[PATCH] Fix early_ioremap on x86-64

From: Andi Kleen
Date: Sun Jan 20 2008 - 12:29:02 EST


Fix early_ioremap on x86-64

[Venki, sorry for blaming PAT for this earlier. It was innocent.]
[Note the patch is on top of git-x86 + gbpages applied. I think
there will be an trivial reject without gbpages-direct applied first]

I had ACPI failures on several machines since a few days. Symptom
was NUMA nodes not getting detected or worse cores not getting detected.
They all came from ACPI not being able to read various of its tables. I finally
bisected it down to Jeremy's "put _PAGE_GLOBAL into PAGE_KERNEL" change.
With that the fix was fairly obvious. The problem was that early_ioremap()
didn't use a "_all" flush that would affect the global PTEs too. So
with global bits getting used everywhere now an early_ioremap would
not actually flush a mapping if something else was mapped previously
on that slot (which can happen with early_iounmap inbetween)

This patch changes all flushes in init_64.c to be __flush_tlb_all()
and fixes the problem here.

Signed-off-by: Andi Kleen <ak@xxxxxxx>

Index: linux/arch/x86/mm/init_64.c
===================================================================
--- linux.orig/arch/x86/mm/init_64.c
+++ linux/arch/x86/mm/init_64.c
@@ -242,7 +242,7 @@ void *early_ioremap(unsigned long addr,
addr &= PMD_MASK;
for (i = 0; i < pmds; i++, addr += PMD_SIZE)
set_pmd(pmd+i, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
- __flush_tlb();
+ __flush_tlb_all();
printk(KERN_CONT "%016ld\n", vaddr);
return (void *)vaddr;
next:
@@ -265,7 +265,7 @@ void early_iounmap(void *addr, unsigned
pmd = level2_kernel_pgt + pmd_index(vaddr);
for (i = 0; i < pmds; i++)
pmd_clear(pmd + i);
- __flush_tlb();
+ __flush_tlb_all();
}

static unsigned long direct_entry(unsigned long paddr)
@@ -339,7 +339,7 @@ static void __meminit phys_pud_init(pud_
spin_unlock(&init_mm.page_table_lock);
unmap_low_page(pmd);
}
- __flush_tlb();
+ __flush_tlb_all();
}

static void __init find_early_table_space(unsigned long end)
--
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