[PATCH v4 00/13] mips: Prepare MIPS-arch code for Baikal-T1 SoC support

[PATCH v4 00/13] mips: Prepare MIPS-arch code for Baikal-T1 SoC support

[Serge Semin]

This is a first patchset of a series of about 25 ones, which are intended to
add the full Baikal-T1 SoC [1] support to the Linux kernel. Since they will
concern various kernel subsystems, I decided to split the whole work up into
the patchesets in accordance with the subsystems/devices their changes are
introduced for. Nearly 2/3 of the work is already done and will be sent out
very soon. While the rest of the changes specifically related to the fast-speed
interfaces (DW 12G PHY, PCIe, SATA, xGBE, GMAC, USB, DDRC, IC) are still in
refactoring and preparation for integration into the mainline kernel. Hopefully
I'll finish them up in the next two-three months, and submit them straight
away.

Getting back to this patchset. As the subject states this is intended to
prepare the MIPS-arch and generic kernel code for further Baikal-T1 SoC
platform support integration (note the Baikal-T1 SoC platform code will be
submitted last after the whole series of patchsets as a closure of the
submission process). First of all the patchset starts with a set of changes
to the dt-bindings kernel concerning MIPS CPC and CDMM nodes to make them
being represented by dt schemas. In addition we updated the vendors prefix
schema with Baikal Electronics JSC prefix so being further committed
vendor-specific device drivers would be correctly accepted by the
checkpatch script.

While I was working with the MIPS architecture code, I discovered, that there
is a bug in the Coherency Manager v2 error causes declaration and the errors
handler lacked of CM2 L2 ECC/parity errors support. So the fixes are here in
the patchset.

Baikal-T1 SoC is based on the MIPS P5600 Warrior IP-core, which itself has
MIPS32 Release 5 architecture. Even though on ISA level it doesn't differ much
from the MIPS32 Release 2 release, there are still some peculiarities, which
make it's justified to add the direct MIPS32r5 support into the kernel (see
the specific patch for details). In addition seeing there is more than one
real chip based on the MIPS P5600 core on the market, it would be good to have
the direct P5600 CPU config in the MIPS-arch.

There were some issues we discovered while were working with MIPS-arch code.
So the cleanups and fixes are introduced in this patchset. First of all the
Write-Merge CPU feature hasn't been handled in a generic way. Even if a
platform defined the writecombine flag as _CACHE_UNCACHED_ACCELERATED, the
feature might have been disabled in the CP0 register. We either enable it or
leave it as is in accordance with the knowledge of whether the corresponding
platform really supports it. Secondly Memory Accessibility Attribute Registers
(MAAR) haven't been properly initialized when Extended Physical Address (XPA)
mode was enabled. Thirdly since some of the platforms may have a very strict
limitations on the IO-memory access instructions. For instance Baikal-T1 SoC
IO-memory can be accessed by the lw/sw instructions only. In this case
for early-printk and CPS-debug code we suggest to use the instructions in
accordance with the UART-registers offset (lb/sb if offset = 0, lh/sh
if offset = 1 and so on). Fourthly in case if CPUFREQ feature is enabled
and frequency of the CPU is changed by the reference clock alteration, we
must make sure that MIPS r4k timer related services are properly updated
when CPU-frequency changes. It concerns udelay lpj adjustment, MIPS timer
clockevent frequency update. In addition when CPU reference frequency changes
it isn't recommended to use the timer as clocksource at all, since currently
the subsystem isn't tolerant to the unstable clock sources. So in this case
we suggest to use the r4k timer for clocksourcing only as a last resort.
Fifthly we discovered a bug in a method of CPUFREQ boost feature enable
procedure and fixed it in one of the patches within this patchset. And finally
there are a few fixups/cleanups we suggest to integrate into the MIPS FDC
and CDMM related code (see the patches for details).

This patchset is rebased and tested on the mips-next branch:
base-commit: bbb5946eb545 ("Linux 5.7-rc1" + mips-next)
tag: v5.7-rc1

[1] http://www.baikalelectronics.com/products/168/

Link: https://lore.kernel.org/linux-mips/20200306124807.3596F80307C2@mail.baikalelectronics.ru/
Changelog v2:
- Replace "be" vendor prefix with "baikal" one.
- Remove patches adding the platform devices to the trivial-devices.yaml
  bindings file (Rob nacked it).
- Add yaml-based bindings file for MIPS CDMM dt-node.
- Convert mti,mips-cpc to DT schema.
- Use a shorter summary describing the bindings modification patches.
- Rearrange the SoBs with adding Alexey' co-development tag.
- Lowercase the hex numbers in the dt-bindings.
- Fix author and SoB emails mismatch in the patch of adding the Baikal
  Electronis JSC prefix to the dt schema of the prefixes.
- Remove patch "tty: mips_ejtag_fdc: Mark expected switch fall-through" from
  the patchset as being already applied to the Greg' tty-next branch.
- Our corporate email server doesn't change Message-Id anymore, so the patchset
  is resubmitted being in the cover-letter-threaded format.

Link: https://lore.kernel.org/linux-mips/20200506174238.15385-1-Sergey.Semin@baikalelectronics.ru/
Changelog v3:
- Discard commit 0ea2a268a7d3 ("mips: cm: Fix an invalid error code of INTVN_*_ERR")
  from the series since being integrated into the mips-next supported by Thomas.
- Discard commit d8163378fa4a ("mips: cm: Add L2 ECC/parity errors reporting")
  from the series since being integrated into the mips-next supported by Thomas.
- Discard commit 424de4cd3170 ("mips: MAAR: Add XPA mode support")
  from the series since being integrated into the mips-next supported by Thomas.
- Discard commit e128d941798d ("cpufreq: Return zero on success in boost sw setting")
  from the series as a fixup has been integrated into the kernel.
- Discard commit 08a3eb747882 ("dt-bindings: Add vendor prefix for Baikal
  Electronics, JSC") from the series since being integrated into the for-next
  supported by Rob.
- Discard commit 126510566cc7 ("mips: early_printk_8250: Use offset-sized IO-mem
  accessors") as being rejected by Thomas. Baikal-T1 SoC platform code will have to
  implement its own prom_putchar() method. It's probably for good. I'll use it to
  declare a common zboot and early printk method for a single UART.
- Use cpu_has_64bits to make sure the CPU has 64bits ISA instead of
  creating and using a new macro __isa_range_and_flag().
- Add r4k_ prefix to the cpufreq change notifier methods.
- In accordance with MIPS32/64 Privileged Resource Architecture Extend
  the MAAR Addr mask to value [12:55] instead of P5600-specific [12:35].
- In accordance with MIPS32/64 Privileged Resource Architecture Extend
  the MAAR Addr mask to value [12:55] instead of P5600-specific [12:35].
- Use cpu_has_64bits to make sure the CPU has 64bits ISA instead of
  creating and using a new macro __isa_range_and_flag().
- Mark r4k clocksource as unstable instead of lowering its rating.
- Along with MIPS32 Release 5 add MIPS64 Release 5 CPU support.
- Add CONFIG_CPS_NS16550_WIDTH config to select the UART registers accessors.

Changelog v4:
- Discard commit 37353ec964e8 ("mips: MAAR: Use more precise address mask")
  from the series as a fixup has been integrated into the kernel.
- Rebase onto the mips-next branch.

Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Maxim Kaurkin <Maxim.Kaurkin@baikalelectronics.ru>
Cc: Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Ekaterina Skachko <Ekaterina.Skachko@baikalelectronics.ru>
Cc: Vadim Vlasov <V.Vlasov@baikalelectronics.ru>
Cc: Alexey Kolotnikov <Alexey.Kolotnikov@baikalelectronics.ru>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Serge Semin (13):
  dt-bindings: power: Convert mti,mips-cpc to DT schema
  dt-bindings: bus: Add MIPS CDMM controller
  mips: Add MIPS Release 5 support
  mips: Add MIPS Warrior P5600 support
  mips: Fix cpu_has_mips64r1/2 activation for MIPS32 CPUs
  mips: Add CP0 Write Merge config support
  mips: Add CONFIG/CONFIG6/Cause reg fields macro
  mips: Add CPS_NS16550_WIDTH config
  mips: cdmm: Add mti,mips-cdmm dtb node support
  bus: cdmm: Add MIPS R5 arch support
  mips: Add udelay lpj numbers adjustment
  mips: csrc-r4k: Mark R4K timer as unstable if CPU freq changes
  mips: cevt-r4k: Update the r4k-clockevent frequency in sync with CPU

 .../bindings/bus/mti,mips-cdmm.yaml           | 35 ++++++++
 .../bindings/power/mti,mips-cpc.txt           |  8 --
 .../bindings/power/mti,mips-cpc.yaml          | 35 ++++++++
 arch/mips/Kconfig                             | 84 +++++++++++++++++--
 arch/mips/Kconfig.debug                       | 10 +++
 arch/mips/Makefile                            |  3 +
 arch/mips/include/asm/asmmacro.h              | 18 ++--
 arch/mips/include/asm/compiler.h              |  5 ++
 arch/mips/include/asm/cpu-features.h          | 41 +++++++--
 arch/mips/include/asm/cpu-info.h              |  2 +-
 arch/mips/include/asm/cpu-type.h              |  7 +-
 arch/mips/include/asm/cpu.h                   | 14 ++--
 arch/mips/include/asm/fpu.h                   |  4 +-
 arch/mips/include/asm/hazards.h               |  8 +-
 arch/mips/include/asm/mipsregs.h              | 22 +++++
 arch/mips/include/asm/module.h                |  6 ++
 arch/mips/include/asm/stackframe.h            |  2 +-
 arch/mips/include/asm/switch_to.h             |  8 +-
 arch/mips/kernel/cevt-r4k.c                   | 44 ++++++++++
 arch/mips/kernel/cps-vec-ns16550.S            | 18 +++-
 arch/mips/kernel/cpu-probe.c                  | 65 ++++++++++++++
 arch/mips/kernel/csrc-r4k.c                   | 40 +++++++++
 arch/mips/kernel/entry.S                      |  6 +-
 arch/mips/kernel/proc.c                       |  4 +
 arch/mips/kernel/r4k_fpu.S                    | 14 ++--
 arch/mips/kernel/spram.c                      |  4 +-
 arch/mips/kernel/time.c                       | 70 ++++++++++++++++
 arch/mips/kvm/vz.c                            |  6 +-
 arch/mips/lib/csum_partial.S                  |  6 +-
 arch/mips/mm/c-r4k.c                          |  7 +-
 arch/mips/mm/sc-mips.c                        |  7 +-
 drivers/bus/Kconfig                           |  2 +-
 drivers/bus/mips_cdmm.c                       | 15 ++++
 33 files changed, 547 insertions(+), 73 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/bus/mti,mips-cdmm.yaml
 delete mode 100644 Documentation/devicetree/bindings/power/mti,mips-cpc.txt
 create mode 100644 Documentation/devicetree/bindings/power/mti,mips-cpc.yaml

-- 
2.25.1

[PATCH v4 01/13] dt-bindings: power: Convert mti,mips-cpc to DT schema

[Serge Semin]

It's a Cluster Power Controller embedded into the MIPS IP cores.
Currently the corresponding dts node is supposed to have compatible
and reg properties.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
---
 .../bindings/power/mti,mips-cpc.txt           |  8 -----
 .../bindings/power/mti,mips-cpc.yaml          | 35 +++++++++++++++++++
 2 files changed, 35 insertions(+), 8 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/power/mti,mips-cpc.txt
 create mode 100644 Documentation/devicetree/bindings/power/mti,mips-cpc.yaml

diff --git a/Documentation/devicetree/bindings/power/mti,mips-cpc.txt b/Documentation/devicetree/bindings/power/mti,mips-cpc.txt
deleted file mode 100644
index c6b82511ae8a..000000000000
--- a/Documentation/devicetree/bindings/power/mti,mips-cpc.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-Binding for MIPS Cluster Power Controller (CPC).
-
-This binding allows a system to specify where the CPC registers are
-located.
-
-Required properties:
-compatible : Should be "mti,mips-cpc".
-regs: Should describe the address & size of the CPC register region.
diff --git a/Documentation/devicetree/bindings/power/mti,mips-cpc.yaml b/Documentation/devicetree/bindings/power/mti,mips-cpc.yaml
new file mode 100644
index 000000000000..9cd92a57130c
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/mti,mips-cpc.yaml
@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/mti,mips-cpc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MIPS Cluster Power Controller
+
+description: |
+  Defines a location of the MIPS Cluster Power Controller registers.
+
+maintainers:
+  - Paul Burton <paulburton@kernel.org>
+
+properties:
+  compatible:
+    const: mti,mips-cpc
+
+  reg:
+    description: |
+      Base address and size of an unoccupied memory region, which will be
+      used to map the MIPS CPC registers block.
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    cpc@1bde0000 {
+      compatible = "mti,mips-cpc";
+      reg = <0 0x1bde0000 0 0x8000>;
+    };
+...
-- 
2.25.1

[PATCH v4 02/13] dt-bindings: bus: Add MIPS CDMM controller

[Serge Semin]

It's a Common Device Memory Map controller embedded into the MIPS IP
cores, which dts node is supposed to have compatible and reg properties.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-mips@vger.kernel.org
---
 .../bindings/bus/mti,mips-cdmm.yaml           | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/mti,mips-cdmm.yaml

diff --git a/Documentation/devicetree/bindings/bus/mti,mips-cdmm.yaml b/Documentation/devicetree/bindings/bus/mti,mips-cdmm.yaml
new file mode 100644
index 000000000000..d28d65ae57b2
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/mti,mips-cdmm.yaml
@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bus/mti,mips-cdmm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MIPS Common Device Memory Map
+
+description: |
+  Defines a location of the MIPS Common Device Memory Map registers.
+
+maintainers:
+  - James Hogan <jhogan@kernel.org>
+
+properties:
+  compatible:
+    const: mti,mips-cdmm
+
+  reg:
+    description: |
+      Base address and size of an unoccupied memory region, which will be
+      used to map the MIPS CDMM registers block.
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    cdmm@1bde8000 {
+      compatible = "mti,mips-cdmm";
+      reg = <0 0x1bde8000 0 0x8000>;
+    };
+...
-- 
2.25.1

[PATCH v4 03/13] mips: Add MIPS Release 5 support

[Serge Semin]

There are five MIPS32/64 architecture releases currently available:
from 1 to 6 except fourth one, which was intentionally skipped.
Three of them can be called as major: 1st, 2nd and 6th, that not only
have some system level alterations, but also introduced significant
core/ISA level updates. The rest of the MIPS architecture releases are
minor.

Even though they don't have as much ISA/system/core level changes
as the major ones with respect to the previous releases, they still
provide a set of updates (I'd say they were intended to be the
intermediate releases before a major one) that might be useful for the
kernel and user-level code, when activated by the kernel or compiler.
In particular the following features were introduced or ended up being
available at/after MIPS32/64 Release 5 architecture:
+ the last release of the misaligned memory access instructions,
+ virtualisation - VZ ASE - is optional component of the arch,
+ SIMD - MSA ASE - is optional component of the arch,
+ DSP ASE is optional component of the arch,
+ CP0.Status.FR=1 for CP1.FIR.F64=1 (pure 64-bit FPU general registers)
  must be available if FPU is implemented,
+ CP1.FIR.Has2008 support is required so CP1.FCSR.{ABS2008,NAN2008} bits
  are available.
+ UFR/UNFR aliases to access CP0.Status.FR from user-space by means of
  ctc1/cfc1 instructions (enabled by CP0.Config5.UFR),
+ CP0.COnfig5.LLB=1 and eretnc instruction are implemented to without
  accidentally clearing LL-bit when returning from an interrupt,
  exception, or error trap,
+ XPA feature together with extended versions of CPx registers is
  introduced, which needs to have mfhc0/mthc0 instructions available.

So due to these changes GNU GCC provides an extended instructions set
support for MIPS32/64 Release 5 by default like eretnc/mfhc0/mthc0. Even
though the architecture alteration isn't that big, it still worth to be
taken into account by the kernel software. Finally we can't deny that
some optimization/limitations might be found in future and implemented
on some level in kernel or compiler. In this case having even
intermediate MIPS architecture releases support would be more than
useful.

So the most of the changes provided by this commit can be split into
either compile- or runtime configs related. The compile-time related
changes are caused by adding the new CONFIG_CPU_MIPS32_R5/CONFIG_CPU_MIPSR5
configs and concern the code activating MIPSR2 or MIPSR6 already
implemented features (like eretnc/LLbit, mthc0/mfhc0). In addition
CPU_HAS_MSA can be now freely enabled for MIPS32/64 release 5 based
platforms as this is done for CPU_MIPS32_R6 CPUs. The runtime changes
concerns the features which are handled with respect to the MIPS ISA
revision detected at run-time by means of CP0.Config.{AT,AR} bits. Alas
these fields can be used to detect either r1 or r2 or r6 releases.
But since we know which CPUs in fact support the R5 arch, we can manually
set MIPS_CPU_ISA_M32R5/MIPS_CPU_ISA_M64R5 bit of c->isa_level and then
use cpu_has_mips32r5/cpu_has_mips64r5 where it's appropriate.

Since XPA/EVA provide too complex alterationss and to have them used with
MIPS32 Release 2 charged kernels (for compatibility with current platform
configs) they are left to be setup as a separate kernel configs.

Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 arch/mips/Kconfig                    | 56 +++++++++++++++++++++++++---
 arch/mips/Makefile                   |  2 +
 arch/mips/include/asm/asmmacro.h     | 18 +++++----
 arch/mips/include/asm/compiler.h     |  5 +++
 arch/mips/include/asm/cpu-features.h | 27 ++++++++++----
 arch/mips/include/asm/cpu-info.h     |  2 +-
 arch/mips/include/asm/cpu-type.h     |  7 +++-
 arch/mips/include/asm/cpu.h          | 10 +++--
 arch/mips/include/asm/fpu.h          |  4 +-
 arch/mips/include/asm/hazards.h      |  8 ++--
 arch/mips/include/asm/module.h       |  4 ++
 arch/mips/include/asm/stackframe.h   |  2 +-
 arch/mips/include/asm/switch_to.h    |  8 ++--
 arch/mips/kernel/cpu-probe.c         | 17 +++++++++
 arch/mips/kernel/entry.S             |  6 +--
 arch/mips/kernel/proc.c              |  4 ++
 arch/mips/kernel/r4k_fpu.S           | 14 +++----
 arch/mips/kvm/vz.c                   |  6 +--
 arch/mips/lib/csum_partial.S         |  6 ++-
 arch/mips/mm/c-r4k.c                 |  7 ++--
 arch/mips/mm/sc-mips.c               |  7 ++--
 21 files changed, 163 insertions(+), 57 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index b2ff77f8366f..9dc173ff7293 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1516,6 +1516,21 @@ config CPU_MIPS32_R2
 	  specific type of processor in your system, choose those that one
 	  otherwise CPU_MIPS32_R1 is a safe bet for any MIPS32 system.
 
+config CPU_MIPS32_R5
+	bool "MIPS32 Release 5"
+	depends on SYS_HAS_CPU_MIPS32_R5
+	select CPU_HAS_PREFETCH
+	select CPU_SUPPORTS_32BIT_KERNEL
+	select CPU_SUPPORTS_HIGHMEM
+	select CPU_SUPPORTS_MSA
+	select HAVE_KVM
+	select MIPS_O32_FP64_SUPPORT
+	help
+	  Choose this option to build a kernel for release 5 or later of the
+	  MIPS32 architecture.  New MIPS processors, starting with the Warrior
+	  family, are based on a MIPS32r5 processor. If you own an older
+	  processor, you probably need to select MIPS32r1 or MIPS32r2 instead.
+
 config CPU_MIPS32_R6
 	bool "MIPS32 Release 6"
 	depends on SYS_HAS_CPU_MIPS32_R6
@@ -1568,6 +1583,23 @@ config CPU_MIPS64_R2
 	  specific type of processor in your system, choose those that one
 	  otherwise CPU_MIPS64_R1 is a safe bet for any MIPS64 system.
 
+config CPU_MIPS64_R5
+	bool "MIPS64 Release 5"
+	depends on SYS_HAS_CPU_MIPS64_R5
+	select CPU_HAS_PREFETCH
+	select CPU_SUPPORTS_32BIT_KERNEL
+	select CPU_SUPPORTS_64BIT_KERNEL
+	select CPU_SUPPORTS_HIGHMEM
+	select CPU_SUPPORTS_HUGEPAGES
+	select CPU_SUPPORTS_MSA
+	select MIPS_O32_FP64_SUPPORT if 32BIT || MIPS32_O32
+	select HAVE_KVM
+	help
+	  Choose this option to build a kernel for release 5 or later of the
+	  MIPS64 architecture.  This is a intermediate MIPS architecture
+	  release partly implementing release 6 features. Though there is no
+	  any hardware known to be based on this release.
+
 config CPU_MIPS64_R6
 	bool "MIPS64 Release 6"
 	depends on SYS_HAS_CPU_MIPS64_R6
@@ -1762,7 +1794,7 @@ endchoice
 config CPU_MIPS32_3_5_FEATURES
 	bool "MIPS32 Release 3.5 Features"
 	depends on SYS_HAS_CPU_MIPS32_R3_5
-	depends on CPU_MIPS32_R2 || CPU_MIPS32_R6
+	depends on CPU_MIPS32_R2 || CPU_MIPS32_R5 || CPU_MIPS32_R6
 	help
 	  Choose this option to build a kernel for release 2 or later of the
 	  MIPS32 architecture including features from the 3.5 release such as
@@ -1782,7 +1814,7 @@ config CPU_MIPS32_3_5_EVA
 config CPU_MIPS32_R5_FEATURES
 	bool "MIPS32 Release 5 Features"
 	depends on SYS_HAS_CPU_MIPS32_R5
-	depends on CPU_MIPS32_R2
+	depends on CPU_MIPS32_R2 || CPU_MIPS32_R5
 	help
 	  Choose this option to build a kernel for release 2 or later of the
 	  MIPS32 architecture including features from release 5 such as
@@ -2020,11 +2052,13 @@ endmenu
 #
 config CPU_MIPS32
 	bool
-	default y if CPU_MIPS32_R1 || CPU_MIPS32_R2 || CPU_MIPS32_R6
+	default y if CPU_MIPS32_R1 || CPU_MIPS32_R2 || CPU_MIPS32_R5 || \
+		     CPU_MIPS32_R6
 
 config CPU_MIPS64
 	bool
-	default y if CPU_MIPS64_R1 || CPU_MIPS64_R2 || CPU_MIPS64_R6
+	default y if CPU_MIPS64_R1 || CPU_MIPS64_R2 || CPU_MIPS64_R5 || \
+		     CPU_MIPS64_R6
 
 #
 # These indicate the revision of the architecture
@@ -2040,6 +2074,13 @@ config CPU_MIPSR2
 	select CPU_HAS_DIEI if !CPU_DIEI_BROKEN
 	select MIPS_SPRAM
 
+config CPU_MIPSR5
+	bool
+	default y if CPU_MIPS32_R5 || CPU_MIPS64_R5
+	select CPU_HAS_RIXI
+	select CPU_HAS_DIEI if !CPU_DIEI_BROKEN
+	select MIPS_SPRAM
+
 config CPU_MIPSR6
 	bool
 	default y if CPU_MIPS32_R6 || CPU_MIPS64_R6
@@ -2054,6 +2095,7 @@ config TARGET_ISA_REV
 	int
 	default 1 if CPU_MIPSR1
 	default 2 if CPU_MIPSR2
+	default 5 if CPU_MIPSR5
 	default 6 if CPU_MIPSR6
 	default 0
 	help
@@ -2643,7 +2685,11 @@ config NEED_PER_CPU_EMBED_FIRST_CHUNK
 
 config RELOCATABLE
 	bool "Relocatable kernel"
-	depends on SYS_SUPPORTS_RELOCATABLE && (CPU_MIPS32_R2 || CPU_MIPS64_R2 || CPU_MIPS32_R6 || CPU_MIPS64_R6 || CAVIUM_OCTEON_SOC)
+	depends on SYS_SUPPORTS_RELOCATABLE
+	depends on CPU_MIPS32_R2 || CPU_MIPS64_R2 || \
+		   CPU_MIPS32_R5 || CPU_MIPS64_R5 || \
+		   CPU_MIPS32_R6 || CPU_MIPS64_R6 || \
+		   CAVIUM_OCTEON_SOC
 	help
 	  This builds a kernel image that retains relocation information
 	  so it can be loaded someplace besides the default 1MB.
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index b50377ec3ab5..5d7a33ae86a4 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -146,9 +146,11 @@ cflags-$(CONFIG_CPU_R4X00)	+= -march=r4600 -Wa,--trap
 cflags-$(CONFIG_CPU_TX49XX)	+= -march=r4600 -Wa,--trap
 cflags-$(CONFIG_CPU_MIPS32_R1)	+= -march=mips32 -Wa,--trap
 cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -Wa,--trap
+cflags-$(CONFIG_CPU_MIPS32_R5)	+= -march=mips32r5 -Wa,--trap -modd-spreg
 cflags-$(CONFIG_CPU_MIPS32_R6)	+= -march=mips32r6 -Wa,--trap -modd-spreg
 cflags-$(CONFIG_CPU_MIPS64_R1)	+= -march=mips64 -Wa,--trap
 cflags-$(CONFIG_CPU_MIPS64_R2)	+= -march=mips64r2 -Wa,--trap
+cflags-$(CONFIG_CPU_MIPS64_R5)	+= -march=mips64r5 -Wa,--trap
 cflags-$(CONFIG_CPU_MIPS64_R6)	+= -march=mips64r6 -Wa,--trap
 cflags-$(CONFIG_CPU_R5000)	+= -march=r5000 -Wa,--trap
 cflags-$(CONFIG_CPU_R5500)	+= $(call cc-option,-march=r5500,-march=r5000) \
diff --git a/arch/mips/include/asm/asmmacro.h b/arch/mips/include/asm/asmmacro.h
index 655f40ddb6d1..86f2323ebe6b 100644
--- a/arch/mips/include/asm/asmmacro.h
+++ b/arch/mips/include/asm/asmmacro.h
@@ -44,7 +44,8 @@
 	.endm
 #endif
 
-#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
+#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
+    defined(CONFIG_CPU_MIPSR6)
 	.macro	local_irq_enable reg=t0
 	ei
 	irq_enable_hazard
@@ -54,7 +55,7 @@
 	di
 	irq_disable_hazard
 	.endm
-#else
+#else /* !CONFIG_CPU_MIPSR2 && !CONFIG_CPU_MIPSR5 && !CONFIG_CPU_MIPSR6 */
 	.macro	local_irq_enable reg=t0
 	mfc0	\reg, CP0_STATUS
 	ori	\reg, \reg, 1
@@ -79,7 +80,7 @@
 	sw      \reg, TI_PRE_COUNT($28)
 #endif
 	.endm
-#endif /* CONFIG_CPU_MIPSR2 */
+#endif  /* !CONFIG_CPU_MIPSR2 && !CONFIG_CPU_MIPSR5 && !CONFIG_CPU_MIPSR6 */
 
 	.macro	fpu_save_16even thread tmp=t0
 	.set	push
@@ -131,7 +132,7 @@
 
 	.macro	fpu_save_double thread status tmp
 #if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPSR2) || \
-		defined(CONFIG_CPU_MIPSR6)
+    defined(CONFIG_CPU_MIPSR5) || defined(CONFIG_CPU_MIPSR6)
 	sll	\tmp, \status, 5
 	bgez	\tmp, 10f
 	fpu_save_16odd \thread
@@ -190,7 +191,7 @@
 
 	.macro	fpu_restore_double thread status tmp
 #if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPSR2) || \
-		defined(CONFIG_CPU_MIPSR6)
+    defined(CONFIG_CPU_MIPSR5) || defined(CONFIG_CPU_MIPSR6)
 	sll	\tmp, \status, 5
 	bgez	\tmp, 10f				# 16 register mode?
 
@@ -200,16 +201,17 @@
 	fpu_restore_16even \thread \tmp
 	.endm
 
-#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
+#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
+    defined(CONFIG_CPU_MIPSR6)
 	.macro	_EXT	rd, rs, p, s
 	ext	\rd, \rs, \p, \s
 	.endm
-#else /* !CONFIG_CPU_MIPSR2 || !CONFIG_CPU_MIPSR6 */
+#else /* !CONFIG_CPU_MIPSR2 && !CONFIG_CPU_MIPSR5 && !CONFIG_CPU_MIPSR6 */
 	.macro	_EXT	rd, rs, p, s
 	srl	\rd, \rs, \p
 	andi	\rd, \rd, (1 << \s) - 1
 	.endm
-#endif /* !CONFIG_CPU_MIPSR2 || !CONFIG_CPU_MIPSR6 */
+#endif /* !CONFIG_CPU_MIPSR2 && !CONFIG_CPU_MIPSR5 && !CONFIG_CPU_MIPSR6 */
 
 /*
  * Temporary until all gas have MT ASE support
diff --git a/arch/mips/include/asm/compiler.h b/arch/mips/include/asm/compiler.h
index f77e99f1722e..a2cb2d2b1c07 100644
--- a/arch/mips/include/asm/compiler.h
+++ b/arch/mips/include/asm/compiler.h
@@ -57,6 +57,11 @@
 #define MIPS_ISA_ARCH_LEVEL MIPS_ISA_LEVEL
 #define MIPS_ISA_LEVEL_RAW mips64r6
 #define MIPS_ISA_ARCH_LEVEL_RAW MIPS_ISA_LEVEL_RAW
+#elif defined(CONFIG_CPU_MIPSR5)
+#define MIPS_ISA_LEVEL "mips64r5"
+#define MIPS_ISA_ARCH_LEVEL MIPS_ISA_LEVEL
+#define MIPS_ISA_LEVEL_RAW mips64r5
+#define MIPS_ISA_ARCH_LEVEL_RAW MIPS_ISA_LEVEL_RAW
 #else
 /* MIPS64 is a superset of MIPS32 */
 #define MIPS_ISA_LEVEL "mips64r2"
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 400b123cb6da..227d7416591c 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -284,6 +284,9 @@
 #ifndef cpu_has_mips32r2
 # define cpu_has_mips32r2	__isa_range_or_flag(2, 6, MIPS_CPU_ISA_M32R2)
 #endif
+#ifndef cpu_has_mips32r5
+# define cpu_has_mips32r5	__isa_range_or_flag(5, 6, MIPS_CPU_ISA_M32R5)
+#endif
 #ifndef cpu_has_mips32r6
 # define cpu_has_mips32r6	__isa_ge_or_flag(6, MIPS_CPU_ISA_M32R6)
 #endif
@@ -293,6 +296,10 @@
 #ifndef cpu_has_mips64r2
 # define cpu_has_mips64r2	__isa_range_or_flag(2, 6, MIPS_CPU_ISA_M64R2)
 #endif
+#ifndef cpu_has_mips64r5
+# define cpu_has_mips64r5	(cpu_has_64bits && \
+				 __isa_range_or_flag(5, 6, MIPS_CPU_ISA_M64R5))
+#endif
 #ifndef cpu_has_mips64r6
 # define cpu_has_mips64r6	__isa_ge_and_flag(6, MIPS_CPU_ISA_M64R6)
 #endif
@@ -313,19 +320,25 @@
 				(cpu_has_mips_3 | cpu_has_mips_4_5_64_r2_r6)
 #define cpu_has_mips_4_5_64_r2_r6					\
 				(cpu_has_mips_4_5 | cpu_has_mips64r1 |	\
-				 cpu_has_mips_r2 | cpu_has_mips_r6)
+				 cpu_has_mips_r2 | cpu_has_mips_r5 | \
+				 cpu_has_mips_r6)
 
-#define cpu_has_mips32	(cpu_has_mips32r1 | cpu_has_mips32r2 | cpu_has_mips32r6)
-#define cpu_has_mips64	(cpu_has_mips64r1 | cpu_has_mips64r2 | cpu_has_mips64r6)
+#define cpu_has_mips32	(cpu_has_mips32r1 | cpu_has_mips32r2 | \
+			 cpu_has_mips32r5 | cpu_has_mips32r6)
+#define cpu_has_mips64	(cpu_has_mips64r1 | cpu_has_mips64r2 | \
+			 cpu_has_mips64r5 | cpu_has_mips64r6)
 #define cpu_has_mips_r1 (cpu_has_mips32r1 | cpu_has_mips64r1)
 #define cpu_has_mips_r2 (cpu_has_mips32r2 | cpu_has_mips64r2)
+#define cpu_has_mips_r5	(cpu_has_mips32r5 | cpu_has_mips64r5)
 #define cpu_has_mips_r6	(cpu_has_mips32r6 | cpu_has_mips64r6)
 #define cpu_has_mips_r	(cpu_has_mips32r1 | cpu_has_mips32r2 | \
-			 cpu_has_mips32r6 | cpu_has_mips64r1 | \
-			 cpu_has_mips64r2 | cpu_has_mips64r6)
+			 cpu_has_mips32r5 | cpu_has_mips32r6 | \
+			 cpu_has_mips64r1 | cpu_has_mips64r2 | \
+			 cpu_has_mips64r5 | cpu_has_mips64r6)
 
-/* MIPSR2 and MIPSR6 have a lot of similarities */
-#define cpu_has_mips_r2_r6	(cpu_has_mips_r2 | cpu_has_mips_r6)
+/* MIPSR2 - MIPSR6 have a lot of similarities */
+#define cpu_has_mips_r2_r6	(cpu_has_mips_r2 | cpu_has_mips_r5 | \
+				 cpu_has_mips_r6)
 
 /*
  * cpu_has_mips_r2_exec_hazard - return if IHB is required on current processor
diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
index ed7ffe4e63a3..bce3ea7fff7c 100644
--- a/arch/mips/include/asm/cpu-info.h
+++ b/arch/mips/include/asm/cpu-info.h
@@ -142,7 +142,7 @@ struct proc_cpuinfo_notifier_args {
 static inline unsigned int cpu_cluster(struct cpuinfo_mips *cpuinfo)
 {
 	/* Optimisation for systems where multiple clusters aren't used */
-	if (!IS_ENABLED(CONFIG_CPU_MIPSR6))
+	if (!IS_ENABLED(CONFIG_CPU_MIPSR5) && !IS_ENABLED(CONFIG_CPU_MIPSR6))
 		return 0;
 
 	return (cpuinfo->globalnumber & MIPS_GLOBALNUMBER_CLUSTER) >>
diff --git a/arch/mips/include/asm/cpu-type.h b/arch/mips/include/asm/cpu-type.h
index 49f0061a6051..75a7a382da09 100644
--- a/arch/mips/include/asm/cpu-type.h
+++ b/arch/mips/include/asm/cpu-type.h
@@ -51,13 +51,18 @@ static inline int __pure __get_cpu_type(const int cpu_type)
 	case CPU_M14KEC:
 	case CPU_INTERAPTIV:
 	case CPU_PROAPTIV:
-	case CPU_P5600:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_MIPS32_R5
 	case CPU_M5150:
+	case CPU_P5600:
 #endif
 
 #if defined(CONFIG_SYS_HAS_CPU_MIPS32_R2) || \
+    defined(CONFIG_SYS_HAS_CPU_MIPS32_R5) || \
     defined(CONFIG_SYS_HAS_CPU_MIPS32_R6) || \
     defined(CONFIG_SYS_HAS_CPU_MIPS64_R2) || \
+    defined(CONFIG_SYS_HAS_CPU_MIPS64_R5) || \
     defined(CONFIG_SYS_HAS_CPU_MIPS64_R6)
 	case CPU_QEMU_GENERIC:
 #endif
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index 46c190e78acf..4b84fd1df0c7 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -347,14 +347,16 @@ enum cpu_type_enum {
 #define MIPS_CPU_ISA_M32R2	0x00000020
 #define MIPS_CPU_ISA_M64R1	0x00000040
 #define MIPS_CPU_ISA_M64R2	0x00000080
-#define MIPS_CPU_ISA_M32R6	0x00000100
-#define MIPS_CPU_ISA_M64R6	0x00000200
+#define MIPS_CPU_ISA_M32R5	0x00000100
+#define MIPS_CPU_ISA_M64R5	0x00000200
+#define MIPS_CPU_ISA_M32R6	0x00000400
+#define MIPS_CPU_ISA_M64R6	0x00000800
 
 #define MIPS_CPU_ISA_32BIT (MIPS_CPU_ISA_II | MIPS_CPU_ISA_M32R1 | \
-	MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M32R6)
+	MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M32R6)
 #define MIPS_CPU_ISA_64BIT (MIPS_CPU_ISA_III | MIPS_CPU_ISA_IV | \
 	MIPS_CPU_ISA_V | MIPS_CPU_ISA_M64R1 | MIPS_CPU_ISA_M64R2 | \
-	MIPS_CPU_ISA_M64R6)
+	MIPS_CPU_ISA_M64R5 | MIPS_CPU_ISA_M64R6)
 
 /*
  * CPU Option encodings
diff --git a/arch/mips/include/asm/fpu.h b/arch/mips/include/asm/fpu.h
index a9d5123e2a2a..08f9dd6903b7 100644
--- a/arch/mips/include/asm/fpu.h
+++ b/arch/mips/include/asm/fpu.h
@@ -71,8 +71,8 @@ static inline int __enable_fpu(enum fpu_mode mode)
 		goto fr_common;
 
 	case FPU_64BIT:
-#if !(defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6) \
-      || defined(CONFIG_64BIT))
+#if !(defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
+      defined(CONFIG_CPU_MIPSR6) || defined(CONFIG_64BIT))
 		/* we only have a 32-bit FPU */
 		return SIGFPE;
 #endif
diff --git a/arch/mips/include/asm/hazards.h b/arch/mips/include/asm/hazards.h
index a0b92205f933..f855478d12fa 100644
--- a/arch/mips/include/asm/hazards.h
+++ b/arch/mips/include/asm/hazards.h
@@ -22,8 +22,9 @@
 /*
  * TLB hazards
  */
-#if (defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)) && \
-	!defined(CONFIG_CPU_CAVIUM_OCTEON) && !defined(CONFIG_CPU_LOONGSON64)
+#if (defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
+     defined(CONFIG_CPU_MIPSR6)) && \
+    !defined(CONFIG_CPU_CAVIUM_OCTEON) && !defined(CONFIG_CPU_LOONGSON64)
 
 /*
  * MIPSR2 defines ehb for hazard avoidance
@@ -278,7 +279,8 @@ do {									\
 
 #define __disable_fpu_hazard
 
-#elif defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
+#elif defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
+      defined(CONFIG_CPU_MIPSR6)
 
 #define __enable_fpu_hazard						\
 	___ehb
diff --git a/arch/mips/include/asm/module.h b/arch/mips/include/asm/module.h
index 9846047b3d3d..84776e1ec8e5 100644
--- a/arch/mips/include/asm/module.h
+++ b/arch/mips/include/asm/module.h
@@ -89,12 +89,16 @@ search_module_dbetables(unsigned long addr)
 #define MODULE_PROC_FAMILY "MIPS32_R1 "
 #elif defined CONFIG_CPU_MIPS32_R2
 #define MODULE_PROC_FAMILY "MIPS32_R2 "
+#elif defined CONFIG_CPU_MIPS32_R5
+#define MODULE_PROC_FAMILY "MIPS32_R5 "
 #elif defined CONFIG_CPU_MIPS32_R6
 #define MODULE_PROC_FAMILY "MIPS32_R6 "
 #elif defined CONFIG_CPU_MIPS64_R1
 #define MODULE_PROC_FAMILY "MIPS64_R1 "
 #elif defined CONFIG_CPU_MIPS64_R2
 #define MODULE_PROC_FAMILY "MIPS64_R2 "
+#elif defined CONFIG_CPU_MIPS64_R5
+#define MODULE_PROC_FAMILY "MIPS64_R5 "
 #elif defined CONFIG_CPU_MIPS64_R6
 #define MODULE_PROC_FAMILY "MIPS64_R6 "
 #elif defined CONFIG_CPU_R3000
diff --git a/arch/mips/include/asm/stackframe.h b/arch/mips/include/asm/stackframe.h
index 4d6ad907ae54..3e8d2aaf96af 100644
--- a/arch/mips/include/asm/stackframe.h
+++ b/arch/mips/include/asm/stackframe.h
@@ -424,7 +424,7 @@
 
 		.macro	RESTORE_SP_AND_RET docfi=0
 		RESTORE_SP \docfi
-#ifdef CONFIG_CPU_MIPSR6
+#if defined(CONFIG_CPU_MIPSR5) || defined(CONFIG_CPU_MIPSR6)
 		eretnc
 #else
 		.set	push
diff --git a/arch/mips/include/asm/switch_to.h b/arch/mips/include/asm/switch_to.h
index 09cbe9042828..0b0a93bf83cd 100644
--- a/arch/mips/include/asm/switch_to.h
+++ b/arch/mips/include/asm/switch_to.h
@@ -67,11 +67,11 @@ do {									\
 #endif
 
 /*
- * Clear LLBit during context switches on MIPSr6 such that eretnc can be used
+ * Clear LLBit during context switches on MIPSr5+ such that eretnc can be used
  * unconditionally when returning to userland in entry.S.
  */
-#define __clear_r6_hw_ll_bit() do {					\
-	if (cpu_has_mips_r6)						\
+#define __clear_r5_hw_ll_bit() do {					\
+	if (cpu_has_mips_r5 || cpu_has_mips_r6)				\
 		write_c0_lladdr(0);					\
 } while (0)
 
@@ -129,7 +129,7 @@ do {									\
 		}							\
 		clear_c0_status(ST0_CU2);				\
 	}								\
-	__clear_r6_hw_ll_bit();						\
+	__clear_r5_hw_ll_bit();						\
 	__clear_software_ll_bit();					\
 	if (cpu_has_userlocal)						\
 		write_c0_userlocal(task_thread_info(next)->tp_value);	\
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index a0ef21b2d8b3..33600287daf7 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -92,6 +92,7 @@ static void cpu_set_fpu_2008(struct cpuinfo_mips *c)
 {
 	if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
 			    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
+			    MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
 		unsigned long sr, fir, fcsr, fcsr0, fcsr1;
 
@@ -172,6 +173,7 @@ static void cpu_set_nofpu_2008(struct cpuinfo_mips *c)
 	case STRICT:
 		if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
 				    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
+				    MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
 				    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
 			c->options |= MIPS_CPU_NAN_2008 | MIPS_CPU_NAN_LEGACY;
 		} else {
@@ -263,9 +265,11 @@ static void cpu_set_nofpu_id(struct cpuinfo_mips *c)
 	value = 0;
 	if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
 			    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
+			    MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6))
 		value |= MIPS_FPIR_D | MIPS_FPIR_S;
 	if (c->isa_level & (MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
+			    MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6))
 		value |= MIPS_FPIR_F64 | MIPS_FPIR_L | MIPS_FPIR_W;
 	if (c->options & MIPS_CPU_NAN_2008)
@@ -286,6 +290,7 @@ static void cpu_set_fpu_opts(struct cpuinfo_mips *c)
 
 	if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
 			    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
+			    MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
 			    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
 		if (c->fpu_id & MIPS_FPIR_3D)
 			c->ases |= MIPS_ASE_MIPS3D;
@@ -532,6 +537,10 @@ static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
 static void set_isa(struct cpuinfo_mips *c, unsigned int isa)
 {
 	switch (isa) {
+	case MIPS_CPU_ISA_M64R5:
+		c->isa_level |= MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5;
+		set_elf_base_platform("mips64r5");
+		/* fall through */
 	case MIPS_CPU_ISA_M64R2:
 		c->isa_level |= MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2;
 		set_elf_base_platform("mips64r2");
@@ -563,6 +572,10 @@ static void set_isa(struct cpuinfo_mips *c, unsigned int isa)
 		set_elf_base_platform("mips32r6");
 		/* Break here so we don't add incompatible ISAs */
 		break;
+	case MIPS_CPU_ISA_M32R5:
+		c->isa_level |= MIPS_CPU_ISA_M32R5;
+		set_elf_base_platform("mips32r5");
+		/* fall through */
 	case MIPS_CPU_ISA_M32R2:
 		c->isa_level |= MIPS_CPU_ISA_M32R2;
 		set_elf_base_platform("mips32r2");
@@ -1751,6 +1764,10 @@ static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
 	spram_config();
 
 	switch (__get_cpu_type(c->cputype)) {
+	case CPU_M5150:
+	case CPU_P5600:
+		set_isa(c, MIPS_CPU_ISA_M32R5);
+		break;
 	case CPU_I6500:
 		c->options |= MIPS_CPU_SHARED_FTLB_ENTRIES;
 		fallthrough;
diff --git a/arch/mips/kernel/entry.S b/arch/mips/kernel/entry.S
index 4849a48afc0f..4b896f5023ff 100644
--- a/arch/mips/kernel/entry.S
+++ b/arch/mips/kernel/entry.S
@@ -169,8 +169,8 @@ syscall_exit_work:
 	jal	syscall_trace_leave
 	b	resume_userspace
 
-#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6) || \
-    defined(CONFIG_MIPS_MT)
+#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
+    defined(CONFIG_CPU_MIPSR6) || defined(CONFIG_MIPS_MT)
 
 /*
  * MIPS32R2 Instruction Hazard Barrier - must be called
@@ -183,4 +183,4 @@ LEAF(mips_ihb)
 	nop
 	END(mips_ihb)
 
-#endif /* CONFIG_CPU_MIPSR2 or CONFIG_CPU_MIPSR6 or CONFIG_MIPS_MT */
+#endif /* CONFIG_CPU_MIPSR2 - CONFIG_CPU_MIPSR6 or CONFIG_MIPS_MT */
diff --git a/arch/mips/kernel/proc.c b/arch/mips/kernel/proc.c
index f8d36710cd58..4184d641f05e 100644
--- a/arch/mips/kernel/proc.c
+++ b/arch/mips/kernel/proc.c
@@ -98,12 +98,16 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 		seq_printf(m, "%s", " mips32r1");
 	if (cpu_has_mips32r2)
 		seq_printf(m, "%s", " mips32r2");
+	if (cpu_has_mips32r5)
+		seq_printf(m, "%s", " mips32r5");
 	if (cpu_has_mips32r6)
 		seq_printf(m, "%s", " mips32r6");
 	if (cpu_has_mips64r1)
 		seq_printf(m, "%s", " mips64r1");
 	if (cpu_has_mips64r2)
 		seq_printf(m, "%s", " mips64r2");
+	if (cpu_has_mips64r5)
+		seq_printf(m, "%s", " mips64r5");
 	if (cpu_has_mips64r6)
 		seq_printf(m, "%s", " mips64r6");
 	seq_printf(m, "\n");
diff --git a/arch/mips/kernel/r4k_fpu.S b/arch/mips/kernel/r4k_fpu.S
index 59be5c812aa2..b91e91106475 100644
--- a/arch/mips/kernel/r4k_fpu.S
+++ b/arch/mips/kernel/r4k_fpu.S
@@ -41,7 +41,7 @@
 LEAF(_save_fp)
 EXPORT_SYMBOL(_save_fp)
 #if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPSR2) || \
-		defined(CONFIG_CPU_MIPSR6)
+    defined(CONFIG_CPU_MIPSR5) || defined(CONFIG_CPU_MIPSR6)
 	mfc0	t0, CP0_STATUS
 #endif
 	fpu_save_double a0 t0 t1		# clobbers t1
@@ -53,7 +53,7 @@ EXPORT_SYMBOL(_save_fp)
  */
 LEAF(_restore_fp)
 #if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPSR2) || \
-		defined(CONFIG_CPU_MIPSR6)
+    defined(CONFIG_CPU_MIPSR5) || defined(CONFIG_CPU_MIPSR6)
 	mfc0	t0, CP0_STATUS
 #endif
 	fpu_restore_double a0 t0 t1		# clobbers t1
@@ -103,10 +103,10 @@ LEAF(_save_fp_context)
 	.set	pop
 
 #if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPSR2) || \
-		defined(CONFIG_CPU_MIPSR6)
+    defined(CONFIG_CPU_MIPSR5) || defined(CONFIG_CPU_MIPSR6)
 	.set	push
 	SET_HARDFLOAT
-#ifdef CONFIG_CPU_MIPSR2
+#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5)
 	.set	mips32r2
 	.set	fp=64
 	mfc0	t0, CP0_STATUS
@@ -170,11 +170,11 @@ LEAF(_save_fp_context)
 LEAF(_restore_fp_context)
 	EX	lw t1, 0(a1)
 
-#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPSR2)  || \
-		defined(CONFIG_CPU_MIPSR6)
+#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPSR2) || \
+    defined(CONFIG_CPU_MIPSR5) || defined(CONFIG_CPU_MIPSR6)
 	.set	push
 	SET_HARDFLOAT
-#ifdef CONFIG_CPU_MIPSR2
+#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5)
 	.set	mips32r2
 	.set	fp=64
 	mfc0	t0, CP0_STATUS
diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
index 389dd0fbd051..51f51009a53f 100644
--- a/arch/mips/kvm/vz.c
+++ b/arch/mips/kvm/vz.c
@@ -2980,7 +2980,7 @@ static int kvm_vz_vcpu_setup(struct kvm_vcpu *vcpu)
 	 */
 
 	/* PageGrain */
-	if (cpu_has_mips_r6)
+	if (cpu_has_mips_r5 || cpu_has_mips_r6)
 		kvm_write_sw_gc0_pagegrain(cop0, PG_RIE | PG_XIE | PG_IEC);
 	/* Wired */
 	if (cpu_has_mips_r6)
@@ -2988,7 +2988,7 @@ static int kvm_vz_vcpu_setup(struct kvm_vcpu *vcpu)
 				       read_gc0_wired() & MIPSR6_WIRED_LIMIT);
 	/* Status */
 	kvm_write_sw_gc0_status(cop0, ST0_BEV | ST0_ERL);
-	if (cpu_has_mips_r6)
+	if (cpu_has_mips_r5 || cpu_has_mips_r6)
 		kvm_change_sw_gc0_status(cop0, ST0_FR, read_gc0_status());
 	/* IntCtl */
 	kvm_write_sw_gc0_intctl(cop0, read_gc0_intctl() &
@@ -3086,7 +3086,7 @@ static int kvm_vz_vcpu_setup(struct kvm_vcpu *vcpu)
 	}
 
 	/* reset HTW registers */
-	if (cpu_guest_has_htw && cpu_has_mips_r6) {
+	if (cpu_guest_has_htw && (cpu_has_mips_r5 || cpu_has_mips_r6)) {
 		/* PWField */
 		kvm_write_sw_gc0_pwfield(cop0, 0x0c30c302);
 		/* PWSize */
diff --git a/arch/mips/lib/csum_partial.S b/arch/mips/lib/csum_partial.S
index fda7b57b826e..87fda0713b84 100644
--- a/arch/mips/lib/csum_partial.S
+++ b/arch/mips/lib/csum_partial.S
@@ -279,7 +279,8 @@ EXPORT_SYMBOL(csum_partial)
 #endif
 
 	/* odd buffer alignment? */
-#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_LOONGSON64)
+#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
+    defined(CONFIG_CPU_LOONGSON64)
 	.set	push
 	.set	arch=mips32r2
 	wsbh	v1, sum
@@ -732,7 +733,8 @@ EXPORT_SYMBOL(csum_partial)
 	addu	sum, v1
 #endif
 
-#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_LOONGSON64)
+#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
+    defined(CONFIG_CPU_LOONGSON64)
 	.set	push
 	.set	arch=mips32r2
 	wsbh	v1, sum
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 54c18b8a2406..a9f55bf90967 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -1709,9 +1709,10 @@ static void setup_scache(void)
 		return;
 
 	default:
-		if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M32R2 |
-				    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R1 |
-				    MIPS_CPU_ISA_M64R2 | MIPS_CPU_ISA_M64R6)) {
+		if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
+				    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
+				    MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
+				    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
 #ifdef CONFIG_MIPS_CPU_SCACHE
 			if (mips_sc_init ()) {
 				scache_size = c->scache.ways * c->scache.sets * c->scache.linesz;
diff --git a/arch/mips/mm/sc-mips.c b/arch/mips/mm/sc-mips.c
index dbdbfe5d8408..eedad47df24f 100644
--- a/arch/mips/mm/sc-mips.c
+++ b/arch/mips/mm/sc-mips.c
@@ -194,9 +194,10 @@ static inline int __init mips_sc_probe(void)
 		return mips_sc_probe_cm3();
 
 	/* Ignore anything but MIPSxx processors */
-	if (!(c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M32R2 |
-			      MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R1 |
-			      MIPS_CPU_ISA_M64R2 | MIPS_CPU_ISA_M64R6)))
+	if (!(c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
+			      MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
+			      MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
+			      MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)))
 		return 0;
 
 	/* Does this MIPS32/MIPS64 CPU have a config2 register? */
-- 
2.25.1

[PATCH v4 04/13] mips: Add MIPS Warrior P5600 support

[Serge Semin]

This is a MIPS32 Release 5 based IP core with XPA, EVA, dual/quad issue
exec pipes, MMU with two-levels TLB, UCA, MSA, MDU core level features
and system level features like up to six P5600 calculation cores, CM2
with L2 cache, IOCU/IOMMU (though might be unused depending on the
system-specific IP core configuration), GIC, CPC, virtualisation module,
eJTAG and PDtrace.

As being MIPS32 Release 5 based core it provides all the features
available by the CPU_MIPS32_R5 config, while adding a few more like
UCA attribute support, availability of CPU-freq (by means of L2/CM
clock ratio setting), EI/VI GIC modes detection at runtime.

In addition to this if P5600 architecture is enabled modern GNU GCC
provides a specific tuning for P5600 processors with respect to the
classic MIPS32 Release 5. First of all branch-likely avoidance is
activated only when the code is compiled with the speed optimization
(avoidance is always enabled for the pure MIPS32 Release 5
architecture). Secondly the madd/msub avoidance is enabled since
madd/msub utilization isn't profitable due to overhead of getting the
result out of the HI/LO registers. Multiply-accumulate instructions are
activated and utilized together with the necessary code reorder when
multiply-add/multiply-subtract statements are met. Finally load/store
bonding is activated by default. All of these optimizations may make
the code relatively faster than if just MIP32 release 5 architecture
was requested.

Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 arch/mips/Kconfig              | 37 +++++++++++++++++++++++++++++-----
 arch/mips/Makefile             |  1 +
 arch/mips/include/asm/module.h |  2 ++
 3 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 9dc173ff7293..2747b1b2d435 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1618,6 +1618,28 @@ config CPU_MIPS64_R6
 	  family, are based on a MIPS64r6 processor. If you own an older
 	  processor, you probably need to select MIPS64r1 or MIPS64r2 instead.
 
+config CPU_P5600
+	bool "MIPS Warrior P5600"
+	depends on SYS_HAS_CPU_P5600
+	select CPU_HAS_PREFETCH
+	select CPU_SUPPORTS_32BIT_KERNEL
+	select CPU_SUPPORTS_HIGHMEM
+	select CPU_SUPPORTS_MSA
+	select CPU_SUPPORTS_UNCACHED_ACCELERATED
+	select CPU_SUPPORTS_CPUFREQ
+	select CPU_MIPSR2_IRQ_VI
+	select CPU_MIPSR2_IRQ_EI
+	select HAVE_KVM
+	select MIPS_O32_FP64_SUPPORT
+	help
+	  Choose this option to build a kernel for MIPS Warrior P5600 CPU.
+	  It's based on MIPS32r5 ISA with XPA, EVA, dual/quad issue exec pipes,
+	  MMU with two-levels TLB, UCA, MSA, MDU core level features and system
+	  level features like up to six P5600 calculation cores, CM2 with L2
+	  cache, IOCU/IOMMU (though might be unused depending on the system-
+	  specific IP core configuration), GIC, CPC, virtualisation module,
+	  eJTAG and PDtrace.
+
 config CPU_R3000
 	bool "R3000"
 	depends on SYS_HAS_CPU_R3000
@@ -1794,7 +1816,8 @@ endchoice
 config CPU_MIPS32_3_5_FEATURES
 	bool "MIPS32 Release 3.5 Features"
 	depends on SYS_HAS_CPU_MIPS32_R3_5
-	depends on CPU_MIPS32_R2 || CPU_MIPS32_R5 || CPU_MIPS32_R6
+	depends on CPU_MIPS32_R2 || CPU_MIPS32_R5 || CPU_MIPS32_R6 || \
+		   CPU_P5600
 	help
 	  Choose this option to build a kernel for release 2 or later of the
 	  MIPS32 architecture including features from the 3.5 release such as
@@ -1814,7 +1837,7 @@ config CPU_MIPS32_3_5_EVA
 config CPU_MIPS32_R5_FEATURES
 	bool "MIPS32 Release 5 Features"
 	depends on SYS_HAS_CPU_MIPS32_R5
-	depends on CPU_MIPS32_R2 || CPU_MIPS32_R5
+	depends on CPU_MIPS32_R2 || CPU_MIPS32_R5 || CPU_P5600
 	help
 	  Choose this option to build a kernel for release 2 or later of the
 	  MIPS32 architecture including features from release 5 such as
@@ -1969,6 +1992,10 @@ config SYS_HAS_CPU_MIPS64_R6
 	bool
 	select ARCH_HAS_SYNC_DMA_FOR_CPU if DMA_NONCOHERENT
 
+config SYS_HAS_CPU_P5600
+	bool
+	select ARCH_HAS_SYNC_DMA_FOR_CPU if DMA_NONCOHERENT
+
 config SYS_HAS_CPU_R3000
 	bool
 
@@ -2053,7 +2080,7 @@ endmenu
 config CPU_MIPS32
 	bool
 	default y if CPU_MIPS32_R1 || CPU_MIPS32_R2 || CPU_MIPS32_R5 || \
-		     CPU_MIPS32_R6
+		     CPU_MIPS32_R6 || CPU_P5600
 
 config CPU_MIPS64
 	bool
@@ -2076,7 +2103,7 @@ config CPU_MIPSR2
 
 config CPU_MIPSR5
 	bool
-	default y if CPU_MIPS32_R5 || CPU_MIPS64_R5
+	default y if CPU_MIPS32_R5 || CPU_MIPS64_R5 || CPU_P5600
 	select CPU_HAS_RIXI
 	select CPU_HAS_DIEI if !CPU_DIEI_BROKEN
 	select MIPS_SPRAM
@@ -2689,7 +2716,7 @@ config RELOCATABLE
 	depends on CPU_MIPS32_R2 || CPU_MIPS64_R2 || \
 		   CPU_MIPS32_R5 || CPU_MIPS64_R5 || \
 		   CPU_MIPS32_R6 || CPU_MIPS64_R6 || \
-		   CAVIUM_OCTEON_SOC
+		   CPU_P5600 || CAVIUM_OCTEON_SOC
 	help
 	  This builds a kernel image that retains relocation information
 	  so it can be loaded someplace besides the default 1MB.
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 5d7a33ae86a4..0d0f29d662c9 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -152,6 +152,7 @@ cflags-$(CONFIG_CPU_MIPS64_R1)	+= -march=mips64 -Wa,--trap
 cflags-$(CONFIG_CPU_MIPS64_R2)	+= -march=mips64r2 -Wa,--trap
 cflags-$(CONFIG_CPU_MIPS64_R5)	+= -march=mips64r5 -Wa,--trap
 cflags-$(CONFIG_CPU_MIPS64_R6)	+= -march=mips64r6 -Wa,--trap
+cflags-$(CONFIG_CPU_P5600)	+= -march=p5600 -Wa,--trap -modd-spreg
 cflags-$(CONFIG_CPU_R5000)	+= -march=r5000 -Wa,--trap
 cflags-$(CONFIG_CPU_R5500)	+= $(call cc-option,-march=r5500,-march=r5000) \
 			-Wa,--trap
diff --git a/arch/mips/include/asm/module.h b/arch/mips/include/asm/module.h
index 84776e1ec8e5..7be4c68081a8 100644
--- a/arch/mips/include/asm/module.h
+++ b/arch/mips/include/asm/module.h
@@ -131,6 +131,8 @@ search_module_dbetables(unsigned long addr)
 #define MODULE_PROC_FAMILY "LOONGSON64 "
 #elif defined CONFIG_CPU_CAVIUM_OCTEON
 #define MODULE_PROC_FAMILY "OCTEON "
+#elif defined CONFIG_CPU_P5600
+#define MODULE_PROC_FAMILY "P5600 "
 #elif defined CONFIG_CPU_XLR
 #define MODULE_PROC_FAMILY "XLR "
 #elif defined CONFIG_CPU_XLP
-- 
2.25.1

[PATCH v4 05/13] mips: Fix cpu_has_mips64r1/2 activation for MIPS32 CPUs

[Serge Semin]

Commit 1aeba347b3a9 ("MIPS: Hardcode cpu_has_mips* where target ISA
allows") updated the cpu_has_mips* macro to be replaced with a constant
expression where it's possible. By mistake it wasn't done correctly
for cpu_has_mips64r1/cpu_has_mips64r2 macro. They are defined to
be replaced with conditional expression __isa_range_or_flag(), which
means either ISA revision being within the range or the corresponding
CPU options flag was set at the probe stage or both being true at the
same time. But the ISA level value doesn't indicate whether the ISA is
MIPS32 or MIPS64. Due to this if we select MIPS32r1 - MIPS32r5
architectures the __isa_range() macro will activate the
cpu_has_mips64rX flags, which is incorrect. In order to fix the
problem we make sure the 64bits CPU support is enabled by means of
checking the flag cpu_has_64bits aside with proper ISA range and specific
Revision flag being set.

Fixes: 1aeba347b3a9 ("MIPS: Hardcode cpu_has_mips* where target ISA allows")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 arch/mips/include/asm/cpu-features.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 227d7416591c..14532cd25807 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -291,10 +291,12 @@
 # define cpu_has_mips32r6	__isa_ge_or_flag(6, MIPS_CPU_ISA_M32R6)
 #endif
 #ifndef cpu_has_mips64r1
-# define cpu_has_mips64r1	__isa_range_or_flag(1, 6, MIPS_CPU_ISA_M64R1)
+# define cpu_has_mips64r1	(cpu_has_64bits && \
+				 __isa_range_or_flag(1, 6, MIPS_CPU_ISA_M64R1))
 #endif
 #ifndef cpu_has_mips64r2
-# define cpu_has_mips64r2	__isa_range_or_flag(2, 6, MIPS_CPU_ISA_M64R2)
+# define cpu_has_mips64r2	(cpu_has_64bits && \
+				 __isa_range_or_flag(2, 6, MIPS_CPU_ISA_M64R2))
 #endif
 #ifndef cpu_has_mips64r5
 # define cpu_has_mips64r5	(cpu_has_64bits && \
-- 
2.25.1

[PATCH v4 06/13] mips: Add CP0 Write Merge config support

[Serge Semin]

CP0 config register may indicate whether write-through merging
is allowed. Currently there are two types of the merging available:
SysAD Valid and Full modes. Whether each of them are supported by
the core is implementation dependent. Moreover whether the ability
to change the mode also depends on the chip family instance. Taking
into account all of this we created a dedicated mm_config() method
to detect and enable merging if it's supported. It is called for
MIPS-type processors at CPU-probe stage and attempts to detect whether
the write merging is available. If it's known to be supported and
switchable, then switch on the full mode. Otherwise just perform the
CP0.Config.MM field analysis.

In addition there are platforms like InterAptiv/ProAptiv, which do have
the MM bit field set by default, but having write-through cacheing
unsupported makes write-merging also unsupported. In this case we just
ignore the MM field value.

Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 arch/mips/include/asm/cpu-features.h |  8 +++++
 arch/mips/include/asm/cpu.h          |  4 ++-
 arch/mips/include/asm/mipsregs.h     |  3 ++
 arch/mips/kernel/cpu-probe.c         | 48 ++++++++++++++++++++++++++++
 4 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 14532cd25807..caecbae4b599 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -629,6 +629,14 @@
 # endif
 #endif
 
+#ifndef cpu_has_mm_sysad
+# define cpu_has_mm_sysad	__opt(MIPS_CPU_MM_SYSAD)
+#endif
+
+#ifndef cpu_has_mm_full
+# define cpu_has_mm_full	__opt(MIPS_CPU_MM_FULL)
+#endif
+
 /*
  * Guest capabilities
  */
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index 4b84fd1df0c7..104a509312b3 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -422,7 +422,9 @@ enum cpu_type_enum {
 #define MIPS_CPU_MT_PER_TC_PERF_COUNTERS \
 				BIT_ULL(56)	/* CPU has perf counters implemented per TC (MIPSMT ASE) */
 #define MIPS_CPU_MMID		BIT_ULL(57)	/* CPU supports MemoryMapIDs */
-#define MIPS_CPU_MAC_2008_ONLY	BIT_ULL(58)	/* CPU Only support MAC2008 Fused multiply-add instruction */
+#define MIPS_CPU_MM_SYSAD	BIT_ULL(58)	/* CPU supports write-through SysAD Valid merge */
+#define MIPS_CPU_MM_FULL	BIT_ULL(59)	/* CPU supports write-through full merge */
+#define MIPS_CPU_MAC_2008_ONLY	BIT_ULL(60)	/* CPU Only support MAC2008 Fused multiply-add instruction */
 
 /*
  * CPU ASE encodings
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index 246b8b2ebdf8..a284da54efd5 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -563,6 +563,9 @@
 #define MIPS_CONF_MT_FTLB	(_ULCAST_(4) <<  7)
 #define MIPS_CONF_AR		(_ULCAST_(7) << 10)
 #define MIPS_CONF_AT		(_ULCAST_(3) << 13)
+#define MIPS_CONF_MM		(_ULCAST_(3) << 17)
+#define MIPS_CONF_MM_SYSAD	(_ULCAST_(1) << 17)
+#define MIPS_CONF_MM_FULL	(_ULCAST_(2) << 17)
 #define MIPS_CONF_M		(_ULCAST_(1) << 31)
 
 /*
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 33600287daf7..04366f58ce4a 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -672,6 +672,52 @@ static int set_ftlb_enable(struct cpuinfo_mips *c, enum ftlb_flags flags)
 	return 0;
 }
 
+static int mm_config(struct cpuinfo_mips *c)
+{
+	unsigned int config0, update, mm;
+
+	config0 = read_c0_config();
+	mm = config0 & MIPS_CONF_MM;
+
+	/*
+	 * It's implementation dependent what type of write-merge is supported
+	 * and whether it can be enabled/disabled. If it is settable lets make
+	 * the merging allowed by default. Some platforms might have
+	 * write-through caching unsupported. In this case just ignore the
+	 * CP0.Config.MM bit field value.
+	 */
+	switch (c->cputype) {
+	case CPU_24K:
+	case CPU_34K:
+	case CPU_74K:
+	case CPU_P5600:
+	case CPU_P6600:
+		c->options |= MIPS_CPU_MM_FULL;
+		update = MIPS_CONF_MM_FULL;
+		break;
+	case CPU_1004K:
+	case CPU_1074K:
+	case CPU_INTERAPTIV:
+	case CPU_PROAPTIV:
+		mm = 0;
+		fallthrough;
+	default:
+		update = 0;
+		break;
+	}
+
+	if (update) {
+		config0 = (config0 & ~MIPS_CONF_MM) | update;
+		write_c0_config(config0);
+	} else if (mm == MIPS_CONF_MM_SYSAD) {
+		c->options |= MIPS_CPU_MM_SYSAD;
+	} else if (mm == MIPS_CONF_MM_FULL) {
+		c->options |= MIPS_CPU_MM_FULL;
+	}
+
+	return 0;
+}
+
 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
 {
 	unsigned int config0;
@@ -1763,6 +1809,8 @@ static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
 
 	spram_config();
 
+	mm_config(c);
+
 	switch (__get_cpu_type(c->cputype)) {
 	case CPU_M5150:
 	case CPU_P5600:
-- 
2.25.1

[PATCH v4 07/13] mips: Add CONFIG/CONFIG6/Cause reg fields macro

[Serge Semin]

There are bit fields which persist in the MIPS CONFIG and CONFIG6
registers, but haven't been described in the generic mipsregs.h
header so far. In particular, the generic CONFIG bitfields are
BE - endian mode, BM - burst mode, SB - SimpleBE, OCP interface mode
indicator, UDI - user-defined "CorExtend" instructions, DSP - data
scratch pad RAM present, ISP - instruction scratch pad RAM present,
etc. The core-specific CONFIG6 bitfields are JRCD - jump register
cache prediction disable, R6 - MIPSr6 extensions enable, IFUPerfCtl -
IFU performance control, SPCD - sleep state performance counter, DLSB -
disable load/store bonding. A new exception code reported in the
ExcCode field of the Cause register: 30 - Parity/ECC error exception
happened on either fetch, load or cache refill. Lets add them to the
mipsregs.h header to be used in future platform code, which have them
utilized.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 arch/mips/include/asm/mipsregs.h | 19 +++++++++++++++++++
 arch/mips/kernel/spram.c         |  4 ++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index a284da54efd5..fe6293f5b939 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -468,6 +468,7 @@
 #define EXCCODE_THREAD		25	/* Thread exceptions (MT) */
 #define EXCCODE_DSPDIS		26	/* DSP disabled exception */
 #define EXCCODE_GE		27	/* Virtualized guest exception (VZ) */
+#define EXCCODE_CACHEERR	30	/* Parity/ECC occured on a core */
 
 /* Implementation specific trap codes used by MIPS cores */
 #define MIPS_EXCCODE_TLBPAR	16	/* TLB parity error exception */
@@ -563,9 +564,17 @@
 #define MIPS_CONF_MT_FTLB	(_ULCAST_(4) <<  7)
 #define MIPS_CONF_AR		(_ULCAST_(7) << 10)
 #define MIPS_CONF_AT		(_ULCAST_(3) << 13)
+#define MIPS_CONF_BE		(_ULCAST_(1) << 15)
+#define MIPS_CONF_BM		(_ULCAST_(1) << 16)
 #define MIPS_CONF_MM		(_ULCAST_(3) << 17)
 #define MIPS_CONF_MM_SYSAD	(_ULCAST_(1) << 17)
 #define MIPS_CONF_MM_FULL	(_ULCAST_(2) << 17)
+#define MIPS_CONF_SB		(_ULCAST_(1) << 21)
+#define MIPS_CONF_UDI		(_ULCAST_(1) << 22)
+#define MIPS_CONF_DSP		(_ULCAST_(1) << 23)
+#define MIPS_CONF_ISP		(_ULCAST_(1) << 24)
+#define MIPS_CONF_KU		(_ULCAST_(3) << 25)
+#define MIPS_CONF_K23		(_ULCAST_(3) << 28)
 #define MIPS_CONF_M		(_ULCAST_(1) << 31)
 
 /*
@@ -677,9 +686,19 @@
 #define MIPS_CONF5_CV		(_ULCAST_(1) << 29)
 #define MIPS_CONF5_K		(_ULCAST_(1) << 30)
 
+/* Jump register cache prediction disable */
+#define MIPS_CONF6_JRCD		(_ULCAST_(1) << 0)
+/* MIPSr6 extensions enable */
+#define MIPS_CONF6_R6		(_ULCAST_(1) << 2)
+/* IFU Performance Control */
+#define MIPS_CONF6_IFUPERFCTL	(_ULCAST_(3) << 10)
 #define MIPS_CONF6_SYND		(_ULCAST_(1) << 13)
+/* Sleep state performance counter disable */
+#define MIPS_CONF6_SPCD		(_ULCAST_(1) << 14)
 /* proAptiv FTLB on/off bit */
 #define MIPS_CONF6_FTLBEN	(_ULCAST_(1) << 15)
+/* Disable load/store bonding */
+#define MIPS_CONF6_DLSB		(_ULCAST_(1) << 21)
 /* Loongson-3 FTLB on/off bit */
 #define MIPS_CONF6_FTLBDIS	(_ULCAST_(1) << 22)
 /* FTLB probability bits */
diff --git a/arch/mips/kernel/spram.c b/arch/mips/kernel/spram.c
index 26d355462ace..d5d96214cce5 100644
--- a/arch/mips/kernel/spram.c
+++ b/arch/mips/kernel/spram.c
@@ -209,11 +209,11 @@ void spram_config(void)
 	case CPU_P6600:
 		config0 = read_c0_config();
 		/* FIXME: addresses are Malta specific */
-		if (config0 & (1<<24)) {
+		if (config0 & MIPS_CONF_ISP) {
 			probe_spram("ISPRAM", 0x1c000000,
 				    &ispram_load_tag, &ispram_store_tag);
 		}
-		if (config0 & (1<<23))
+		if (config0 & MIPS_CONF_DSP)
 			probe_spram("DSPRAM", 0x1c100000,
 				    &dspram_load_tag, &dspram_store_tag);
 	}
-- 
2.25.1

[PATCH v4 08/13] mips: Add CPS_NS16550_WIDTH config

[Serge Semin]

On some platforms IO-memory might require to use a proper load/store
instructions (like Baikal-T1 IO-memory). To fix the cps-vec UART debug
printout let's add the CONFIG_CPS_NS16550_WIDTH config to determine which
instructions lb/sb, lh/sh or lw/sw are required for MMIO operations.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 arch/mips/Kconfig.debug            | 10 ++++++++++
 arch/mips/kernel/cps-vec-ns16550.S | 18 ++++++++++++++++--
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/arch/mips/Kconfig.debug b/arch/mips/Kconfig.debug
index 93a2974d2ab7..7a8d94cdd493 100644
--- a/arch/mips/Kconfig.debug
+++ b/arch/mips/Kconfig.debug
@@ -148,4 +148,14 @@ config MIPS_CPS_NS16550_SHIFT
 	  form their addresses. That is, log base 2 of the span between
 	  adjacent ns16550 registers in the system.
 
+config MIPS_CPS_NS16550_WIDTH
+	int "UART Register Width"
+	default 1
+	help
+	  ns16550 registers width. UART registers IO access methods will be
+	  selected in accordance with this parameter. By setting it to 1, 2 or
+	  4 UART registers will be accessed by means of lb/sb, lh/sh or lw/sw
+	  instructions respectively. Any value not from that set activates
+	  lb/sb instructions.
+
 endif # MIPS_CPS_NS16550_BOOL
diff --git a/arch/mips/kernel/cps-vec-ns16550.S b/arch/mips/kernel/cps-vec-ns16550.S
index d5a67b4ce9f6..30725e1df987 100644
--- a/arch/mips/kernel/cps-vec-ns16550.S
+++ b/arch/mips/kernel/cps-vec-ns16550.S
@@ -14,16 +14,30 @@
 #define UART_TX_OFS	(UART_TX << CONFIG_MIPS_CPS_NS16550_SHIFT)
 #define UART_LSR_OFS	(UART_LSR << CONFIG_MIPS_CPS_NS16550_SHIFT)
 
+#if CONFIG_MIPS_CPS_NS16550_WIDTH == 1
+# define UART_L		lb
+# define UART_S		sb
+#elif CONFIG_MIPS_CPS_NS16550_WIDTH == 2
+# define UART_L		lh
+# define UART_S		sh
+#elif CONFIG_MIPS_CPS_NS16550_WIDTH == 4
+# define UART_L		lw
+# define UART_S		sw
+#else
+# define UART_L		lb
+# define UART_S		sb
+#endif
+
 /**
  * _mips_cps_putc() - write a character to the UART
  * @a0: ASCII character to write
  * @t9: UART base address
  */
 LEAF(_mips_cps_putc)
-1:	lw		t0, UART_LSR_OFS(t9)
+1:	UART_L		t0, UART_LSR_OFS(t9)
 	andi		t0, t0, UART_LSR_TEMT
 	beqz		t0, 1b
-	sb		a0, UART_TX_OFS(t9)
+	UART_S		a0, UART_TX_OFS(t9)
 	jr		ra
 	END(_mips_cps_putc)
 
-- 
2.25.1

[PATCH v4 09/13] mips: cdmm: Add mti,mips-cdmm dtb node support

[Serge Semin]

Since having and mapping the CDMM block is platform specific, then
instead of just returning a zero-address, lets make the default CDMM
base address search method (mips_cdmm_phys_base()) to do something
useful. For instance to find the address in a dedicated dtb-node in
order to support of-based platforms by default.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 drivers/bus/mips_cdmm.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/bus/mips_cdmm.c b/drivers/bus/mips_cdmm.c
index 1b14256376d2..7faa8c049f07 100644
--- a/drivers/bus/mips_cdmm.c
+++ b/drivers/bus/mips_cdmm.c
@@ -16,6 +16,8 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/smp.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
 #include <asm/cdmm.h>
 #include <asm/hazards.h>
 #include <asm/mipsregs.h>
@@ -337,9 +339,22 @@ static phys_addr_t mips_cdmm_cur_base(void)
  * Picking a suitable physical address at which to map the CDMM region is
  * platform specific, so this weak function can be overridden by platform
  * code to pick a suitable value if none is configured by the bootloader.
+ * By default this method tries to find a CDMM-specific node in the system
+ * dtb. Note that this won't work for early serial console.
  */
 phys_addr_t __weak mips_cdmm_phys_base(void)
 {
+	struct device_node *np;
+	struct resource res;
+	int err;
+
+	np = of_find_compatible_node(NULL, NULL, "mti,mips-cdmm");
+	if (np) {
+		err = of_address_to_resource(np, 0, &res);
+		if (!err)
+			return res.start;
+	}
+
 	return 0;
 }
 
-- 
2.25.1

[PATCH v4 10/13] bus: cdmm: Add MIPS R5 arch support

[Serge Semin]

CDMM may be available not only on MIPS R2 architectures, but also on
newer MIPS R5 chips. For instance our P5600 chip has one. Let's mark
the CDMM bus being supported for that MIPS arch too.

Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 drivers/bus/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 6d4e4497b59b..971c07bc92d4 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -58,7 +58,7 @@ config IMX_WEIM
 
 config MIPS_CDMM
 	bool "MIPS Common Device Memory Map (CDMM) Driver"
-	depends on CPU_MIPSR2
+	depends on CPU_MIPSR2 || CPU_MIPSR5
 	help
 	  Driver needed for the MIPS Common Device Memory Map bus in MIPS
 	  cores. This bus is for per-CPU tightly coupled devices such as the
-- 
2.25.1

[PATCH v4 11/13] mips: Add udelay lpj numbers adjustment

[Serge Semin]

Loops-per-jiffies is a special number which represents a number of
noop-loop cycles per CPU-scheduler quantum - jiffies. As you
understand aside from CPU-specific implementation it depends on
the CPU frequency. So when a platform has the CPU frequency fixed,
we have no problem and the current udelay interface will work
just fine. But as soon as CPU-freq driver is enabled and the cores
frequency changes, we'll end up with distorted udelay's. In order
to fix this we have to accordinly adjust the per-CPU udelay_val
(the same as the global loops_per_jiffy) number. This can be done
in the CPU-freq transition event handler. We subscribe to that event
in the MIPS arch time-inititalization method.

Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 arch/mips/kernel/time.c | 70 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c
index 37e9413a393d..caa01457dce6 100644
--- a/arch/mips/kernel/time.c
+++ b/arch/mips/kernel/time.c
@@ -18,12 +18,82 @@
 #include <linux/smp.h>
 #include <linux/spinlock.h>
 #include <linux/export.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
 
 #include <asm/cpu-features.h>
 #include <asm/cpu-type.h>
 #include <asm/div64.h>
 #include <asm/time.h>
 
+#ifdef CONFIG_CPU_FREQ
+
+static DEFINE_PER_CPU(unsigned long, pcp_lpj_ref);
+static DEFINE_PER_CPU(unsigned long, pcp_lpj_ref_freq);
+static unsigned long glb_lpj_ref;
+static unsigned long glb_lpj_ref_freq;
+
+static int cpufreq_callback(struct notifier_block *nb,
+			    unsigned long val, void *data)
+{
+	struct cpufreq_freqs *freq = data;
+	struct cpumask *cpus = freq->policy->cpus;
+	unsigned long lpj;
+	int cpu;
+
+	/*
+	 * Skip lpj numbers adjustment if the CPU-freq transition is safe for
+	 * the loops delay. (Is this possible?)
+	 */
+	if (freq->flags & CPUFREQ_CONST_LOOPS)
+		return NOTIFY_OK;
+
+	/* Save the initial values of the lpjes for future scaling. */
+	if (!glb_lpj_ref) {
+		glb_lpj_ref = boot_cpu_data.udelay_val;
+		glb_lpj_ref_freq = freq->old;
+
+		for_each_online_cpu(cpu) {
+			per_cpu(pcp_lpj_ref, cpu) =
+				cpu_data[cpu].udelay_val;
+			per_cpu(pcp_lpj_ref_freq, cpu) = freq->old;
+		}
+	}
+
+	/*
+	 * Adjust global lpj variable and per-CPU udelay_val number in
+	 * accordance with the new CPU frequency.
+	 */
+	if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
+	    (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)) {
+		loops_per_jiffy = cpufreq_scale(glb_lpj_ref,
+						glb_lpj_ref_freq,
+						freq->new);
+
+		for_each_cpu(cpu, cpus) {
+			lpj = cpufreq_scale(per_cpu(pcp_lpj_ref, cpu),
+					    per_cpu(pcp_lpj_ref_freq, cpu),
+					    freq->new);
+			cpu_data[cpu].udelay_val = (unsigned int)lpj;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cpufreq_notifier = {
+	.notifier_call  = cpufreq_callback,
+};
+
+static int __init register_cpufreq_notifier(void)
+{
+	return cpufreq_register_notifier(&cpufreq_notifier,
+					 CPUFREQ_TRANSITION_NOTIFIER);
+}
+core_initcall(register_cpufreq_notifier);
+
+#endif /* CONFIG_CPU_FREQ */
+
 /*
  * forward reference
  */
-- 
2.25.1

[PATCH v4 12/13] mips: csrc-r4k: Mark R4K timer as unstable if CPU freq changes

[Serge Semin]

Commit 07d69579e7fe ("MIPS: Don't register r4k sched clock when CPUFREQ
enabled") disabled the r4k-clock usage for scheduler ticks counting due
to the scheduler being non-tolerant for unstable clocks sources. For the
same reason the clock should be used in the system clocksource framework
with care. As soon as CPU frequency changes the clocksource framework
should be notified about this by marking the R4K timer being unstable
(which it really is, since the ticks rate has been changed synchronously
with the CPU frequency).

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 arch/mips/Kconfig           |  1 +
 arch/mips/kernel/csrc-r4k.c | 40 +++++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 2747b1b2d435..f347312ecd74 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1108,6 +1108,7 @@ config CSRC_IOASIC
 	bool
 
 config CSRC_R4K
+	select CLOCKSOURCE_WATCHDOG if CPU_FREQ
 	bool
 
 config CSRC_SB1250
diff --git a/arch/mips/kernel/csrc-r4k.c b/arch/mips/kernel/csrc-r4k.c
index 437dda64fd7a..edc4afc080fa 100644
--- a/arch/mips/kernel/csrc-r4k.c
+++ b/arch/mips/kernel/csrc-r4k.c
@@ -6,6 +6,7 @@
  * Copyright (C) 2007 by Ralf Baechle
  */
 #include <linux/clocksource.h>
+#include <linux/cpufreq.h>
 #include <linux/init.h>
 #include <linux/sched_clock.h>
 
@@ -65,6 +66,45 @@ static bool rdhwr_count_usable(void)
 	return false;
 }
 
+#ifdef CONFIG_CPU_FREQ
+
+static bool __read_mostly r4k_clock_unstable;
+
+static void r4k_clocksource_unstable(char *reason)
+{
+	if (r4k_clock_unstable)
+		return;
+
+	r4k_clock_unstable = true;
+
+	pr_info("R4K timer is unstable due to %s\n", reason);
+
+	clocksource_mark_unstable(&clocksource_mips);
+}
+
+static int r4k_cpufreq_callback(struct notifier_block *nb,
+				unsigned long val, void *data)
+{
+	if (val == CPUFREQ_POSTCHANGE)
+		r4k_clocksource_unstable("CPU frequency change");
+
+	return 0;
+}
+
+static struct notifier_block r4k_cpufreq_notifier = {
+	.notifier_call  = r4k_cpufreq_callback,
+};
+
+static int __init r4k_register_cpufreq_notifier(void)
+{
+	return cpufreq_register_notifier(&r4k_cpufreq_notifier,
+					 CPUFREQ_TRANSITION_NOTIFIER);
+
+}
+core_initcall(r4k_register_cpufreq_notifier);
+
+#endif /* !CONFIG_CPU_FREQ */
+
 int __init init_r4k_clocksource(void)
 {
 	if (!cpu_has_counter || !mips_hpt_frequency)
-- 
2.25.1

[PATCH v4 13/13] mips: cevt-r4k: Update the r4k-clockevent frequency in sync with CPU

[Serge Semin]

Due to being embedded into the CPU cores MIPS count/compare timer
frequency is changed together with the CPU clocks alteration.
In case if frequency really changes the kernel clockevent framework
must be notified, otherwise the kernel timers won't work correctly.
Fix this by calling clockevents_update_freq() for each r4k clockevent
handlers registered per available CPUs.

Traditionally MIPS r4k-clock are clocked with CPU frequency divided by 2.
But this isn't true for some of the platforms. Due to this we have to save
the basic CPU frequency, so then use it to scale the initial timer
frequency (mips_hpt_frequency) and pass the updated value further to the
clockevent framework.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 arch/mips/kernel/cevt-r4k.c | 44 +++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c
index 17a9cbb8b3df..995ad9e69ded 100644
--- a/arch/mips/kernel/cevt-r4k.c
+++ b/arch/mips/kernel/cevt-r4k.c
@@ -8,6 +8,7 @@
  */
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
+#include <linux/cpufreq.h>
 #include <linux/percpu.h>
 #include <linux/smp.h>
 #include <linux/irq.h>
@@ -250,6 +251,49 @@ unsigned int __weak get_c0_compare_int(void)
 	return MIPS_CPU_IRQ_BASE + cp0_compare_irq;
 }
 
+#ifdef CONFIG_CPU_FREQ
+
+static unsigned long mips_ref_freq;
+
+static int r4k_cpufreq_callback(struct notifier_block *nb,
+				unsigned long val, void *data)
+{
+	struct cpufreq_freqs *freq = data;
+	struct clock_event_device *cd;
+	unsigned long rate;
+	int cpu;
+
+	if (!mips_ref_freq)
+		mips_ref_freq = freq->old;
+
+	if (val == CPUFREQ_POSTCHANGE) {
+		rate = cpufreq_scale(mips_hpt_frequency, mips_ref_freq,
+				     freq->new);
+
+		for_each_cpu(cpu, freq->policy->cpus) {
+			cd = &per_cpu(mips_clockevent_device, cpu);
+
+			clockevents_update_freq(cd, rate);
+		}
+	}
+
+	return 0;
+}
+
+static struct notifier_block r4k_cpufreq_notifier = {
+	.notifier_call  = r4k_cpufreq_callback,
+};
+
+static int __init r4k_register_cpufreq_notifier(void)
+{
+	return cpufreq_register_notifier(&r4k_cpufreq_notifier,
+					 CPUFREQ_TRANSITION_NOTIFIER);
+
+}
+core_initcall(r4k_register_cpufreq_notifier);
+
+#endif /* !CONFIG_CPU_FREQ */
+
 int r4k_clockevent_init(void)
 {
 	unsigned long flags = IRQF_PERCPU | IRQF_TIMER | IRQF_SHARED;
-- 
2.25.1

Re: [PATCH v4 03/13] mips: Add MIPS Release 5 support

[Maciej W. Rozycki]

On Thu, 21 May 2020, Serge Semin wrote:

> There are five MIPS32/64 architecture releases currently available:
> from 1 to 6 except fourth one, which was intentionally skipped.
> Three of them can be called as major: 1st, 2nd and 6th, that not only
> have some system level alterations, but also introduced significant
> core/ISA level updates. The rest of the MIPS architecture releases are
> minor.

 Well, strictly speaking R3 added microMIPS support, which was all but
minor (of course there were minor updates too, such as 2008-NaN support).

  Maciej

Re: [PATCH v4 03/13] mips: Add MIPS Release 5 support

[Thomas Bogendoerfer]

On Thu, May 21, 2020 at 05:07:14PM +0300, Serge Semin wrote:
> There are five MIPS32/64 architecture releases currently available:
> from 1 to 6 except fourth one, which was intentionally skipped.
> Three of them can be called as major: 1st, 2nd and 6th, that not only
> have some system level alterations, but also introduced significant
> core/ISA level updates. The rest of the MIPS architecture releases are
> minor.
> 
> Even though they don't have as much ISA/system/core level changes
> as the major ones with respect to the previous releases, they still
> provide a set of updates (I'd say they were intended to be the
> intermediate releases before a major one) that might be useful for the
> kernel and user-level code, when activated by the kernel or compiler.
> In particular the following features were introduced or ended up being
> available at/after MIPS32/64 Release 5 architecture:
> + the last release of the misaligned memory access instructions,
> + virtualisation - VZ ASE - is optional component of the arch,
> + SIMD - MSA ASE - is optional component of the arch,
> + DSP ASE is optional component of the arch,
> + CP0.Status.FR=1 for CP1.FIR.F64=1 (pure 64-bit FPU general registers)
>   must be available if FPU is implemented,
> + CP1.FIR.Has2008 support is required so CP1.FCSR.{ABS2008,NAN2008} bits
>   are available.
> + UFR/UNFR aliases to access CP0.Status.FR from user-space by means of
>   ctc1/cfc1 instructions (enabled by CP0.Config5.UFR),
> + CP0.COnfig5.LLB=1 and eretnc instruction are implemented to without
>   accidentally clearing LL-bit when returning from an interrupt,
>   exception, or error trap,
> + XPA feature together with extended versions of CPx registers is
>   introduced, which needs to have mfhc0/mthc0 instructions available.
> 
> So due to these changes GNU GCC provides an extended instructions set
> support for MIPS32/64 Release 5 by default like eretnc/mfhc0/mthc0. Even
> though the architecture alteration isn't that big, it still worth to be
> taken into account by the kernel software. Finally we can't deny that
> some optimization/limitations might be found in future and implemented
> on some level in kernel or compiler. In this case having even
> intermediate MIPS architecture releases support would be more than
> useful.
> 
> So the most of the changes provided by this commit can be split into
> either compile- or runtime configs related. The compile-time related
> changes are caused by adding the new CONFIG_CPU_MIPS32_R5/CONFIG_CPU_MIPSR5
> configs and concern the code activating MIPSR2 or MIPSR6 already
> implemented features (like eretnc/LLbit, mthc0/mfhc0). In addition
> CPU_HAS_MSA can be now freely enabled for MIPS32/64 release 5 based
> platforms as this is done for CPU_MIPS32_R6 CPUs. The runtime changes
> concerns the features which are handled with respect to the MIPS ISA
> revision detected at run-time by means of CP0.Config.{AT,AR} bits. Alas
> these fields can be used to detect either r1 or r2 or r6 releases.
> But since we know which CPUs in fact support the R5 arch, we can manually
> set MIPS_CPU_ISA_M32R5/MIPS_CPU_ISA_M64R5 bit of c->isa_level and then
> use cpu_has_mips32r5/cpu_has_mips64r5 where it's appropriate.
> 
> Since XPA/EVA provide too complex alterationss and to have them used with
> MIPS32 Release 2 charged kernels (for compatibility with current platform
> configs) they are left to be setup as a separate kernel configs.
> 
> Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  arch/mips/Kconfig                    | 56 +++++++++++++++++++++++++---
>  arch/mips/Makefile                   |  2 +
>  arch/mips/include/asm/asmmacro.h     | 18 +++++----
>  arch/mips/include/asm/compiler.h     |  5 +++
>  arch/mips/include/asm/cpu-features.h | 27 ++++++++++----
>  arch/mips/include/asm/cpu-info.h     |  2 +-
>  arch/mips/include/asm/cpu-type.h     |  7 +++-
>  arch/mips/include/asm/cpu.h          | 10 +++--
>  arch/mips/include/asm/fpu.h          |  4 +-
>  arch/mips/include/asm/hazards.h      |  8 ++--
>  arch/mips/include/asm/module.h       |  4 ++
>  arch/mips/include/asm/stackframe.h   |  2 +-
>  arch/mips/include/asm/switch_to.h    |  8 ++--
>  arch/mips/kernel/cpu-probe.c         | 17 +++++++++
>  arch/mips/kernel/entry.S             |  6 +--
>  arch/mips/kernel/proc.c              |  4 ++
>  arch/mips/kernel/r4k_fpu.S           | 14 +++----
>  arch/mips/kvm/vz.c                   |  6 +--
>  arch/mips/lib/csum_partial.S         |  6 ++-
>  arch/mips/mm/c-r4k.c                 |  7 ++--
>  arch/mips/mm/sc-mips.c               |  7 ++--
>  21 files changed, 163 insertions(+), 57 deletions(-)

applied to mips-next. I've changed the two /* fall through */ by fallthrough;
while appliny. Running checkpatch would have caught that ;-)

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v4 04/13] mips: Add MIPS Warrior P5600 support

[Thomas Bogendoerfer]

On Thu, May 21, 2020 at 05:07:15PM +0300, Serge Semin wrote:
> This is a MIPS32 Release 5 based IP core with XPA, EVA, dual/quad issue
> exec pipes, MMU with two-levels TLB, UCA, MSA, MDU core level features
> and system level features like up to six P5600 calculation cores, CM2
> with L2 cache, IOCU/IOMMU (though might be unused depending on the
> system-specific IP core configuration), GIC, CPC, virtualisation module,
> eJTAG and PDtrace.
> 
> As being MIPS32 Release 5 based core it provides all the features
> available by the CPU_MIPS32_R5 config, while adding a few more like
> UCA attribute support, availability of CPU-freq (by means of L2/CM
> clock ratio setting), EI/VI GIC modes detection at runtime.
> 
> In addition to this if P5600 architecture is enabled modern GNU GCC
> provides a specific tuning for P5600 processors with respect to the
> classic MIPS32 Release 5. First of all branch-likely avoidance is
> activated only when the code is compiled with the speed optimization
> (avoidance is always enabled for the pure MIPS32 Release 5
> architecture). Secondly the madd/msub avoidance is enabled since
> madd/msub utilization isn't profitable due to overhead of getting the
> result out of the HI/LO registers. Multiply-accumulate instructions are
> activated and utilized together with the necessary code reorder when
> multiply-add/multiply-subtract statements are met. Finally load/store
> bonding is activated by default. All of these optimizations may make
> the code relatively faster than if just MIP32 release 5 architecture
> was requested.
> 
> Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  arch/mips/Kconfig              | 37 +++++++++++++++++++++++++++++-----
>  arch/mips/Makefile             |  1 +
>  arch/mips/include/asm/module.h |  2 ++
>  3 files changed, 35 insertions(+), 5 deletions(-)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v4 05/13] mips: Fix cpu_has_mips64r1/2 activation for MIPS32 CPUs

[Thomas Bogendoerfer]

On Thu, May 21, 2020 at 05:07:16PM +0300, Serge Semin wrote:
> Commit 1aeba347b3a9 ("MIPS: Hardcode cpu_has_mips* where target ISA
> allows") updated the cpu_has_mips* macro to be replaced with a constant
> expression where it's possible. By mistake it wasn't done correctly
> for cpu_has_mips64r1/cpu_has_mips64r2 macro. They are defined to
> be replaced with conditional expression __isa_range_or_flag(), which
> means either ISA revision being within the range or the corresponding
> CPU options flag was set at the probe stage or both being true at the
> same time. But the ISA level value doesn't indicate whether the ISA is
> MIPS32 or MIPS64. Due to this if we select MIPS32r1 - MIPS32r5
> architectures the __isa_range() macro will activate the
> cpu_has_mips64rX flags, which is incorrect. In order to fix the
> problem we make sure the 64bits CPU support is enabled by means of
> checking the flag cpu_has_64bits aside with proper ISA range and specific
> Revision flag being set.
> 
> Fixes: 1aeba347b3a9 ("MIPS: Hardcode cpu_has_mips* where target ISA allows")
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  arch/mips/include/asm/cpu-features.h | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v4 06/13] mips: Add CP0 Write Merge config support

[Thomas Bogendoerfer]

On Thu, May 21, 2020 at 05:07:17PM +0300, Serge Semin wrote:
> CP0 config register may indicate whether write-through merging
> is allowed. Currently there are two types of the merging available:
> SysAD Valid and Full modes. Whether each of them are supported by
> the core is implementation dependent. Moreover whether the ability
> to change the mode also depends on the chip family instance. Taking
> into account all of this we created a dedicated mm_config() method
> to detect and enable merging if it's supported. It is called for
> MIPS-type processors at CPU-probe stage and attempts to detect whether
> the write merging is available. If it's known to be supported and
> switchable, then switch on the full mode. Otherwise just perform the
> CP0.Config.MM field analysis.
> 
> In addition there are platforms like InterAptiv/ProAptiv, which do have
> the MM bit field set by default, but having write-through cacheing
> unsupported makes write-merging also unsupported. In this case we just
> ignore the MM field value.
> 
> Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  arch/mips/include/asm/cpu-features.h |  8 +++++
>  arch/mips/include/asm/cpu.h          |  4 ++-
>  arch/mips/include/asm/mipsregs.h     |  3 ++
>  arch/mips/kernel/cpu-probe.c         | 48 ++++++++++++++++++++++++++++
>  4 files changed, 62 insertions(+), 1 deletion(-)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v4 07/13] mips: Add CONFIG/CONFIG6/Cause reg fields macro

[Thomas Bogendoerfer]

On Thu, May 21, 2020 at 05:07:18PM +0300, Serge Semin wrote:
> There are bit fields which persist in the MIPS CONFIG and CONFIG6
> registers, but haven't been described in the generic mipsregs.h
> header so far. In particular, the generic CONFIG bitfields are
> BE - endian mode, BM - burst mode, SB - SimpleBE, OCP interface mode
> indicator, UDI - user-defined "CorExtend" instructions, DSP - data
> scratch pad RAM present, ISP - instruction scratch pad RAM present,
> etc. The core-specific CONFIG6 bitfields are JRCD - jump register
> cache prediction disable, R6 - MIPSr6 extensions enable, IFUPerfCtl -
> IFU performance control, SPCD - sleep state performance counter, DLSB -
> disable load/store bonding. A new exception code reported in the
> ExcCode field of the Cause register: 30 - Parity/ECC error exception
> happened on either fetch, load or cache refill. Lets add them to the
> mipsregs.h header to be used in future platform code, which have them
> utilized.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  arch/mips/include/asm/mipsregs.h | 19 +++++++++++++++++++
>  arch/mips/kernel/spram.c         |  4 ++--
>  2 files changed, 21 insertions(+), 2 deletions(-)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v4 08/13] mips: Add CPS_NS16550_WIDTH config

[Thomas Bogendoerfer]

On Thu, May 21, 2020 at 05:07:19PM +0300, Serge Semin wrote:
> On some platforms IO-memory might require to use a proper load/store
> instructions (like Baikal-T1 IO-memory). To fix the cps-vec UART debug
> printout let's add the CONFIG_CPS_NS16550_WIDTH config to determine which
> instructions lb/sb, lh/sh or lw/sw are required for MMIO operations.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  arch/mips/Kconfig.debug            | 10 ++++++++++
>  arch/mips/kernel/cps-vec-ns16550.S | 18 ++++++++++++++++--
>  2 files changed, 26 insertions(+), 2 deletions(-)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v4 11/13] mips: Add udelay lpj numbers adjustment

[Thomas Bogendoerfer]

On Thu, May 21, 2020 at 05:07:22PM +0300, Serge Semin wrote:
> Loops-per-jiffies is a special number which represents a number of
> noop-loop cycles per CPU-scheduler quantum - jiffies. As you
> understand aside from CPU-specific implementation it depends on
> the CPU frequency. So when a platform has the CPU frequency fixed,
> we have no problem and the current udelay interface will work
> just fine. But as soon as CPU-freq driver is enabled and the cores
> frequency changes, we'll end up with distorted udelay's. In order
> to fix this we have to accordinly adjust the per-CPU udelay_val
> (the same as the global loops_per_jiffy) number. This can be done
> in the CPU-freq transition event handler. We subscribe to that event
> in the MIPS arch time-inititalization method.
> 
> Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  arch/mips/kernel/time.c | 70 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 70 insertions(+)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v4 12/13] mips: csrc-r4k: Mark R4K timer as unstable if CPU freq changes

[Thomas Bogendoerfer]

On Thu, May 21, 2020 at 05:07:23PM +0300, Serge Semin wrote:
> Commit 07d69579e7fe ("MIPS: Don't register r4k sched clock when CPUFREQ
> enabled") disabled the r4k-clock usage for scheduler ticks counting due
> to the scheduler being non-tolerant for unstable clocks sources. For the
> same reason the clock should be used in the system clocksource framework
> with care. As soon as CPU frequency changes the clocksource framework
> should be notified about this by marking the R4K timer being unstable
> (which it really is, since the ticks rate has been changed synchronously
> with the CPU frequency).
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  arch/mips/Kconfig           |  1 +
>  arch/mips/kernel/csrc-r4k.c | 40 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 41 insertions(+)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v4 13/13] mips: cevt-r4k: Update the r4k-clockevent frequency in sync with CPU

[Thomas Bogendoerfer]

On Thu, May 21, 2020 at 05:07:24PM +0300, Serge Semin wrote:
> Due to being embedded into the CPU cores MIPS count/compare timer
> frequency is changed together with the CPU clocks alteration.
> In case if frequency really changes the kernel clockevent framework
> must be notified, otherwise the kernel timers won't work correctly.
> Fix this by calling clockevents_update_freq() for each r4k clockevent
> handlers registered per available CPUs.
> 
> Traditionally MIPS r4k-clock are clocked with CPU frequency divided by 2.
> But this isn't true for some of the platforms. Due to this we have to save
> the basic CPU frequency, so then use it to scale the initial timer
> frequency (mips_hpt_frequency) and pass the updated value further to the
> clockevent framework.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  arch/mips/kernel/cevt-r4k.c | 44 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 44 insertions(+)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v4 03/13] mips: Add MIPS Release 5 support

[Serge Semin]

On Fri, May 22, 2020 at 09:27:43AM +0200, Thomas Bogendoerfer wrote:
> On Thu, May 21, 2020 at 05:07:14PM +0300, Serge Semin wrote:
> > There are five MIPS32/64 architecture releases currently available:
> > from 1 to 6 except fourth one, which was intentionally skipped.
> > Three of them can be called as major: 1st, 2nd and 6th, that not only
> > have some system level alterations, but also introduced significant
> > core/ISA level updates. The rest of the MIPS architecture releases are
> > minor.
> > 
> > Even though they don't have as much ISA/system/core level changes
> > as the major ones with respect to the previous releases, they still
> > provide a set of updates (I'd say they were intended to be the
> > intermediate releases before a major one) that might be useful for the
> > kernel and user-level code, when activated by the kernel or compiler.
> > In particular the following features were introduced or ended up being
> > available at/after MIPS32/64 Release 5 architecture:
> > + the last release of the misaligned memory access instructions,
> > + virtualisation - VZ ASE - is optional component of the arch,
> > + SIMD - MSA ASE - is optional component of the arch,
> > + DSP ASE is optional component of the arch,
> > + CP0.Status.FR=1 for CP1.FIR.F64=1 (pure 64-bit FPU general registers)
> >   must be available if FPU is implemented,
> > + CP1.FIR.Has2008 support is required so CP1.FCSR.{ABS2008,NAN2008} bits
> >   are available.
> > + UFR/UNFR aliases to access CP0.Status.FR from user-space by means of
> >   ctc1/cfc1 instructions (enabled by CP0.Config5.UFR),
> > + CP0.COnfig5.LLB=1 and eretnc instruction are implemented to without
> >   accidentally clearing LL-bit when returning from an interrupt,
> >   exception, or error trap,
> > + XPA feature together with extended versions of CPx registers is
> >   introduced, which needs to have mfhc0/mthc0 instructions available.
> > 
> > So due to these changes GNU GCC provides an extended instructions set
> > support for MIPS32/64 Release 5 by default like eretnc/mfhc0/mthc0. Even
> > though the architecture alteration isn't that big, it still worth to be
> > taken into account by the kernel software. Finally we can't deny that
> > some optimization/limitations might be found in future and implemented
> > on some level in kernel or compiler. In this case having even
> > intermediate MIPS architecture releases support would be more than
> > useful.
> > 
> > So the most of the changes provided by this commit can be split into
> > either compile- or runtime configs related. The compile-time related
> > changes are caused by adding the new CONFIG_CPU_MIPS32_R5/CONFIG_CPU_MIPSR5
> > configs and concern the code activating MIPSR2 or MIPSR6 already
> > implemented features (like eretnc/LLbit, mthc0/mfhc0). In addition
> > CPU_HAS_MSA can be now freely enabled for MIPS32/64 release 5 based
> > platforms as this is done for CPU_MIPS32_R6 CPUs. The runtime changes
> > concerns the features which are handled with respect to the MIPS ISA
> > revision detected at run-time by means of CP0.Config.{AT,AR} bits. Alas
> > these fields can be used to detect either r1 or r2 or r6 releases.
> > But since we know which CPUs in fact support the R5 arch, we can manually
> > set MIPS_CPU_ISA_M32R5/MIPS_CPU_ISA_M64R5 bit of c->isa_level and then
> > use cpu_has_mips32r5/cpu_has_mips64r5 where it's appropriate.
> > 
> > Since XPA/EVA provide too complex alterationss and to have them used with
> > MIPS32 Release 2 charged kernels (for compatibility with current platform
> > configs) they are left to be setup as a separate kernel configs.
> > 
> > Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> > Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> > Cc: Paul Burton <paulburton@kernel.org>
> > Cc: Ralf Baechle <ralf@linux-mips.org>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: devicetree@vger.kernel.org
> > ---
> >  arch/mips/Kconfig                    | 56 +++++++++++++++++++++++++---
> >  arch/mips/Makefile                   |  2 +
> >  arch/mips/include/asm/asmmacro.h     | 18 +++++----
> >  arch/mips/include/asm/compiler.h     |  5 +++
> >  arch/mips/include/asm/cpu-features.h | 27 ++++++++++----
> >  arch/mips/include/asm/cpu-info.h     |  2 +-
> >  arch/mips/include/asm/cpu-type.h     |  7 +++-
> >  arch/mips/include/asm/cpu.h          | 10 +++--
> >  arch/mips/include/asm/fpu.h          |  4 +-
> >  arch/mips/include/asm/hazards.h      |  8 ++--
> >  arch/mips/include/asm/module.h       |  4 ++
> >  arch/mips/include/asm/stackframe.h   |  2 +-
> >  arch/mips/include/asm/switch_to.h    |  8 ++--
> >  arch/mips/kernel/cpu-probe.c         | 17 +++++++++
> >  arch/mips/kernel/entry.S             |  6 +--
> >  arch/mips/kernel/proc.c              |  4 ++
> >  arch/mips/kernel/r4k_fpu.S           | 14 +++----
> >  arch/mips/kvm/vz.c                   |  6 +--
> >  arch/mips/lib/csum_partial.S         |  6 ++-
> >  arch/mips/mm/c-r4k.c                 |  7 ++--
> >  arch/mips/mm/sc-mips.c               |  7 ++--
> >  21 files changed, 163 insertions(+), 57 deletions(-)
> 
> applied to mips-next. I've changed the two /* fall through */ by fallthrough;
> while appliny. Running checkpatch would have caught that ;-)

Good. Thanks. Actually I've seen that warning, but just didn't know what way to
choose.) So I've decided to leave the comment-based Fall-through fixup seeing
the rest of the file is using the older way. By doing so I've kept the locally
implemented coding style. Though I've heard the explicit attribute "fallthrough;"
utilization is a preferred way of marking combined case statements.

-Sergey

> 
> Thomas.
> 
> -- 
> Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
> good idea.                                                [ RFC1925, 2.3 ]