[PATCH v3 0/1] Common csr_read_num() and csr_write_num() for RISC-V

From: Anup Patel <apatel@ventanamicro.com>
To: Sunil V L <sunilvl@ventanamicro.com>,
	"Rafael J . Wysocki" <rafael@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Alexandre Ghiti <alex@ghiti.fr>, Len Brown <lenb@kernel.org>,
	Atish Patra <atish.patra@linux.dev>,
	Andrew Jones <ajones@ventanamicro.com>,
	Anup Patel <anup@brainfault.org>, Will Deacon <will@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	linux-acpi@vger.kernel.org, linux-riscv@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Anup Patel <apatel@ventanamicro.com>
Subject: [PATCH v3 0/1] Common csr_read_num() and csr_write_num() for RISC-V
Date: Tue, 14 Oct 2025 18:51:05 +0530	[thread overview]
Message-ID: <20251014132106.181155-1-apatel@ventanamicro.com> (raw)

Some of the RISC-V drivers (such as RISC-V PMU and ACPI CPPC) need to
access CSR based on CSR number discovered from somewhere. Add common
RISC-V csr_read_num() and csr_write_num() functions under arch/riscv
for such drivers.

These patches can be found in the riscv_csr_read_num_v3 branch at:
https://github.com/avpatel/linux.git

Changes since v2:
 - Rebase on Linux-6.18-rc1
 - Added reviewed-by tags

Changes since v1:
 - Make "out_err" mandatory for csr_read_num() and csr_write_num()
   in PATCH2 as suggested by Sunil and Drew. This also helps further
   simplify csr_read_num() and csr_write_num().

Anup Patel (1):
  RISC-V: Add common csr_read_num() and csr_write_num() functions

 arch/riscv/include/asm/csr.h |   3 +
 arch/riscv/kernel/Makefile   |   1 +
 arch/riscv/kernel/csr.c      | 165 +++++++++++++++++++++++++++++++++++
 drivers/acpi/riscv/cppc.c    |  17 ++--
 drivers/perf/riscv_pmu.c     |  54 ++----------
 5 files changed, 184 insertions(+), 56 deletions(-)
 create mode 100644 arch/riscv/kernel/csr.c

-- 
2.43.0