From b7cfda9fc3d7aa60cffab5367f2a72a4a70060cd Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 7 Sep 2009 15:06:42 +0100 Subject: ARM: Fix pfn_valid() for sparse memory On OMAP platforms, some people want to declare to segment up the memory between the kernel and a separate application such that there is a hole in the middle of the memory as far as Linux is concerned. However, they want to be able to mmap() the hole. This currently causes problems, because update_mmu_cache() thinks that there are valid struct pages for the "hole". Fix this by making pfn_valid() slightly more expensive, by checking whether the PFN is contained within the meminfo array. Signed-off-by: Russell King Tested-by: Khasim Syed Mohammed --- arch/arm/mm/init.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'arch/arm/mm/init.c') diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 3a7279c1ce5..ea36186f32c 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -349,12 +350,43 @@ static void __init bootmem_free_node(int node, struct meminfo *mi) free_area_init_node(node, zone_size, min, zhole_size); } +#ifndef CONFIG_SPARSEMEM +int pfn_valid(unsigned long pfn) +{ + struct meminfo *mi = &meminfo; + unsigned int left = 0, right = mi->nr_banks; + + do { + unsigned int mid = (right + left) / 2; + struct membank *bank = &mi->bank[mid]; + + if (pfn < bank_pfn_start(bank)) + right = mid; + else if (pfn >= bank_pfn_end(bank)) + left = mid + 1; + else + return 1; + } while (left < right); + return 0; +} +EXPORT_SYMBOL(pfn_valid); +#endif + +static int __init meminfo_cmp(const void *_a, const void *_b) +{ + const struct membank *a = _a, *b = _b; + long cmp = bank_pfn_start(a) - bank_pfn_start(b); + return cmp < 0 ? -1 : cmp > 0 ? 1 : 0; +} + void __init bootmem_init(void) { struct meminfo *mi = &meminfo; unsigned long min, max_low, max_high; int node, initrd_node; + sort(&mi->bank, mi->nr_banks, sizeof(mi->bank[0]), meminfo_cmp, NULL); + /* * Locate which node contains the ramdisk image, if any. */ -- cgit v1.2.3-70-g09d2