summaryrefslogtreecommitdiff
path: root/arch/arm/mm/Kconfig
diff options
context:
space:
mode:
authorFlorian Fainelli <f.fainelli@gmail.com>2015-01-09 21:34:43 +0300
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-04-02 12:06:35 +0300
commite1e2f6e4c5759aab3a8cfb1a0c19017ea770dfd2 (patch)
tree1943f678a84fa3369f3bfd3c805560a94b329ef1 /arch/arm/mm/Kconfig
parent49f28aa6b0d0735dbe5f04263c49a199ed0c5bb7 (diff)
downloadlinux-e1e2f6e4c5759aab3a8cfb1a0c19017ea770dfd2.tar.xz
ARM: 8276/1: Make CPU_DCACHE_DISABLE depend on !SMP
Enabling CPU_DCACHE_DISABLE on a SMP capable system will prevent the kernel from booting because of the following ldrex instruction in arch_spin_lock: (gdb) x/10i $pc => 0xc053cfa8 <_raw_spin_lock+4>: ldrex r3, [r0] 0xc053cfac <_raw_spin_lock+8>: add r2, r3, #65536 ; 0x10000 which is taken by the very first printk call: at /home/fainelli/work/linux/arch/arm/include/asm/spinlock.h:65 fmt=0xc0637650 " 01 66Booting Linux on physical CPU 0x%xn", args=<incomplete type>) at kernel/printk/printk.c:1525 fmt=0xc05370f4 <printk+52> " 24320215342 04340235344 20320215342 36377/341 17") at kernel/printk/printk.c:1688 ldrex requires exclusive monitor(s) (local or global) which are no longer working when the Data cache is disabled in CP15 and will just hang the CPU there. Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/Kconfig')
-rw-r--r--arch/arm/mm/Kconfig2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 9b4f29e595a4..133ecff6664e 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -738,7 +738,7 @@ config CPU_ICACHE_DISABLE
config CPU_DCACHE_DISABLE
bool "Disable D-Cache (C-bit)"
- depends on CPU_CP15
+ depends on CPU_CP15 && !SMP
help
Say Y here to disable the processor data cache. Unless
you have a reason not to or are unsure, say N.