From 91dfc423cc8cfd399fb308a837102a7ab7fa067e Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Tue, 2 Feb 2010 08:52:20 -0800 Subject: MIPS: 64-bit: Detect virtual memory size Linux kernel 2.6.32 and later allocate address space from the top of the kernel virtual memory address space. This patch implements virtual memory size detection for 64 bit MIPS CPUs to avoid resulting crashes. Signed-off-by: Guenter Roeck Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/935/ Reviewed-by: David Daney Signed-off-by: Ralf Baechle --- arch/mips/kernel/cpu-probe.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch/mips/kernel/cpu-probe.c') diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index 80e202eca056..9c187a64649b 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -284,6 +284,15 @@ static inline int __cpu_has_fpu(void) return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE); } +static inline void cpu_probe_vmbits(struct cpuinfo_mips *c) +{ +#ifdef __NEED_VMBITS_PROBE + write_c0_entryhi(0x3ffffffffffff000ULL); + back_to_back_c0_hazard(); + c->vmbits = fls64(read_c0_entryhi() & 0x3ffffffffffff000ULL); +#endif +} + #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \ | MIPS_CPU_COUNTER) @@ -969,6 +978,8 @@ __cpuinit void cpu_probe(void) c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1; else c->srsets = 1; + + cpu_probe_vmbits(c); } __cpuinit void cpu_report(void) -- cgit v1.2.2 From 5b7efa898b357e6ebe4024c520e62024eb969b5f Mon Sep 17 00:00:00 2001 From: David Daney Date: Mon, 8 Feb 2010 12:27:00 -0800 Subject: MIPS: Don't probe reserved EntryHi bits. The patch that adds cpu_probe_vmbits is erroneously writing to reserved bit 12. Since we are really only probing high bits, don't write this bit with a one. Signed-off-by: David Daney To: linux-mips@linux-mips.org Cc: Guenter Roeck Patchwork: http://patchwork.linux-mips.org/patch/949/ Acked-by: Guenter Roeck Signed-off-by: Ralf Baechle --- arch/mips/kernel/cpu-probe.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/mips/kernel/cpu-probe.c') diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index 9c187a64649b..758ad426c57f 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -287,9 +287,9 @@ static inline int __cpu_has_fpu(void) static inline void cpu_probe_vmbits(struct cpuinfo_mips *c) { #ifdef __NEED_VMBITS_PROBE - write_c0_entryhi(0x3ffffffffffff000ULL); + write_c0_entryhi(0x3fffffffffffe000ULL); back_to_back_c0_hazard(); - c->vmbits = fls64(read_c0_entryhi() & 0x3ffffffffffff000ULL); + c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL); #endif } -- cgit v1.2.2