lkml.org 
[lkml]   [2011]   [Oct]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] uio: Support 36-bit physical addresses on 32-bit systems
From
Date

On Oct 12, 2011, at 10:32 AM, Hans J. Koch wrote:

> On Wed, Oct 12, 2011 at 09:35:45AM -0500, Kumar Gala wrote:
>> From: Kai Jiang <Kai.Jiang@freescale.com>
>>
>> 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 'unsigned long long'
>> regardless of which type is utilized.
>
> No. There's phys_addr_t for that purpose, defined in include/linux/types.h.
> Please use that.

Do we believe phys_addr_t is always greater than or equal to size need for logical & virtual addresses?

- k


> Thanks,
> Hans
>
>>
>> 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>
>> ---
>> drivers/uio/uio.c | 8 ++++----
>> include/linux/uio_driver.h | 2 +-
>> 2 files changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
>> index d2efe82..a927c51 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", 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", mem->addr & ~PAGE_MASK);
>> }
>>
>> struct map_sysfs_entry {
>> @@ -634,8 +634,8 @@ 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);
>> else
>> - page = vmalloc_to_page((void *)idev->info->mem[mi].addr
>> - + offset);
>> + page = vmalloc_to_page((void *)(unsigned long)
>> + idev->info->mem[mi].addr + offset);
>> get_page(page);
>> vmf->page = page;
>> return 0;
>> diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
>> index 665517c..c1fdb19 100644
>> --- a/include/linux/uio_driver.h
>> +++ b/include/linux/uio_driver.h
>> @@ -31,7 +31,7 @@ struct uio_map;
>> */
>> struct uio_mem {
>> const char *name;
>> - unsigned long addr;
>> + unsigned long long addr;
>> unsigned long size;
>> int memtype;
>> void __iomem *internal_addr;
>> --
>> 1.7.3.4
>>
>>



\
 
 \ /
  Last update: 2011-10-12 18:09    [W:0.090 / U:14.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site