x86: Add NMI types for kmap_atomic, fix

I just realized this has a kmap_atomic bug in...

The below would fix it - but it's complicating this code
some more.

Alternatively I would have to introduce something like
pte_offset_map_irq() which would make the irq/nmi detection and leave
the regular code paths alone, however that would mean either duplicating
the gup_fast() pagewalk or passing down a pte function pointer, which
would only duplicate the gup_pte_range() bit, neither is really
attractive ...

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Nick Piggin <npiggin@suse.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 10 insertions, 6 deletions

diff --git a/arch/x86/include/asm/kmap_types.h b/arch/x86/include/asm/kmap_types.h
index ff00a44b7d0d..f86613846198 100644
--- a/arch/x86/include/asm/kmap_types.h
+++ b/arch/x86/include/asm/kmap_types.h
@@ -19,11 +19,12 @@ D(7)	KM_PTE0,
 D(8)    KM_PTE1,
 D(9)    KM_IRQ0,
 D(10)   KM_IRQ1,
-D(11)   KM_SOFTIRQ0,
-D(12)   KM_SOFTIRQ1,
-D(13)   KM_NMI,
-D(14)   KM_NMI_PTE,
-D(15)   KM_TYPE_NR
+D(11)   KM_IRQ_PTE,
+D(12)   KM_SOFTIRQ0,
+D(13)   KM_SOFTIRQ1,
+D(14)   KM_NMI,
+D(15)   KM_NMI_PTE,
+D(16)   KM_TYPE_NR
 };
 
 #undef D
diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
index 85464971bca0..01fd9461d323 100644
--- a/arch/x86/include/asm/pgtable_32.h
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -49,7 +49,10 @@ extern void set_pmd_pfn(unsigned long, unsigned long, pgprot_t);
 #endif
 
 #if defined(CONFIG_HIGHPTE)
-#define __KM_PTE        (in_nmi() ? KM_NMI_PTE : KM_PTE0)
+#define __KM_PTE                        \
+        (in_nmi() ? KM_NMI_PTE :        \
+         in_irq() ? KM_IRQ_PTE :        \
+         KM_PTE0)
 #define pte_offset_map(dir, address)                                    \
         ((pte_t *)kmap_atomic_pte(pmd_page(*(dir)), __KM_PTE) +         \
          pte_index((address)))