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>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
index 126044308de..b39def3f6e0 100644
--- a/arch/mips/include/asm/cpu-info.h
+++ b/arch/mips/include/asm/cpu-info.h
@@ -58,6 +58,9 @@ struct cpuinfo_mips {
         struct cache_desc       tcache; /* Tertiary/split secondary cache */
         int                     srsets; /* Shadow register sets */
         int                     core;   /* physical core number */
+#ifdef CONFIG_64BIT
+        int                     vmbits; /* Virtual memory size in bits */
+#endif
 #if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC)
         /*
          * In the MIPS MT "SMTC" model, each TC is considered