From d68612b257b5f4ea2e6535859c5a26b10011a9df Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Tue, 28 Oct 2008 11:45:42 -0700 Subject: [PATCH] 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 Signed-off-by: Ingo Molnar --- kernel/resource.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) 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 #include #include +#include #include @@ -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", -- GitLab