diff options
author | Jean-Philippe Brucker <jean-philippe@linaro.org> | 2021-05-07 12:20:23 +0200 |
---|---|---|
committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2023-12-04 10:14:56 +0000 |
commit | fb51901cc76e067aebbfa68328e09a41d1bcd23d (patch) | |
tree | d0f615ad9f1d6e5e2622c55b049b89b8db81df93 /arch/arm64/kernel/smp.c | |
parent | e9e90626d503c2e01b1a4575b8004cc0909fcfb6 (diff) |
arm64: psci: Ignore DENIED CPUs
When a CPU is marked as disabled, but online capable in the MADT, PSCI
applies some firmware policy to control when it can be brought online.
PSCI returns DENIED to a CPU_ON request if this is not currently
permitted. The OS can learn the current policy from the _STA enabled bit.
Handle the PSCI DENIED return code gracefully instead of printing an
error.
See https://developer.arm.com/documentation/den0022/f/?lang=en page 58.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
[ morse: Rewrote commit message ]
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
Changes since RFC v2
* Add specification reference
* Use EPERM rather than EPROBE_DEFER
Changes since RFC v3:
* Use EPERM everywhere
* Drop unnecessary changes to drivers/firmware/psci/psci.c
Diffstat (limited to 'arch/arm64/kernel/smp.c')
-rw-r--r-- | arch/arm64/kernel/smp.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index defbab84e9e5..6bc9094feb19 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -132,7 +132,8 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) /* Now bring the CPU into our world */ ret = boot_secondary(cpu, idle); if (ret) { - pr_err("CPU%u: failed to boot: %d\n", cpu, ret); + if (ret != -EPERM) + pr_err("CPU%u: failed to boot: %d\n", cpu, ret); return ret; } |