* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86/microcode: Fix double vfree() and remove redundant pointer checks before vfree()
arm: export dma_set_coherent_mask
While a regression was fixed with commit 710224fa27 (arm: fix
"arm: fix pci_set_consistent_dma_mask for dmabounce devices"), a
new one was introduced as dma_set_coherent_mask wasn't exported
for modules. This patch takes care for this issue.
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In arch/x86/kernel/microcode_intel.c::generic_load_microcode()
we have this:
while (leftover) {
...
if (get_ucode_data(mc, ucode_ptr, mc_size) ||
microcode_sanity_check(mc) < 0) {
vfree(mc);
break;
}
...
}
if (mc)
vfree(mc);
This will cause a double free of 'mc'. This patch fixes that by
just removing the vfree() call in the loop since 'mc' will be
freed nicely just after we break out of the loop.
There's also a second change in the patch. I noticed a lot of
checks for pointers being NULL before passing them to vfree().
That's completely redundant since vfree() deals gracefully with
being passed a NULL pointer. Removing the redundant checks
yields a nice size decrease for the object file.
Size before the patch:
text data bss dec hex filename
4578 240 1032 5850 16da arch/x86/kernel/microcode_intel.o
Size after the patch:
text data bss dec hex filename
4489 240 984 5713 1651 arch/x86/kernel/microcode_intel.o
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Shaohua Li <shaohua.li@intel.com>
LKML-Reference: <alpine.LNX.2.00.1012251946100.10759@swampdragon.chaosbits.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'merge' of git://git.secretlab.ca/git/linux-2.6:
spi/mpc52xx-spi: fix annotation for remove()-pointer
spi/fsl_espi: fix wrong setting of the address in the command buffer
spi/fsl_espi: change the read behaviour of the SPIRF
of/i2c: Fix request module by alias
powerpc/mpc5200: include fs.h in mpc52xx_gpt.c
The master clock initialization for SH7201 was wholly bogus. Users of the
legacy API must initialize the clock rate through the struct clk itself
rather than returning the clock frequency. Given that the init function
itself is void, returning the frequency isn't terribly effective.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
With some recent tidying of duplicate register definitions the se7206 IRQ
code broke:
arch/sh/boards/mach-se/7206/irq.c: error: 'INTC_ICR' undeclared (first use in this function)
arch/sh/boards/mach-se/7206/irq.c: error: (Each undeclared identifier is reported only once
arch/sh/boards/mach-se/7206/irq.c: error: for each function it appears in.)
Fix it up.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Some of the SH4-202 code was overlooked in the set_rate() API conversion,
resulting in:
arch/sh/kernel/cpu/sh4/clock-sh4-202.c: error: too many arguments to function 'clk->ops->set_rate'
Fix it up.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf probe: Fix to support libdwfl older than 0.148
perf tools: Fix lazy wildcard matching
perf buildid-list: Fix error return for success
perf buildid-cache: Fix symbolic link handling
perf symbols: Stop using vmlinux files with no symbols
perf probe: Fix use of kernel image path given by 'k' option
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, kexec: Limit the crashkernel address appropriately
Fix build errors like these (from a randconfig and my defconfig for a custom board):
src/arch/powerpc/platforms/52xx/mpc52xx_gpt.c:549: error: dereferencing pointer to incomplete type: 1 errors in 1 logs
src/arch/powerpc/platforms/52xx/mpc52xx_gpt.c:636: error: implicit declaration of function 'nonseekable_open': 1 errors in 1 logs
src/arch/powerpc/platforms/52xx/mpc52xx_gpt.c:657: error: variable 'mpc52xx_wdt_fops' has initializer but incomplete type: 1 errors in 1 logs
src/arch/powerpc/platforms/52xx/mpc52xx_gpt.c:658: error: excess elements in struct initializer: 1 errors in 1 logs
src/arch/powerpc/platforms/52xx/mpc52xx_gpt.c:658: error: unknown field 'owner' specified in initializer: 1 errors in 1 logs
...
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The AT91 MCI has special SDIO transfer types: SDIO block and SDIO byte
transfers, but at91_mci driver doesn't use them and handles all SDIO
transfers as ordinary MMC block transfers. This causes problems for
multiple-block SDIO transfers (in particular for 256-bytes blocks).
Fix this situation by checking the opcode for SDIO CMD53 and setting
the transfer type in the AT91_MCI_CMDR register properly.
This patch was tested with libertas SDIO driver: problem with TX
timeouts on big packets was eliminated.
Signed-off-by: Yauhen Kharuzhy <yauhen.kharuzhy@promwad.com>
Cc: <stable@kernel.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
* 's5p-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
ARM: S5PV210: update MAX8998 platform data to get rid of WARN()
ARM S3C24XX: Fix compilation of PM code for S3C2416
ARM: S3C24XX: Fix CONFIG_S3C_DEV_NAND Kconfig entry
The cnt32_to_63 algorithm relies on proper counter data evaluation
ordering to work properly. This was missing from the provided
documentation.
Let's augment the documentation with the missing usage constraint and
fix the only instance that got it wrong.
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-32: Make sure we can map all of lowmem if we need to
x86, vt-d: Handle previous faults after enabling fault handling
x86: Enable the intr-remap fault handling after local APIC setup
x86, vt-d: Fix the vt-d fault handling irq migration in the x2apic mode
x86, vt-d: Quirk for masking vtd spec errors to platform error handling logic
x86, xsave: Use alloc_bootmem_align() instead of alloc_bootmem()
bootmem: Add alloc_bootmem_align()
x86, gcc-4.6: Use gcc -m options when building vdso
x86: HPET: Chose a paranoid safe value for the ETIME check
x86: io_apic: Avoid unused variable warning when CONFIG_GENERIC_PENDING_IRQ=n
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf: Fix off by one in perf_swevent_init()
perf: Fix duplicate events with multiple-pmu vs software events
ftrace: Have recordmcount honor endianness in fn_ELF_R_INFO
scripts/tags.sh: Add magic for trace-events
tracing: Fix panic when lseek() called on "trace" opened for writing
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
arch/tile: handle rt_sigreturn() more cleanly
arch/tile: handle CLONE_SETTLS in copy_thread(), not user space
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
x86: avoid high BIOS area when allocating address space
x86: avoid E820 regions when allocating address space
x86: avoid low BIOS area when allocating address space
resources: add arch hook for preventing allocation in reserved areas
Revert "resources: support allocating space within a region from the top down"
Revert "PCI: allocate bus resources from the top down"
Revert "x86/PCI: allocate space from the end of a region, not the beginning"
Revert "x86: allocate space within a region top-down"
Revert "PCI: fix pci_bus_alloc_resource() hang, prefer positive decode"
PCI: Update MCP55 quirk to not affect non HyperTransport variants
Keep the crash kernel address below 512 MiB for 32 bits and 896 MiB
for 64 bits. For 32 bits, this retains compatibility with earlier
kernel releases, and makes it work even if the vmalloc= setting is
adjusted.
For 64 bits, we should be able to increase this substantially once a
hard-coded limit in kexec-tools is fixed.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20101217195035.GE14502@redhat.com>
The current tile rt_sigreturn() syscall pattern uses the common idiom
of loading up pt_regs with all the saved registers from the time of
the signal, then anticipating the fact that we will clobber the ABI
"return value" register (r0) as we return from the syscall by setting
the rt_sigreturn return value to whatever random value was in the pt_regs
for r0.
However, this breaks in our 64-bit kernel when running "compat" tasks,
since we always sign-extend the "return value" register to properly
handle returned pointers that are in the upper 2GB of the 32-bit compat
address space. Doing this to the sigreturn path then causes occasional
random corruption of the 64-bit r0 register.
Instead, we stop doing the crazy "load the return-value register"
hack in sigreturn. We already have some sigreturn-specific assembly
code that we use to pass the pt_regs pointer to C code. We extend that
code to also set the link register to point to a spot a few instructions
after the usual syscall return address so we don't clobber the saved r0.
Now it no longer matters what the rt_sigreturn syscall returns, and the
pt_regs structure can be cleanly and completely reloaded.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Previously we were just setting up the "tp" register in the
new task as started by clone() in libc. However, this is not
quite right, since in principle a signal might be delivered to
the new task before it had its TLS set up. (Of course, this race
window still exists for resetting the libc getpid() cached value
in the new task, in principle. But in any case, we are now doing
this exactly the way all other architectures do it.)
This change is important for 2.6.37 since the tile glibc we will
be submitting upstream will not set TLS in user space any more,
so it will only work on a kernel that has this fix. It should
also be taken for 2.6.36.x in the stable tree if possible.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: stable <stable@kernel.org>
Seen with malta_defconfig on Linus' tree:
CC arch/mips/mm/sc-mips.o
arch/mips/mm/sc-mips.c: In function 'mips_sc_is_activated':
arch/mips/mm/sc-mips.c:77: error: 'config2' undeclared (first use in this function)
arch/mips/mm/sc-mips.c:77: error: (Each undeclared identifier is reported only once
arch/mips/mm/sc-mips.c:77: error: for each function it appears in.)
arch/mips/mm/sc-mips.c:81: error: 'tmp' undeclared (first use in this function)
make[2]: *** [arch/mips/mm/sc-mips.o] Error 1
make[1]: *** [arch/mips/mm] Error 2
make: *** [arch/mips] Error 2
[Ralf: Cosmetic changes to minimize the number of arguments passed to
mips_sc_is_activated]
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1752/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This prevents allocation of the last 2MB before 4GB.
The experiment described here shows Windows 7 ignoring the last 1MB:
https://bugzilla.kernel.org/show_bug.cgi?id=23542#c27
This patch ignores the top 2MB instead of just 1MB because H. Peter Anvin
says "There will be ROM at the top of the 32-bit address space; it's a fact
of the architecture, and on at least older systems it was common to have a
shadow 1 MiB below."
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
When we allocate address space, e.g., to assign it to a PCI device, don't
allocate anything mentioned in the BIOS E820 memory map.
On recent machines (2008 and newer), we assign PCI resources from the
windows described by the ACPI PCI host bridge _CRS. On many Dell
machines, these windows overlap some E820 reserved areas, e.g.,
BIOS-e820: 00000000bfe4dc00 - 00000000c0000000 (reserved)
pci_root PNP0A03:00: host bridge window [mem 0xbff00000-0xdfffffff]
If we put devices at 0xbff00000, they don't work, probably because
that's really RAM, not I/O memory. This patch prevents that by removing
the 0xbfe4dc00-0xbfffffff area from the "available" resource.
I'm not very happy with this solution because Windows solves the problem
differently (it seems to ignore E820 reserved areas and it allocates
top-down instead of bottom-up; details at comment 45 of the bugzilla
below). That means we're vulnerable to BIOS defects that Windows would not
trip over. For example, if BIOS described a device in ACPI but didn't
mention it in E820, Windows would work fine but Linux would fail.
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=16228
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This implements arch_remove_reservations() so allocate_resource() can
avoid any arch-specific reserved areas. This currently just avoids the
BIOS area (the first 1MB), but could be used for E820 reserved areas if
that turns out to be necessary.
We previously avoided this area in pcibios_align_resource(). This patch
moves the test from that PCI-specific path to a generic path, so *all*
resource allocations will avoid this area.
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* 'for_linus' of git://github.com/at91linux/linux-2.6-at91:
at91: Refactor Stamp9G20 and PControl G20 board file
at91: Fix uhpck clock rate in upll case
* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: Fix preemption counter leak in kvm_timer_init()
KVM: enlarge number of possible CPUID leaves
KVM: SVM: Do not report xsave in supported cpuid
KVM: Fix OSXSAVE after migration
As PControl G20 is a carrier board for the Stamp9G20 SoM, some code can
be shared. Therefore board-stamp9g20.c is refactored to allow reusing the
SoM initialization and board-pcontrol-g20.c is modified to use it.
Signed-off-by: Christian Glindkamp <christian.glindkamp@taskit.de>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
The uhpck clock should be divided from the utmi clock, not its parent
(main). This change is mostly cosmetic as the uhpck rate value is not
used anywhere except for the debugfs clock output.
Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Fix interrupt priority level handling on SH-Mobile ARM.
SH-Mobile ARM platforms using multiple interrupt priority
levels need this patch to fix a potential dead lock that
may occur if multiple interrupts with different levels
are pending simultaneously.
The default INTC configuration is to use the same priority
level for all interrupts, so this issue does not trigger by
default. It is however common for board code to override the
interrupt priority for certain interrupt sources depending
on the application. Without this fix such boards may lock up.
In detail, this patch updates the INTC code in entry-macro.S
to make sure that the INTLVLA register gets set as expected.
To trigger this bug modify the board specific code to adjust
the interrupt priority level for the ethernet chip. After
changing the priority level simply use flood ping to drown
the board with interrupts.
This patch applies to INTCA-based processors such as sh7372,
sh7377 and sh7372. GIC-based processors are not affected.
Suitable for v2.6.37-rc and stable from v2.6.34 to v2.6.36.
Cc: stable@kernel.org
Signed-off-by: Magnus Damm <damm@opensource.se>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Turn down the warning noise from the compiler,
basically a SH-Mobile specific version of the
patch located in the RMK patch tracker:
6484/1: "fix compile warning in mm/init.c",
Without this patch the following warning triggers:
CC arch/arm/kernel/sys_arm.o
arch/arm/mm/init.c: In function 'mem_init':
arch/arm/mm/init.c:606: warning: format '%08lx' expects type 'long unsigned int', but argument 12 has type 'unsigned int'
CC arch/arm/kernel/traps.o
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch adds new entries required by the new version of MAX8998
driver. Without them, the driver fails to init. See commit 50f19a4596
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
S3C2416 PM code uses low-level sleep routines from S3C2412 code,
but these routines are compiled only for S3C2412 SoC.
Split S3C2412_PM to two parts: S3C2412_PM, S3C2412_PM_SLEEP and
select last in S3C2416's Kconfig.
Signed-off-by: Yauhen Kharuzhy <jekhor@gmail.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
A relocatable kernel can be anywhere in lowmem -- and in the case of a
kdump kernel, is likely to be fairly high. Since the early page
tables map everything from address zero up we need to make sure we
allocate enough brk that we can map all of lowmem if we need to.
Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Tested-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4D0AD3ED.8070607@kernel.org>
* 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus: (28 commits)
MIPS: Add a CONFIG_FORCE_MAX_ZONEORDER Kconfig option.
MIPS: LD/SD o32 macro GAS fix update
MIPS: Alchemy: fix build with SERIAL_8250=n
MIPS: Rename mips_dma_cache_sync back to dma_cache_sync
MIPS: MT: Fix typo in comment.
SSB: Fix nvram_get on BCM47xx platform
MIPS: BCM47xx: Swap serial console if ttyS1 was specified.
MIPS: BCM47xx: Use sscanf for parsing mac address
MIPS: BCM47xx: Fill values for b43 into SSB sprom
MIPS: BCM47xx: Do not read config from CFE
MIPS: FDT size is a be32
MIPS: Fix CP0 COUNTER clockevent race
MIPS: Fix regression on BCM4710 processor detection
MIPS: JZ4740: Fix pcm device name
MIPS: Separate two consecutive loads in memset.S
MIPS: Send proper signal and siginfo on FP emulator faults.
MIPS: AR7: Fix loops per jiffies on TNETD7200 devices
MIPS: AR7: Fix double ar7_gpio_init declaration
MIPS: Rework GENERIC_HARDIRQS Kconfig.
MIPS: Alchemy: Add return value check for strict_strtoul()
...
For huge page support with base page size of 16K or 32K, we have to
increase the MAX_ORDER so that huge pages can be allocated.
[Ralf: I don't think a user should have to configure obscure constants like
this but for the time being this will have to suffice.]
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1685/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
I am about to commit:
http://sourceware.org/ml/binutils/2010-10/msg00033.html
that fixes a problem with the LD/SD macro currently implemented by GAS for
the o32 ABI in an inconsistent way. This is best illustrated with a
simple program, which I'm copying here from the message above for easier
reference:
$ cat ld.s
ld $5,32767($4)
ld $5,32768($4)
This gets assebled into the following output:
$ mips-linux-as -32 -mips3 -o ld.o ld.s
$ mips-linux-objdump -d ld.o
ld.o: file format elf32-tradbigmips
Disassembly of section .text:
00000000 <.text>:
0: dc857fff ld a1,32767(a0)
4: 3c010001 lui at,0x1
8: 00810821 addu at,a0,at
c: 8c258000 lw a1,-32768(at)
10: 8c268004 lw a2,-32764(at)
...
Oops!
The GAS fix makes the macro behave in a consistent way and pairs of LW/SW
instructions to be output as appropriate regardless of the size of the
offset associated with the address used. The machine instruction is still
available, but to reach it macros have to be disabled first. This has a
side effect of requiring the use of a machine-addressable memory operand.
As some platforms require 64-bit operations for accesses to some I/O
registers LD/SD instructions are used in a couple of places in Linux
regardless of the ABI selected. Here's a fix for some pieces of code
affected I've been able to track down. The fix should be backwards
compatible with all supported binutils releases in existence and can be
used as a reference for any other places or off-tree code. The use of the
"R" constraint guarantees a machine-addressable operand.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1680/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In commit 7d172bfe ("Alchemy: Add UART PM methods") I introduced
platform PM methods which call a function of the 8250 driver;
this patch works around link failures when the kernel is built
without 8250 support.
Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
To: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/1737/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Some devices like the Netgear WGT634U are using ttyS1 for default console
output. We should switch to that console if it was given in the kernel_args
parameters.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
To: linux-mips@linux-mips.org
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: https://patchwork.linux-mips.org/patch/1848/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Instead of writing own function for parsing the mac address we now
use sscanf.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
To: linux-mips@linux-mips.org
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: https://patchwork.linux-mips.org/patch/1847/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fill the sprom with all available values from the nvram. Most of these
new values are needed for the b43 or b43legacy driver.
Parts of this patch have been in OpenWRT for a long time and were written
by Michael Buesch.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
To: linux-mips@linux-mips.org
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: https://patchwork.linux-mips.org/patch/1846/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The config options read out here are not stored in CFE but only in NVRAM on
the devices. Remove reading from CFE and only access the NVRAM. Reading out
CFE does not harm but is useless here.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
To: linux-mips@linux-mips.org
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: https://patchwork.linux-mips.org/patch/1845/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Consider the following test case:
write_c0_compare(read_c0_count());
Even if the counter doesn't increment during execution, this might not
generate an interrupt until the counter wraps around. The CPU may
perform the comparison each time CP0 COUNT increments, not when CP0
COMPARE is written.
If mips_next_event() is called with a very small delta, and CP0 COUNT
increments during the calculation of "cnt += delta", it is possible
that CP0 COMPARE will be written with the current value of CP0 COUNT.
If this is detected, the function should return -ETIME, to indicate
that the interrupt might not have actually gotten scheduled.
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1836/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Linus Torvalds