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author | David Daney <ddaney@caviumnetworks.com> | 2009-10-14 12:16:56 -0700 |
---|---|---|
committer | Ralf Baechle <ralf@linux-mips.org> | 2009-12-17 01:57:01 +0000 |
commit | 82622284dd2f8791f9759f3cef601520a8bc63b2 (patch) | |
tree | ee47f43af373d0c021cc83ff9e22925942e9d001 /arch/mips/mm | |
parent | 92078e0618f525e22945040b5daea21d4b6d4a16 (diff) | |
download | lwn-82622284dd2f8791f9759f3cef601520a8bc63b2.tar.gz lwn-82622284dd2f8791f9759f3cef601520a8bc63b2.zip |
MIPS: Put PGD in C0_CONTEXT for 64-bit R2 processors.
Processors that support the mips64r2 ISA can in four instructions
convert a shifted PGD pointer stored in the upper bits of c0_context
into a usable pointer. By doing this we save a memory load and
associated potential cache miss in the TLB exception handlers.
Since the upper bits of c0_context were holding the CPU number, we
move this to the upper bits of c0_xcontext which doesn't have enough
bits to hold the PGD pointer, but has plenty for the CPU number.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/mm')
-rw-r--r-- | arch/mips/mm/init.c | 2 | ||||
-rw-r--r-- | arch/mips/mm/tlbex.c | 28 |
2 files changed, 27 insertions, 3 deletions
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index 8d1f4f363049..9e8d00389eef 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -462,7 +462,9 @@ void __init_refok free_initmem(void) __pa_symbol(&__init_end)); } +#ifndef CONFIG_MIPS_PGD_C0_CONTEXT unsigned long pgd_current[NR_CPUS]; +#endif /* * On 64-bit we've got three-level pagetables with a slightly * different layout ... diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index bb1719a55d22..3d0baa4a842d 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -160,6 +160,12 @@ static u32 tlb_handler[128] __cpuinitdata; static struct uasm_label labels[128] __cpuinitdata; static struct uasm_reloc relocs[128] __cpuinitdata; +#ifndef CONFIG_MIPS_PGD_C0_CONTEXT +/* + * CONFIG_MIPS_PGD_C0_CONTEXT implies 64 bit and lack of pgd_current, + * we cannot do r3000 under these circumstances. + */ + /* * The R3000 TLB handler is simple. */ @@ -199,6 +205,7 @@ static void __cpuinit build_r3000_tlb_refill_handler(void) dump_handler((u32 *)ebase, 32); } +#endif /* CONFIG_MIPS_PGD_C0_CONTEXT */ /* * The R4000 TLB handler is much more complicated. We have two @@ -497,8 +504,9 @@ static void __cpuinit build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int tmp, unsigned int ptr) { +#ifndef CONFIG_MIPS_PGD_C0_CONTEXT long pgdc = (long)pgd_current; - +#endif /* * The vmalloc handling is not in the hotpath. */ @@ -506,7 +514,15 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, uasm_il_bltz(p, r, tmp, label_vmalloc); /* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */ -#ifdef CONFIG_SMP +#ifdef CONFIG_MIPS_PGD_C0_CONTEXT + /* + * &pgd << 11 stored in CONTEXT [23..63]. + */ + UASM_i_MFC0(p, ptr, C0_CONTEXT); + uasm_i_dins(p, ptr, 0, 0, 23); /* Clear lower 23 bits of context. */ + uasm_i_ori(p, ptr, ptr, 0x540); /* 1 0 1 0 1 << 6 xkphys cached */ + uasm_i_drotr(p, ptr, ptr, 11); +#elif defined(CONFIG_SMP) # ifdef CONFIG_MIPS_MT_SMTC /* * SMTC uses TCBind value as "CPU" index @@ -520,7 +536,7 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, */ uasm_i_dmfc0(p, ptr, C0_CONTEXT); uasm_i_dsrl(p, ptr, ptr, 23); -#endif +# endif UASM_i_LA_mostly(p, tmp, pgdc); uasm_i_daddu(p, ptr, ptr, tmp); uasm_i_dmfc0(p, tmp, C0_BADVADDR); @@ -1033,6 +1049,7 @@ build_pte_modifiable(u32 **p, struct uasm_reloc **r, iPTE_LW(p, pte, ptr); } +#ifndef CONFIG_MIPS_PGD_C0_CONTEXT /* * R3000 style TLB load/store/modify handlers. */ @@ -1184,6 +1201,7 @@ static void __cpuinit build_r3000_tlb_modify_handler(void) dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm)); } +#endif /* CONFIG_MIPS_PGD_C0_CONTEXT */ /* * R4000 style TLB load/store/modify handlers. @@ -1400,6 +1418,7 @@ void __cpuinit build_tlb_refill_handler(void) case CPU_TX3912: case CPU_TX3922: case CPU_TX3927: +#ifndef CONFIG_MIPS_PGD_C0_CONTEXT build_r3000_tlb_refill_handler(); if (!run_once) { build_r3000_tlb_load_handler(); @@ -1407,6 +1426,9 @@ void __cpuinit build_tlb_refill_handler(void) build_r3000_tlb_modify_handler(); run_once++; } +#else + panic("No R3000 TLB refill handler"); +#endif break; case CPU_R6000: |