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Date: Sun, 29 Jun 2008 00:39:06 -0700
From: Yinghai Lu <yhlu.kernel@...il.com>
To: Ingo Molnar <mingo@...e.hu>, Thomas Gleixner <tglx@...utronix.de>,
"H. Peter Anvin" <hpa@...or.com>,
Jeremy Fitzhardinge <jeremy@...p.org>
Cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: [PATCH] x86: fix init_memory_mapping over boundary v4 - diff to v3
some end boundary is only page alignment, instead of 2M alignment,
so call ker_phycial_mapping_init three times.
then don't overmap above the max_low_pfn
v2: make init_memory_mapping more solid: start could be any value other than 0
v3: fix NON PAE by handling left over in kernel_physical_mapping
v4: revert back to v2, and use PMD_SHIFT to calculate boundary
also adjust size for pre-allocated table size
Signed-off-by: Yinghai Lu <yhlu.kernel@...il.com>
---
arch/x86/mm/init_32.c | 89 +++++++++++++++++++++++++++++++++++++-------------
1 file changed, 67 insertions(+), 22 deletions(-)
Index: linux-2.6/arch/x86/mm/init_32.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/init_32.c
+++ linux-2.6/arch/x86/mm/init_32.c
@@ -184,8 +184,9 @@ static inline int is_kernel_text(unsigne
* PAGE_OFFSET:
*/
static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
- unsigned long start,
- unsigned long end)
+ unsigned long start_pfn,
+ unsigned long end_pfn,
+ int use_pse)
{
int pgd_idx, pmd_idx, pte_ofs;
unsigned long pfn;
@@ -193,33 +194,33 @@ static void __init kernel_physical_mappi
pmd_t *pmd;
pte_t *pte;
unsigned pages_2m = 0, pages_4k = 0;
- unsigned limit_pfn = end >> PAGE_SHIFT;
- pgd_idx = pgd_index(start + PAGE_OFFSET);
- pgd = pgd_base + pgd_idx;
- pfn = start >> PAGE_SHIFT;
+ if (!cpu_has_pse)
+ use_pse = 0;
+ pfn = start_pfn;
+ pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
+ pgd = pgd_base + pgd_idx;
for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
pmd = one_md_table_init(pgd);
- if (pfn >= limit_pfn)
- continue;
- for (pmd_idx = 0;
- pmd_idx < PTRS_PER_PMD && pfn < limit_pfn;
+ if (pfn >= end_pfn)
+ continue;
+#ifdef CONFIG_X86_PAE
+ pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
+ pmd += pmd_idx;
+#else
+ pmd_idx = 0;
+#endif
+ for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
pmd++, pmd_idx++) {
unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
/*
* Map with big pages if possible, otherwise
* create normal page tables:
- *
- * Don't use a large page for the first 2/4MB of memory
- * because there are often fixed size MTRRs in there
- * and overlapping MTRRs into large pages can cause
- * slowdowns.
*/
- if (cpu_has_pse && !(pgd_idx == 0 && pmd_idx == 0) &&
- (pfn + PTRS_PER_PTE) <= limit_pfn) {
+ if (use_pse) {
unsigned int addr2;
pgprot_t prot = PAGE_KERNEL_LARGE;
@@ -238,8 +239,9 @@ static void __init kernel_physical_mappi
}
pte = one_page_table_init(pmd);
- for (pte_ofs = 0;
- pte_ofs < PTRS_PER_PTE && pfn < limit_pfn;
+ pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
+ pte += pte_ofs;
+ for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
pgprot_t prot = PAGE_KERNEL;
@@ -738,14 +740,18 @@ static void __init find_early_table_spac
if (cpu_has_pse) {
unsigned long extra;
- extra = end - ((end>>21) << 21);
- extra += (2UL<<20);
+
+ extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
+ extra += PMD_SIZE;
ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
} else
ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
tables += PAGE_ALIGN(ptes * sizeof(pte_t));
+ /* for fixmap */
+ tables += PAGE_SIZE * 2;
+
/*
* RED-PEN putting page tables only on node 0 could
* cause a hotspot and fill up ZONE_DMA. The page tables
@@ -770,6 +776,8 @@ unsigned long __init_refok init_memory_m
unsigned long end)
{
pgd_t *pgd_base = swapper_pg_dir;
+ unsigned long start_pfn, end_pfn;
+ unsigned long big_page_start;
/*
* Find space for the kernel direct mapping tables.
@@ -794,7 +802,44 @@ unsigned long __init_refok init_memory_m
__PAGE_KERNEL_EXEC |= _PAGE_GLOBAL;
}
- kernel_physical_mapping_init(pgd_base, start, end);
+ /*
+ * Don't use a large page for the first 2/4MB of memory
+ * because there are often fixed size MTRRs in there
+ * and overlapping MTRRs into large pages can cause
+ * slowdowns.
+ */
+ big_page_start = PMD_SIZE;
+
+ if (start < big_page_start) {
+ start_pfn = start >> PAGE_SHIFT;
+ end_pfn = min(big_page_start>>PAGE_SHIFT, end>>PAGE_SHIFT);
+ } else {
+ /* head is not big page alignment ? */
+ start_pfn = start >> PAGE_SHIFT;
+ end_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
+ << (PMD_SHIFT - PAGE_SHIFT);
+ }
+ if (start_pfn < end_pfn)
+ kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn, 0);
+
+ /* big page range */
+ start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
+ << (PMD_SHIFT - PAGE_SHIFT);
+ if (start_pfn < (big_page_start >> PAGE_SHIFT))
+ start_pfn = big_page_start >> PAGE_SHIFT;
+ end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
+ if (start_pfn < end_pfn)
+ kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn,
+ cpu_has_pse);
+
+ /* tail is not big page alignment ? */
+ start_pfn = end_pfn;
+ if (start_pfn > (big_page_start>>PAGE_SHIFT)) {
+ end_pfn = end >> PAGE_SHIFT;
+ if (start_pfn < end_pfn)
+ kernel_physical_mapping_init(pgd_base, start_pfn,
+ end_pfn, 0);
+ }
early_ioremap_page_table_range_init(pgd_base);
--
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