x86: make 32-bit init_memory_mapping range change more like 64-bit
Impact: cleanup make code more readable and more like 64-bit Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <49AE48B4.8010907@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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1 changed files with 94 additions and 32 deletions
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@ -885,29 +885,55 @@ static void __init find_early_table_space(unsigned long end, int use_pse)
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(table_start << PAGE_SHIFT) + tables);
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}
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struct map_range {
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unsigned long start;
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unsigned long end;
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unsigned page_size_mask;
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};
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#define NR_RANGE_MR 3
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static int save_mr(struct map_range *mr, int nr_range,
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unsigned long start_pfn, unsigned long end_pfn,
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unsigned long page_size_mask)
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{
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if (start_pfn < end_pfn) {
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if (nr_range >= NR_RANGE_MR)
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panic("run out of range for init_memory_mapping\n");
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mr[nr_range].start = start_pfn<<PAGE_SHIFT;
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mr[nr_range].end = end_pfn<<PAGE_SHIFT;
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mr[nr_range].page_size_mask = page_size_mask;
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nr_range++;
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}
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return nr_range;
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}
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unsigned long __init_refok init_memory_mapping(unsigned long start,
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unsigned long end)
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{
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pgd_t *pgd_base = swapper_pg_dir;
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unsigned long page_size_mask = 0;
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unsigned long start_pfn, end_pfn;
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unsigned long big_page_start;
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unsigned long pos;
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struct map_range mr[NR_RANGE_MR];
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int nr_range, i;
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int use_pse;
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printk(KERN_INFO "init_memory_mapping: %08lx-%08lx\n", start, end);
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#ifdef CONFIG_DEBUG_PAGEALLOC
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/*
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* For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
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* This will simplify cpa(), which otherwise needs to support splitting
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* large pages into small in interrupt context, etc.
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*/
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int use_pse = 0;
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use_pse = 0;
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#else
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int use_pse = cpu_has_pse;
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use_pse = cpu_has_pse;
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#endif
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/*
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* Find space for the kernel direct mapping tables.
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*/
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if (!after_init_bootmem)
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find_early_table_space(end, use_pse);
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#ifdef CONFIG_X86_PAE
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set_nx();
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if (nx_enabled)
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@ -924,45 +950,81 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
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__supported_pte_mask |= _PAGE_GLOBAL;
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}
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memset(mr, 0, sizeof(mr));
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nr_range = 0;
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if (use_pse)
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page_size_mask |= 1 << PG_LEVEL_2M;
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/*
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* Don't use a large page for the first 2/4MB of memory
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* because there are often fixed size MTRRs in there
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* and overlapping MTRRs into large pages can cause
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* slowdowns.
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*/
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big_page_start = PMD_SIZE;
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if (start < big_page_start) {
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start_pfn = start >> PAGE_SHIFT;
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end_pfn = min(big_page_start>>PAGE_SHIFT, end>>PAGE_SHIFT);
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} else {
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/* head is not big page alignment ? */
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start_pfn = start >> PAGE_SHIFT;
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end_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
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/* head could not be big page alignment ? */
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start_pfn = start >> PAGE_SHIFT;
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pos = start_pfn << PAGE_SHIFT;
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if (pos == 0)
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end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT);
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else
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end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
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<< (PMD_SHIFT - PAGE_SHIFT);
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if (end_pfn > (end>>PAGE_SHIFT))
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end_pfn = end>>PAGE_SHIFT;
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if (start_pfn < end_pfn) {
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nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
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pos = end_pfn << PAGE_SHIFT;
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}
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if (start_pfn < end_pfn)
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kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn, 0);
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/* big page range */
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start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
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start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
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<< (PMD_SHIFT - PAGE_SHIFT);
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if (start_pfn < (big_page_start >> PAGE_SHIFT))
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start_pfn = big_page_start >> PAGE_SHIFT;
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end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
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if (start_pfn < end_pfn)
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kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn,
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use_pse);
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if (start_pfn < end_pfn) {
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nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
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page_size_mask & (1<<PG_LEVEL_2M));
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pos = end_pfn << PAGE_SHIFT;
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}
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/* tail is not big page alignment ? */
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start_pfn = end_pfn;
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if (start_pfn > (big_page_start>>PAGE_SHIFT)) {
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end_pfn = end >> PAGE_SHIFT;
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if (start_pfn < end_pfn)
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kernel_physical_mapping_init(pgd_base, start_pfn,
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end_pfn, 0);
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start_pfn = pos>>PAGE_SHIFT;
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end_pfn = end>>PAGE_SHIFT;
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if (start_pfn < end_pfn)
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nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
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/* try to merge same page size and continuous */
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for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
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unsigned long old_start;
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if (mr[i].end != mr[i+1].start ||
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mr[i].page_size_mask != mr[i+1].page_size_mask)
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continue;
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/* move it */
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old_start = mr[i].start;
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memmove(&mr[i], &mr[i+1],
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(nr_range - 1 - i) * sizeof(struct map_range));
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mr[i--].start = old_start;
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nr_range--;
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}
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for (i = 0; i < nr_range; i++)
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printk(KERN_DEBUG " %08lx - %08lx page %s\n",
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mr[i].start, mr[i].end,
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(mr[i].page_size_mask & (1<<PG_LEVEL_2M)) ?
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"big page" : "4k");
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/*
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* Find space for the kernel direct mapping tables.
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*/
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if (!after_init_bootmem)
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find_early_table_space(end, use_pse);
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for (i = 0; i < nr_range; i++)
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kernel_physical_mapping_init(pgd_base,
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mr[i].start >> PAGE_SHIFT,
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mr[i].end >> PAGE_SHIFT,
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mr[i].page_size_mask == (1<<PG_LEVEL_2M));
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early_ioremap_page_table_range_init(pgd_base);
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load_cr3(swapper_pg_dir);
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