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| author | Suresh Siddha <suresh.b.siddha@intel.com> | 2008-10-28 11:45:42 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-10-28 19:56:17 +0100 |
| commit | d68612b257b5f4ea2e6535859c5a26b10011a9df (patch) | |
| tree | abbc11c7ec95d97d11c9c7f9e0e87fd4ef0b4a58 /kernel/resource.c | |
| parent | e946217e4fdaa67681bbabfa8e6b18641921f750 (diff) | |
| download | lwn-d68612b257b5f4ea2e6535859c5a26b10011a9df.tar.gz lwn-d68612b257b5f4ea2e6535859c5a26b10011a9df.zip | |
resources: fix x86info results ioremap.c:226 __ioremap_caller+0xf2/0x2d6() WARNINGs
Impact: avoid false-positive WARN_ON()
Andi Kleen reported:
> When running x86info on a 2.6.27-git8 system I get
>
> resource map sanity check conflict: 0x9e000 0x9efff 0x10000 0x9e7ff System RAM
> ------------[ cut here ]------------
> WARNING: at /home/lsrc/linux/arch/x86/mm/ioremap.c:226 __ioremap_caller+0xf2/0x2d6()
> ...
Some of the pages below the 1MB ISA addresses will be shared typically by both
BIOS and system usable RAM. For example:
BIOS-e820: 0000000000000000 - 000000000009f800 (usable)
BIOS-e820: 000000000009f800 - 00000000000a0000 (reserved)
x86info reads the low physical address using /dev/mem, which internally
uses ioremap() for accessing non RAM pages. ioremap() of such low
pages conflicts with multiple resource entities leading to the
above warning.
Change the iomem_map_sanity_check() to allow mapping a page spanning multiple
resource entities (minimum granularity that one can map is a page anyhow).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/resource.c')
| -rw-r--r-- | kernel/resource.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index 7fec0e427234..6aac5c60b25d 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -17,6 +17,7 @@ #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/device.h> +#include <linux/pfn.h> #include <asm/io.h> @@ -849,7 +850,8 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size) continue; if (p->end < addr) continue; - if (p->start <= addr && (p->end >= addr + size - 1)) + if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && + PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) continue; printk(KERN_WARNING "resource map sanity check conflict: " "0x%llx 0x%llx 0x%llx 0x%llx %s\n", |