This patch switches MIPS to make use of generically implemented queued
spinlocks, rather than the ticket spinlocks used previously. This allows
us to drop a whole load of inline assembly, share more generic code, and
is also a performance win.

Results from running the AIM7 short workload on a MIPS Creator Ci40 (ie.
2 core 2 thread interAptiv CPU clocked at 546MHz) with v4.12-rc4
pistachio_defconfig, with ftrace disabled due to a current bug, and both
with & without use of queued rwlocks & spinlocks:

  Forks | v4.12-rc4 | +qlocks  | Change
 -------|-----------|----------|--------
     10 | 52630.32  | 53316.31 | +1.01%
     20 | 51777.80  | 52623.15 | +1.02%
     30 | 51645.92  | 52517.26 | +1.02%
     40 | 51634.88  | 52419.89 | +1.02%
     50 | 51506.75  | 52307.81 | +1.02%
     60 | 51500.74  | 52322.72 | +1.02%
     70 | 51434.81  | 52288.60 | +1.02%
     80 | 51423.22  | 52434.85 | +1.02%
     90 | 51428.65  | 52410.10 | +1.02%

The kernels used for these tests also had my "MIPS: Hardcode cpu_has_*
where known at compile time due to ISA" patch applied, which allows the
kernel_uses_llsc checks in cmpxchg() & xchg() to be optimised away at
compile time.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16358/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

This patch switches MIPS to make use of generically implemented queued
read/write locks, rather than the custom implementation used previously.
This allows us to drop a whole load of inline assembly, share more
generic code, and is also a performance win.

Results from running the AIM7 short workload on a MIPS Creator Ci40 (ie.
2 core 2 thread interAptiv CPU clocked at 546MHz) with v4.12-rc4
pistachio_defconfig, with ftrace disabled due to a current bug, and both
with & without use of queued rwlocks & spinlocks:

  Forks | v4.12-rc4 | +qlocks  | Change
 -------|-----------|----------|--------
     10 | 52630.32  | 53316.31 | +1.01%
     20 | 51777.80  | 52623.15 | +1.02%
     30 | 51645.92  | 52517.26 | +1.02%
     40 | 51634.88  | 52419.89 | +1.02%
     50 | 51506.75  | 52307.81 | +1.02%
     60 | 51500.74  | 52322.72 | +1.02%
     70 | 51434.81  | 52288.60 | +1.02%
     80 | 51423.22  | 52434.85 | +1.02%
     90 | 51428.65  | 52410.10 | +1.02%

The kernels used for these tests also had my "MIPS: Hardcode cpu_has_*
where known at compile time due to ISA" patch applied, which allows the
kernel_uses_llsc checks in cmpxchg() & xchg() to be optimised away at
compile time.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16357/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

The __xchg() function declares its first 2 arguments in reverse order
compared to the xchg() macro, which is confusing & serves no purpose.
Reorder the arguments such that __xchg() & xchg() match.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16356/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Implement support for 1 & 2 byte cmpxchg() using read-modify-write atop
a 4 byte cmpxchg(). This allows us to support these atomic operations
despite the MIPS ISA only providing 4 & 8 byte atomic operations.

This is required in order to support queued rwlocks (qrwlock) in a later
patch, since these make use of a 1 byte cmpxchg() in their slow path.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16355/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Implement 1 & 2 byte xchg() using read-modify-write atop a 4 byte
cmpxchg(). This allows us to support these atomic operations despite the
MIPS ISA only providing for 4 & 8 byte atomic operations.

This is required in order to support queued spinlocks (qspinlock) in a
later patch, since these make use of a 2 byte xchg() in their slow path.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16354/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Replace the macro definition of __cmpxchg() with an inline function,
which is easier to read & modify. The cmpxchg() & cmpxchg_local() macros
are adjusted to call the new __cmpxchg() function.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16353/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

The __xchg_u32() & __xchg_u64() functions now add very little value.
This patch therefore removes them, by:

  - Moving memory barriers out of them & into xchg(), which also removes
    the duplication & readies us to support xchg_relaxed() if we wish to.

  - Calling __xchg_asm() directly from __xchg().

  - Performing the check for CONFIG_64BIT being enabled in the size=8
    case of __xchg().

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16352/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

xchg() has up until now simply returned the x parameter in cases where
it is called with a pointer to a value of an unsupported size. This will
often cause the calling code to hit a failure path, presuming that the
value of x differs from the content of the memory pointed at by ptr, but
we can do better by producing a compile-time or link-time error such
that unsupported calls to xchg() are detectable earlier than runtime.

This patch does this in the same was as is already done for cmpxchg(),
using a call to a missing function annotated with __compiletime_error().

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16351/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Our cmpxchg() implementation relies upon generating a call to a function
which doesn't really exist (__cmpxchg_called_with_bad_pointer) to create
a link failure in cases where cmpxchg() is called with a pointer to a
value of an unsupported size.

The __compiletime_error macro can be used to decorate a function such
that a call to it generates a compile-time, rather than a link-time,
error. This patch uses __compiletime_error to cause bad cmpxchg() calls
to error out at compile time rather than link time, allowing errors to
occur more quickly & making it easier to spot where the problem comes
from.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16350/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Use a macro to generate the 32 & 64 bit variants of the backing code for
xchg(), much as is already done for cmpxchg(). This removes the
duplication that could previously be found in __xchg_u32() &
__xchg_u64().

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16349/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Prior to this patch the xchg & cmpxchg functions have duplicated code
which is for all intents & purposes identical apart from use of a
branch-likely instruction in the R10000_LLSC_WAR case & a regular branch
instruction in the non-R10000_LLSC_WAR case.

This patch removes the duplication, declaring a __scbeqz macro to select
the branch instruction suitable for use when checking the result of an
sc instruction & making use of it to unify the 2 cases.

In __xchg_u{32,64}() this means writing the branch in asm, where it was
previously being done in C as a do...while loop for the
non-R10000_LLSC_WAR case. As this is a single instruction, and adds
consistency with the R10000_LLSC_WAR cases & the cmpxchg() code, this
seems worthwhile.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16348/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Add handling of missaligned access for DSP load instructions
lwx & lhx.

Since DSP instructions share SPECIAL3 opcode with other non-DSP
instructions, necessary logic was inserted for distinguishing
between instructions with SPECIAL3 opcode. For that purpose,
the instruction format for DSP instructions is added to
arch/mips/include/uapi/asm/inst.h.

Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtech.com>
Cc: James.Hogan@imgtec.com
Cc: Paul.Burton@imgtec.com
Cc: Raghu.Gandham@imgtec.com
Cc: Leonid.Yegoshin@imgtec.com
Cc: Douglas.Leung@imgtec.com
Cc: Petar.Jovanovic@imgtec.com
Cc: Goran.Ferenc@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16511/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Disable usage of PREF instruction usage by memcpy for MIPS R6.

MIPS R6 redefines PREF instruction with smaller offset than
ordinary MIPS. However, the memcpy code uses PREF instruction
with offsets bigger than +-256 bytes.

Malta kernels already disable usage of PREF for memcpy.

This was found during adaptation of MIPS R6 for virtual board
used by Android emulator.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtech.com>
Cc: James.Hogan@imgtec.com
Cc: Paul.Burton@imgtec.com
Cc: Raghu.Gandham@imgtec.com
Cc: Leonid.Yegoshin@imgtec.com
Cc: Douglas.Leung@imgtec.com
Cc: Petar.Jovanovic@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16510/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Add "-modd-spreg" when compiling the kernel for mips32r6 target.

This makes sure the kernel builds properly even with toolchains that
use "-mno-odd-spreg" by default. This is the case with Android gcc.
Prior to this patch, kernel builds using gcc for Android failed with
following error messages, if target architecture is set to mips32r6:

arch/mips/kernel/r4k_switch.S: Assembler messages:
.../r4k_switch.S:210: Error: float register should be even, was 1
.../r4k_switch.S:212: Error: float register should be even, was 3
.../r4k_switch.S:214: Error: float register should be even, was 5
.../r4k_switch.S:216: Error: float register should be even, was 7
.../r4k_switch.S:218: Error: float register should be even, was 9
.../r4k_switch.S:220: Error: float register should be even, was 11
.../r4k_switch.S:222: Error: float register should be even, was 13
.../r4k_switch.S:224: Error: float register should be even, was 15
.../r4k_switch.S:226: Error: float register should be even, was 17
.../r4k_switch.S:228: Error: float register should be even, was 19
.../r4k_switch.S:230: Error: float register should be even, was 21
.../r4k_switch.S:232: Error: float register should be even, was 23
.../r4k_switch.S:234: Error: float register should be even, was 25
.../r4k_switch.S:236: Error: float register should be even, was 27
.../r4k_switch.S:238: Error: float register should be even, was 29
.../r4k_switch.S:240: Error: float register should be even, was 31
make[2]: *** [arch/mips/kernel/r4k_switch.o] Error 1

Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: James.Hogan@imgtec.com
Cc: Paul.Burton@imgtec.com
Cc: Raghu.Gandham@imgtec.com
Cc: Leonid.Yegoshin@imgtec.com
Cc: Douglas.Leung@imgtec.com
Cc: Petar.Jovanovic@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16509/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Implement support for parsing 'memmap' kernel command line parameter.

This patch covers parsing of the following two formats for 'memmap'
parameter values:

  - nn[KMG]@ss[KMG]
  - nn[KMG]$ss[KMG]

  ([KMG] = K M or G (kilo, mega, giga))

These two allowed formats for parameter value are already documented
in file kernel-parameters.txt in Documentation/admin-guide folder.
Some architectures already support them, but Mips did not prior to
this patch.

Excerpt from Documentation/admin-guide/kernel-parameters.txt:

memmap=nn[KMG]@ss[KMG]
    [KNL] Force usage of a specific region of memory.
    Region of memory to be used is from ss to ss+nn.

memmap=nn[KMG]$ss[KMG]
    Mark specific memory as reserved.
    Region of memory to be reserved is from ss to ss+nn.
    Example: Exclude memory from 0x18690000-0x1869ffff
        memmap=64K$0x18690000
        or
        memmap=0x10000$0x18690000

There is no need to update this documentation file with respect to
this patch.

Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: James.Hogan@imgtec.com
Cc: Paul.Burton@imgtec.com
Cc: Raghu.Gandham@imgtec.com
Cc: Leonid.Yegoshin@imgtec.com
Cc: Douglas.Leung@imgtec.com
Cc: Petar.Jovanovic@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16508/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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: Huacai 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: Ralf Baechle <ralf@linux-mips.org>

With this patch we can set irq affinity via procfs, so as to improve
network performance.

Signed-off-by: Huacai 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: Ralf 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: Huacai 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: Ralf Baechle <ralf@linux-mips.org>

Loongson-3 machines may have as many as 4 physical packages.

Signed-off-by: Huacai 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/16588/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Huacai 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: Ralf 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: Huacai 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: Ralf 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: Paul 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: Ralf 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: Paul Burton <paul.burton@imgtec.com>
Reported-by: Keng Koh <keng.koh@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16187/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Add an entry to MAINTAINERS for the generic platform code, such that
relevant people, starting with myself, can be CC'd on patches.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16186/
Signed-off-by: Ralf 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: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16185/
Signed-off-by: Ralf 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: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16184/
Signed-off-by: Ralf 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: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16183/
Signed-off-by: Ralf 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: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16182/
Signed-off-by: Ralf 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: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16181/
Signed-off-by: Ralf 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: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16188/
Signed-off-by: Ralf 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: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16150/
Signed-off-by: Ralf 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: James 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: Ralf 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: James 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: Ralf 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: James 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: Ralf 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: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16362/
Signed-off-by: Ralf 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: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16190/
Signed-off-by: Ralf 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: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Tested-by: Bryan 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: Ralf 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: David 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: Ralf 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: David 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: Ralf 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: David 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: Ralf Baechle <ralf@linux-mips.org>