In preparation for removing ioremap_cache() introduce arch_memremap()
for x86. For now, arch_memremap(..., MEMREMAP_WB) and
arch_memremap(..., MEMREMAP_WT) are aliases for ioremap_cache() and
ioremap_wt() respectively. While the memremap() conversion patches are
filtering through the other sub-systems further development of the
memremap interface may proceed.
This also initiates the guarantee that a successful call to
memremap(..., MEMREMAP_WB) has indeed established a cached mapping and
has not silently fallen back to uncached.
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
Documentation/x86/pat.txt | 2 ++
arch/x86/Kconfig | 1 +
arch/x86/mm/ioremap.c | 17 +++++++++++++++++
drivers/nvdimm/Kconfig | 2 +-
include/linux/io.h | 1 +
kernel/memremap.c | 25 +++++++++++++------------
lib/Kconfig | 5 ++++-
7 files changed, 39 insertions(+), 14 deletions(-)
diff --git a/Documentation/x86/pat.txt b/Documentation/x86/pat.txt
index 54944c71b819..8c908fa5ea26 100644
--- a/Documentation/x86/pat.txt
+++ b/Documentation/x86/pat.txt
@@ -40,6 +40,8 @@ ioremap_nocache | -- | UC- | UC- |
| | | |
ioremap_wc | -- | -- | WC |
| | | |
+memremap(MEMREMAP_WB) | WB | WB | WB |
+ | | | |
ioremap_wt | -- | -- | WT |
| | | |
set_memory_uc | UC- | -- | -- |
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 328c8352480c..488cb210d055 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -27,6 +27,7 @@ config X86
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FAST_MULTIPLIER
select ARCH_HAS_GCOV_PROFILE_ALL
+ select ARCH_HAS_MEMREMAP
select ARCH_HAS_PMEM_API if X86_64
select ARCH_HAS_MMIO_FLUSH
select ARCH_HAS_SG_CHAIN
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index b9c78f3bcd67..123431ae702f 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -317,6 +317,23 @@ void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
}
EXPORT_SYMBOL(ioremap_cache);
+void *arch_memremap(resource_size_t phys_addr, size_t size,
+ unsigned long flags)
+{
+ int prot;
+
+ if (flags & MEMREMAP_WB)
+ prot = _PAGE_CACHE_MODE_WB;
+ else if (flags & MEMREMAP_WT)
+ prot = _PAGE_CACHE_MODE_WT;
+ else
+ return NULL;
+
+ return (void __force *) __ioremap_caller(phys_addr, size, prot,
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL(arch_memremap);
+
void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
unsigned long prot_val)
{
diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index 53c11621d5b1..b8e9d8b46f33 100644
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -1,5 +1,6 @@
menuconfig LIBNVDIMM
tristate "NVDIMM (Non-Volatile Memory Device) Support"
+ depends on ARCH_HAS_MEMREMAP
depends on PHYS_ADDR_T_64BIT
depends on BLK_DEV
help
@@ -19,7 +20,6 @@ if LIBNVDIMM
config BLK_DEV_PMEM
tristate "PMEM: Persistent memory block device support"
default LIBNVDIMM
- depends on HAS_IOMEM
select ND_BTT if BTT
select ND_PFN if NVDIMM_PFN
help
diff --git a/include/linux/io.h b/include/linux/io.h
index de64c1e53612..4f150781735d 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -153,5 +153,6 @@ enum {
void *memremap(resource_size_t offset, size_t size, unsigned long flags);
void memunmap(void *addr);
+void *arch_memremap(resource_size_t offset, size_t size, unsigned long flags);
#endif /* _LINUX_IO_H */
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 72b0c66628b6..8bd5fe05d4a4 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -24,6 +24,16 @@ __weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size)
}
#endif
+/* temporary while we convert arch implementations to arch_memremap */
+__weak void *arch_memremap(resource_size_t offset, size_t size,
+ unsigned long flags)
+{
+ if (flags & MEMREMAP_WB)
+ return (void __force *) ioremap_cache(offset, size);
+ else if (flags & MEMREMAP_WT)
+ return (void __force *) ioremap_wt(offset, size);
+}
+
/**
* memremap() - remap an iomem_resource as cacheable memory
* @offset: iomem resource start address
@@ -48,7 +58,6 @@ __weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size)
void *memremap(resource_size_t offset, size_t size, unsigned long flags)
{
int is_ram = region_intersects(offset, size, "System RAM");
- void *addr = NULL;
if (is_ram == REGION_MIXED) {
WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n",
@@ -58,7 +67,6 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags)
/* Try all mapping types requested until one returns non-NULL */
if (flags & MEMREMAP_WB) {
- flags &= ~MEMREMAP_WB;
/*
* MEMREMAP_WB is special in that it can be satisifed
* from the direct map. Some archs depend on the
@@ -66,9 +74,7 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags)
* the requested range is potentially in "System RAM"
*/
if (is_ram == REGION_INTERSECTS)
- addr = __va(offset);
- else
- addr = ioremap_cache(offset, size);
+ return __va(offset);
}
/*
@@ -77,18 +83,13 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags)
* address mapping. Enforce that this mapping is not aliasing
* "System RAM"
*/
- if (!addr && is_ram == REGION_INTERSECTS && flags) {
+ if (is_ram == REGION_INTERSECTS) {
WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n",
&offset, (unsigned long) size);
return NULL;
}
- if (!addr && (flags & MEMREMAP_WT)) {
- flags &= ~MEMREMAP_WT;
- addr = ioremap_wt(offset, size);
- }
-
- return addr;
+ return arch_memremap(offset, size, flags);
}
EXPORT_SYMBOL(memremap);
diff --git a/lib/Kconfig b/lib/Kconfig
index 2e491ac15622..8d99b4e6a45b 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -520,7 +520,10 @@ config SG_SPLIT
#
config ARCH_HAS_SG_CHAIN
- def_bool n
+ bool
+
+config ARCH_HAS_MEMREMAP
+ bool
config ARCH_HAS_PMEM_API
bool
--
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