mm: provide a fallback for PAGE_KERNEL_RO for architectures

Some architectures do not define certain PAGE_KERNEL_* flags, this is
either because:

 a) The way to implement some of these flags is *not yet ported*, or
 b) The architecture *has no way* to describe them

Over time we have accumulated a few PAGE_KERNEL_* fallback workarounds
for architectures in the kernel which do not define them using
*relatively safe* equivalents.  Move these scattered fallback hacks into
asm-generic.

We start off with PAGE_KERNEL_RO using PAGE_KERNEL as a fallback.  This
has been in place on the firmware loader for years.  Move the fallback
into the respective asm-generic header.

Link: http://lkml.kernel.org/r/20180510185507.2439-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Luis R. Rodriguez
2018-08-17 15:46:29 -07:00
committed by Linus Torvalds
parent 3172e5e61c
commit a3266bd49c
2 changed files with 14 additions and 5 deletions

View File

@@ -219,11 +219,6 @@ static ssize_t firmware_loading_show(struct device *dev,
return sprintf(buf, "%d\n", loading);
}
/* Some architectures don't have PAGE_KERNEL_RO */
#ifndef PAGE_KERNEL_RO
#define PAGE_KERNEL_RO PAGE_KERNEL
#endif
/* one pages buffer should be mapped/unmapped only once */
static int map_fw_priv_pages(struct fw_priv *fw_priv)
{