From ff401e52100dcdc85e572d1ad376d3307b3fe28e Mon Sep 17 00:00:00 2001
From: "Steven J. Hill" <sjhill@mips.com>
Date: Tue, 28 Aug 2012 23:20:39 -0500
Subject: MIPS: Optimise TLB handlers for MIPS32/64 R2 cores.
The EXT and INS instructions can be used to decrease code size and
thus speed up TLB handlers on MIPS32R2 and MIPS64R2 cores.
Signed-off-by: Steven J. Hill <sjhill@mips.com>
---
arch/mips/mm/tlbex.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 22ba108d708..70a70085ffd 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -933,6 +933,13 @@ build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
#endif
uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
+
+ if (cpu_has_mips_r2) {
+ uasm_i_ext(p, tmp, tmp, PGDIR_SHIFT, (32 - PGDIR_SHIFT));
+ uasm_i_ins(p, ptr, tmp, PGD_T_LOG2, (32 - PGDIR_SHIFT));
+ return;
+ }
+
uasm_i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */
uasm_i_sll(p, tmp, tmp, PGD_T_LOG2);
uasm_i_addu(p, ptr, ptr, tmp); /* add in pgd offset */
@@ -968,6 +975,15 @@ static void __cpuinit build_adjust_context(u32 **p, unsigned int ctx)
static void __cpuinit build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr)
{
+ if (cpu_has_mips_r2) {
+ /* PTE ptr offset is obtained from BadVAddr */
+ UASM_i_MFC0(p, tmp, C0_BADVADDR);
+ UASM_i_LW(p, ptr, 0, ptr);
+ uasm_i_ext(p, tmp, tmp, PAGE_SHIFT+1, PGDIR_SHIFT-PAGE_SHIFT-1);
+ uasm_i_ins(p, ptr, tmp, PTE_T_LOG2+1, PGDIR_SHIFT-PAGE_SHIFT-1);
+ return;
+ }
+
/*
* Bug workaround for the Nevada. It seems as if under certain
* circumstances the move from cp0_context might produce a
--
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