From: Andy Lutomirski <l...@kernel.org>
This allows the cpu entry area PMDs to be shared between the kernel and
user space page tables.
[ tglx: Fixed bottom of by one and added guards so other fixmaps can be
added later ]
Signed-off-by: Andy Lutomirski <l...@kernel.org>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
---
arch/x86/include/asm/fixmap.h | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -134,16 +134,22 @@ enum fixed_addresses {
#ifdef CONFIG_PARAVIRT
FIX_PARAVIRT_BOOTMAP,
#endif
- FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */
- FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
#ifdef CONFIG_X86_INTEL_MID
FIX_LNW_VRTC,
#endif
- /* Fixmap entries to remap the GDTs, one per processor. */
+ FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */
+ FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
+
+ /*
+ * Fixmap entries to remap the IDT, and the per cpu entry areas.
+ * Aligend to a PMD boundary.
+ */
+ FIX_USR_SHARED_TOP = round_up(FIX_TEXT_POKE0 + 1, PTRS_PER_PMD),
FIX_CPU_ENTRY_AREA_TOP,
FIX_CPU_ENTRY_AREA_BOTTOM = FIX_CPU_ENTRY_AREA_TOP +
(CPU_ENTRY_AREA_PAGES * NR_CPUS) - 1,
+ FIX_USR_SHARED_BOTTOM = round_up(FIX_CPU_ENTRY_AREA_BOTTOM + 2,
PTRS_PER_PMD) - 1,
- __end_of_permanent_fixed_addresses,
+ __end_of_permanent_fixed_addresses = FIX_USR_SHARED_BOTTOM,
/*
* 512 temporary boot-time mappings, used by early_ioremap(),
