summaryrefslogtreecommitdiff
path: root/arch/x86/mm/init_32.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/mm/init_32.c')
-rw-r--r--arch/x86/mm/init_32.c35
1 files changed, 18 insertions, 17 deletions
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index ee1091a46964..1500dc8d63e4 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -51,6 +51,8 @@
unsigned int __VMALLOC_RESERVE = 128 << 20;
+unsigned long max_pfn_mapped;
+
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
unsigned long highstart_pfn, highend_pfn;
@@ -179,8 +181,13 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
/*
* 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) {
+ if (cpu_has_pse && !(pgd_idx == 0 && pmd_idx == 0)) {
unsigned int addr2;
pgprot_t prot = PAGE_KERNEL_LARGE;
@@ -194,6 +201,7 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
set_pmd(pmd, pfn_pmd(pfn, prot));
pfn += PTRS_PER_PTE;
+ max_pfn_mapped = pfn;
continue;
}
pte = one_page_table_init(pmd);
@@ -208,6 +216,7 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
set_pte(pte, pfn_pte(pfn, prot));
}
+ max_pfn_mapped = pfn;
}
}
}
@@ -723,25 +732,17 @@ void mark_rodata_ro(void)
unsigned long start = PFN_ALIGN(_text);
unsigned long size = PFN_ALIGN(_etext) - start;
-#ifndef CONFIG_KPROBES
-#ifdef CONFIG_HOTPLUG_CPU
- /* It must still be possible to apply SMP alternatives. */
- if (num_possible_cpus() <= 1)
-#endif
- {
- set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
- printk(KERN_INFO "Write protecting the kernel text: %luk\n",
- size >> 10);
+ set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
+ printk(KERN_INFO "Write protecting the kernel text: %luk\n",
+ size >> 10);
#ifdef CONFIG_CPA_DEBUG
- printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
- start, start+size);
- set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
+ printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
+ start, start+size);
+ set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
- printk(KERN_INFO "Testing CPA: write protecting again\n");
- set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
-#endif
- }
+ printk(KERN_INFO "Testing CPA: write protecting again\n");
+ set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
#endif
start += size;
size = (unsigned long)__end_rodata - start;