The command register of the PCI controller is
not initialized correctly by the bootloader on
some boards and this leads to non working PCI
bus.
Add code to initialize the command register
from the Linux code to avoid this.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4916/
Signed-off-by: John Crispin <blogic@openwrt.org>
Change to the code to use per-controller IRQ base.
This is needed for multiple PCI controller support.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4915/
Signed-off-by: John Crispin <blogic@openwrt.org>
Static resources become impractical when multiple
PCI controllers are present. Move the resources
into the platform device registration code and
change the probe routine to get those from there
platform device's resources.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4914/
Signed-off-by: John Crispin <blogic@openwrt.org>
The current code uses static variables to store the
PCI controller specific data. This works if the system
contains one PCI controller only, however it becomes
impractical when multiple PCI controllers are present.
Move the variables into a dynamically allocated controller
specific structure, and use that instead of the static
variables.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4912/
Signed-off-by: John Crispin <blogic@openwrt.org>
This is needed for multiple PCI bus support.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4913/
Signed-off-by: John Crispin <blogic@openwrt.org>
The pci_load_of_ranges function is only available if
CONFIG_OF is selected. If the function is used without
CONFIG_OF being enabled it will cause a build error.
Add a dummy inline function to avoid this.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4911/
Signed-off-by: John Crispin <blogic@openwrt.org>
The IO and memory resources of a PCI controller
might already have a parent resource set when
they are passed to 'register_pci_controller'.
If the parent resource is set, the request_resource
call will fail due to resource conflict and the
current code will not be able to register the
PCI controller.
Use the parent resource if it is available in the
request_resource call to avoid the isssue.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4910/
Signed-off-by: John Crispin <blogic@openwrt.org>
The functions are unused now, so remove them.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4909/
Signed-off-by: John Crispin <blogic@openwrt.org>
The pci-ar71xx and pci-ar724x drivers were converted
into platform drivers. Register the corresponding
platform devices for the PCI controllers instead
of using the ar7{1x,24}x_pcibios_init functions.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4908/
Signed-off-by: John Crispin <blogic@openwrt.org>
The constants will be used by a subsequent patch.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4907/
Signed-off-by: John Crispin <blogic@openwrt.org>
The patch converts the pci-ar71xx driver into a
platform driver. This makes it possible to register
the PCI controller as a plain platform device.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4906/
Signed-off-by: John Crispin <blogic@openwrt.org>
The patch converts the pci-ar724x driver into a
platform driver. This makes it possible to register
the PCI controller as a plain platform device.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4905/
Signed-off-by: John Crispin <blogic@openwrt.org>
Convert the ralink IRQ code to make use of the new MIPS IRQ controller OF
mappings.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John Crispin <blogic@openwrt.org>
Acked-by: David Daney <david.daney@cavium.com>
Patchwork: http://patchwork.linux-mips.org/patch/4900/
Add code to load a irq_domain for the MIPS IRQ controller from a devicetree
file.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John Crispin <blogic@openwrt.org>
Acked-by: David Daney <david.daney@cavium.com>
Patchwork: http://patchwork.linux-mips.org/patch/4902/
Add the Kbuild symbols and Makefiles needed to actually build the ralink code
from this series
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4899/
This adds the devicetree file that describes the rt305x evaluation kit.
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4898/
Add support code for rt3050, rt3052, rt3350, rt3352 and rt5350 SOC.
The code detects the SoC and registers the clk / pinmux settings.
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4896/
Add the code needed to make early printk work.
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4897/
Until there is a generic MIPS way of handing the DTB over from bootloader to
kernel we rely on a built in devicetrees. The OF code also remaps those register
ranges that we use global in our drivers.
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4895/
These SoCs have a limited number of fixed rate clocks. Add support for the
clk and clkdev api.
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4894/
Resetting these SoCs requires no real magic. The code is straight forward.
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4891/
All of the Ralink Wifi SoC currently supported by this series share the same
interrupt controller (INTC).
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4890/
Before we start adding the platform code we add the common include files.
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4893/
The current code uses multiple if statements for
demultiplexing the different interrupt sources.
Additionally, the MISC interrupt controller has
32 interrupt sources and the current code does not
handles all of them.
Get rid of the if statements and process all interrupt
sources in a loop to fix these issues.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4874/
Signed-off-by: John Crispin <blogic@openwrt.org>
Make ath79_gpio_function_{en,dis}able to be wrappers
around ath79_gpio_function_setup.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4871/
Signed-off-by: John Crispin <blogic@openwrt.org>
GPIO function selection is not working on the AR934x
SoCs because the offset of the function selection
register is different on those.
Add a helper routine which returns the correct
register address based on the SoC type, and use
that in the 'ath79_gpio_function_*' routines.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4870/
Signed-off-by: John Crispin <blogic@openwrt.org>
Add new clocksource that uses the counter present on the MIPS
Global Interrupt Controller.
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Patchwork: http://patchwork.linux-mips.org/patch/4681/
Signed-off-by: John Crispin <blogic@openwrt.org>
Simplify the DSP macros for vanilla (non-microMIPS) kernels and
toolchains that do not support the DSP ASEs.
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Patchwork: http://patchwork.linux-mips.org/patch/4687/
Signed-off-by: John Crispin <blogic@openwrt.org>
Add macros to support the DSP ASE with microMIPS kernels when the
toolchain does not have support.
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Patchwork: http://patchwork.linux-mips.org/patch/4686/
Signed-off-by: John Crispin <blogic@openwrt.org>
Newer toolchains support the DSP and DSP Rev2 instructions. This patch
performs a check for that support and adds compiler and assembler
flags for only the files that need use those instructions.
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Acked-by: Florian Fainelli <florian@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4752/
Signed-off-by: John Crispin <blogic@openwrt.org>
Clean up standard header text and remove unused #define.
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Patchwork: http://patchwork.linux-mips.org/patch/4703/
Signed-off-by: John Crispin <blogic@openwrt.org>
On a multi-chip XLP board, each node can have 4 PCIe links. Update
XLP PCI code to initialize PCIe on all the nodes.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4803/
Signed-off-by: John Crispin <blogic@openwrt.org>
On multi-chip boards, the first core on slave SoCs may take much
more time to wakeup. Add code to wait for the core to come up before
proceeding with the rest of the boot up.
Update xlp_wakeup_core to also skip the boot node and the boot CPU
initialization which is already complete.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4783/
Signed-off-by: John Crispin <blogic@openwrt.org>
Doing calibrate delay on a hardware thread will be inaccurate since
it depends on the load on other threads in the core. It will also
slow down the boot process when done for 128 hardware threads. Switch
to a pre-computed loops per jiffy based on the core frequency. The
value is computed based on the core frequency and roughly matches the
value calculated by calibrate_delay().
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4791/
Signed-off-by: John Crispin <blogic@openwrt.org>
TLB and COP0 hazards are handled in hardware for Netlogic XLR/XLS
SoCs. Update hazards.h to pick more optimal set of definitions when
compiling for XLR/XLS.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4788/
Signed-off-by: John Crispin <blogic@openwrt.org>
Reading PCI extended register at 0x255 on a bridge will hang if there
is no device connected on the link. Make PCI read routine skip this
register.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4789/
Signed-off-by: John Crispin <blogic@openwrt.org>
The XLR/XLS/XLP PIC has a 8 countdown timers which run at the PIC
frequencey. One of these can be used as a clocksource to provide
timestamps that is common across cores. This can be used in place
of the count/compare clocksource which is per-CPU.
On XLR/XLS PIC registers are 32-bit, so we just use the lower 32-bits
of the PIC counter. On XLP, the whole 64-bit can be used.
Provide common macros and functions for PIC timer registers on XLR/XLS
and XLP, and use them to register a PIC clocksource.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4786/
Signed-off-by: John Crispin <blogic@openwrt.org>
Since we now use r4k cache code for Netlogic XLP, it is
better to split L1 icache among the active threads, so that
threads won't step on each other while flushing icache.
The L1 dcache is already split among the threads in the core.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4787/
Signed-off-by: John Crispin <blogic@openwrt.org>
Rename function xlp_enable_pci_bswap() to xlp_config_pci_bswap(), which
is a better description for its functionality. When compiled in
big-endian mode, xlp_config_pci_bswap() will configure the PCIe links
to byteswap. In little-endian mode, no swap configuration is needed
for the PCIe controller, and the function is empty.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4802/
Signed-off-by: John Crispin <blogic@openwrt.org>
Provide functions ack_c0_eirr(), set_c0_eimr(), clear_c0_eimr()
and read_c0_eirr_and_eimr() that do the EIMR and EIRR operations
and update the interrupt handling code to use these functions.
Also, use the EIMR register functions to mask interrupts in the
irq code.
The 64-bit interrupt request and mask registers (EIRR and EIMR) are
accessed when the interrupts are off, and the common operations are
to set or clear a bit in these registers. Using the 64-bit c0 access
functions for these operations is not optimal in 32-bit, because it
will disable/restore interrupts and split/join the 64-bit value during
each register access.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4790/
Signed-off-by: John Crispin <blogic@openwrt.org>
Add support for XLS6xx CPUs to the Fast Message Network (FMN)
configuration.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4785/
Signed-off-by: John Crispin <blogic@openwrt.org>
This code makes the irqs used by the EIU loadable from the DT. Additionally we
add a helper that allows the pinctrl layer to map external irqs to real irq
numbers.
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4818/
We need to make sure that the reset gpio is available and also set a sane
default state.
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4817/
Explicitly enable the clock gate of the internal GPHYs found on xrx200.
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4816/
The Lantiq DSL SoCs have an internal networking processor. Add code to read
the static clock rate.
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4815/
Very ancient out-of-tree KDB versions were using BRK_KDB code but it's
unused in modern kernels since a long time. Delete it.
The microMIPS encoding only reserves 4 bits for a trap code so it's time
for further weedkilling.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The BRK_BUG value is used in the BUG and __BUG_ON inline macros. For
standard MIPS cores the code in the 'tne' instruction is 10-bits long.
In microMIPS, the 'tne' instruction is recoded and the code can only be
4-bits long. We change the value to 12 instead of 512 so that both classic
and microMIPS kernels build.
[ralf@linux-mips.org: Many of the break codes starting from 0 are used
across many MIPS UNIX variants. Codes starting from 512 are operating
system specific additions. 1023 again is also used by other operating
systems]
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Display the MIPS ISA version release in the /proc/cpuinfo file.
[ralf@linux-mips.org: Add support for MIPS I ... IV legacy architecture
revisions. Also differenciate between MIPS32 and MIPS64 versions instead
of lumping them together as just r1 and r2.
Note to application programmers: this indicates the CPU's ISA level
It does not imply the current execution environment does support it. For
example an O32 application seeing "mips64r2" would still be restricted by
by the execution environment to 32-bit - but the kernel could run mips64r2
code. The same for a 32-bit kernel running on a 64-bit processor. This
field doesn't include ASEs or optional architecture modules nor other
detailed flags such as the availability of an FPU.]
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/4714/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
A struct clk value is intended to be an abstract pointer, so it should be
manipulated using the various API functions.
clk_put is additionally added on the failure paths.
The semantic match that finds the first problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression e,e1;
identifier i;
@@
*e = clk_get(...)
... when != e = e1
when any
*e->i
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: kernel-janitors@vger.kernel.org
Cc: linux-mips@linux-mips.org,
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/4751/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
An SoC normally do not define path variables for board_rev and
board_type and the Broadcom SDK also uses the nvram values without a
prefix in such cases. Do the same to fill these sprom attributes from
nvram and do not leave them empty, because brcmsmac do not like this.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4679/
Signed-off-by: John Crispin <blogic@openwrt.org>
The kernel is loaded to 0x80001000 so there is some space left for the
exception handlers and the kernel do not have to reserve some extra
space for them.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4747/
Signed-off-by: John Crispin <blogic@openwrt.org>
All the boot loaders I have seen are booting the kernel in raw mode by
default. CFE seems to support elf kernel images too, but the default
case is raw for the devices I know of. Select this option to make the
kernel boot on most of the devices with the default options.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4746/
Signed-off-by: John Crispin <blogic@openwrt.org>
Some nvram values on some devices have a newline character at the end
of the value, that caused read errors. Trim the string before reading
the number.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4745/
Signed-off-by: John Crispin <blogic@openwrt.org>
The nvram functions are exported and used by some normal drivers. To
prevent name clashes with ofter parts of the kernel code add a bcm47xx_
prefix in front of the function names and the header file name.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4744/
Signed-off-by: John Crispin <blogic@openwrt.org>
The old code just worked for nvram with a size of 0x8000 bytes. This
patch adds support for reading nvram from partitions of 0xF000 and
0x10000 bytes.
There is just 32KB space for the nvram, but most devices do not use the
full size and this code reads the first 32KB in that case and prints a
warning.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4743/
Signed-off-by: John Crispin <blogic@openwrt.org>
This makes it possible to handle the case of not being able to read the
nvram ram. This could happen when the code searching for the specific
flash chip have not run jet.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4740/
Signed-off-by: John Crispin <blogic@openwrt.org>
Instead of using our own error codes use some common codes.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4739/
Signed-off-by: John Crispin <blogic@openwrt.org>
Also check if parallel flash is present at all before accessing it and
add support for serial flash on BCMA bus.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4738/
Signed-off-by: John Crispin <blogic@openwrt.org>
__ARCH_WANT_SYS_RT_SIGACTION,
__ARCH_WANT_SYS_RT_SIGSUSPEND,
__ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND,
__ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL - not used anymore
CONFIG_GENERIC_{SIGALTSTACK,COMPAT_RT_SIG{ACTION,QUEUEINFO,PENDING,PROCMASK}} -
can be assumed always set.
Synchronize with 'net' in order to sort out some l2tp, wireless, and
ipv6 GRE fixes that will be built on top of in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
The IRQ_PER_CPU Kconfig symbol was removed in the following commit:
Commit 6a58fb3bad ("genirq: Remove
CONFIG_IRQ_PER_CPU") merged in v2.6.39-rc1.
But IRQ_PER_CPU wasn't removed from any of the architecture Kconfig
files where it was defined or selected. It's completely unused so remove
the remaining references.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: <uclinux-dist-devel@blackfin.uclinux.org>
Cc: <linux-mips@linux-mips.org>
Cc: <linuxppc-dev@lists.ozlabs.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Richard Kuo <rkuo@codeaurora.org>
Link: http://lkml.kernel.org/r/1359972583-17134-1-git-send-email-james.hogan@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
we still need the wrappers to store callee-saved registers in
pt_regs, but once that done we can jump to kernel/fork.c variants.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
mips was the last architecture not using the generic variant.
Both native and compat variants switched to generic, which is
made unconditional now.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
we want to do that before branchpoint for arch-* to be able to
consolidate sys_rt_sigsuspend() declarations.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Only alpha and sparc are unusual - they have ka_restorer in it.
And nobody needs that exposed to userland.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now that Yosemite's gone we can move the MSP71xx code one level up.
Shane McDonald <mcdonald.shane@gmail.com>'s
https://patchwork.linux-mips.org/patch/4736/ has been folded into this
patch.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Activate USE_OF for SEAD-3 platform. Add basic DTS file and convert memory
detection and reservations to use OF.
[ralf@linux-mips.org: Remove unnecessary #ifdef wrapper in generic.h. Make
<asm/mips-boards/generic.h> inclusion work even without prior
<linux/of_fdt.h> inclusion.]
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4809/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Function tracing is currently broken for all 32 bit MIPS platforms.
When tracing is enabled, the kernel immediately hangs on boot.
This is a result of commit b732d439cb
that changes the kernel/trace/Kconfig file so that is no longer
forces FRAME_POINTER when FUNCTION_TRACING is enabled.
MIPS frame pointers are generally considered to be useless because
they cannot be used to unwind the stack. Unfortunately the MIPS
function tracing code has bugs that are masked by the use of frame
pointers. This commit fixes the bugs so that MIPS frame pointers
don't need to be enabled.
The bugs are a result of the odd calling sequence used to call the trace
routine. This calling sequence is inserted into every traceable function
when the tracing CONFIG option is enabled. This sequence is generated
for 32bit MIPS platforms by the compiler via the "-pg" flag.
Part of the sequence is "addiu sp,sp,-8" in the delay slot after every
call to the trace routine "_mcount" (some legacy thing where 2 arguments
used to be pushed on the stack). The _mcount routine is expected to
adjust the sp by +8 before returning. So when not disabled, the original
jalr and addiu will be there, so _mcount has to adjust sp.
The problem is that when tracing is disabled for a function, the
"jalr _mcount" instruction is replaced with a nop, but the
"addiu sp,sp,-8" is still executed and the stack pointer is left
trashed. When frame pointers are enabled the problem is masked
because any access to the stack is done through the frame
pointer and the stack pointer is restored from the frame pointer when
the function returns.
This patch writes two nops starting at the address of the "jalr _mcount"
instruction whenever tracing is disabled. This means that the
"addiu sp,sp.-8" will be converted to a nop along with the "jalr". When
disabled, there will be two nops.
This is SMP safe because the first time this happens is during
ftrace_init() which is before any other processor has been started.
Subsequent calls to enable/disable tracing when other CPUs ARE running
will still be safe because the enable will only change the first nop
to a "jalr" and the disable, while writing 2 nops, will only be changing
the "jalr". This patch also stops using stop_machine() to call the
tracer enable/disable routines and calls them directly because the
routines are SMP safe.
When the kernel first boots we have to be able to handle the gcc
generated jalr, addui sequence until ftrace_init gets a chance to run
and change the sequence. At this point mcount just adjusts the stack
and returns. When ftrace_init runs, we convert the jalr/addui to nops.
Then whenever tracing is enabled we convert the first nop to a "jalr
mcount+8". The mcount+8 entry point skips the stack adjust.
[ralf@linux-mips.org: Folded in Steven Rostedt's build fix.]
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Cc: rostedt@goodmis.org
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/4806/
Patchwork: https://patchwork.linux-mips.org/patch/4841/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
