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Date: Thu, 21 Aug 2008 14:27:22 +0100
From: "Jan Beulich" <jbeulich@...ell.com>
To: <mingo@...e.hu>, <tglx@...utronix.de>, <hpa@...or.com>
Cc: <linux-kernel@...r.kernel.org>
Subject: [PATCH] x86-64: fix 1:1 mapping init (hotplug case)
While I don't have a hotplug capable system at hand, I think two issues need
fixing:
- pud_phys (in kernel_physical_ampping_init()) would remain uninitialized in
the after_bootmem case
- the locking done just around phys_pmd_{init,update}() would leave out pgd
updates, and it was needlessly covering code portions that do allocations
(perhaps using a more friendly gfp value in alloc_low_page() would then be
possible)
Signed-off-by: Jan Beulich <jbeulich@...ell.com>
---
arch/x86/mm/init_64.c | 32 ++++++++++++++++++--------------
1 file changed, 18 insertions(+), 14 deletions(-)
--- linux-2.6.27-rc4/arch/x86/mm/init_64.c 2008-08-21 15:02:41.000000000 +0200
+++ 2.6.27-rc4-x86_64-init-mem-map/arch/x86/mm/init_64.c 2008-08-21 11:49:44.000000000 +0200
@@ -336,9 +336,12 @@ phys_pmd_init(pmd_t *pmd_page, unsigned
}
if (pmd_val(*pmd)) {
- if (!pmd_large(*pmd))
+ if (!pmd_large(*pmd)) {
+ spin_lock(&init_mm.page_table_lock);
last_map_addr = phys_pte_update(pmd, address,
- end);
+ end);
+ spin_unlock(&init_mm.page_table_lock);
+ }
/* Count entries we're using from level2_ident_pgt */
if (start == 0)
pages++;
@@ -347,8 +350,10 @@ phys_pmd_init(pmd_t *pmd_page, unsigned
if (page_size_mask & (1<<PG_LEVEL_2M)) {
pages++;
+ spin_lock(&init_mm.page_table_lock);
set_pte((pte_t *)pmd,
pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
+ spin_unlock(&init_mm.page_table_lock);
last_map_addr = (address & PMD_MASK) + PMD_SIZE;
continue;
}
@@ -357,7 +362,9 @@ phys_pmd_init(pmd_t *pmd_page, unsigned
last_map_addr = phys_pte_init(pte, address, end);
unmap_low_page(pte);
+ spin_lock(&init_mm.page_table_lock);
pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
+ spin_unlock(&init_mm.page_table_lock);
}
update_page_count(PG_LEVEL_2M, pages);
return last_map_addr;
@@ -370,9 +377,7 @@ phys_pmd_update(pud_t *pud, unsigned lon
pmd_t *pmd = pmd_offset(pud, 0);
unsigned long last_map_addr;
- spin_lock(&init_mm.page_table_lock);
last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask);
- spin_unlock(&init_mm.page_table_lock);
__flush_tlb_all();
return last_map_addr;
}
@@ -408,20 +413,21 @@ phys_pud_init(pud_t *pud_page, unsigned
if (page_size_mask & (1<<PG_LEVEL_1G)) {
pages++;
+ spin_lock(&init_mm.page_table_lock);
set_pte((pte_t *)pud,
pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
+ spin_unlock(&init_mm.page_table_lock);
last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
continue;
}
pmd = alloc_low_page(&pmd_phys);
-
- spin_lock(&init_mm.page_table_lock);
last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask);
unmap_low_page(pmd);
+
+ spin_lock(&init_mm.page_table_lock);
pud_populate(&init_mm, pud, __va(pmd_phys));
spin_unlock(&init_mm.page_table_lock);
-
}
__flush_tlb_all();
update_page_count(PG_LEVEL_1G, pages);
@@ -513,16 +519,14 @@ static unsigned long __init kernel_physi
continue;
}
- if (after_bootmem)
- pud = pud_offset(pgd, start & PGDIR_MASK);
- else
- pud = alloc_low_page(&pud_phys);
-
+ pud = alloc_low_page(&pud_phys);
last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
page_size_mask);
unmap_low_page(pud);
- pgd_populate(&init_mm, pgd_offset_k(start),
- __va(pud_phys));
+
+ spin_lock(&init_mm.page_table_lock);
+ pgd_populate(&init_mm, pgd, __va(pud_phys));
+ spin_unlock(&init_mm.page_table_lock);
}
return last_map_addr;
--
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