3705ff6da5
There is a subtle race in the CPU hotplug code, where a CPU which has been offlined can online itself before being requested, which results in things going astray on the next online/offline cycle. What happens in the normal online/offline/online cycle is: CPU0 CPU3 requests boot of CPU3 pen_release = 3 flush cache line checks pen_release, reads 3 starts boot pen_release = -1 ... requests CPU3 offline ... ... dies ... checks pen_release, reads -1 requests boot of CPU3 pen_release = 3 flush cache line checks pen_release, reads 3 starts boot pen_release = -1 However, as the write of -1 of pen_release is not fully flushed back to memory, and the checking of pen_release is done with caches disabled, this allows CPU3 the opportunity to read the old value of pen_release: CPU0 CPU3 requests boot of CPU3 pen_release = 3 flush cache line checks pen_release, reads 3 starts boot pen_release = -1 ... requests CPU3 offline ... ... dies ... checks pen_release, reads 3 starts boot pen_release = -1 requests boot of CPU3 pen_release = 3 flush cache line Fix this by grouping the write of pen_release along with its cache line flushing code to ensure that any update to pen_release is always pushed out to physical memory. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> |
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.. | ||
include/mach | ||
clock.c | ||
cpu.c | ||
gpiolib.c | ||
headsmp.S | ||
hotplug.c | ||
init.c | ||
irq-combiner.c | ||
irq-eint.c | ||
Kconfig | ||
localtimer.c | ||
mach-smdkc210.c | ||
mach-smdkv310.c | ||
mach-universal_c210.c | ||
Makefile | ||
Makefile.boot | ||
platsmp.c | ||
setup-i2c0.c | ||
setup-i2c1.c | ||
setup-i2c2.c | ||
setup-i2c3.c | ||
setup-i2c4.c | ||
setup-i2c5.c | ||
setup-i2c6.c | ||
setup-i2c7.c | ||
setup-sdhci-gpio.c | ||
setup-sdhci.c | ||
time.c |