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| author |   Nicholas Piggin <npiggin@gmail.com> | 2017-08-13 11:33:41 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2017-08-31 14:25:59 +1000 |
| commit | d55071905ee1719094c66dd3c40e2a9ef5c65eaf (patch) | |
| tree | f41f1c168fe88093f34517b32e5baa8e3a2bff47 | |
| parent | powerpc/powernv: powernv platform is not constrained by RMA (diff) | |
| download | linux-dev-d55071905ee1719094c66dd3c40e2a9ef5c65eaf.tar.xz linux-dev-d55071905ee1719094c66dd3c40e2a9ef5c65eaf.zip | |
powerpc/64s/radix: Remove bolted-SLB address limit for per-cpu stacks
Radix MMU does not take SLB or TLB interrupts when accessing kernel
linear address. Remove this restriction for radix mode.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index af23d4b576ec..7393bac3c7f4 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -564,6 +564,9 @@ static __init u64 safe_stack_limit(void) /* Other BookE, we assume the first GB is bolted */ return 1ul << 30; #else + if (early_radix_enabled()) + return ULONG_MAX; + /* BookS, the first segment is bolted */ if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) return 1UL << SID_SHIFT_1T; @@ -578,7 +581,8 @@ void __init irqstack_early_init(void) /* * Interrupt stacks must be in the first segment since we - * cannot afford to take SLB misses on them. + * cannot afford to take SLB misses on them. They are not + * accessed in realmode. */ for_each_possible_cpu(i) { softirq_ctx[i] = (struct thread_info *) @@ -649,8 +653,9 @@ void __init emergency_stack_init(void) * aligned. * * Since we use these as temporary stacks during secondary CPU - * bringup, we need to get at them in real mode. This means they - * must also be within the RMO region. + * bringup, machine check, system reset, and HMI, we need to get + * at them in real mode. This means they must also be within the RMO + * region. * * The IRQ stacks allocated elsewhere in this file are zeroed and * initialized in kernel/irq.c. These are initialized here in order |