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authorClemens Ladisch <clemens@ladisch.de>2011-01-13 10:12:17 +0100
committerStefan Richter <stefanr@s5r6.in-berlin.de>2011-01-13 15:48:29 +0100
commit1427130425c1239d977e8891c3a8923f53a6e352 (patch)
tree940207bbaf155d7ed36c6b8fab201dae6773ec1f /drivers/firewire
parent410cf2bd3dc6ec1ed9e1b36b25b9d7aa927ed14e (diff)
downloadlinux-1427130425c1239d977e8891c3a8923f53a6e352.tar.bz2
firewire: ohci: fix compilation on arches without PAGE_KERNEL_RO
PAGE_KERNEL_RO is not available on all architectures, so its use in the new AR code broke compilation on sparc64. Because the read-only mapping was just a debugging aid, just use PAGE_KERNEL instead. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> James Bottomley wrote: > On Thu, 2011-01-13 at 08:27 +0100, Clemens Ladisch wrote: >> firewire: ohci: fix compilation on arches without PAGE_KERNEL_RO, e.g. sparc >> >> PAGE_KERNEL_RO is not available on all architectures, so its use in the >> new AR code broke compilation on sparc64. >> >> Because the R/O mapping is only used to catch drivers that try to write >> to the reception buffer and not actually required for correct operation, >> we can just use a normal PAGE_KERNEL mapping where _RO is not available. [...] >> +/* >> + * For archs where PAGE_KERNEL_RO is not supported; >> + * mapping the AR buffers readonly for the CPU is just a debugging aid. >> + */ >> +#ifndef PAGE_KERNEL_RO >> +#define PAGE_KERNEL_RO PAGE_KERNEL >> +#endif > > This might cause interesting issues on sparc64 if it ever acquired a > PAGE_KERNEL_RO. Sparc64 has extern pgprot_t for it's PAGE_KERNEL types > rather than #defines, so the #ifdef check wouldn't see this. > > I think either PAGE_PROT_RO becomes part of our arch API (so all > architectures are forced to add it), or, if it's not part of the API, > ohci isn't entitled to use it. The latter seems simplest since you have > no real use for write protection anyway. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'drivers/firewire')
-rw-r--r--drivers/firewire/ohci.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index d77d120ddc25..bd3c61b6dd8d 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -961,7 +961,7 @@ static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
pages[AR_BUFFERS + i] = ctx->pages[i];
ctx->buffer = vm_map_ram(pages, AR_BUFFERS + AR_WRAPAROUND_PAGES,
- -1, PAGE_KERNEL_RO);
+ -1, PAGE_KERNEL);
if (!ctx->buffer)
goto out_of_memory;