powerpc/lib: Implement PMEM API

Implement the architecture specific cache maintence functions that make
up the "PMEM API". Currently the writeback and invalidate functions
are the same since the function of the DCBST (data cache block store)
instruction is typically interpreted as "writeback to the point of
coherency" rather than to memory. As a result implementing the API
requires a full cache flush rather than just a cache write back. This
will probably change in the not-too-distant future.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Oliver O'Halloran 2017-10-19 18:13:54 +11:00 committed by Michael Ellerman
parent 1b2c2b1238
commit 32ce3862af
3 changed files with 36 additions and 1 deletions

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@ -138,6 +138,7 @@ config PPC
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_PMEM_API if PPC64
select ARCH_HAS_SCALED_CPUTIME if VIRT_CPU_ACCOUNTING_NATIVE
select ARCH_HAS_SG_CHAIN
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST

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@ -23,7 +23,7 @@ endif
obj64-y += copypage_64.o copyuser_64.o mem_64.o hweight_64.o \
copyuser_power7.o string_64.o copypage_power7.o memcpy_power7.o \
memcpy_64.o memcmp_64.o
memcpy_64.o memcmp_64.o pmem.o
obj64-$(CONFIG_SMP) += locks.o
obj64-$(CONFIG_ALTIVEC) += vmx-helper.o

34
arch/powerpc/lib/pmem.c Normal file
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@ -0,0 +1,34 @@
/*
* Copyright(c) 2017 IBM Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <linux/string.h>
#include <linux/export.h>
#include <asm/cacheflush.h>
/*
* CONFIG_ARCH_HAS_PMEM_API symbols
*/
void arch_wb_cache_pmem(void *addr, size_t size)
{
unsigned long start = (unsigned long) addr;
flush_inval_dcache_range(start, start + size);
}
EXPORT_SYMBOL(arch_wb_cache_pmem);
void arch_invalidate_pmem(void *addr, size_t size)
{
unsigned long start = (unsigned long) addr;
flush_inval_dcache_range(start, start + size);
}
EXPORT_SYMBOL(arch_invalidate_pmem);