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authorWill Deacon <will.deacon@arm.com>2018-12-10 14:21:13 +0000
committerWill Deacon <will.deacon@arm.com>2018-12-10 18:42:18 +0000
commit66f16a24512fa44680504effe908df8326885594 (patch)
tree9f56153b17ba2f9d443052654a8919f3c68009fb /arch/arm64/kernel
parent68d23da4373aba76f5300017c4746440f276698e (diff)
arm64: smp: Rework early feature mismatched detection
Rather than add additional variables to detect specific early feature mismatches with secondary CPUs, we can instead dedicate the upper bits of the CPU boot status word to flag specific mismatches. This allows us to communicate both granule and VA-size mismatches back to the primary CPU without the need for additional book-keeping. Tested-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r--arch/arm64/kernel/head.S12
-rw-r--r--arch/arm64/kernel/smp.c11
2 files changed, 9 insertions, 14 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 6b70dd625f01..eaa68ce6a06d 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -809,13 +809,8 @@ ENTRY(__cpu_secondary_check52bitva)
and x0, x0, #(0xf << ID_AA64MMFR2_LVA_SHIFT)
cbnz x0, 2f
- adr_l x0, va52mismatch
- mov w1, #1
- strb w1, [x0]
- dmb sy
- dc ivac, x0 // Invalidate potentially stale cache line
-
- update_early_cpu_boot_status CPU_STUCK_IN_KERNEL, x0, x1
+ update_early_cpu_boot_status \
+ CPU_STUCK_IN_KERNEL | CPU_STUCK_REASON_52_BIT_VA, x0, x1
1: wfe
wfi
b 1b
@@ -826,7 +821,8 @@ ENDPROC(__cpu_secondary_check52bitva)
__no_granule_support:
/* Indicate that this CPU can't boot and is stuck in the kernel */
- update_early_cpu_boot_status CPU_STUCK_IN_KERNEL, x1, x2
+ update_early_cpu_boot_status \
+ CPU_STUCK_IN_KERNEL | CPU_STUCK_REASON_NO_GRAN, x1, x2
1:
wfe
wfi
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 1ff18f5fbecb..4e3bfbde829a 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -108,7 +108,6 @@ static int boot_secondary(unsigned int cpu, struct task_struct *idle)
}
static DECLARE_COMPLETION(cpu_running);
-bool va52mismatch __ro_after_init;
int __cpu_up(unsigned int cpu, struct task_struct *idle)
{
@@ -138,10 +137,6 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
if (!cpu_online(cpu)) {
pr_crit("CPU%u: failed to come online\n", cpu);
-
- if (IS_ENABLED(CONFIG_ARM64_USER_VA_BITS_52) && va52mismatch)
- pr_crit("CPU%u: does not support 52-bit VAs\n", cpu);
-
ret = -EIO;
}
} else {
@@ -156,7 +151,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
if (status == CPU_MMU_OFF)
status = READ_ONCE(__early_cpu_boot_status);
- switch (status) {
+ switch (status & CPU_BOOT_STATUS_MASK) {
default:
pr_err("CPU%u: failed in unknown state : 0x%lx\n",
cpu, status);
@@ -170,6 +165,10 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
pr_crit("CPU%u: may not have shut down cleanly\n", cpu);
case CPU_STUCK_IN_KERNEL:
pr_crit("CPU%u: is stuck in kernel\n", cpu);
+ if (status & CPU_STUCK_REASON_52_BIT_VA)
+ pr_crit("CPU%u: does not support 52-bit VAs\n", cpu);
+ if (status & CPU_STUCK_REASON_NO_GRAN)
+ pr_crit("CPU%u: does not support %luK granule \n", cpu, PAGE_SIZE / SZ_1K);
cpus_stuck_in_kernel++;
break;
case CPU_PANIC_KERNEL: