[PATCH] [6/8] Account overlapped mappings in end_pfn_map

Andi Kleen
2008-02-11T09:36:38Z

When end_pfn is not aligned to 2MB (or 1GB) then the kernel might
map more memory than end_pfn. Account this in end_pfn_mapped.

This is needed for other code that needs to know the true
mapping alias state (in this case EFI).

But it's also more correct in general

Cc: ying.huang@intel.com

Signed-off-by: Andi Kleen <ak@suse.de>

---
arch/x86/kernel/setup_64.c | 4 +++-
arch/x86/mm/init_64.c | 33 +++++++++++++++++++++++----------
include/asm-x86/proto.h | 2 +-
3 files changed, 27 insertions(+), 12 deletions(-)

Index: linux/arch/x86/mm/init_64.c
===================================================================
--- linux.orig/arch/x86/mm/init_64.c
+++ linux/arch/x86/mm/init_64.c
@@ -287,7 +287,7 @@ __meminit void early_iounmap(void *addr,
__flush_tlb_all();
}

-static void __meminit
+static unsigned long __meminit
phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
{
int i = pmd_index(address);
@@ -309,21 +309,25 @@ phys_pmd_init(pmd_t *pmd_page, unsigned
set_pte((pte_t *)pmd,
pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
}
+ return address;
}

-static void __meminit
+static unsigned long __meminit
phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
{
+ unsigned long r;
pmd_t *pmd = pmd_offset(pud, 0);
spin_lock(&init_mm.page_table_lock);
- phys_pmd_init(pmd, address, end);
+ r = phys_pmd_init(pmd, address, end);
spin_unlock(&init_mm.page_table_lock);
__flush_tlb_all();
+ return r;
}

-static void __meminit
+static unsigned long __meminit
phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
{
+ unsigned long true_end = end;
int i = pud_index(addr);

for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
@@ -342,13 +346,14 @@ phys_pud_init(pud_t *pud_page, unsigned

if (pud_val(*pud)) {
if (!pud_large(*pud))
- phys_pmd_update(pud, addr, end);
+ true_end = phys_pmd_update(pud, addr, end);
continue;
}

if (direct_gbpages) {
set_pte((pte_t *)pud,
pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
+ true_end = (addr & PUD_MASK) + PUD_SIZE;
continue;
}

@@ -356,12 +361,14 @@ phys_pud_init(pud_t *pud_page, unsigned

spin_lock(&init_mm.page_table_lock);
set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
- phys_pmd_init(pmd, addr, end);
+ true_end = phys_pmd_init(pmd, addr, end);
spin_unlock(&init_mm.page_table_lock);

unmap_low_page(pmd);
}
__flush_tlb_all();
+
+ return true_end >> PAGE_SHIFT;
}

static void __init find_early_table_space(unsigned long end)
@@ -406,9 +413,10 @@ static void __init init_gbpages(void)
* This runs before bootmem is initialized and gets pages directly from
* the physical memory. To access them they are temporarily mapped.
*/
-void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
+unsigned long __init_refok
+init_memory_mapping(unsigned long start, unsigned long end)
{
- unsigned long next;
+ unsigned long next, true_end = end;

pr_debug("init_memory_mapping\n");

@@ -446,7 +454,7 @@ void __init_refok init_memory_mapping(un
next = start + PGDIR_SIZE;
if (next > end)
next = end;
- phys_pud_init(pud, __pa(start), __pa(next));
+ true_end = phys_pud_init(pud, __pa(start), __pa(next));
set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
unmap_low_page(pud);
}
@@ -458,6 +466,8 @@ void __init_refok init_memory_mapping(un
if (!after_bootmem)
reserve_early(table_start << PAGE_SHIFT,
table_end << PAGE_SHIFT, "PGTABLE");
+
+ return true_end;
}

#ifndef CONFIG_NUMA
@@ -499,9 +509,12 @@ int arch_add_memory(int nid, u64 start,
struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
+ unsigned long r;
int ret;

- init_memory_mapping(start, start + size-1);
+ r = init_memory_mapping(start, start + size-1);
+ if (r > end_pfn_map)
+ end_pfn_map = r;

ret = __add_pages(zone, start_pfn, nr_pages);
WARN_ON(1);
Index: linux/include/asm-x86/proto.h
===================================================================
--- linux.orig/include/asm-x86/proto.h
+++ linux/include/asm-x86/proto.h
@@ -7,7 +7,8 @@

extern void early_idt_handler(void);

-extern void init_memory_mapping(unsigned long start, unsigned long end);
+extern unsigned long init_memory_mapping(unsigned long start,
+ unsigned long end);

extern void system_call(void);
extern void syscall_init(void);
Index: linux/arch/x86/kernel/setup_64.c
===================================================================
--- linux.orig/arch/x86/kernel/setup_64.c
+++ linux/arch/x86/kernel/setup_64.c
@@ -341,7 +341,7 @@ void __init setup_arch(char **cmdline_p)

check_efer();

- init_memory_mapping(0, (end_pfn_map << PAGE_SHIFT));
+ end_pfn_map = init_memory_mapping(0, (end_pfn_map << PAGE_SHIFT));
if (efi_enabled)
efi_init();