This patch populates the L1 entries for MT_MEMORY and MT_MEMORY_NONCACHED
types so that at boot-up, we can map memories outside system memory
at page level granularity
Previously the mapping was limiting to section level, which creates
unnecessary additional mapping for which physical memory may not
present. On the newer ARM with speculation, this is dangerous and can
result in untraceable aborts.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When the policy for user space is to ignore misaligned accesses from user
space, the processor then performs a documented rotation on the accessed
data. This is the result of the access being trapped, and the kernel
disabling the alignment trap before returning to user space again.
In kernel space we always want misaligned accesses to be fixed up. This
is enforced by always re-enabling the alignment trap on every entry into
kernel space from user space. No such re-enabling is performed when an
exception occurs while already in kernel space as the alignment trap is
always supposed to be enabled in that case.
There is however a small race window when a misaligned access in user
space is trapped and the alignment trap disabled, but the CPU didn't
return to user space just yet. Any exception would be entered from kernel
space at that point and the kernel would then execute with the alignment
trap disabled.
Thanks to Maxime Bizon <mbizon@freebox.fr> for providing a test module
that made this issue reproducible.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARMv7 onwards requires that there are no aliases to the same physical
location using different memory types (i.e. Normal vs Strongly Ordered).
Access to SO mappings when the unaligned accesses are handled in
hardware is also Unpredictable (pgprot_noncached() mappings in user
space).
The /dev/mem driver requires uncached mappings with O_SYNC. The patch
implements the phys_mem_access_prot() function which generates Strongly
Ordered memory attributes if !pfn_valid() (independent of O_SYNC) and
Normal Noncacheable (writecombine) if O_SYNC.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Setting of these bits can cause issues on other SMP SoC's not produced
by ARM.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On the r2p0, r2p1 and r2p2 versions of the Cortex-A9, data corruption
can occur if a shared cache line is replaced on one CPU as another CPU
is accessing it.
This workaround sets two bits in the diagnostic register of the Cortex-A9,
reducing the linefill issuing capabilities of the processor and
avoiding the erroneous behaviour.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On versions of the Cortex-A9 up to and including r2p2, under rare
circumstances, a DMB instruction between 2 write operations may not
ensure the correct visibility ordering of the 2 writes.
This workaround sets a bit in the diagnostic register of the Cortex-A9,
causing the DMB instruction to behave like a DSB, which functions
correctly on the affected cores.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Kconfig doesn't have any knowledge of specific v7 cores, so it is possible
to select errata workarounds that may cause inadvertent behaviour when
executed on a core other than those targetted by the fix.
This patch improves the variant and revision checking in proc-v7.S so
that the primary part number is also considered when applying errata
workarounds.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Stephen Rothwell reported this build failure:
arch/arm/mm/init.c: In function 'arm_memory_present':
arch/arm/mm/init.c:260: warning: ISO C90 forbids mixed declarations and code
Caused by commit 719c1514f2 ("memblock/arm: Use new accessors")
which forgot a closing brace on a new for_each_memblock() in
arm_memory_present().
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Russell King <linux@arm.linux.org.uk>
LKML-Reference: <4C91C544.5050907@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Dave Hylands reports:
| We've observed a problem with dma_alloc_writecombine when the system
| is under heavy load (heavy bus traffic). We've managed to reduce the
| problem to the following snippet, which is run from a kthread in a
| continuous loop:
|
| void *virtAddr;
| dma_addr_t physAddr;
| unsigned int numBytes = 256;
|
| for (;;) {
| virtAddr = dma_alloc_writecombine(NULL,
| numBytes, &physAddr, GFP_KERNEL);
| if (virtAddr == NULL) {
| printk(KERN_ERR "Running out of memory\n");
| break;
| }
|
| /* access DMA memory allocated */
| tmp = virtAddr;
| *tmp = 0x77;
|
| /* free DMA memory */
| dma_free_writecombine(NULL,
| numBytes, virtAddr, physAddr);
|
| ...sleep here...
| }
|
| By itself, the code will run forever with no issues. However, as we
| increase our bus traffic (typically using DMA) then the *tmp = 0x77
| line will eventually cause a page fault. If we add a small delay (a
| few microseconds) before the *tmp = 0x77, then we don't see a page
| fault, even under heavy load.
A dsb() is required after modifying the PTE entries to ensure that they
will always be visible. Add this dsb().
Reported-by: Dave Hylands <dhylands@gmail.com>
Tested-by: Dave Hylands <dhylands@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
CPU_32v6K is selected by CPU_V7 but it only depends on CPU_V6.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
kunmap_atomic() is currently at level -4 on Rusty's "Hard To Misuse"
list[1] ("Follow common convention and you'll get it wrong"), except in
some architectures when CONFIG_DEBUG_HIGHMEM is set[2][3].
kunmap() takes a pointer to a struct page; kunmap_atomic(), however, takes
takes a pointer to within the page itself. This seems to once in a while
trip people up (the convention they are following is the one from
kunmap()).
Make it much harder to misuse, by moving it to level 9 on Rusty's list[4]
("The compiler/linker won't let you get it wrong"). This is done by
refusing to build if the type of its first argument is a pointer to a
struct page.
The real kunmap_atomic() is renamed to kunmap_atomic_notypecheck()
(which is what you would call in case for some strange reason calling it
with a pointer to a struct page is not incorrect in your code).
The previous version of this patch was compile tested on x86-64.
[1] http://ozlabs.org/~rusty/index.cgi/tech/2008-04-01.html
[2] In these cases, it is at level 5, "Do it right or it will always
break at runtime."
[3] At least mips and powerpc look very similar, and sparc also seems to
share a common ancestor with both; there seems to be quite some
degree of copy-and-paste coding here. The include/asm/highmem.h file
for these three archs mention x86 CPUs at its top.
[4] http://ozlabs.org/~rusty/index.cgi/tech/2008-03-30.html
[5] As an aside, could someone tell me why mn10300 uses unsigned long as
the first parameter of kunmap_atomic() instead of void *?
Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Cc: Russell King <linux@arm.linux.org.uk> (arch/arm)
Cc: Ralf Baechle <ralf@linux-mips.org> (arch/mips)
Cc: David Howells <dhowells@redhat.com> (arch/frv, arch/mn10300)
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> (arch/mn10300)
Cc: Kyle McMartin <kyle@mcmartin.ca> (arch/parisc)
Cc: Helge Deller <deller@gmx.de> (arch/parisc)
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> (arch/parisc)
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> (arch/powerpc)
Cc: Paul Mackerras <paulus@samba.org> (arch/powerpc)
Cc: "David S. Miller" <davem@davemloft.net> (arch/sparc)
Cc: Thomas Gleixner <tglx@linutronix.de> (arch/x86)
Cc: Ingo Molnar <mingo@redhat.com> (arch/x86)
Cc: "H. Peter Anvin" <hpa@zytor.com> (arch/x86)
Cc: Arnd Bergmann <arnd@arndb.de> (include/asm-generic)
Cc: Rusty Russell <rusty@rustcorp.com.au> ("Hard To Misuse" list)
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
v2: Fixes from Mike Rapoport
- remove unused header files (mach/dma.h and mach/nand.h)
- remove tegra 1 references from Makefile.boot
v2: fixes from Russell King
- remove mach/io.h include from mach/iomap.h
- fix whitespace in Kconfig
v2: from Colin Cross
- fix invalid immediate in debug-macro.S
v3:
- allow selection of multiple boards
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Erik Gilling <konkers@android.com>
This patch adds the Kconfig and Makefile for the new S5PV310 SoC.
It also updates arch/arm Kconfig, Makefile and arch/arm/mm/Kconfig
to include support for the new S5PV310.
Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
The implementation is pretty much similar. There is a -small- added
overhead by having another function call and the address shift.
If that becomes a concern, I suppose we could actually have memblock
itself expose a memblock_pfn_valid() which then ARM can use directly
with an appropriate #define...
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (291 commits)
ARM: AMBA: Add pclk support to AMBA bus infrastructure
ARM: 6278/2: fix regression in RealView after the introduction of pclk
ARM: 6277/1: mach-shmobile: Allow users to select HZ, default to 128
ARM: 6276/1: mach-shmobile: remove duplicate NR_IRQS_LEGACY
ARM: 6246/1: mmci: support larger MMCIDATALENGTH register
ARM: 6245/1: mmci: enable hardware flow control on Ux500 variants
ARM: 6244/1: mmci: add variant data and default MCICLOCK support
ARM: 6243/1: mmci: pass power_mode to the translate_vdd callback
ARM: 6274/1: add global control registers definition header file for nuc900
mx2_camera: fix type of dma buffer virtual address pointer
mx2_camera: Add soc_camera support for i.MX25/i.MX27
arm/imx/gpio: add spinlock protection
ARM: Add support for the LPC32XX arch
ARM: LPC32XX: Arch config menu supoport and makefiles
ARM: LPC32XX: Phytec 3250 platform support
ARM: LPC32XX: Misc support functions
ARM: LPC32XX: Serial support code
ARM: LPC32XX: System suspend support
ARM: LPC32XX: GPIO, timer, and IRQ drivers
ARM: LPC32XX: Clock driver
...
smp_processor_id() must not be called from a preemptible context (this
is checked by CONFIG_DEBUG_PREEMPT). kmap_high_l1_vipt() was doing so.
This lead to a problem where the wrong per_cpu kmap_high_l1_vipt_depth
could be incremented, causing a BUG_ON(*depth <= 0); in
kunmap_high_l1_vipt().
The solution is to move the call to smp_processor_id() after the call
to preempt_disable().
Originally by: Andrew Howe <ahowe@nvidia.com>
Signed-off-by: Gary King <gking@nvidia.com>
Acked-by: Nicolas Pitre <nico.as.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch is in preparation for a subsequent patch which adds barriers
to the I/O accessors. Since the mandatory barriers may do an L2 cache
sync, this patch avoids a recursive call into l2x0_cache_sync() via the
write*() accessors and wmb() and a call into l2x0_cache_sync() with the
l2x0_lock held.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
All implementations of cpu_proc_fin() start by disabling interrupts
and then flush caches. Rather than have every processors proc_fin()
implementation do this, move it out into generic code - and move the
cache flush past setup_mm_for_reboot() (so it can benefit from having
caches still enabled.)
This allows cpu_proc_fin() to become independent of the L1/L2 cache
types, and eventually move the L2 cache flushing into the L2 support
code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Statuses 3 (0b00011) and 6 (0x00110) of DFSR are Access Flags faults on
ARMv6K and ARMv7. Let's patch fsr_info[] at runtime if we are on ARMv7
or later.
Unfortunately, we don't have runtime check for 'K' extension, so we
can't check for it.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On ARM one Linux PGD entry contains two hardware entries (see page
tables layout in pgtable.h). We normally guarantee that we always
fill both L1 entries. But create_mapping() doesn't follow the rule.
It can create inidividual L1 entries, so here we have to call
pmd_none() check in do_translation_fault() for the entry really
corresponded to address, not for the first of pair.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add one more parameter to hook_fault_code() to be able to set 'code'
field of struct fsr_info.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
POSIX specify to use signal SIGBUS with code BUS_ADRALN for invalid
address alignment.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The DMA coherent remap area is used to provide an uncached mapping
of memory for coherency with DMA engines. Currently, we look for
any free hole which our allocation will fit in with page alignment.
However, this can lead to fragmentation of the area, and allows small
allocations to cross L1 entry boundaries. This is undesirable as we
want to move towards allocating sections of memory.
Align allocations according to the size, limiting the alignment between
the page and section sizes.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We don't need our own implementation of this, use the generic
library implementation instead.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This changes the TCM handling so that a fixed area is reserved at
0xfffe0000-0xfffeffff for TCM. This areas is used by XScale but
XScale does not have TCM so the mechanisms are mutually exclusive.
This change is needed to make TCM detection more dynamic while
still being able to compile code into it, and is a must for the
unified ARM goals: the current TCM allocation at different places
in memory for each machine would be a nightmare if you want to
compile a single image for more than one machine with TCM so it
has to be nailed down in one place.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If TCM is in use, we should display it in the virtual memory
layout along with everything else.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The earlier TCM memory regions were mapped as MT_MEMORY_UNCACHED
which doesn't really work on platforms supporting the new v6
features like the NX bit. Add unique MT_MEMORY_[I|D]TCM types
instead.
Cc: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add a common early allocator function, in preparation for switching
over to LMB. When we do, this function will need to do a little more
than just allocating memory; we need it zero initialized too.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move the platform specific bootmem memory reservations out of
arch/arm/mm/mmu.c into their respective platform files.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Everything should now be using sparsemem rather than discontigmem, so
remove the code supporting discontigmem from ARM.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than storing the minimum size of the vmalloc area, store the
maximum permitted address of the vmalloc area instead.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Ingo Molnar