linux/arch
Michael Holzheu b2a68c2356 s390: allow absolute memory access for /dev/mem
Currently dev/mem for s390 provides only real memory access. This means
that the CPU prefix pages are swapped. The prefix swap for real memory
works as follows:

Each CPU owns a prefix register that points to a page aligned memory
location "P". If this CPU accesses the address range [0,0x1fff], it is
translated by the hardware to [P,P+0x1fff]. Accordingly if this CPU
accesses the address range [P,P+0x1fff], it is translated by the hardware
to [0,0x1fff].  Therefore, if [P,P+0x1fff] or [0,0x1fff] is read from
the current /dev/mem device, the incorrectly swapped memory content is
returned.

With this patch the /dev/mem architecture code is modified to provide
absolute memory access. This is done via the arch specific functions
xlate_dev_mem_ptr() and unxlate_dev_mem_ptr(). For swapped pages on
s390 the function xlate_dev_mem_ptr() now returns a new buffer with a
copy of the requested absolute memory. In case the buffer was allocated,
the unxlate_dev_mem_ptr() function frees it after /dev/mem code has
called copy_to_user().

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16 14:42:38 +02:00
..
alpha alpha: silence 'const' warning in sys_marvel.c 2012-05-02 15:54:06 -04:00
arm ARM: SoC fixes for 3.4-rc 2012-05-12 17:27:41 -07:00
avr32 avr32: fix nop compile fails from system.h split up 2012-04-04 08:23:44 -07:00
blackfin blackfin: fix ifdef fustercluck in mach-bf538/boards/ezkit.c 2012-04-26 14:46:51 -04:00
c6x irq: Kill pointless irqd_to_hw export 2012-04-10 22:39:17 -06:00
cris Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
frv frv: fix warnings in mb93090-mb00/pci-dma.c about implicit EXPORT_SYMBOL 2012-04-02 14:41:26 -07:00
h8300 Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
hexagon hexagon: add missing cpu.h include 2012-04-23 12:57:24 -05:00
ia64 KVM: ia64: fix build due to typo 2012-05-09 13:53:28 +03:00
m32r Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
m68k m68knommu: enable qspi support when SPI_COLDFIRE_QSPI = m 2012-05-08 13:06:51 +10:00
microblaze Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping 2012-04-04 17:13:43 -07:00
mips MIPS: Remove get_current_pgd(). 2012-04-27 17:16:29 +01:00
mn10300 mn10300/CPU hotplug: Add missing call to notify_cpu_starting() 2012-05-15 18:16:57 -07:00
openrisc Disintegrate and delete asm/system.h 2012-03-28 15:58:21 -07:00
parisc parisc/CPU hotplug: Add missing call to notify_cpu_starting() 2012-05-15 18:16:57 -07:00
powerpc powerpc/irq: Fix another case of lazy IRQ state getting out of sync 2012-05-12 09:40:41 +10:00
s390 s390: allow absolute memory access for /dev/mem 2012-05-16 14:42:38 +02:00
score Delete all instances of asm/system.h 2012-03-28 18:30:03 +01:00
sh sh: Fix up tracepoint build fallout from static key introduction. 2012-04-27 11:12:38 +09:30
sparc sparc64: Do not clobber %g2 in xcall_fetch_glob_regs(). 2012-05-10 11:00:46 -07:00
tile arch/tile: fix a couple of functions that should be __init 2012-04-25 12:45:26 -04:00
um um: uml_setup_stubs': warning: unused variable 'pages' 2012-04-10 00:13:45 +02:00
unicore32 Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping 2012-04-04 17:13:43 -07:00
x86 Merge git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-09 11:14:13 -07:00
xtensa xtensa: fix build fail on undefined ack_bad_irq 2012-04-26 18:35:32 -04:00
.gitignore
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2012-03-29 14:49:45 -07:00