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  1. 26 Jul, 2018 1 commit
  3. 25 Jul, 2018 11 commits
  5. 24 Jul, 2018 9 commits
    • Paul Burton's avatar
      MIPS: Hardcode cpu_has_* where known at compile time due to ISA · 93e01942
      Paul Burton authored 
      Many architectural features have over time moved from being optional to
either be required or removed by newer architecture releases. This means
that in many cases we can know at compile time whether a feature will be
supported or not purely due to the knowledge we have about the ISA the
kernel build is targeting.

This patch introduces a bunch of utility macros for checking for
supported options, ASEs & combinations of those with ISA revisions. It
then makes use of these in the default definitions of cpu_has_* macros.
The result is that many of the macros become compile-time constant,
allowing more optimisation opportunities for the compiler - particularly
with kernels built for later ISA revisions.

To demonstrate the effect of this patch, the following table shows the
size in bytes of the kernel binary as reported by scripts/bloat-o-meter
for v4.12-rc4 maltasmvp_defconfig kernels with & without this patch. A
variant of maltasmvp_defconfig with CONFIG_CPU_MIPS32_R6 selected is
also shown, to demonstrate that MIPSr6 systems benefit more due to extra
features becoming required by that architecture revision. Builds of
pistachio_defconfig are also shown, as although this is a MIPSr2
platform it doesn't hardcode any features in a machine-specific
cpu-feature-overrides.h, which allows it to gain more from this patch
than the equivalent Malta r2 build.

     Config         | Before  | After   |  Change
    ----------------|---------|---------|---------
     maltasmvp      | 7248316 | 7247714 |    -602
     maltasmvp + r6 | 6955595 | 6950777 |   -4818
     pistachio      | 8650977 | 8363898 | -287079
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/16360/
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
      93e01942
    • Mathieu Malaterre's avatar
      MIPS: jz4780: DTS: Probe the spi-gpio driver from devicetree · c24f5762
      Mathieu Malaterre authored 
      Make use of the spi-gpio driver to provide SPI support on the Ingenic
JZ4780 SoC using the pins that can be used with the SSI0 device as
GPIOs, until such time as we have support for the Ingenic SPI/SSI
controller.

[paul.burton@mips.com: Rewrite commit message.]
Signed-off-by: default avatarMathieu Malaterre <malat@debian.org>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19489/
Cc: James Hogan <jhogan@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: devicetree@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
      c24f5762
    • Mathieu Malaterre's avatar
      MIPS: Ci20: Enable SPI/GPIO driver · 2e90396a
      Mathieu Malaterre authored 
      Enable CONFIG_SPI_GPIO in ci20_defconfig, in order to make use of the
spi-gpio driver in a further commit.

[paul.burton@mips.com: Rewrite commit message.]
Signed-off-by: default avatarMathieu Malaterre <malat@debian.org>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19488/
Cc: James Hogan <jhogan@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: devicetree@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
      2e90396a
    • Alexander Sverdlin's avatar
      MIPS: Octeon: Select HAS_RAPIDIO · 491ec155
      Alexander Sverdlin authored 
      All Octeons starting with Octeon II have RAPIDIO controller which
can function even with PCI disabled.
Signed-off-by: default avatarAlexander Sverdlin <alexander.sverdlin@nokia.com>
Acked-by: default avatarAlexandre Bounine <alex.bou9@gmail.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19988/
Cc: linux-mips@linux-mips.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
      491ec155
    • Alexander Sverdlin's avatar
      MIPS: Introduce HAS_RAPIDIO Kconfig option · fc5d9888
      Alexander Sverdlin authored 
      Introduce the same option as PPC and ARM already have because
RAPIDIO can function in the absence of PCI.
Signed-off-by: default avatarAlexander Sverdlin <alexander.sverdlin@nokia.com>
Acked-by: default avatarAlexandre Bounine <alex.bou9@gmail.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19987/
Cc: linux-mips@linux-mips.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
      fc5d9888
    • Thomas Petazzoni's avatar
      mips: use asm-generic version of msi.h · 34a4399f
      Thomas Petazzoni authored 
      This is necessary to be able to include <linux/msi.h> when
CONFIG_GENERIC_MSI_IRQ_DOMAIN is enabled. Without this, a build with
CONFIG_GENERIC_MSI_IRQ_DOMAIN fails with:

   In file included from include/linux/kvm_host.h:20:0,
                    from arch/mips/kernel/asm-offsets.c:24:
>> include/linux/msi.h:197:10: fatal error: asm/msi.h: No such file or directory
    #include <asm/msi.h>
             ^~~~~~~~~~~
   compilation terminated.
   make[2]: *** [arch/mips/kernel/asm-offsets.s] Error 1
   make[2]: Target '__build' not remade because of errors.
   make[1]: *** [prepare0] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [sub-make] Error 2
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19986/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Hanna Hawa <hannah@marvell.com>
      34a4399f
    • Huacai Chen's avatar
      MIPS: Loongson64: Define and use some CP0 registers · 97ab1bb4
      Huacai Chen authored 
      Defines CP0_CONFIG3, CP0_CONFIG6, CP0_PAGEGRAIN and use them in
kernel-entry-init.h for Loongson64.
Signed-off-by: default avatarHuacai Chen <chenhc@lemote.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19264/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <james.hogan@mips.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhuacai@gmail.com>
      97ab1bb4
    • Huacai Chen's avatar
      MIPS: Loongson: Add Loongson-3A R3.1 basic support · 7cff3f16
      Huacai Chen authored 
      Loongson-3A R3.1 is the bugfix revision of Loongson-3A R3.

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-3A R3.1  Loongson-3A3000  0x630d
Loongson-3B R1    Loongson-3B1000  0x6306
Loongson-3B R2    Loongson-3B1500  0x6307
Signed-off-by: default avatarHuacai Chen <chenhc@lemote.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19263/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <james.hogan@mips.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhuacai@gmail.com>
      7cff3f16
    • Paul Cercueil's avatar
      MIPS: jz4740: Bump zload address · c6ea7e97
      Paul Cercueil authored 
      Having the zload address at 0x8060.0000 means the size of the
uncompressed kernel cannot be bigger than around 6 MiB, as it is
deflated at address 0x8001.0000.

This limit is too small; a kernel with some built-in drivers and things
like debugfs enabled will already be over 6 MiB in size, and so will
fail to extract properly.

To fix this, we bump the zload address from 0x8060.0000 to 0x8100.0000.

This is fine, as all the boards featuring Ingenic JZ SoCs have at least
32 MiB of RAM, and use u-boot or compatible bootloaders which won't
hardcode the load address but read it from the uImage's header.
Signed-off-by: default avatarPaul Cercueil <paul@crapouillou.net>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19787/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
      c6ea7e97
  7. 23 Jul, 2018 2 commits
    • Hauke Mehrtens's avatar
      MIPS: lantiq: Use dma_zalloc_coherent() in dma code · 2b5c4913
      Hauke Mehrtens authored 
      Instead of using dma_alloc_coherent() and memset() directly use
dma_zalloc_coherent().
Signed-off-by: default avatarHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19962/
Cc: ralf@linux-mips.org
Cc: jhogan@kernel.org
Cc: john@phrozen.org
Cc: linux-mips@linux-mips.org
Cc: dev@kresin.me
      2b5c4913
    • Huacai Chen's avatar
      MIPS: Change definition of cpu_relax() for Loongson-3 · a3071886
      Huacai Chen authored 
      Linux expects that if a CPU modifies a memory location, then that
modification will eventually become visible to other CPUs in the system.

Loongson 3 CPUs include a Store Fill Buffer (SFB) which sits between a
core & its L1 data cache, queueing memory accesses & allowing for faster
forwarding of data from pending stores to younger loads from the core.
Unfortunately the SFB prioritizes loads such that a continuous stream of
loads may cause a pending write to be buffered indefinitely. This is
problematic if we end up with 2 CPUs which each perform a store that the
other polls for - one or both CPUs may end up with their stores buffered
in the SFB, never reaching cache due to the continuous reads from the
poll loop. Such a deadlock condition has been observed whilst running
qspinlock code.

This patch changes the definition of cpu_relax() to smp_mb() for
Loongson-3, forcing a flush of the SFB on SMP systems which will cause
any pending writes to make it as far as the L1 caches where they will
become visible to other CPUs. If the kernel is not compiled for SMP
support, this will expand to a barrier() as before.

This workaround matches that currently implemented for ARM when
CONFIG_ARM_ERRATA_754327=y, which was introduced by commit 534be1d5
("ARM: 6194/1: change definition of cpu_relax() for ARM11MPCore").

Although the workaround is only required when the Loongson 3 SFB
functionality is enabled, and we only began explicitly enabling that
functionality in v4.7 with commit 1e820da3 ("MIPS: Loongson-3:
Introduce CONFIG_LOONGSON3_ENHANCEMENT"), existing or future firmware
may enable the SFB which means we may need the workaround backported to
earlier kernels too.

[paul.burton@mips.com:
  - Reword commit message & comment.
  - Limit stable backport to v3.15+ where we support Loongson 3 CPUs.]
Signed-off-by: default avatarHuacai Chen <chenhc@lemote.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
References: 534be1d5 ("ARM: 6194/1: change definition of cpu_relax() for ARM11MPCore")
References: 1e820da3 ("MIPS: Loongson-3: Introduce CONFIG_LOONGSON3_ENHANCEMENT")
Patchwork: https://patchwork.linux-mips.org/patch/19830/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhuacai@gmail.com>
Cc: stable@vger.kernel.org # v3.15+
      a3071886
  9. 20 Jul, 2018 1 commit
  11. 19 Jul, 2018 4 commits
    • Maciej W. Rozycki's avatar
      MIPS: Add FP_MODE regset support · 1ae22a0e
      Maciej W. Rozycki authored 
      Define an NT_MIPS_FP_MODE core file note and implement a corresponding
regset holding the state handled by PR_SET_FP_MODE and PR_GET_FP_MODE
prctl(2) requests.  This lets debug software correctly interpret the
contents of floating-point general registers both in live debugging and
in core files, and also switch floating-point modes of a live process.

[paul.burton@mips.com:
  - Changed NT_MIPS_FP_MODE to 0x801 to match first nibble of
    NT_MIPS_DSP, which was also changed to avoid a conflict.]
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19331/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
      1ae22a0e
    • Maciej W. Rozycki's avatar
      MIPS: Add DSP ASE regset support · 44109c60
      Maciej W. Rozycki authored 
      Define an NT_MIPS_DSP core file note type and implement a corresponding
regset holding the DSP ASE register context, following the layout of the
`mips_dsp_state' structure, except for the DSPControl register stored as
a 64-bit rather than 32-bit quantity in a 64-bit note.

The lack of DSP ASE register saving to core files can be considered a
design flaw with commit e50c0a8f ("Support the MIPS32 / MIPS64 DSP
ASE."), leading to an incomplete state being saved.  Consequently no DSP
ASE regset has been created with commit 7aeb753b ("MIPS: Implement
task_user_regset_view."), when regset support was added to the MIPS
port.

Additionally there is no way for ptrace(2) to correctly access the DSP
accumulator registers in n32 processes with the existing interfaces.
This is due to 32-bit truncation of data passed with PTRACE_PEEKUSR and
PTRACE_POKEUSR requests, which cannot be avoided owing to how the data
types for ptrace(3) have been defined.  This new NT_MIPS_DSP regset
fills the missing interface gap.

[paul.burton@mips.com:
  - Change NT_MIPS_DSP to 0x800 to avoid conflict with NT_VMCOREDD
    introduced by commit 2724273e ("vmcore: add API to collect
    hardware dump in second kernel").
  - Drop stable tag. Whilst I agree the lack of this functionality can
    be considered a flaw in earlier DSP ASE support, it's still new
    functionality which doesn't meet up to the requirements set out in
    Documentation/process/stable-kernel-rules.rst.]
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
References: 7aeb753b ("MIPS: Implement task_user_regset_view.")
Patchwork: https://patchwork.linux-mips.org/patch/19330/
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
      44109c60
    • Maciej W. Rozycki's avatar
      MIPS: Correct the 64-bit DSP accumulator register size · f5958b4c
      Maciej W. Rozycki authored 
      Use the `unsigned long' rather than `__u32' type for DSP accumulator
registers, like with the regular MIPS multiply/divide accumulator and
general-purpose registers, as all are 64-bit in 64-bit implementations
and using a 32-bit data type leads to contents truncation on context
saving.

Update `arch_ptrace' and `compat_arch_ptrace' accordingly, removing
casts that are similarly not used with multiply/divide accumulator or
general-purpose register accesses.
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Fixes: e50c0a8f ("Support the MIPS32 / MIPS64 DSP ASE.")
Patchwork: https://patchwork.linux-mips.org/patch/19329/
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # 2.6.15+
      f5958b4c
    • Maciej W. Rozycki's avatar
      binfmt_elf: Respect error return from `regset->active' · 2f819db5
      Maciej W. Rozycki authored 
      The regset API documented in <linux/regset.h> defines -ENODEV as the
result of the `->active' handler to be used where the feature requested
is not available on the hardware found.  However code handling core file
note generation in `fill_thread_core_info' interpretes any non-zero
result from the `->active' handler as the regset requested being active.
Consequently processing continues (and hopefully gracefully fails later
on) rather than being abandoned right away for the regset requested.

Fix the problem then by making the code proceed only if a positive
result is returned from the `->active' handler.
Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Fixes: 4206d3aa ("elf core dump: notes user_regset")
Patchwork: https://patchwork.linux-mips.org/patch/19332/
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
      2f819db5
  13. 17 Jul, 2018 2 commits
    • Paul Burton's avatar
      MIPS: loongson64: cs5536: Fix PCI_OHCI_INT_REG reads · cd87668d
      Paul Burton authored 
      The PCI_OHCI_INT_REG case in pci_ohci_read_reg() contains the following
if statement:

  if ((lo & 0x00000f00) == CS5536_USB_INTR)

CS5536_USB_INTR expands to the constant 11, which gives us the following
condition which can never evaluate true:

  if ((lo & 0xf00) == 11)

At least when using GCC 8.1.0 this falls foul of the tautoligcal-compare
warning, and since the code is built with the -Werror flag the build
fails.

Fix this by shifting lo right by 8 bits in order to match the
corresponding PCI_OHCI_INT_REG case in pci_ohci_write_reg().
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19861/
Cc: Huacai Chen <chenhc@lemote.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
      cd87668d
    • Alexander Sverdlin's avatar
      mips: unify prom_putchar() declarations · 5c93316c
      Alexander Sverdlin authored 
      prom_putchar() is used centrally in early printk infrastructure therefore
at least MIPS should agree on the function return type.

[paul.burton@mips.com:
  - Include linux/types.h in asm/setup.h to gain the bool typedef before
    we start include asm/setup.h elsewhere.
  - Include asm/setup.h in all files that use or define prom_putchar().
  - Also standardise on signed rather than unsigned char argument.]
Signed-off-by: default avatarAlexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19842/
Cc: linux-mips@linux-mips.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jonas Gorski <jonas.gorski@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
      5c93316c
  15. 12 Jul, 2018 3 commits
    • Joshua Kinard's avatar
      MIPS: Cleanup R10000_LLSC_WAR logic in atomic.h · 4936084c
      Joshua Kinard authored 
      This patch reduces down the conditionals in MIPS atomic code that deal
with a silicon bug in early R10000 cpus that required a workaround of
a branch-likely instruction following a store-conditional in order to
to guarantee the whole ll/sc sequence is atomic.  As the only real
difference is a branch-likely instruction (beqzl) over a standard
branch (beqz), the conditional is reduced down to a single preprocessor
check at the top to pick the required instruction.

This requires writing the uses in assembler, thus we discard the
non-R10000 case that uses a mixture of a C do...while loop with
embedded assembler that was added back in commit 7837314d ("MIPS:
Get rid of branches to .subsections.").  A note found in the git log
for commit 5999eca25c1f ("[MIPS] Improve branch prediction in ll/sc
atomic operations.") is also addressed.

The macro definition for the branch instruction and the code comment
derives from a patch sent in earlier by Paul Burton for various cmpxchg
cleanups.

[paul.burton@mips.com:
  - Minor whitespace fix for checkpatch.]
Signed-off-by: default avatarJoshua Kinard <kumba@gentoo.org>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/17736/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <james.hogan@mips.com>
Cc: "Maciej W. Rozycki" <macro@mips.com>
Cc: linux-mips@linux-mips.org
      4936084c
    • Joshua Kinard's avatar
      MIPS: Fix delay slot bug in `atomic*_sub_if_positive' for R10000_LLSC_WAR · a0a5ac3c
      Joshua Kinard authored 
      This patch fixes an old bug in MIPS ll/sc atomics, in the
`atomic_sub_if_positive' and `atomic64_sub_if_positive' functions, for
the R10000_LLSC_WAR case where the result of the subu/dsubu instruction
would potentially not be made available to the sc/scd instruction due
to being in the delay-slot of the branch-likely (beqzl) instruction.

This also removes the need for the `noreorder' directive, allowing GAS
to use delay slot scheduling as needed.

The same fix is also applied to the standard branch (beqz) case in
preparation for a follow-up patch that will cleanup/merge the
R10000_LLSC_WAR and non-R10K sections together.
Signed-off-by: default avatarJoshua Kinard <kumba@gentoo.org>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Tested-by: default avatarJoshua Kinard <kumba@gentoo.org>
Patchwork: https://patchwork.linux-mips.org/patch/17735/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <james.hogan@mips.com>
Cc: "Maciej W. Rozycki" <macro@mips.com>
Cc: linux-mips@linux-mips.org
      a0a5ac3c
    • Thomas Bogendoerfer's avatar
      mips/jazz: provide missing dma_mask/coherent_dma_mask · b5d69129
      Thomas Bogendoerfer authored 
      Commit 205e1b7f ("dma-mapping: warn when there is no
coherent_dma_mask") introduced a warning, if a device is missing a
coherent_dma_mask. ESP and sonic are using dma mapping functions, so
they need dma masks.

[paul.burton@mips.com:
  - Wrap commit message.]
Signed-off-by: default avatarThomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19828/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
      b5d69129
  17. 10 Jul, 2018 2 commits
    • Serge Semin's avatar
      mips: mm: Discard ioremap_uncached_accelerated() method · ddba595b
      Serge Semin authored 
      Adaptive ioremap_wc() method is now available as of commit 9748e33e
("mips: mm: Create UCA-based ioremap_wc() method"). We can use it to
obtain UnCached Accelerated (UCA) mappings safely on all MIPS systems,
and so we don't need the MIPS-specific ioremap_uncached_accelerated()
any longer. This macro hard-coded the UCA Cache Coherency Attribute
(CCA) in a manner that isn't safe for kernels that may run on different
CPUs, and it is also entirely unused so we can trivially remove it.

[paul.burton@mips.com:
  - Reword the commit message a little.
  - Remove CC stable.]
Signed-off-by: default avatarSerge Semin <fancer.lancer@gmail.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19790/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: okaya@codeaurora.org
Cc: chenhc@lemote.com
Cc: Sergey.Semin@t-platforms.ru
Cc: linux-kernel@vger.kernel.org
      ddba595b
    • Serge Semin's avatar
      mips: mm: Create UCA-based ioremap_wc() method · 9748e33e
      Serge Semin authored 
      Modern MIPS cores (like P5600/6600, M5150/6520, end so on) which
got L2-cache on chip also can enable a special type Cache-Coherency
attribute (CCA) named UnCached Accelerated attribute (UCA). In this
way uncached accelerated accesses are treated the same way as
non-accelerated uncached accesses, but uncached stores are gathered
together for more efficient bus utilization. So to speak this CCA
enables uncached transactions to better utilize bus bandwidth via
burst transactions.

This is exactly why ioremap_wc() method has been introduced in Linux.
Alas MIPS-platform code hasn't implemented it so far, instead default
one has been used which was an alias to ioremap_nocache. In order to
fix this we added MIPS-specific ioremap_wc() macro substituted by
generic __ioremap_mode() method call with writecombine CPU-info
field passed. It shall create real ioremap_wc() method if CPU-cache
supports UCA feature and fall-back to _CACHE_UNCACHED attribute
if one doesn't. Additionally platform-specific io.h shall declare
ARCH_HAS_IOREMAP_WC macro as indication of architectural definition
of ioremap_wc() (similar to x86/powerpc).

[paul.burton@mips.com:
  - Remove CC stable, this is new functionality.]
Signed-off-by: default avatarSerge Semin <fancer.lancer@gmail.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19789/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: okaya@codeaurora.org
Cc: chenhc@lemote.com
Cc: Sergey.Semin@t-platforms.ru
Cc: linux-kernel@vger.kernel.org
      9748e33e
  19. 03 Jul, 2018 5 commits
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