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>

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index b8b75b4..c844dbc 100644 (file)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -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

diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 50d5bf9..7aa237d 100644 (file)
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -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

diff --git a/arch/powerpc/lib/pmem.c b/arch/powerpc/lib/pmem.c
new file mode 100644 (file)
index 0000000..0fa0926
--- /dev/null
+++ b/arch/powerpc/lib/pmem.c
@@ -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);