Sort enum loongson_cpu_type in a more reasonable manner, this makes the
CPU names more clear and extensible. Those already defined enum values
are renamed to Legacy_* for compatibility.
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16591/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

With this patch we can set irq affinity via procfs, so as to improve
network performance.
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16590/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

IRQ0 (HPET), IRQ1 (Keyboard), IRQ2 (Cascade), IRQ7 (SCI), IRQ8 (RTC)
and IRQ12 (Mouse) are handled by core-0 locally. Other PCI IRQs (3, 4,
5, 6, 14, 15) are balanced by all cores from Node-0. This can improve
I/O performance significantly.
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16589/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16587/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Loongson-3A R3 is very similar to Loongson-3A R2.

All Loongson-3 CPU family:

Code-name       Brand-name       PRId
Loongson-3A R1  Loongson-3A1000  0x6305
Loongson-3A R2  Loongson-3A2000  0x6308
Loongson-3A R3  Loongson-3A3000  0x6309
Loongson-3B R1  Loongson-3B1000  0x6306
Loongson-3B R2  Loongson-3B1500  0x6307
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16585/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The various interrupt specifiers in the device tree are not in a valid
format for the MIPS GIC interrupt controller binding. Where each
interrupt should provide 3 values - GIC_LOCAL or GIC_SHARED, the
pin number & the type of interrupt - the device tree was only providing
the pin number. This causes interrupts for those devices to not be used
when a GIC is present. SEAD-3 systems without a GIC are unaffected since
the DT fixup code generates interrupt specifiers that are valid for the
CPU interrupt controller.

Fix this by adding the GIC_SHARED & IRQ_TYPE_LEVEL_HIGH values to each
interrupt specifier.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: c11e3b48 ("MIPS: SEAD3: Probe UARTs using DT")
Fixes: a34e9388 ("MIPS: SEAD3: Probe ethernet controller using DT")
Fixes: 7afd2a5a ("MIPS: SEAD3: Probe EHCI controller using DT")
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org  # v4.9+
Patchwork: https://patchwork.linux-mips.org/patch/16189/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The SEAD-3 board may be configured with or without a MIPS Global
Interrupt Controller (GIC). Because of this we have a device tree with a
default case of a GIC present, and code to fixup the device tree based
upon a configuration register that indicates the presence of the GIC.

In order to keep this DT fixup code simple, the interrupt-parent
property was specified at the root node of the SEAD-3 DT, allowing the
fixup code to simply change this property to the phandle of the CPU
interrupt controller if a GIC is not present & affect all
interrupt-using devices at once. This however causes a problem if we do
have a GIC & the device tree is used as-is, because the interrupt-parent
property of the root node applies to the CPU interrupt controller node.
This causes a cycle when of_irq_init() attempts to probe interrupt
controllers in order and boots fail due to a lack of configured
interrupts, with this message printed on the kernel console:

[    0.000000] OF: of_irq_init: children remain, but no parents

Fix this by removing the interrupt-parent property from the DT root node
& instead setting it for each device which uses interrupts, ensuring
that the CPU interrupt controller node has no interrupt-parent &
allowing of_irq_init() to identify it as the root interrupt controller.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Reported-by: NKeng Koh <keng.koh@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16187/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Drivers for the mc146818 RTC generally check control registers to
determine whether a value is encoded as binary or as a binary coded
decimal. Setting RTC_ALWAYS_BCD to 1 effectively bypasses these checks
and causes drivers to always expect binary coded decimal values,
regardless of control register values.

This does not seem like a sane default - defaulting to 0 allows the
drivers to check control registers to determine encoding type & allows
the driver to work generically with both binary & BCD encodings. Set
this in mach-generic/mc146818rtc.h such that the generic kernel, or
platforms which don't provide a custom mc146818rtc.h, can have an RTC
driver which works with both encodings.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16185/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Introduce an apply_mips_fdt_fixups() function which can apply fixups to
an FDT based upon an array of fixup descriptions. This abstracts that
functionality such that legacy board code can apply FDT fixups without
requiring lots of duplication.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16184/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Name aliases in the SEAD-3 device tree serial0 & serial1, rather than
uart0 & uart1. This allows the core serial code to make use of the
aliases to ensure that the UARTs are consistently numbered as expected
rather than having the numbering depend upon probe order.

When translating YAMON-provided serial configuration to a device tree
stdout-path property adjust accordingly, such that we continue to
reference a valid alias.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16183/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

YAMON can expose more than 256MB of RAM to Linux on Malta by passing an
ememsize environment variable with the full size, but the kernel then
needs to be careful to choose the corresponding physical memory regions,
avoiding the IO memory window. This is platform dependent, and on Malta
it also depends on the memory layout which varies between system
controllers.

Extend yamon_dt_amend_memory() to generically handle this by taking
[e]memsize bytes of memory from an array of memory regions passed in as
a new parameter. Board code provides this array as appropriate depending
on its own memory map.

[paul.burton@imgtec.com: SEAD-3 supports 384MB DDR from 0]
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16182/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

In preparation for supporting other YAMON-using boards (Malta) & sharing
code to translate information from YAMON into device tree properties,
pull the code doing so for the kernel command line, system memory &
serial configuration out of the SEAD-3 board code.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16181/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The SEAD-3 board doesn't & never has configured the GIC frequency.
Remove the timer node from the DT in order to avoid attempting to probe
the GIC clocksource/clockevent driver which will produce error messages
such as these during boot:

[    0.000000] GIC frequency not specified.
[    0.000000] Failed to initialize '/interrupt-controller@1b1c0000/timer': -22
[    0.000000] clocksource_probe: no matching clocksources found
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16188/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Adjust the atomic loop in the MIPS_ATOMIC_SET operation of the sysmips
system call to branch straight back to the linked load rather than
jumping via a different subsection (whose purpose remains a mystery to
me).
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16150/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

EVA linked loads (LLE) and conditional stores (SCE) should be used on
EVA kernels for the MIPS_ATOMIC_SET operation of the sysmips system
call, or else the atomic set will apply to the kernel view of the
virtual address space (potentially unmapped on EVA kernels) rather than
the user view (TLB mapped).
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.15.x-
Patchwork: https://patchwork.linux-mips.org/patch/16151/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The MIPS sysmips system call handler may return directly from the
MIPS_ATOMIC_SET case (mips_atomic_set()) to syscall_exit. This path
restores the static (callee saved) registers, however they won't have
been saved on entry to the system call.

Use the save_static_function() macro to create a __sys_sysmips wrapper
function which saves the static registers before calling sys_sysmips, so
that the correct static register state is restored by syscall_exit.

Fixes: f1e39a4a ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16149/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The inline asm retry check in the MIPS_ATOMIC_SET operation of the
sysmips system call has been backwards since commit f1e39a4a ("MIPS:
Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler")
merged in v2.6.32, resulting in the non R10000_LLSC_WAR case retrying
until the operation was inatomic, before returning the new value that
was probably just written multiple times instead of the old value.

Invert the branch condition to fix that particular issue.

Fixes: f1e39a4a ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16148/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Add a definition of the perf registers for the new I6500 core.

Since I6500 has the same event definitions as I6400, re-use the existing
i6400 map structures by renaming them to a slightly more generic
'i6x00_***_map'.
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16362/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Introduce the I6500 PRID & probe it just the same way as I6400. The MIPS
I6500 is the latest in Imagination Technologies' I-Class range of CPUs,
with a focus on scalability & heterogeneity. It introduces the notion of
multiple clusters to the MIPS Coherent Processing System, allowing for a
far higher total number of cores & threads in a system when compared
with its predecessors. Clusters don't need to be identical, and may
contain differing numbers of cores & IOCUs, or cores with differing
properties.

This patch alone adds the basic support for booting Linux on an I6500
CPU without support for any of its new functionality, for which support
will be introduced in further patches.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16190/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Recent CPUs from Imagination Technologies such as the I6400 or P6600 are
able to speculatively fetch data from memory into caches. This means
that if used in a system with non-coherent DMA they require that caches
be invalidated after a device performs DMA, and before the CPU reads the
DMA'd data, in order to ensure that stale values weren't speculatively
prefetched.

Such CPUs also introduced Memory Accessibility Attribute Registers
(MAARs) in order to control the regions in which they are allowed to
speculate. Thus we can use the presence of MAARs as a good indication
that the CPU requires the above cache maintenance. Use the presence of
MAARs to determine the result of cpu_needs_post_dma_flush() in the
default case, in order to handle these recent CPUs correctly.

Note that the return type of cpu_needs_post_dma_flush() is changed to
bool, such that it's clearer what's happening when cpu_has_maar is cast
to bool for the return value. If this patch were backported to a
pre-v4.7 kernel then MIPS_CPU_MAAR was 1ull<<34, so when cast to an int
we would incorrectly return 0. It so happens that MIPS_CPU_MAAR is
currently 1ull<<30, so when truncated to an int gives a non-zero value
anyway, but even so the implicit conversion from long long int to bool
makes it clearer to understand what will happen than the implicit
conversion from long long int to int would. The bool return type also
fits this usage better semantically, so seems like an all-round win.

Thanks to Ed for spotting the issue for pre-v4.7 kernels & suggesting
the return type change.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Reviewed-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Tested-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Ed Blake <ed.blake@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16363/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

KProbes of __seccomp_filter() are not very useful without access to
the syscall arguments.

Do what x86 does, and populate a struct seccomp_data to be passed to
__secure_computing().  This allows samples/bpf/tracex5 to extract a
sensible trace.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16368/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Since the eBPF machine has 64-bit registers, we only support this in
64-bit kernels.  As of the writing of this commit log test-bpf is showing:

  test_bpf: Summary: 316 PASSED, 0 FAILED, [308/308 JIT'ed]

All current test cases are successfully compiled.

Many examples in samples/bpf are usable, specifically tracex5 which
uses tail calls works.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16369/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Follow on patches for eBPF JIT require these additional instructions:

   insn_bgtz, insn_blez, insn_break, insn_ddivu, insn_dmultu,
   insn_dsbh, insn_dshd, insn_dsllv, insn_dsra32, insn_dsrav,
   insn_dsrlv, insn_lbu, insn_movn, insn_movz, insn_multu, insn_nor,
   insn_sb, insn_sh, insn_slti, insn_dinsu, insn_lwu

... so, add them.

Sort the insn_* enumeration values alphabetically.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16367/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

DSHD was incorrectly classified as being BSHFL, and DSHD was missing
altogether.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16366/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Instead of doing a linear search through the insn_table for each
instruction, use the opcode as direct index into the table.  This will
give constant time lookup performance as the number of supported
opcodes increases.  Make the tables const as they are only ever read.
For uasm-mips.c sort the table alphabetically, and remove duplicate
entries, uasm-micromips.c was already sorted and duplicate free.
There is a small savings in object size as struct insn loses a field:

$ size arch/mips/mm/uasm-mips.o arch/mips/mm/uasm-mips.o.save
   text	   data	    bss	    dec	    hex	filename
  10040	      0	      0	  10040	   2738	arch/mips/mm/uasm-mips.o
   9240	   1120	      0	  10360	   2878	arch/mips/mm/uasm-mips.o.save
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16365/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The module load code has previously had entirely separate
implementations for rel & rela style relocs, which unnecessarily
duplicates a whole lot of code. Unify the implementations of both types
of reloc, sharing the bulk of the code.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15832/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

If we hit an error whilst processing a reloc then we would return early
from apply_relocate & potentially not free entries in r_mips_hi16_list,
thereby leaking memory. Fix this by ensuring that we always run the code
to free r_mipps_hi16_list when errors occur.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 861667dc ("MIPS: Fix race condition in module relocation code.")
Fixes: 04211a57 ("MIPS: Bail on unsupported module relocs")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15831/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Remove old, dead Kconfig options (in order appearing in this commit):
 - EXPERIMENTAL is gone since v3.9;
 - INET_LRO: commit 7bbf3cae ("ipv4: Remove inet_lro library");
 - MTD_CONCAT: commit f53fdebc ("mtd: drop MTD_CONCAT from Kconfig
   entirely");
 - MTD_CHAR: commit 660685d9 ("mtd: merge mtdchar module with
   mtdcore");
 - NETDEV_1000 and NETDEV_10000: commit f860b052 ("drivers/net:
   Kconfig and Makefile cleanup"); NET_ETHERNET should be replaced with
   just ETHERNET but that is separate change;
 - MISC_DEVICES: commit 7c5763b8 ("drivers: misc: Remove
   MISC_DEVICES config option");
 - HID_SUPPORT: commit 1f41a6a9 ("HID: Fix the generic Kconfig
   options");
 - BT_L2CAP and BT_SCO: commit f1e91e16 ("Bluetooth: Always compile
   SCO and L2CAP in Bluetooth Core");
 - DEBUG_ERRORS: commit b025a3f8 ("ARM: 6876/1: Kconfig.debug:
   Remove unused CONFIG_DEBUG_ERRORS");
 - USB_DEVICE_CLASS: commit 007bab91 ("USB: remove
   CONFIG_USB_DEVICE_CLASS");
 - RCU_CPU_STALL_DETECTOR: commit a00e0d71 ("rcu: Remove conditional
   compilation for RCU CPU stall warnings");
 - IP_NF_QUEUE: commit 3dd6664f ("netfilter: remove unused "config
   IP_NF_QUEUE"");
 - IP_NF_TARGET_ULOG: commit d4da843e ("netfilter: kill remnants of
   ulog targets");
 - IP6_NF_QUEUE: commit d16cf20e ("netfilter: remove ip_queue
   support");
 - IP6_NF_TARGET_LOG: commit 6939c33a ("netfilter: merge ipt_LOG and
   ip6_LOG into xt_LOG");
 - USB_LED: commit a335aaf3 ("usb: misc: remove outdated USB LED
   driver");
 - MMC_UNSAFE_RESUME: commit 2501c917 ("mmc: core: Use
   MMC_UNSAFE_RESUME as default behavior");
 - AUTOFS_FS: commit 561c5cf9 ("staging: Remove autofs3");
 - VIDEO_OUTPUT_CONTROL: commit f167a64e ("video / output: Drop
   display output class support");
 - USB_LIBUSUAL: commit f61870ee ("usb: remove libusual");
 - CRYPTO_ZLIB: 11049218 ("crypto: compress - remove unused pcomp
   interface");
 - BLK_DEV_UB: commit 68a5059e ("block: remove the deprecated ub
   driver");
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: linux-mips@linux-mips.org
Cc: linux-arm-kernel@lists.infradead.org
Patchwork: https://patchwork.linux-mips.org/patch/16342/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Sort the entries in config MIPS alphabetically so as to make entries
easier to find.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16068/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This commit fixes a "maybe-uninitialized" build failure in
arch/mips/kvm/tlb.c when KVM, DYNAMIC_DEBUG and JUMP_LABEL are all
enabled. The failure is:

In file included from ./include/linux/printk.h:329:0,
                 from ./include/linux/kernel.h:13,
                 from ./include/asm-generic/bug.h:15,
                 from ./arch/mips/include/asm/bug.h:41,
                 from ./include/linux/bug.h:4,
                 from ./include/linux/thread_info.h:11,
                 from ./include/asm-generic/current.h:4,
                 from ./arch/mips/include/generated/asm/current.h:1,
                 from ./include/linux/sched.h:11,
                 from arch/mips/kvm/tlb.c:13:
arch/mips/kvm/tlb.c: In function ‘kvm_mips_host_tlb_inv’:
./include/linux/dynamic_debug.h:126:3: error: ‘idx_kernel’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
   __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \
   ^~~~~~~~~~~~~~~~~~
arch/mips/kvm/tlb.c:169:16: note: ‘idx_kernel’ was declared here
  int idx_user, idx_kernel;
                ^~~~~~~~~~

There is a similar error relating to "idx_user". Both errors were
observed with GCC 6.

As far as I can tell, it is impossible for either idx_user or idx_kernel
to be uninitialized when they are later read in the calls to kvm_debug,
but to satisfy the compiler, add zero initializers to both variables.
Signed-off-by: NJames Cowgill <James.Cowgill@imgtec.com>
Fixes: 57e3869c ("KVM: MIPS/TLB: Generalise host TLB invalidate to kernel ASID")
Cc: <stable@vger.kernel.org> # 4.11+
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.

This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.

Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.

One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications.  For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).

Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.

Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.
Original-patch-by: NOleg Nesterov <oleg@redhat.com>
Original-patch-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NHugh Dickins <hughd@google.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The .its targets require information about the kernel binary, such as
its entry point, which is extracted from the vmlinux ELF. We therefore
require that the ELF is built before the .its files are generated.
Declare this requirement in the Makefile such that make will ensure this
is always the case, otherwise in corner cases we can hit issues as the
.its is generated with an incorrect (either invalid or stale) entry
point.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: cf2a5e0b ("MIPS: Support generating Flattened Image Trees (.itb)")
Cc: linux-mips@linux-mips.org
Cc: stable <stable@vger.kernel.org> # v4.9+
Patchwork: https://patchwork.linux-mips.org/patch/16179/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The code handling the pop76 opcode (ie. bnezc & jialc instructions) in
__compute_return_epc_for_insn() needs to set the value of $31 in the
jialc case, which is encoded with rs = 0. However its check to
differentiate bnezc (rs != 0) from jialc (rs = 0) was unfortunately
backwards, meaning that if we emulate a bnezc instruction we clobber $31
& if we emulate a jialc instruction it actually behaves like a jic
instruction.

Fix this by inverting the check of rs to match the way the instructions
are actually encoded.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 28d6f93d ("MIPS: Emulate the new MIPS R6 BNEZC and JIALC instructions")
Cc: stable <stable@vger.kernel.org> # v4.0+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16178/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When ftrace is used with kprobes, it is possible for a kprobe to contain
an invalid location (ie. only initialised to 0 and not to a specific
location in the code). Trying to perform a cache flush on such location
leads to a crash r4k_flush_icache_range().

Fixes: c1bf207d ("MIPS: kprobe: Add support.")
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16296/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Since introduction of tracing for init functions the in_kernel_space()
check is no longer correct, as it ignores the init sections. As a
result, when probes are inserted (and disabled) in the init functions,
a branch instruction is inserted instead of a nop, which is likely to
result in random crashes during boot.

Remove the MIPS-specific in_kernel_space() method and replace it with a
generic core_kernel_text() that also checks for init sections during
system boot stage.

Fixes: 42c269c8 ("ftrace: Allow for function tracing to record init functions on boot up")
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Tested-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16092/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Space reserved for PKMap should span from PKMAP_BASE to FIXADDR_START.
For large page sizes this is not the case as eg. for 64k pages the range
currently defined is from 0xfe000000 to 0x102000000(!!) which obviously
isn't right.
Remove the hardcoded location and set the BASE address as an offset from
FIXADDR_START.

Since all PKMAP ptes have to be placed in a contiguous memory, ensure
that this is the case by placing them all in a single page. This is
achieved by aligning the end address to pkmap pages count pages.
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15950/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

All PTEs used by PKMAP should be allocated in a contiguous memory area,
but we do not currently have a mechanism to enforce that, so ensure that
we don't try to allocate more entries than would fit in a single page.

Current fixed value of 1024 would not work with XPA enabled when
sizeof(pte_t)==8 and we need two pages to store pte tables.
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15949/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

fixrange_init operates at PMD-granularity and expects the addresses to
be PMD-size aligned, but currently that might not be the case for
PKMAP_BASE unless it is defined properly, so ensure a correct alignment
is used before passing the address to fixrange_init.

fixed mappings: only align the start address that is passed to
fixrange_init rather than the value before adding the size, as we may
end up with uninitialised upper part of the range.
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15948/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

All performance counters on I6400 (odd and even) are capable of counting
any of the available events, so drop current logic of using the extra
bit to determine which counter to use.
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Fixes: 4e88a862 ("MIPS: Add cases for CPU_I6400")
Fixes: fd716fca ("MIPS: perf: Fix I6400 event numbers")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15991/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This fixes a regression in commit 4d6501dc where I didn't notice
that MIPS and OpenRISC were reinitialising p->{set,clear}_child_tid to
NULL after our initialisation in copy_process().

We can simply get rid of the arch-specific initialisation here since it
is now always done in copy_process() before hitting copy_thread{,_tls}().

Review notes:

 - As far as I can tell, copy_process() is the only user of
   copy_thread_tls(), which is the only caller of copy_thread() for
   architectures that don't implement copy_thread_tls().

 - After this patch, there is no arch-specific code touching
   p->set_child_tid or p->clear_child_tid whatsoever.

 - It may look like MIPS/OpenRISC wanted to always have these fields be
   NULL, but that's not true, as copy_process() would unconditionally
   set them again _after_ calling copy_thread_tls() before commit
   4d6501dc.

Fixes: 4d6501dc ("kthread: Fix use-after-free if kthread fork fails")
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net> # MIPS only
Acked-by: NStafford Horne <shorne@gmail.com>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: openrisc@lists.librecores.org
Cc: Jamie Iles <jamie.iles@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NVegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>