Commit Graph

22 Commits

Author SHA1 Message Date
Serge Semin ab7c01fdc3 mips: Add MIPS Release 5 support
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
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-05-22 09:09:01 +02:00
Jiaxun Yang 51522217f6
MIPS: Loongson64: Bump ISA level to MIPSR2
Despite early sample of Loongson-3A1000, the whole Loongson64 family have
implemented all the features required by MIPS64 Release2. Thus we decide to
bump the ISA option to R2.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: chenhc@lemote.com
Cc: paul.burton@mips.com
Cc: linux-kernel@vger.kernel.org
2020-01-23 10:26:48 -08:00
Huacai Chen caed1d1b20
MIPS: Loongson: Unify LOONGSON3/LOONGSON64 Kconfig usage
There are mixed LOONGSON3/LOONGSON64 usages in recently changes, let's
establish some rules:

1, In Kconfig symbols, we only use CPU_LOONGSON64, MACH_LOONGSON64 and
SYS_HAS_CPU_LOONGSON64, all other derived symbols use "LOONGSON3" since
they all not widely-used symbols and sometimes not suitable for all
64-bit Loongson processors. E.g., we use symbols LOONGSON3_ENHANCEMENT,
CPU_LOONGSON3_WORKAROUNDS, etc.

2, Hide GSx64/GSx64E in Kconfig title since it is not useful for
general users. However, in the full description we use a more detailed
manner. E.g., GS264/GS464/GS464E/GS464V.

All Kconfig titles and descriptions of Loongson processors and machines
have also been updated in this patch for consistency.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Cc: linux-mips@vger.kernel.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhuacai@gmail.com>
2019-11-11 10:43:54 -08:00
Jiaxun Yang 268a2d6001
MIPS: Loongson64: Rename CPU TYPES
CPU_LOONGSON2 -> CPU_LOONGSON2EF
CPU_LOONGSON3 -> CPU_LOONGSON64

As newer loongson-2 products (2G/2H/2K1000) can share kernel
implementation with loongson-3 while 2E/2F are less similar with
other LOONGSON64 products.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: chenhc@lemote.com
Cc: paul.burton@mips.com
2019-10-31 15:03:10 -07:00
Paul Burton 378ed6f0e3
MIPS: Avoid using .set mips0 to restore ISA
We currently have 2 commonly used methods for switching ISA within
assembly code, then restoring the original ISA.

  1) Using a pair of .set push & .set pop directives. For example:

     .set	push
     .set	mips32r2
     <some_insn>
     .set	pop

  2) Using .set mips0 to restore the ISA originally specified on the
     command line. For example:

     .set	mips32r2
     <some_insn>
     .set	mips0

Unfortunately method 2 does not work with nanoMIPS toolchains, where the
assembler rejects the .set mips0 directive like so:

     Error: cannot change ISA from nanoMIPS to mips0

In preparation for supporting nanoMIPS builds, switch all instances of
method 2 in generic non-platform-specific code to use push & pop as in
method 1 instead. The .set push & .set pop is arguably cleaner anyway,
and if nothing else it's good to consistently use one method.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21037/
Cc: linux-mips@linux-mips.org
2018-11-09 10:23:19 -08:00
Andrea Gelmini 20430e7648 MIPS: hazards.h: Fix typo
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: chenhc@lemote.com
Cc: james.hogan@imgtec.com
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13317/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28 12:35:06 +02:00
Huacai Chen 1e820da3c9 MIPS: Loongson-3: Introduce CONFIG_LOONGSON3_ENHANCEMENT
New Loongson 3 CPU (since Loongson-3A R2, as opposed to Loongson-3A R1,
Loongson-3B R1 and Loongson-3B R2) has many enhancements, such as FTLB,
L1-VCache, EI/DI/Wait/Prefetch instruction, DSP/DSPv2 ASE, User Local
register, Read-Inhibit/Execute-Inhibit, SFB (Store Fill Buffer), Fast
TLB refill support, etc.

This patch introduce a config option, CONFIG_LOONGSON3_ENHANCEMENT, to
enable those enhancements which are not probed at run time. If you want
a generic kernel to run on all Loongson 3 machines, please say 'N'
here. If you want a high-performance kernel to run on new Loongson 3
machines only, please say 'Y' here.

Some additional explanations:
1) SFB locates between core and L1 cache, it causes memory access out
   of order, so writel/outl (and other similar functions) need a I/O
   reorder barrier.
2) Loongson 3 has a bug that di instruction can not save the irqflag,
   so arch_local_irq_save() is modified. Since CPU_MIPSR2 is selected
   by CONFIG_LOONGSON3_ENHANCEMENT, generic kernel doesn't use ei/di
   at all.
3) CPU_HAS_PREFETCH is selected by CONFIG_LOONGSON3_ENHANCEMENT, so
   MIPS_CPU_PREFETCH (used by uasm) probing is also put in this patch.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12755/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:02:15 +02:00
James Hogan e50f0e3135 MIPS: hazards: Add hazard macros for tlb read
Add hazard macros to <asm/hazards.h> for the following hazards around
tlbr (TLB read) instructions, which are used in TLB dumping code and
some KVM TLB management code:

- mtc0_tlbr_hazard
  Between mtc0 (Index) and tlbr. This is copied from mtc0_tlbw_hazard in
  all cases on the assumption that tlbr always has similar data user
  timings to tlbw.

- tlb_read_hazard
  Between tlbr and mfc0 (various TLB registers). This is copied from
  tlbw_use_hazard in all cases on the assumption that tlbr has similar
  data writer characteristics to tlbw, and mfc0 has similar data user
  characteristics to loads and stores.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10078/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-06-21 21:52:28 +02:00
Markos Chandras f52fca9713 MIPS: asm: hazards: Add MIPSR6 definitions
Add the MIPSR6 related definitions to MIPS hazards

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:19 +00:00
Ralf Baechle 02b849f761 MIPS: Get rid of the use of .macro in C code.
It fails with LTO and probably has always been a fragile.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-04-11 15:39:51 +02:00
Ralf Baechle 8bfc245f9a Merge branch 'mips-next-3.9' of git://git.linux-mips.org/pub/scm/john/linux-john into mips-for-linux-next 2013-02-21 12:51:33 +01:00
Jayachandran C 5a4cbe3811 MIPS: Netlogic: No hazards needed for XLR/XLS
TLB and COP0 hazards are handled in hardware for Netlogic XLR/XLS
SoCs. Update hazards.h to pick more optimal set of definitions when
compiling for XLR/XLS.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4788/
Signed-off-by: John Crispin <blogic@openwrt.org>
2013-02-17 00:15:21 +01:00
Ralf Baechle 7034228792 MIPS: Whitespace cleanup.
Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-02-01 10:00:22 +01:00
Ralf Baechle bdf20507da MIPS: PMC-Sierra Yosemite: Remove support.
Nobody seems to be interested anymore and upstream also never had an
ethernet driver.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-12-13 18:15:30 +01:00
Kevin Cernekee 1c7c44519a MIPS: BMIPS: Add CFLAGS, Makefile entries for BMIPS
Add CONFIG_CPU_BMIPS* in all of the right places, so that BMIPS kernel
images will compile and run.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2955/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-12-07 22:03:17 +00:00
Kevin Cernekee 15fb0a1509 MIPS: Clean up whitespace warning in hazards.h
Use a tab on second and subsequent lines of multiline #if's, for
consistency with the next commit.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2954/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-12-07 22:03:17 +00:00
Manuel Lauss 42a4f17dc3 MIPS: Alchemy: remove SOC_AU1X00 in favor of MIPS_ALCHEMY
Remove the CONFIG_SOC_AU1X00 Kconfig symbol since its job can also be done
by MACH_ALCHEMY, now renamed to MIPS_ALCHEMY.

Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
To: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/1461/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-08-05 13:26:06 +01:00
Zhang Le 5d57c31e57 MIPS: Loongson 2 needs no hazard barriers.
Quoting from Loongson2FUserGuide.pdf:

5.22.1 Hazards
The processor detects most of the pipeline hazards in hardware, including
CP0 hazards and load hazards. No NOP instructions are required to correct
instruction sequences.

Signed-off-by: Zhang Le <r0bertz@gentoo.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-05-14 13:50:26 +01:00
Manuel Lauss 2f794d099d MIPS: Alchemy: MIPS hazard workarounds are not required.
The Alchemy manuals state:

"All pipeline hazards and dependencies are enforced by hardware interlocks
 so that any sequence of instructions is guaranteed to execute correctly.
 Therefore, it is not necessary to pad legacy MIPS hazards (such as
 load delay slots and coprocessor accesses) with NOPs."

Run-tested on Au12x0, without any ill effects.

Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-03-30 14:49:46 +02:00
Shinya Kuribayashi a644b2774d MIPS: NEC VR5500 processor support fixup
Current VR5500 processor support lacks of some functions which are
expected to be configured/synthesized on arch initialization.

Here're some VR5500A spec notes:

* All execution hazards are handled in hardware.

* Once VR5500A stops the operation of the pipeline by WAIT instruction,
  it could return from the standby mode only when either a reset, NMI
  request, or all enabled interrupts is/are detected.  In other words,
  if interrupts are disabled by Status.IE=0, it keeps in standby mode
  even when interrupts are internally asserted.

  Notes on WAIT: The operation of the processor is undefined if WAIT
  insn is in the branch delay slot.  The operation is also undefined
  if WAIT insn is executed when Status.EXL and Status.ERL are set to 1.

* VR5500A core only implements the Load prefetch.

With these changes, it boots fine.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-03-11 21:11:07 +01:00
David Daney bd6d85c21a MIPS: For Cavium OCTEON handle hazards as per the R10000 handling.
For Cavium CPU, we treat the same as R10000, in that all hazards
are dealt with in hardware.

Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: Paul Gortmaker <Paul.Gortmaker@windriver.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-01-11 09:57:21 +00:00
Ralf Baechle 384740dc49 MIPS: Move headfiles to new location below arch/mips/include
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-10-11 16:18:52 +01:00