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由 Florian Fainelli 提交于
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: NArnd Bergmann <arnd@arndb.de> Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com> Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
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