[PATCH 4.9 28/61] powerpc/rfi-flush: Make it possible to call setup_rfi_flush() again

Greg Kroah-Hartman
2018-06-05T17:18:12Z

From: Michael Ellerman <mpe@ellerman.id.au>

commit abf110f3e1cea40f5ea15e85f5d67c39c14568a7 upstream.

For PowerVM migration we want to be able to call setup_rfi_flush()
again after we've migrated the partition.

To support that we need to check that we're not trying to allocate the
fallback flush area after memblock has gone away (i.e., boot-time only).

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/include/asm/setup.h | 2 +-
arch/powerpc/kernel/setup_64.c | 6 +++++-
2 files changed, 6 insertions(+), 2 deletions(-)

--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -48,7 +48,7 @@ enum l1d_flush_type {
L1D_FLUSH_MTTRIG = 0x8,
};

-void __init setup_rfi_flush(enum l1d_flush_type, bool enable);
+void setup_rfi_flush(enum l1d_flush_type, bool enable);
void do_rfi_flush_fixups(enum l1d_flush_type types);

#endif /* !__ASSEMBLY__ */
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -731,6 +731,10 @@ static void init_fallback_flush(void)
u64 l1d_size, limit;
int cpu;

+ /* Only allocate the fallback flush area once (at boot time). */
+ if (l1d_flush_fallback_area)
+ return;
+
l1d_size = ppc64_caches.dsize;
limit = min(safe_stack_limit(), ppc64_rma_size);

@@ -748,7 +752,7 @@ static void init_fallback_flush(void)
}
}

-void __init setup_rfi_flush(enum l1d_flush_type types, bool enable)
+void setup_rfi_flush(enum l1d_flush_type types, bool enable)
{
if (types & L1D_FLUSH_FALLBACK) {
pr_info("rfi-flush: Using fallback displacement flush\n");