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>
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 1f4df64..272c5ef 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -191,6 +191,9 @@
# ifndef cpu_has_64bit_addresses
# define cpu_has_64bit_addresses 0
# endif
+# ifndef cpu_vmbits
+# define cpu_vmbits 31
+# endif
#endif
#ifdef CONFIG_64BIT
@@ -209,6 +212,10 @@
# ifndef cpu_has_64bit_addresses
# define cpu_has_64bit_addresses 1
# endif
+# ifndef cpu_vmbits
+# define cpu_vmbits cpu_data[0].vmbits
+# define __NEED_VMBITS_PROBE
+# endif
#endif
#if defined(CONFIG_CPU_MIPSR2_IRQ_VI) && !defined(cpu_has_vint)
diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
index 1260443..b39def3 100644
--- a/arch/mips/include/asm/cpu-info.h
+++ b/arch/mips/include/asm/cpu-info.h
@@ -58,6 +58,9 @@
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
diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h
index 9cd5089..8eda30b 100644
--- a/arch/mips/include/asm/pgtable-64.h
+++ b/arch/mips/include/asm/pgtable-64.h
@@ -110,7 +110,9 @@
#define VMALLOC_START MAP_BASE
#define VMALLOC_END \
(VMALLOC_START + \
- PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE - (1UL << 32))
+ min(PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, \
+ (1UL << cpu_vmbits)) - (1UL << 32))
+
#if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \
VMALLOC_START != CKSSEG
/* Load modules into 32bit-compatible segment. */