Re: [PATCH] uio: Support 36-bit physical addresses on 32-bit systems
From: Hans J. Koch <hidden>
Date: 2011-10-14 18:32:12
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On Thu, Oct 13, 2011 at 10:50:58AM -0500, Kumar Gala wrote:
From: Kai Jiang <redacted> 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 <redacted> Signed-off-by: Minghuan Lian <redacted> Signed-off-by: Kumar Gala <redacted>
Signed-off-by: "Hans J. Koch" <redacted> That looks good to me. There's an unnecessary cast (see below), but I fixed that on the way. Greg, please pull this from branch uio-for-gregkh from git://hansjkoch.de/git/linux-hjk Thanks, Hans
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--- v3: * Updated commit message to be correct w/regards to code * Updated comment about addr field in uio_mem v2: * Use phys_addr_t instead of 'unsigned long long' * Updated DocBook detail in uio-howto.tmpl Documentation/DocBook/uio-howto.tmpl | 2 +- drivers/uio/uio.c | 8 ++++---- include/linux/uio_driver.h | 7 +++++-- 3 files changed, 10 insertions(+), 7 deletions(-)diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl index 7c4b514d..54883de 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 </para></listitem> <listitem><para> -<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. </para></listitem>diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 88f4444..43b7096 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 +634,8 @@ 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)
(void *) is enough, the (unsigned long) is not needed.
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+ 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 4c618cd..ad16aa9 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@@ -32,7 +35,7 @@ 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;-- 1.7.3.4