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authorGuenter Roeck <guenter.roeck@ericsson.com>2010-02-02 08:52:20 -0800
committerRalf Baechle <ralf@linux-mips.org>2010-02-02 19:56:23 +0100
commit91dfc423cc8cfd399fb308a837102a7ab7fa067e (patch)
tree21c75672185153084a5ac8e38ca3938ca0cf4ac1 /arch/mips/kernel
parentba284b1f199ef7121489010da6614561a679eab6 (diff)
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 <guenter.roeck@ericsson.com> Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/935/ Reviewed-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel')
-rw-r--r--arch/mips/kernel/cpu-probe.c11
1 files changed, 11 insertions, 0 deletions
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)