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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2017-04-05 10:54:48 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-04-06 12:58:53 +0300 |
| commit | 14d4ae5c4cb89c05262fe41cb7a26f6ba949d8df (patch) | |
| tree | 5aad3d800484640eb9e90df5d0d6f6039c4e7a34 /arch/powerpc/kernel/smp.c | |
| parent | 22bd64a621cc80beeb009abec3d3df98ec0131c5 (diff) | |
| download | linux-14d4ae5c4cb89c05262fe41cb7a26f6ba949d8df.tar.xz | |
powerpc: Add optional smp_ops->prepare_cpu SMP callback
Some platforms (will) need to perform allocations before bringing
a new CPU online. Doing it from smp_ops->setup_cpu is the wrong
thing to do:
- It has no useful failure path (too late)
- Calling any allocator will enable interrupts prematurely
causing problems with large decrementer among others
Instead, add a new callback that is called from __cpu_up (so from
the context trying to online the new CPU) at a point where we
can safely allocate and handle failures.
This will be used by XIVE support.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 46f89e66a273..b12f5f0a408f 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -521,6 +521,16 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle) cpu_idle_thread_init(cpu, tidle); + /* + * The platform might need to allocate resources prior to bringing + * up the CPU + */ + if (smp_ops->prepare_cpu) { + rc = smp_ops->prepare_cpu(cpu); + if (rc) + return rc; + } + /* Make sure callin-map entry is 0 (can be leftover a CPU * hotplug */ |