3.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jacob Shin <jacob.s...@amd.com> commit 844ab6f993b1d32eb40512503d35ff6ad0c57030 upstream. Current logic finds enough space for direct mapping page tables from 0 to end. Instead, we only need to find enough space to cover mr[0].start to mr[nr_range].end -- the range that is actually being mapped by init_memory_mapping() This is needed after 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a, to address the panic reported here: https://lkml.org/lkml/2012/10/20/160 https://lkml.org/lkml/2012/10/21/157 Signed-off-by: Jacob Shin <jacob.s...@amd.com> Link: http://lkml.kernel.org/r/20121024195311.GB11779@jshin-Toonie Tested-by: Tom Rini <tr...@ti.com> Signed-off-by: H. Peter Anvin <h...@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- arch/x86/mm/init.c | 73 +++++++++++++++++++++++++++++++---------------------- 1 file changed, 43 insertions(+), 30 deletions(-) --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -29,36 +29,54 @@ int direct_gbpages #endif ; -static void __init find_early_table_space(unsigned long end, int use_pse, - int use_gbpages) +struct map_range { + unsigned long start; + unsigned long end; + unsigned page_size_mask; +}; + +/* + * First calculate space needed for kernel direct mapping page tables to cover + * mr[0].start to mr[nr_range - 1].end, while accounting for possible 2M and 1GB + * pages. Then find enough contiguous space for those page tables. + */ +static void __init find_early_table_space(struct map_range *mr, int nr_range) { - unsigned long puds, pmds, ptes, tables, start = 0, good_end = end; + int i; + unsigned long puds = 0, pmds = 0, ptes = 0, tables; + unsigned long start = 0, good_end; phys_addr_t base; - puds = (end + PUD_SIZE - 1) >> PUD_SHIFT; - tables = roundup(puds * sizeof(pud_t), PAGE_SIZE); + for (i = 0; i < nr_range; i++) { + unsigned long range, extra; - if (use_gbpages) { - unsigned long extra; + range = mr[i].end - mr[i].start; + puds += (range + PUD_SIZE - 1) >> PUD_SHIFT; - extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT); - pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT; - } else - pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT; - - tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE); + if (mr[i].page_size_mask & (1 << PG_LEVEL_1G)) { + extra = range - ((range >> PUD_SHIFT) << PUD_SHIFT); + pmds += (extra + PMD_SIZE - 1) >> PMD_SHIFT; + } else { + pmds += (range + PMD_SIZE - 1) >> PMD_SHIFT; + } - if (use_pse) { - unsigned long extra; - - extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT); + if (mr[i].page_size_mask & (1 << PG_LEVEL_2M)) { + extra = range - ((range >> PMD_SHIFT) << PMD_SHIFT); #ifdef CONFIG_X86_32 - extra += PMD_SIZE; + extra += PMD_SIZE; #endif - ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT; - } else - ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT; + /* The first 2/4M doesn't use large pages. */ + if (mr[i].start < PMD_SIZE) + extra += range; + + ptes += (extra + PAGE_SIZE - 1) >> PAGE_SHIFT; + } else { + ptes += (range + PAGE_SIZE - 1) >> PAGE_SHIFT; + } + } + tables = roundup(puds * sizeof(pud_t), PAGE_SIZE); + tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE); tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE); #ifdef CONFIG_X86_32 @@ -75,8 +93,9 @@ static void __init find_early_table_spac pgt_buf_end = pgt_buf_start; pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT); - printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n", - end, pgt_buf_start << PAGE_SHIFT, pgt_buf_top << PAGE_SHIFT); + printk(KERN_DEBUG "kernel direct mapping tables up to %#lx @ [mem %#010lx-%#010lx]\n", + mr[nr_range - 1].end - 1, pgt_buf_start << PAGE_SHIFT, + (pgt_buf_top << PAGE_SHIFT) - 1); } void __init native_pagetable_reserve(u64 start, u64 end) @@ -84,12 +103,6 @@ void __init native_pagetable_reserve(u64 memblock_reserve(start, end - start); } -struct map_range { - unsigned long start; - unsigned long end; - unsigned page_size_mask; -}; - #ifdef CONFIG_X86_32 #define NR_RANGE_MR 3 #else /* CONFIG_X86_64 */ @@ -261,7 +274,7 @@ unsigned long __init_refok init_memory_m * nodes are discovered. */ if (!after_bootmem) - find_early_table_space(end, use_pse, use_gbpages); + find_early_table_space(mr, nr_range); for (i = 0; i < nr_range; i++) ret = kernel_physical_mapping_init(mr[i].start, mr[i].end, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
