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Date: Sat, 6 Oct 2012 00:44:27 -0700
From: Yinghai Lu <yinghai@...nel.org>
To: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...e.hu>,
"H. Peter Anvin" <hpa@...or.com>, Jacob Shin <jacob.shin@....com>,
Tejun Heo <tj@...nel.org>
Cc: Stefano Stabellini <stefano.stabellini@...citrix.com>,
linux-kernel@...r.kernel.org, Yinghai Lu <yinghai@...nel.org>
Subject: [PATCH 1/3] x86: get early page table from BRK
set pgt_buf early from BRK, and use it to map page table at first.
also use the left at first, then use new extend one.
-v2: extra xen call back for that new range.
Signed-off-by: Yinghai Lu <yinghai@...nel.org>
---
arch/x86/include/asm/init.h | 4 ++++
arch/x86/include/asm/pgtable.h | 1 +
arch/x86/kernel/setup.c | 2 ++
arch/x86/mm/init.c | 25 +++++++++++++++++++++++++
arch/x86/mm/init_32.c | 8 ++++++--
arch/x86/mm/init_64.c | 8 ++++++--
6 files changed, 44 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/init.h b/arch/x86/include/asm/init.h
index 4f13998..2f32eea 100644
--- a/arch/x86/include/asm/init.h
+++ b/arch/x86/include/asm/init.h
@@ -16,4 +16,8 @@ extern unsigned long __initdata pgt_buf_start;
extern unsigned long __meminitdata pgt_buf_end;
extern unsigned long __meminitdata pgt_buf_top;
+extern unsigned long __initdata early_pgt_buf_start;
+extern unsigned long __meminitdata early_pgt_buf_end;
+extern unsigned long __meminitdata early_pgt_buf_top;
+
#endif /* _ASM_X86_INIT_32_H */
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 52d40a1..25fa5bb 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -599,6 +599,7 @@ static inline int pgd_none(pgd_t pgd)
extern int direct_gbpages;
void init_mem_mapping(void);
+void early_alloc_pgt_buf(void);
/* local pte updates need not use xchg for locking */
static inline pte_t native_local_ptep_get_and_clear(pte_t *ptep)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 4989f80..7eb6855 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -896,6 +896,8 @@ void __init setup_arch(char **cmdline_p)
reserve_ibft_region();
+ early_alloc_pgt_buf();
+
/*
* Need to conclude brk, before memblock_x86_fill()
* it could use memblock_find_in_range, could overlap with
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index cf662ba..c32eed1 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -21,6 +21,10 @@ unsigned long __initdata pgt_buf_start;
unsigned long __meminitdata pgt_buf_end;
unsigned long __meminitdata pgt_buf_top;
+unsigned long __initdata early_pgt_buf_start;
+unsigned long __meminitdata early_pgt_buf_end;
+unsigned long __meminitdata early_pgt_buf_top;
+
int after_bootmem;
int direct_gbpages
@@ -291,6 +295,11 @@ static void __init find_early_table_space(unsigned long start,
if (!base)
panic("Cannot find space for the kernel page tables");
+ init_memory_mapping(base, base + tables);
+ printk(KERN_DEBUG "kernel direct mapping tables from %#llx to %#llx @ [mem %#010lx-%#010lx]\n",
+ base, base + tables - 1, early_pgt_buf_start << PAGE_SHIFT,
+ (early_pgt_buf_end << PAGE_SHIFT) - 1);
+
pgt_buf_start = base >> PAGE_SHIFT;
pgt_buf_end = pgt_buf_start;
pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT);
@@ -430,6 +439,8 @@ void __init init_mem_mapping(void)
x86_init.mapping.pagetable_reserve(PFN_PHYS(pgt_buf_start),
PFN_PHYS(pgt_buf_end));
}
+ x86_init.mapping.pagetable_reserve(PFN_PHYS(early_pgt_buf_start),
+ PFN_PHYS(early_pgt_buf_end));
/* stop the wrong using */
pgt_buf_top = 0;
@@ -437,6 +448,20 @@ void __init init_mem_mapping(void)
early_memtest(0, max_pfn_mapped << PAGE_SHIFT);
}
+RESERVE_BRK(early_pgt_alloc, 16384);
+
+void __init early_alloc_pgt_buf(void)
+{
+ unsigned long tables = 16384;
+ phys_addr_t base;
+
+ base = __pa(extend_brk(tables, PAGE_SIZE));
+
+ early_pgt_buf_start = base >> PAGE_SHIFT;
+ early_pgt_buf_end = early_pgt_buf_start;
+ early_pgt_buf_top = early_pgt_buf_start + (tables >> PAGE_SHIFT);
+}
+
/*
* devmem_is_allowed() checks to see if /dev/mem access to a certain address
* is valid. The argument is a physical page number.
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 11a5800..92c0f12 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -61,10 +61,14 @@ bool __read_mostly __vmalloc_start_set = false;
static __init void *alloc_low_page(void)
{
- unsigned long pfn = pgt_buf_end++;
+ unsigned long pfn;
void *adr;
- if (pfn >= pgt_buf_top)
+ if (early_pgt_buf_end < early_pgt_buf_top)
+ pfn = early_pgt_buf_end++;
+ else if (pgt_buf_end < pgt_buf_top)
+ pfn = pgt_buf_end++;
+ else
panic("alloc_low_page: ran out of memory");
adr = __va(pfn * PAGE_SIZE);
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index ab558eb..5375cf0 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -316,7 +316,7 @@ void __init cleanup_highmap(void)
static __ref void *alloc_low_page(unsigned long *phys)
{
- unsigned long pfn = pgt_buf_end++;
+ unsigned long pfn;
void *adr;
if (after_bootmem) {
@@ -326,7 +326,11 @@ static __ref void *alloc_low_page(unsigned long *phys)
return adr;
}
- if (pfn >= pgt_buf_top)
+ if (early_pgt_buf_end < early_pgt_buf_top)
+ pfn = early_pgt_buf_end++;
+ else if (pgt_buf_end < pgt_buf_top)
+ pfn = pgt_buf_end++;
+ else
panic("alloc_low_page: ran out of memory");
adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
--
1.7.7
--
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