Paul Burton 6fce06b68b MIPS: Fix ioremap() RAM check ... commit 523402fa91 upstream. We currently attempt to check whether a physical address range provided to __ioremap() may be in use by the page allocator by examining the value of PageReserved for each page in the region - lowmem pages not marked reserved are presumed to be in use by the page allocator, and requests to ioremap them fail. The way we check this has been broken since commit 92923ca3aa ("mm: meminit: only set page reserved in the memblock region"), because memblock will typically not have any knowledge of non-RAM pages and therefore those pages will not have the PageReserved flag set. Thus when we attempt to ioremap a region outside of RAM we incorrectly fail believing that the region is RAM that may be in use. In most cases ioremap() on MIPS will take a fast-path to use the unmapped kseg1 or xkphys virtual address spaces and never hit this path, so the only way to hit it is for a MIPS32 system to attempt to ioremap() an address range in lowmem with flags other than _CACHE_UNCACHED. Perhaps the most straightforward way to do this is using ioremap_uncached_accelerated(), which is how the problem was discovered. Fix this by making use of walk_system_ram_range() to test the address range provided to __ioremap() against only RAM pages, rather than all lowmem pages. This means that if we have a lowmem I/O region, which is very common for MIPS systems, we're free to ioremap() address ranges within it. A nice bonus is that the test is no longer limited to lowmem. The approach here matches the way x86 performed the same test after commit c81c8a1eee ("x86, ioremap: Speed up check for RAM pages") until x86 moved towards a slightly more complicated check using walk_mem_res() for unrelated reasons with commit 0e4c12b45a ("x86/mm, resource: Use PAGE_KERNEL protection for ioremap of memory pages"). Signed-off-by: Paul Burton <paul.burton@mips.com> Reported-by: Serge Semin <fancer.lancer@gmail.com> Tested-by: Serge Semin <fancer.lancer@gmail.com> Fixes: 92923ca3aa ("mm: meminit: only set page reserved in the memblock region") Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v4.2+ Patchwork: https://patchwork.linux-mips.org/patch/19786/ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2018-07-17 11:39:23 +02:00
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alpha	locking/xchg/alpha: Fix xchg() and cmpxchg() memory ordering bugs	2018-05-30 07:52:02 +02:00
arc	ARC: setup cpu possible mask according to possible-cpus dts property	2018-05-30 07:52:07 +02:00
arm	ARM: dts: imx6q: Use correct SDMA script for SPI5 core	2018-07-08 15:30:51 +02:00
arm64	ARM64: dts: meson: disable sd-uhs modes on the libretech-cc	2018-07-03 11:24:52 +02:00
blackfin
c6x
cris	bug.h: work around GCC PR82365 in BUG()	2018-05-30 07:52:00 +02:00
frv
h8300
hexagon	hexagon: export csum_partial_copy_nocheck	2018-06-21 04:02:52 +09:00
ia64	ia64/err-inject: Use get_user_pages_fast()	2018-05-30 07:52:11 +02:00
m32r
m68k	m68k/mac: Fix SWIM memory resource end address	2018-07-03 11:24:46 +02:00
metag
microblaze
mips	MIPS: Fix ioremap() RAM check	2018-07-17 11:39:23 +02:00
mn10300
nios2
openrisc
parisc	parisc: Move setup_profiling_timer() out of init section	2018-06-21 04:03:01 +09:00
powerpc	powerpc/fadump: Unregister fadump on kexec down path.	2018-07-03 11:24:51 +02:00
s390	s390: Correct register corruption in critical section cleanup	2018-07-11 16:29:14 +02:00
score
sh	sh: fix build failure for J2 cpu with SMP disabled	2018-06-21 04:02:54 +09:00
sparc	sparc64: Make atomic_xchg() an inline function rather than a macro.	2018-05-30 07:52:25 +02:00
tile
um
unicore32
x86	x86/efi: Fix efi_call_phys_epilog() with CONFIG_X86_5LEVEL=y	2018-07-03 11:25:05 +02:00
xtensa	signal/xtensa: Consistenly use SIGBUS in do_unaligned_user	2018-07-03 11:24:47 +02:00
.gitignore
Kconfig