253cb0748cd50060d04d838c38b07f1ad0e6e5 (diff)
uio: Support physical addresses >32 bits on 32-bit systems
To support >32-bit physical addresses for UIO_MEM_PHYS type we need to extend the width of 'addr' in struct uio_mem. Numerous platforms like embedded PPC, ARM, and X86 have support for systems with larger physical address than logical. Since 'addr' may contain a physical, logical, or virtual address the easiest solution is to just change the type to 'phys_addr_t' which should always be greater than or equal to the sizeof(void *) such that it can properly hold any of the address types. For physical address we can support up to a 44-bit physical address on a typical 32-bit system as we utilize remap_pfn_range() for the mapping of the memory region and pfn's are represnted by shifting the address by the page size (typically 4k). Signed-off-by: Kai Jiang <Kai.Jiang@freescale.com> Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Hans J. Koch <hjk@hansjkoch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
3 files changed, 9 insertions, 7 deletions
diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl
index 7c4b514d62b..54883de5d5f 100644
--- a/Documentation/DocBook/uio-howto.tmpl
+++ b/Documentation/DocBook/uio-howto.tmpl
@@ -529,7 +529,7 @@ memory (e.g. allocated with <function>kmalloc()</function>). There's also
-<varname>unsigned long addr</varname>: Required if the mapping is used.
+<varname>phys_addr_t addr</varname>: Required if the mapping is used.
Fill in the address of your memory block. This address is the one that
appears in sysfs.
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index c89f12a8b11..a783d533a1a 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -69,7 +69,7 @@ static ssize_t map_name_show(struct uio_mem *mem, char *buf)
static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
- return sprintf(buf, "0x%lx\n", mem->addr);
+ return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr);
static ssize_t map_size_show(struct uio_mem *mem, char *buf)
@@ -79,7 +79,7 @@ static ssize_t map_size_show(struct uio_mem *mem, char *buf)
static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
- return sprintf(buf, "0x%lx\n", mem->addr & ~PAGE_MASK);
+ return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK);
struct map_sysfs_entry {
@@ -634,8 +634,7 @@ static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
page = virt_to_page(idev->info->mem[mi].addr + offset);
- page = vmalloc_to_page((void *)idev->info->mem[mi].addr
- + offset);
+ page = vmalloc_to_page((void *)(unsigned long)idev->info->mem[mi].addr + offset);
vmf->page = page;
return 0;
diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
index 665517c05ea..fd99ff9298c 100644
--- a/include/linux/uio_driver.h
+++ b/include/linux/uio_driver.h
@@ -23,7 +23,10 @@ struct uio_map;
* struct uio_mem - description of a UIO memory region
* @name: name of the memory region for identification
- * @addr: address of the device's memory
+ * @addr: address of the device's memory (phys_addr is used since
+ * addr can be logical, virtual, or physical & phys_addr_t
+ * should always be large enough to handle any of the
+ * address types)
* @size: size of IO
* @memtype: type of memory addr points to
* @internal_addr: ioremap-ped version of addr, for driver internal use
@@ -31,7 +34,7 @@ struct uio_map;
struct uio_mem {
const char *name;
- unsigned long addr;
+ phys_addr_t addr;
unsigned long size;
int memtype;
void __iomem *internal_addr;