Svpbmt (the S should be capitalized) is the
"Supervisor-mode: page-based memory types" extension
that specifies attributes for cacheability, idempotency
and ordering.
The relevant settings are done in special bits in PTEs:
Here is the svpbmt PTE format:
| 63 | 62-61 | 60-8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
N MT RSW D A G U X W R V
^
Of the Reserved bits [63:54] in a leaf PTE, the high bit is already
allocated (as the N bit), so bits [62:61] are used as the MT (aka
MemType) field. This field specifies one of three memory types that
are close equivalents (or equivalent in effect) to the three main x86
and ARMv8 memory types - as shown in the following table.
RISC-V
Encoding &
MemType RISC-V Description
---------- ------------------------------------------------
00 - PMA Normal Cacheable, No change to implied PMA memory type
01 - NC Non-cacheable, idempotent, weakly-ordered Main Memory
10 - IO Non-cacheable, non-idempotent, strongly-ordered I/O memory
11 - Rsvd Reserved for future standard use
As the extension will not be present on all implementations,
implement a method to handle cpufeatures via alternatives
to not incur runtime penalties on cpu variants not supporting
specific extensions and patch relevant code parts at runtime.
Co-developed-by: Wei Fu <wefu@redhat.com>
Signed-off-by: Wei Fu <wefu@redhat.com>
Co-developed-by: Liu Shaohua <liush@allwinnertech.com>
Signed-off-by: Liu Shaohua <liush@allwinnertech.com>
Co-developed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
[moved to use the alternatives mechanism]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Link: https://lore.kernel.org/r/20220511192921.2223629-10-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The sscofpmf extension allows counter overflow and filtering for
programmable counters. Enable the perf driver to handle the overflow
interrupt. The overflow interrupt is a hart local interrupt.
Thus, per cpu overflow interrupts are setup as a child under the root
INTC irq domain.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Currently, the /proc/cpuinfo outputs the entire riscv,isa string which
is not ideal when we have multiple ISA extensions present in the ISA
string. Some of them may not be enabled in kernel as well.
Same goes for the single letter extensions as well which prints the
entire ISA string. Some of they may not be valid ISA extensions as
well (e.g 'su')
Parse only the valid & enabled ISA extension and print them.
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Multi-letter extensions can be probed using exising
riscv_isa_extension_available API now. It doesn't support versioning
right now as there is no use case for it.
Individual extension specific implementation will be added during
each extension support.
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This patch adds riscv_isa bitmap which represents Host ISA features
common across all Host CPUs. The riscv_isa is not same as elf_hwcap
because elf_hwcap will only have ISA features relevant for user-space
apps whereas riscv_isa will have ISA features relevant to both kernel
and user-space apps.
One of the use-case for riscv_isa bitmap is in KVM hypervisor where
we will use it to do following operations:
1. Check whether hypervisor extension is available
2. Find ISA features that need to be virtualized (e.g. floating
point support, vector extension, etc.)
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
There are many different formats in each header now, such as
_ASM_XXX_H, __ASM_XXX_H, _ASM_RISCV_XXX_H, RISCV_XXX_H, etc., This patch
tries to unify the format by using _ASM_RISCV_XXX_H, because the most
header use it now. This patch also adds the conditional to the headers
if they lost it.
Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
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 version 2 as
published by the free software foundation 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 you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 503 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch contains the code that interfaces with ELF objects on RISC-V
systems, the vast majority of which is present to load kernel modules.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
