Pull signal handling cleanups from Al Viro:
"sigaltstack infrastructure + conversion for x86, alpha and um,
COMPAT_SYSCALL_DEFINE infrastructure.
Note that there are several conflicts between "unify
SS_ONSTACK/SS_DISABLE definitions" and UAPI patches in mainline;
resolution is trivial - just remove definitions of SS_ONSTACK and
SS_DISABLED from arch/*/uapi/asm/signal.h; they are all identical and
include/uapi/linux/signal.h contains the unified variant."
Fixed up conflicts as per Al.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
alpha: switch to generic sigaltstack
new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those
generic compat_sys_sigaltstack()
introduce generic sys_sigaltstack(), switch x86 and um to it
new helper: compat_user_stack_pointer()
new helper: restore_altstack()
unify SS_ONSTACK/SS_DISABLE definitions
new helper: current_user_stack_pointer()
missing user_stack_pointer() instances
Bury the conditionals from kernel_thread/kernel_execve series
COMPAT_SYSCALL_DEFINE: infrastructure
A few new features this merge-window. The most important one is
probably, that dma-debug now warns if a dma-handle is not checked with
dma_mapping_error by the device driver. This requires minor changes to
some architectures which make use of dma-debug. Most of these changes
have the respective Acks by the Arch-Maintainers.
Besides that there are updates to the AMD IOMMU driver for refactor the
IOMMU-Groups support and to make sure it does not trigger a hardware
erratum.
The OMAP changes (for which I pulled in a branch from Tony Lindgren's
tree) have a conflict in linux-next with the arm-soc tree. The conflict
is in the file arch/arm/mach-omap2/clock44xx_data.c which is deleted in
the arm-soc tree. It is safe to delete the file too so solve the
conflict. Similar changes are done in the arm-soc tree in the common
clock framework migration. A missing hunk from the patch in the IOMMU
tree will be submitted as a seperate patch when the merge-window is
closed.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=pPHZ
-----END PGP SIGNATURE-----
Merge tag 'iommu-updates-v3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU updates from Joerg Roedel:
"A few new features this merge-window. The most important one is
probably, that dma-debug now warns if a dma-handle is not checked with
dma_mapping_error by the device driver. This requires minor changes
to some architectures which make use of dma-debug. Most of these
changes have the respective Acks by the Arch-Maintainers.
Besides that there are updates to the AMD IOMMU driver for refactor
the IOMMU-Groups support and to make sure it does not trigger a
hardware erratum.
The OMAP changes (for which I pulled in a branch from Tony Lindgren's
tree) have a conflict in linux-next with the arm-soc tree. The
conflict is in the file arch/arm/mach-omap2/clock44xx_data.c which is
deleted in the arm-soc tree. It is safe to delete the file too so
solve the conflict. Similar changes are done in the arm-soc tree in
the common clock framework migration. A missing hunk from the patch
in the IOMMU tree will be submitted as a seperate patch when the
merge-window is closed."
* tag 'iommu-updates-v3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (29 commits)
ARM: dma-mapping: support debug_dma_mapping_error
ARM: OMAP4: hwmod data: ipu and dsp to use parent clocks instead of leaf clocks
iommu/omap: Adapt to runtime pm
iommu/omap: Migrate to hwmod framework
iommu/omap: Keep mmu enabled when requested
iommu/omap: Remove redundant clock handling on ISR
iommu/amd: Remove obsolete comment
iommu/amd: Don't use 512GB pages
iommu/tegra: smmu: Move bus_set_iommu after probe for multi arch
iommu/tegra: gart: Move bus_set_iommu after probe for multi arch
iommu/tegra: smmu: Remove unnecessary PTC/TLB flush all
tile: dma_debug: add debug_dma_mapping_error support
sh: dma_debug: add debug_dma_mapping_error support
powerpc: dma_debug: add debug_dma_mapping_error support
mips: dma_debug: add debug_dma_mapping_error support
microblaze: dma-mapping: support debug_dma_mapping_error
ia64: dma_debug: add debug_dma_mapping_error support
c6x: dma_debug: add debug_dma_mapping_error support
ARM64: dma_debug: add debug_dma_mapping_error support
intel-iommu: Prevent devices with RMRRs from being placed into SI Domain
...
All architectures have
CONFIG_GENERIC_KERNEL_THREAD
CONFIG_GENERIC_KERNEL_EXECVE
__ARCH_WANT_SYS_EXECVE
None of them have __ARCH_WANT_KERNEL_EXECVE and there are only two callers
of kernel_execve() (which is a trivial wrapper for do_execve() now) left.
Kill the conditionals and make both callers use do_execve().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull MIPS updates from Ralf Baechle:
"The MIPS bits for 3.8. This also includes a bunch fixes that were
sitting in the linux-mips.org git tree for a long time. This pull
request contains updates to several OCTEON drivers and the board
support code for BCM47XX, BCM63XX, XLP, XLR, XLS, lantiq, Loongson1B,
updates to the SSB bus support, MIPS kexec code and adds support for
kdump.
When pulling this, there are two expected merge conflicts in
include/linux/bcma/bcma_driver_chipcommon.h which are trivial to
resolve, just remove the conflict markers and keep both alternatives."
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (90 commits)
MIPS: PMC-Sierra Yosemite: Remove support.
VIDEO: Newport Fix console crashes
MIPS: wrppmc: Fix build of PCI code.
MIPS: IP22/IP28: Fix build of EISA code.
MIPS: RB532: Fix build of prom code.
MIPS: PowerTV: Fix build.
MIPS: IP27: Correct fucked grammar in ops-bridge.c
MIPS: Highmem: Fix build error if CONFIG_DEBUG_HIGHMEM is disabled
MIPS: Fix potencial corruption
MIPS: Fix for warning from FPU emulation code
MIPS: Handle COP3 Unusable exception as COP1X for FP emulation
MIPS: Fix poweroff failure when HOTPLUG_CPU configured.
MIPS: MT: Fix build with CONFIG_UIDGID_STRICT_TYPE_CHECKS=y
MIPS: Remove unused smvp.h
MIPS/EDAC: Improve OCTEON EDAC support.
MIPS: OCTEON: Add definitions for OCTEON memory contoller registers.
MIPS: OCTEON: Add OCTEON family definitions to octeon-model.h
ata: pata_octeon_cf: Use correct byte order for DMA in when built little-endian.
MIPS/OCTEON/ata: Convert pata_octeon_cf.c to use device tree.
MIPS: Remove usage of CEVT_R4K_LIB config option.
...
This header was added in commit 39b8d52542
(kernel.org) / b6e90cd0ae7a556080d9ea2ec1b8f6d9accad9d4 (lmo( ([MIPS] Add
support for MIPS CMP platform.). None of the functions it declared were
ever included in the tree. Commit cb7f39d2bc
(kernel.org) / b6e90cd0ae7a556080d9ea2ec1b8f6d9accad9d4 (lmo) [MIPS] Remove
unused maltasmp.h.] removeed the sole file that included it because that
file was itself unused.
[ralf@linux-mips.org: The whole mess happened because somebody at MIPS
thought it was a good idea to rename VSMP ("Vitual SMP") to SMVP. Which
is an IBMeque ETLA in contrast to VSMP, so public kernels as opposed to
MTI's inhouse kernels never followed suit.]
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/3950/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The patch needs to eliminate the definition of OCTEON_IRQ_BOOTDMA so
that the device tree code can map the interrupt, so in order to not
temporarily break things, we do a single patch to both the interrupt
registration code and the pata_octeon_cf driver.
Also rolled in is a conversion to use hrtimers and corrections to the
timing calculations.
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Manuel Lauss <manuel.lauss@gmail.com> writes:
I introduced it as a fallback because early revisions of Alchemy hardware
we shipped had a non-functional 32kHz timer and had to rely on the r4k
timer instead. Previously the r4k timer was initialized regardless, but
it's useless with the "wait" instruction.
So long story short: I need either the on-chip 32kHz timer OR the r4k
timer if the 32kHz one is unusable, but not both, and r4k timer is useless
when au1k_idle is in use.
The current in-kernel Alchemy boards all work with the 32kHz timer, so I'm
not against removing R4K_LIB symbols.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Manuel Lauss <manuel.lauss@gmail.com> writes:
I introduced it as a fallback because early revisions of Alchemy hardware
we shipped had a non-functional 32kHz timer and had to rely on the r4k
timer instead. Previously the r4k timer was initialized regardless, but
it's useless with the "wait" instruction.
So long story short: I need either the on-chip 32kHz timer OR the r4k
timer if the 32kHz one is unusable, but not both, and r4k timer is useless
when au1k_idle is in use.
The current in-kernel Alchemy boards all work with the 32kHz timer, so I'm
not against removing R4K_LIB symbols.
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
With the upcoming merge of the ARC architecture there is a small likelyhood
of conflicting use for the CONFIG_ARC config symbol. Rename it to
CONFIG_FW_ARC. Also rename CONFIG_ARC32 to CONFIG_FW_ARC32, CONFIG_ARC64
to CONFIG_FW_ARC64.
For consistence also rename CONFIG_SNIPROM to CONFIG_FW_SNIPROM and
CONFIG_CFE to CONFIG_FW_CFE.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
We have two different implementation of is_zero_pfn() and my_zero_pfn()
helpers: for architectures with and without zero page coloring.
Let's consolidate them in <asm-generic/pgtable.h>.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull big execve/kernel_thread/fork unification series from Al Viro:
"All architectures are converted to new model. Quite a bit of that
stuff is actually shared with architecture trees; in such cases it's
literally shared branch pulled by both, not a cherry-pick.
A lot of ugliness and black magic is gone (-3KLoC total in this one):
- kernel_thread()/kernel_execve()/sys_execve() redesign.
We don't do syscalls from kernel anymore for either kernel_thread()
or kernel_execve():
kernel_thread() is essentially clone(2) with callback run before we
return to userland, the callbacks either never return or do
successful do_execve() before returning.
kernel_execve() is a wrapper for do_execve() - it doesn't need to
do transition to user mode anymore.
As a result kernel_thread() and kernel_execve() are
arch-independent now - they live in kernel/fork.c and fs/exec.c
resp. sys_execve() is also in fs/exec.c and it's completely
architecture-independent.
- daemonize() is gone, along with its parts in fs/*.c
- struct pt_regs * is no longer passed to do_fork/copy_process/
copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump.
- sys_fork()/sys_vfork()/sys_clone() unified; some architectures
still need wrappers (ones with callee-saved registers not saved in
pt_regs on syscall entry), but the main part of those suckers is in
kernel/fork.c now."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits)
do_coredump(): get rid of pt_regs argument
print_fatal_signal(): get rid of pt_regs argument
ptrace_signal(): get rid of unused arguments
get rid of ptrace_signal_deliver() arguments
new helper: signal_pt_regs()
unify default ptrace_signal_deliver
flagday: kill pt_regs argument of do_fork()
death to idle_regs()
don't pass regs to copy_process()
flagday: don't pass regs to copy_thread()
bfin: switch to generic vfork, get rid of pointless wrappers
xtensa: switch to generic clone()
openrisc: switch to use of generic fork and clone
unicore32: switch to generic clone(2)
score: switch to generic fork/vfork/clone
c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone()
take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h
mn10300: switch to generic fork/vfork/clone
h8300: switch to generic fork/vfork/clone
tile: switch to generic clone()
...
Conflicts:
arch/microblaze/include/asm/Kbuild
Instated of providing an own GPIO driver use the one provided by ssb and
bcma.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4592
Acked-by: Florian Fainelli <florian@openwrt.org>
2957c9e61e (kernel.org) rsp.
b934da913f236bca00c41d9e386e980586000461 (lmo) [[MIPS] IRIX: Goodbye and
thanks for all the fish] left two fields in struct thread_struct which
were only being used for the IRIX compat code. Remove them.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
We need Huge TLBs for HUGETLB_PAGE, or the soon to follow
TRANSPARENT_HUGEPAGE. collect this information under a single Kconfig
symbol.
Signed-off-by: David Daney <david.daney@cavium.com>
Problem:
1) Huge page mapping of anonymous memory is initially invalid. Will be
faulted in by copy-on-write mechanism.
2) Userspace attempts store at the end of the huge mapping.
3) TLB Refill exception handler fill TLB with a normal (4K sized)
invalid page at the end of the huge mapping virtual address range.
4) Userspace restarted, and re-attempts the store at the end of the
huge mapping.
5) Page from #3 is invalid, we get a fault and go to the hugepage
fault handler. This tries to map a huge page and calls
huge_ptep_set_access_flags() to install the mapping.
6) We just call the generic ptep_set_access_flags() to set up the page
tables, but the flush there assumes a normal (4K sized) page and
only tries to flush the first part of the huge page virtual address
out of the TLB, since the existing entry from step #3 doesn't
conflict, nothing is flushed.
7) We attempt to load the mapping into the TLB, but because it
conflicts with the entry from step #3, we get a Machine Check
exception.
The fix: Flush the entire rage covered by the huge page in
huge_ptep_set_access_flags(), and remove the optimization in
local_flush_tlb_range() so that the flush actually does the correct
thing.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Hillf Danton <dhillf@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/4661/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit dd617f258cc39d36be26afee9912624a2d23112c)
Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail
to check dma mapping errors on addresses returned by dma_map_single() and
dma_map_page() interfaces.
Signed-off-by: Shuah Khan <shuah.khan@hp.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Pgtable bits are assigned dynamically depending on processor feature and
statically based on kernel configuration. To make sense out of the
disassembled TLB exception handlers a list of the actual assignments
used for a particular configuration and hardware setup can be very useful.
Output the actual TLB exception handlers in a format that simplifies their
post processsing from dmesg output.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
From a software perspective R5000 and R5000A are the same thing which is
why the symbol CPU_R5000A never got used, so finally delete it.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
BCM6345 has an intermediate 16-bits wide test control register between the
peripheral identifier register, and its clock control register is only 16-bits
wide contrary to other platforms where it is 32-bits wide. By shifting all
clocks bits by 16-bits to the left we ensure they get written to the proper
clock control register, without adding specific BCM6345 handling in the clock
code.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4555/
Signed-off-by: John Crispin <blogic@openwrt.org>
In order to promote interoperability between userspace tracers and ftrace,
add a trace_clock that reports raw TSC values which will then be recorded
in the ring buffer. Userspace tracers that also record TSCs are then on
exactly the same time base as the kernel and events can be unambiguously
interlaced.
Tested: Enabled a tracepoint and the "tsc" trace_clock and saw very large
timestamp values.
v2:
Move arch-specific bits out of generic code.
v3:
Rename "x86-tsc", cleanups
v7:
Generic arch bits in Kbuild.
Google-Bug-Id: 6980623
Link: http://lkml.kernel.org/r/1352837903-32191-1-git-send-email-dhsharp@google.com
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Signed-off-by: David Sharp <dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The XRX200 family of SoCs has embedded gigabit PHYs. This patch adds code to
boot them up.
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4522
Use common clock infrastructure instead of private APIs.
1. Enable COMMON_CLK in the Kconfig.
2. Remove private clock APIs, which are replaced by the code in
drivers/clk/clk-ls1x.c.
3. Modify header file for drivers/clk/clk-ls1x.c.
Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
Patchwork: http://patchwork.linux-mips.org/patch/4431
Signed-off-by: John Crispin <blogic@openwrt.org>
On XLR/XLS, the cpu cores communicate with fast on-chip devices
(e.g. network accelerator, security engine etc.) using the Fast
Messaging Network(FMN). The FMN queues and credits needs to be
configured and intialized before it can be used.
The co-processor 2 on XLR/XLS CPU cores has registers for FMN access,
and the XLR/XLS has custom instructions for sending and loading
messages. The FMN can deliver also per-cpu interrupts when messages
are available at the CPU.
This patch adds FMN initialization, adds interrupt setup and handling,
and also provides support for sending and receiving FMN messages.
Signed-off-by: Ganesan Ramalingam <ganesanr@broadcom.com>
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4468
Signed-off-by: John Crispin <blogic@openwrt.org>
Create struct nlm_pic_irq for interrupts handled by the PIC.
This simplifies IRQ handling for multi-SoC as well as
the single SoC cases. Also split the setup of percpu and PIC
interrupts so that we can configure the PIC interrupts for
every node.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4467
Signed-off-by: John Crispin <blogic@openwrt.org>
There can be 1, 2 or 4 SoCs(nodes) in a multi-chip XLP board. Add an
option for multi-chip boards in case of XLP, and make the number of
nodes configurable.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4470
Signed-off-by: John Crispin <blogic@openwrt.org>
Upto 4 Netlogic XLP SoCs can be connected over ICI links to form a
coherent multi-node system. Each SoC has its own set of on-chip
devices including PIC. To support this, add a per SoC stucture and
use it for the PIC and SYS block addresses instead of using global
variables.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4469
Signed-off-by: John Crispin <blogic@openwrt.org>
Initial code to support more than 32 cpus. The platform CPU mask
is updated from 32-bit mask to cpumask_t. Convert places that use
cpu_/cpus_ functions to use cpumask_* functions.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4464
Signed-off-by: John Crispin <blogic@openwrt.org>
Remove unused and trivial PIC accesss functions, update nlm_pic_send_ipi()
and nlm_set_irt_to_cpu() to use similar logic, and use correct type for
reg in nlm_pic_disable_irt().
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4463
Signed-off-by: John Crispin <blogic@openwrt.org>
Used the hardware thread id passed in while writing to IRT in
nlm_pic_init_irt()
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4465
Signed-off-by: John Crispin <blogic@openwrt.org>
Refactor nvram related functions into its own unit for easier expansion
and exposure of the values to other drivers.
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Patchwork: http://patchwork.linux-mips.org/patch/4516
Signed-off-by: John Crispin <blogic@openwrt.org>
Add a reset helper for resetting the different cores.
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Patchwork: http://patchwork.linux-mips.org/patch/4455
Signed-off-by: John Crispin <blogic@openwrt.org>
The softreset register description for BCM6358 was missing, so add it.
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Patchwork: http://patchwork.linux-mips.org/patch/4454
Signed-off-by: John Crispin <blogic@openwrt.org>
There are bcma based devices like the Linksys E2000 out there, which do
have one ieee80211 core, but no PCIe core and they are using no
prefixes for the sprom. In addition some values like boardtype are
stored without a prefix for the main SoC chip also when they have an
additional PCIe wifi chip with an own boardtype var on some devices.
The Ethernet addresses are now also read out correctly without a prefix
so calling bcm47xx_fill_sprom_ethernet is not needed any more.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4364
Signed-off-by: John Crispin <blogic@openwrt.org>
For non MIPSr2 processors, such as the BMIPS 5000, calls to
arch_local_irq_disable() and others may be preempted, and in doing
so a stale value may be restored to c0_status. This fix disables
preemption for such processors prior to the call and enables it
after the call.
Those functions that needed this fix have been "outlined" to
mips-atomic.c, as they are no longer good candidates for inlining.
This bug was observed in a BMIPS 5000, occuring once every few hours
in a continuous reboot test. It was traced to the write_lock_irq()
function which was being invoked in release_task() in exit.c.
By placing a number of "nops" inbetween the mfc0/mtc0 pair in
arch_local_irq_disable(), which is called by write_lock_irq(), we
were able to greatly increase the occurance of this bug. Similarly,
the application of this commit silenced the bug.
Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: David Daney <ddaney.cavm@gmail.com>
Cc: Kevin Cernekee cernekee@gmail.com
Cc: Jim Quinlan <jim2101024@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/4321/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
