[RFC 14/23] ARM: LPAE: factor out T1SZ and TTBR1 computations

From: Cyril Chemparathy
Date: Mon Jul 23 2012 - 21:09:46 EST


This patch moves the TTBR1 offset calculation and the T1SZ calculation out
of the TTB setup assembly code. This should not affect functionality in
any way, but improves code readability as well as readability of subsequent
patches in this series.

Signed-off-by: Cyril Chemparathy <cyril@xxxxxx>
Signed-off-by: Vitaly Andrianov <vitalya@xxxxxx>
---
arch/arm/include/asm/pgtable-3level-hwdef.h | 10 ++++++++++
arch/arm/mm/proc-v7-3level.S | 16 ++++------------
2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/arch/arm/include/asm/pgtable-3level-hwdef.h b/arch/arm/include/asm/pgtable-3level-hwdef.h
index d795282..b501650 100644
--- a/arch/arm/include/asm/pgtable-3level-hwdef.h
+++ b/arch/arm/include/asm/pgtable-3level-hwdef.h
@@ -74,4 +74,14 @@
#define PHYS_MASK_SHIFT (40)
#define PHYS_MASK ((1ULL << PHYS_MASK_SHIFT) - 1)

+#if defined CONFIG_VMSPLIT_2G
+#define TTBR1_OFFSET (1 << 4) /* skip two L1 entries */
+#elif defined CONFIG_VMSPLIT_3G
+#define TTBR1_OFFSET (4096 * (1 + 3)) /* only L2, skip pgd + 3*pmd */
+#else
+#define TTBR1_OFFSET 0
+#endif
+
+#define TTBR1_SIZE (((PAGE_OFFSET >> 30) - 1) << 16)
+
#endif
diff --git a/arch/arm/mm/proc-v7-3level.S b/arch/arm/mm/proc-v7-3level.S
index 0001581..3b1a745 100644
--- a/arch/arm/mm/proc-v7-3level.S
+++ b/arch/arm/mm/proc-v7-3level.S
@@ -120,18 +120,10 @@ ENDPROC(cpu_v7_set_pte_ext)
* booting secondary CPUs would end up using TTBR1 for the identity
* mapping set up in TTBR0.
*/
- bhi 9001f @ PHYS_OFFSET > PAGE_OFFSET?
- orr \tmp, \tmp, #(((PAGE_OFFSET >> 30) - 1) << 16) @ TTBCR.T1SZ
-#if defined CONFIG_VMSPLIT_2G
- /* PAGE_OFFSET == 0x80000000, T1SZ == 1 */
- add \ttbr1, \ttbr1, #1 << 4 @ skip two L1 entries
-#elif defined CONFIG_VMSPLIT_3G
- /* PAGE_OFFSET == 0xc0000000, T1SZ == 2 */
- add \ttbr1, \ttbr1, #4096 * (1 + 3) @ only L2 used, skip pgd+3*pmd
-#endif
- /* CONFIG_VMSPLIT_1G does not need TTBR1 adjustment */
-9001: mcr p15, 0, \tmp, c2, c0, 2 @ TTB control register
- mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1
+ orrls \tmp, \tmp, #TTBR1_SIZE @ TTBCR.T1SZ
+ mcr p15, 0, \tmp, c2, c0, 2 @ TTBCR
+ addls \ttbr1, \ttbr1, #TTBR1_OFFSET
+ mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1
.endm

__CPUINIT
--
1.7.9.5

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