Eric Lee / linux-smarc-t335x-v3.2

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Commit d68612b257b5f4ea2e6535859c5a26b10011a9df

Authored by Suresh Siddha
Committed by Ingo Molnar
1 parent e946217e4f
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

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>

Showing 1 changed file with 3 additions and 1 deletions Side-by-side Diff

... ... @@ -17,6 +17,7 @@
17 17 #include <linux/proc_fs.h>
18 18 #include <linux/seq_file.h>
19 19 #include <linux/device.h>
  20 +#include <linux/pfn.h>
20 21 #include <asm/io.h>
21 22  
22 23  
... ... @@ -849,7 +850,8 @@
849 850 continue;
850 851 if (p->end < addr)
851 852 continue;
852   - if (p->start <= addr && (p->end >= addr + size - 1))
  853 + if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
  854 + PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
853 855 continue;
854 856 printk(KERN_WARNING "resource map sanity check conflict: "
855 857 "0x%llx 0x%llx 0x%llx 0x%llx %s\n",