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authorOlof Johansson <olof@lixom.net>2016-11-18 04:46:45 +0300
committerOlof Johansson <olof@lixom.net>2016-11-18 04:46:45 +0300
commita23ea95789eedb0c386a26f02ea5483bae38b67b (patch)
tree7d2f20bc3e59941c3683046a8c5a87c3683338c7 /include/linux/io.h
parentcb7f3a3e11c6e914d03146ff69c39d3e52651cd6 (diff)
parenta909d3e636995ba7c349e2ca5dbb528154d4ac30 (diff)
downloadlinux-a23ea95789eedb0c386a26f02ea5483bae38b67b.tar.xz
Merge tag 'v4.9-rc3' into next/dt64
Linux 4.9-rc3 * tag 'v4.9-rc3': (292 commits) Linux 4.9-rc3 x86/smpboot: Init apic mapping before usage ACPICA: Dispatcher: Fix interpreter locking around acpi_ev_initialize_region() ACPICA: Dispatcher: Fix an unbalanced lock exit path in acpi_ds_auto_serialize_method() ACPICA: Dispatcher: Fix order issue of method termination ARC: module: print pretty section names ARC: module: elide loop to save reference to .eh_frame ARC: mm: retire ARC_DBG_TLB_MISS_COUNT... ARC: build: retire old toggles ARC: boot log: refactor cpu name/release printing ARC: boot log: remove awkward space comma from MMU line ARC: boot log: don't assume SWAPE instruction support ARC: boot log: refactor printing abt features not captured in BCRs ARCv2: boot log: print IOC exists as well as enabled status ubifs: Fix regression in ubifs_readdir() ubi: fastmap: Fix add_vol() return value test in ubi_attach_fastmap() MAINTAINERS: Add entry for genwqe driver VMCI: Doorbell create and destroy fixes GenWQE: Fix bad page access during abort of resource allocation vme: vme_get_size potentially returning incorrect value on failure ...
Diffstat (limited to 'include/linux/io.h')
-rw-r--r--include/linux/io.h22
1 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/io.h b/include/linux/io.h
index e2c8419278c1..82ef36eac8a1 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -141,4 +141,26 @@ enum {
void *memremap(resource_size_t offset, size_t size, unsigned long flags);
void memunmap(void *addr);
+/*
+ * On x86 PAT systems we have memory tracking that keeps track of
+ * the allowed mappings on memory ranges. This tracking works for
+ * all the in-kernel mapping APIs (ioremap*), but where the user
+ * wishes to map a range from a physical device into user memory
+ * the tracking won't be updated. This API is to be used by
+ * drivers which remap physical device pages into userspace,
+ * and wants to make sure they are mapped WC and not UC.
+ */
+#ifndef arch_io_reserve_memtype_wc
+static inline int arch_io_reserve_memtype_wc(resource_size_t base,
+ resource_size_t size)
+{
+ return 0;
+}
+
+static inline void arch_io_free_memtype_wc(resource_size_t base,
+ resource_size_t size)
+{
+}
+#endif
+
#endif /* _LINUX_IO_H */