[PATCH v2 25/25] pmem: convert to generic memremap

Dan Williams
2015-07-25T02:46:09Z

Update memremap_pmem() to query the architecture for the mapping type of
the given persistent memory range and then pass those flags to generic
memremap(). arch_memremap_pmem_flags() is provided an address range to
evaluate in the event an arch has a need for different mapping types by
address range. For example the ACPI NFIT carries EFI mapping types in
its memory range description table.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
arch/x86/include/asm/io.h | 2 +-
arch/x86/mm/ioremap.c | 16 ++++++++++------
include/linux/pmem.h | 26 +++++++++++++++-----------
3 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index bba4e8968bc7..1388d7d27775 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -253,7 +253,7 @@ static inline void flush_write_buffers(void)
#endif
}

-void __pmem *arch_memremap_pmem(resource_size_t offset, size_t size);
+unsigned long arch_memremap_pmem_flags(resource_size_t offset, size_t size);
#endif /* __KERNEL__ */

extern void native_io_delay(void);
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 987a58e84e2f..d4a67223f6e9 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -205,6 +205,16 @@ err_free_memtype:
return NULL;
}

+unsigned long arch_memremap_pmem_flags(resource_size_t offset, size_t size)
+{
+ /*
+ * TODO: check the mapping type provided by platform firmware,
+ * per range.
+ */
+ return MEMREMAP_CACHE;
+}
+EXPORT_SYMBOL(arch_memremap_pmem_flags);
+
/**
* ioremap_nocache - map bus memory into CPU space
* @phys_addr: bus address of the memory
@@ -310,12 +320,6 @@ void *arch_memremap(resource_size_t phys_addr, size_t size,
}
EXPORT_SYMBOL(arch_memremap);

-void __pmem *arch_memremap_pmem(resource_size_t offset, size_t size)
-{
- return (void __pmem *) arch_memremap(offset, size, MEMREMAP_CACHE);
-}
-EXPORT_SYMBOL(arch_memremap_pmem);
-
void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
unsigned long prot_val)
{
diff --git a/include/linux/pmem.h b/include/linux/pmem.h
index 1bf74c735fa0..03f9d73f3e13 100644
--- a/include/linux/pmem.h
+++ b/include/linux/pmem.h
@@ -28,10 +28,10 @@ static inline bool __arch_has_wmb_pmem(void)
return false;
}

-static inline void __pmem *arch_memremap_pmem(resource_size_t offset,
+static inline unsigned long arch_memremap_pmem_flags(resource_size_t offset,
unsigned long size)
{
- return NULL;
+ return 0;
}

static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src,
@@ -43,8 +43,8 @@ static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src,

/*
* Architectures that define ARCH_HAS_PMEM_API must provide
- * implementations for arch_memremap_pmem(), arch_memcpy_to_pmem(),
- * arch_wmb_pmem(), and __arch_has_wmb_pmem().
+ * implementations for arch_memremap_pmem_flags(),
+ * arch_memcpy_to_pmem(), arch_wmb_pmem(), and __arch_has_wmb_pmem().
*/

static inline void memcpy_from_pmem(void *dst, void __pmem const *src, size_t size)
@@ -54,7 +54,7 @@ static inline void memcpy_from_pmem(void *dst, void __pmem const *src, size_t si

static inline void memunmap_pmem(void __pmem *addr)
{
- iounmap((void __force __iomem *) addr);
+ memunmap((void __force *) addr);
}

/**
@@ -85,16 +85,15 @@ static inline bool arch_has_pmem_api(void)
* default_memremap_pmem + default_memcpy_to_pmem is sufficient for
* making data durable relative to i/o completion.
*/
-static void default_memcpy_to_pmem(void __pmem *dst, const void *src,
+static inline void default_memcpy_to_pmem(void __pmem *dst, const void *src,
size_t size)
{
memcpy((void __force *) dst, src, size);
}

-static void __pmem *default_memremap_pmem(resource_size_t offset,
- unsigned long size)
+static inline unsigned long default_memremap_pmem_flags(void)
{
- return (void __pmem *) memremap(offset, size, MEMREMAP_WT);
+ return MEMREMAP_WT;
}

/**
@@ -112,9 +111,14 @@ static void __pmem *default_memremap_pmem(resource_size_t offset,
static inline void __pmem *memremap_pmem(resource_size_t offset,
unsigned long size)
{
+ unsigned long flags;
+
if (arch_has_pmem_api())
- return arch_memremap_pmem(offset, size);
- return default_memremap_pmem(offset, size);
+ flags = arch_memremap_pmem_flags(offset, size);
+ else
+ flags = default_memremap_pmem_flags();
+
+ return (void __pmem *) memremap(offset, size, flags);
}

/**