mm: create generic early_ioremap() support

This patch creates a generic implementation of early_ioremap() support
based on the existing x86 implementation.  early_ioremp() is useful for
early boot code which needs to temporarily map I/O or memory regions
before normal mapping functions such as ioremap() are available.

Some architectures have optional MMU.  In the no-MMU case, the remap
functions simply return the passed in physical address and the unmap
functions do nothing.

Signed-off-by: Mark Salter <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Acked-by: H. Peter Anvin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Young <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Mark Salter 2014-04-07 15:39:48 -07:00 • committed by Linus Torvalds
commit 9e5c33d7ae
4 changed files with 291 additions and 0 deletions

View file

@ -61,3 +61,4 @@ obj-$(CONFIG_CLEANCACHE) += cleancache.o
obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
obj-$(CONFIG_ZBUD) += zbud.o
obj-$(CONFIG_ZSMALLOC) += zsmalloc.o
obj-$(CONFIG_GENERIC_EARLY_IOREMAP) += early_ioremap.o