18 Commits

Author SHA1 Message Date
Palmer Dabbelt
59a582ad13
Merge patch series "RISC-V: Ensure Zicbom has a valid block size"
Andrew Jones <ajones@ventanamicro.com> says:

When a DT puts zicbom in the isa string, but does not provide a block
size, ALT_CMO_OP() will attempt to do cache operations on address
zero since the start address will be ANDed with zero. We can't simply
BUG() in riscv_init_cbom_blocksize() when we fail to find a block
size because the failure will happen before logging works, leaving
users to scratch their heads as to why the boot hung. Instead, ensure
Zicbom is disabled and output an error which will hopefully alert
people that the DT needs to be fixed. While at it, add a check that
the block size is a power-of-2 too.

* b4-shazam-merge:
  RISC-V: Ensure Zicbom has a valid block size
  RISC-V: Introduce riscv_isa_extension_check
  RISC-V: Improve use of isa2hwcap[]

Link: https://lore.kernel.org/r/20221129143447.49714-1-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-09 19:13:01 -08:00
Tong Tiangen
d33deda095
riscv/mm: hugepage's PG_dcache_clean flag is only set in head page
HugeTLB pages are always fully mapped, so only setting head page's
PG_dcache_clean flag is enough.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Link: https://lore.kernel.org/lkml/20220331065640.5777-2-songmuchun@bytedance.com/
Link: https://lore.kernel.org/r/20221024094725.3054311-2-tongtiangen@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-02 11:25:49 -08:00
Andrew Jones
5c20a3a9df RISC-V: Fix compilation without RISCV_ISA_ZICBOM
riscv_cbom_block_size and riscv_init_cbom_blocksize() should always
be available and riscv_init_cbom_blocksize() should always be
invoked, even when compiling without RISCV_ISA_ZICBOM enabled. This
is because disabling RISCV_ISA_ZICBOM means "don't use zicbom
instructions in the kernel" not "pretend there isn't zicbom, even
when there is". When zicbom is available, whether the kernel enables
its use with RISCV_ISA_ZICBOM or not, KVM will offer it to guests.
Ensure we can build KVM and that the block size is initialized even
when compiling without RISCV_ISA_ZICBOM.

Fixes: 8f7e001e0325 ("RISC-V: Clean up the Zicbom block size probing")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-21 11:52:39 +05:30
Palmer Dabbelt
6224db7881
Merge patch series "Some style cleanups for recent extension additions"
Heiko Stuebner <heiko@sntech.de> says:

As noted by some people, some parts of the recently added extensions
(svpbmt, zicbom) + t-head errata could use some styling upgrades.

So this series provides these.

changes in v2:
- add patch also converting cpufeature probe to BIT()
- update commit message in patch1 (Conor)

Heiko Stuebner (5):
  riscv: cleanup svpbmt cpufeature probing
  riscv: drop some idefs from CMO initialization
  riscv: use BIT() macros in t-head errata init
  riscv: use BIT() marco for cpufeature probing
  riscv: check for kernel config option in t-head memory types errata

arch/riscv/errata/thead/errata.c    | 14 ++++++-----
 arch/riscv/include/asm/cacheflush.h |  2 ++
 arch/riscv/kernel/cpufeature.c      | 39 ++++++++++++-----------------
 3 files changed, 26 insertions(+), 29 deletions(-)

Link: https://lore.kernel.org/r/20220905111027.2463297-1-heiko@sntech.de

* b4-shazam-merge:
  riscv: check for kernel config option in t-head memory types errata
  riscv: use BIT() marco for cpufeature probing
  riscv: use BIT() macros in t-head errata init
  riscv: drop some idefs from CMO initialization
  riscv: cleanup svpbmt cpufeature probing

Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-10-13 08:46:31 -07:00
Heiko Stuebner
f055268e39
riscv: drop some idefs from CMO initialization
Wrapping things in #ifdefs makes the code harder to read
while we also have IS_ENABLED() macros to do this in regular code
and the extension detection is not _that_ runtime critical.

So define a stub for riscv_noncoherent_supported() in the
non-CONFIG_RISCV_DMA_NONCOHERENT case and move the code to
us IS_ENABLED.

Suggested-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20220905111027.2463297-3-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-10-13 08:46:27 -07:00
Palmer Dabbelt
c589e3ca27
RISC-V: Avoid coupling the T-Head CMOs and Zicbom
We could make the T-Head CMOs depend on a new-enough assembler to have
Zicbom, but it's not strictly necessary because the T-Head CMOs
circumvent the assembler.

Fixes: 8f7e001e0325 ("RISC-V: Clean up the Zicbom block size probing")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220915170900.22685-1-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-09-17 01:48:24 -07:00
Palmer Dabbelt
8f7e001e03
RISC-V: Clean up the Zicbom block size probing
This fixes two issues: I truncated the warning's hart ID when porting to
the 64-bit hart ID code, and the original code's warning handling could
fire on an uninitialized hart ID.

The biggest change here is that riscv_cbom_block_size is no longer
initialized, as IMO the default isn't sane: there's nothing in the ISA
that mandates any specific cache block size, so falling back to one will
just silently produce the wrong answer on some systems.  This also
changes the probing order so the cache block size is known before
enabling Zicbom support.

CC: stable@vger.kernel.org
CC: Andrew Jones <ajones@ventanamicro.com>
CC: Heiko Stuebner <heiko@sntech.de>
CC: Atish Patra <atishp@rivosinc.com>
Fixes: 3aefb2ee5bdd ("riscv: implement Zicbom-based CMO instructions + the t-head variant")
Fixes: 1631ba1259d6 ("riscv: Add support for non-coherent devices using zicbom extension")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
[Conor: fixed the redefinition errors]
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220912224800.998121-1-mail@conchuod.ie
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-09-13 02:06:11 -07:00
Heiko Stuebner
1631ba1259
riscv: Add support for non-coherent devices using zicbom extension
The Zicbom ISA-extension was ratified in november 2021
and introduces instructions for dcache invalidate, clean
and flush operations.

Implement cache management operations for non-coherent devices
based on them.

Of course not all cores will support this, so implement an
alternative-based mechanism that replaces empty instructions
with ones done around Zicbom instructions.

As discussed in previous versions, assume the platform
being coherent by default so that non-coherent devices need
to get marked accordingly by firmware.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20220706231536.2041855-4-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-28 15:30:51 -07:00
Christoph Hellwig
885f7f8e30 mm: rename flush_icache_user_range to flush_icache_user_page
The function currently known as flush_icache_user_range only operates on
a single page.  Rename it to flush_icache_user_page as we'll need the
name flush_icache_user_range for something else soon.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20200515143646.3857579-20-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08 11:05:58 -07:00
Christoph Hellwig
396eb69c6e riscv: use asm-generic/cacheflush.h
RISC-V needs almost no cache flushing routines of its own.  Rely on
asm-generic/cacheflush.h for the defaults.

Also remove the pointless __KERNEL__ ifdef while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Link: http://lkml.kernel.org/r/20200515143646.3857579-18-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08 11:05:57 -07:00
Guo Ren
ab70a73aa4
riscv: Use flush_icache_mm for flush_icache_user_range
The only call path is:

__access_remote_vm -> copy_to_user_page -> flush_icache_user_range

Seems it's ok to use flush_icache_mm instead of flush_icache_all and
it could reduce flush_icache_all called on other harts.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
[Palmer: git-am wouldn't apply the patch, I did so manually]
Fixes: 08f051eda33b ("RISC-V: Flush I$ when making a dirty page executable")
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-03-03 10:28:10 -08:00
Paul Walmsley
2d69fbf3d0 riscv: fix build break after macro-to-function conversion in generic cacheflush.h
Commit c296d4dc13ae ("asm-generic: fix a compilation warning")
converted the various flush_*cache_* macros in
asm-generic/cacheflush.h to static inline functions.  This breaks
RISC-V builds, since RISC-V's cacheflush.h includes the generic
cacheflush.h and then undefines the macros to be overridden.

Fix by copying the subset of the no-op functions that are reused from
the generic cacheflush.h into the RISC-V cacheflush.h, and dropping
the include of the generic cacheflush.h.

Fixes: c296d4dc13ae ("asm-generic: fix a compilation warning")
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18 08:16:56 -07:00
Thomas Gleixner
50acfb2b76 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation version 2 this program is distributed
  in the hope that it will be useful but without any warranty without
  even the implied warranty of merchantability or fitness for a
  particular purpose see the gnu general public license for more
  details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 97 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00
Gary Guo
58de77545e
riscv: move flush_icache_{all,mm} to cacheflush.c
Currently, flush_icache_all is macro-expanded into a SBI call, yet no
asm/sbi.h is included in asm/cacheflush.h. This could be moved to
mm/cacheflush.c instead (SBI call will dominate performance-wise and
there is no worry to not have it inlined.

Currently, flush_icache_mm stays in kernel/smp.c, which looks like a
hack to prevent it from being compiled when CONFIG_SMP=n. It should
also be in mm/cacheflush.c.

Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-05-16 20:42:12 -07:00
Luc Van Oostenryck
2861ae302f
riscv: use NULL instead of a plain 0
sbi_remote_sfence_vma() & sbi_remote_fence_i() takes
a pointer as first argument but some macros call them with
a plain 0 which, while legal C, is frowned upon in the kernel.

Change this by replacing the 0 by NULL.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-06-07 08:01:50 -07:00
Andrew Waterman
921ebd8f2c RISC-V: Allow userspace to flush the instruction cache
Despite RISC-V having a direct 'fence.i' instruction available to
userspace (which we can't trap!), that's not actually viable when
running on Linux because the kernel might schedule a process on another
hart.  There is no way for userspace to handle this without invoking the
kernel (as it doesn't know the thread->hart mappings), so we've defined
a RISC-V specific system call to flush the instruction cache.

This patch adds both a system call and a VDSO entry.  If possible, we'd
like to avoid having the system call be considered part of the
user-facing ABI and instead restrict that to the VDSO entry -- both just
in general to avoid having additional user-visible ABI to maintain, and
because we'd prefer that users just call the VDSO entry because there
might be a better way to do this in the future (ie, one that doesn't
require entering the kernel).

Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 12:58:29 -08:00
Andrew Waterman
08f051eda3 RISC-V: Flush I$ when making a dirty page executable
The RISC-V ISA allows for instruction caches that are not coherent WRT
stores, even on a single hart.  As a result, we need to explicitly flush
the instruction cache whenever marking a dirty page as executable in
order to preserve the correct system behavior.

Local instruction caches aren't that scary (our implementations actually
flush the cache, but RISC-V is defined to allow higher-performance
implementations to exist), but RISC-V defines no way to perform an
instruction cache shootdown.  When explicitly asked to do so we can
shoot down remote instruction caches via an IPI, but this is a bit on
the slow side.

Instead of requiring an IPI to all harts whenever marking a page as
executable, we simply flush the currently running harts.  In order to
maintain correct behavior, we additionally mark every other hart as
needing a deferred instruction cache which will be taken before anything
runs on it.

Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 12:58:25 -08:00
Palmer Dabbelt
fab957c11e RISC-V: Atomic and Locking Code
This contains all the code that directly interfaces with the RISC-V
memory model.  While this code corforms to the current RISC-V ISA
specifications (user 2.2 and priv 1.10), the memory model is somewhat
underspecified in those documents.  There is a working group that hopes
to produce a formal memory model by the end of the year, but my
understanding is that the basic definitions we're relying on here won't
change significantly.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:45 -07:00