From: Yangyu Chen <cyy@cyyself.name>
To: linux-riscv@lists.infradead.org
Cc: "Elliott Hughes" <enh@google.com>,
"Charlie Jenkins" <charlie@rivosinc.com>,
"Jonathan Corbet" <corbet@lwn.net>,
"Paul Walmsley" <paul.walmsley@sifive.com>,
"Palmer Dabbelt" <palmer@dabbelt.com>,
"Evan Green" <evan@rivosinc.com>,
"Clément Léger" <cleger@rivosinc.com>,
"Conor Dooley" <conor.dooley@microchip.com>,
"Andrew Jones" <ajones@ventanamicro.com>,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
"Yangyu Chen" <cyy@cyyself.name>
Subject: [PATCH v2 2/3] docs: riscv: hwprobe: Clarify misaligned keys are values not bitmasks
Date: Fri, 24 May 2024 11:35:58 +0800 [thread overview]
Message-ID: <tencent_AC4A216B8D1B7C7882DCDA648E1AB8653108@qq.com> (raw)
In-Reply-To: <tencent_1E3506F09D08066B8F3BAEE136C4F887540A@qq.com>
The original documentation says hwprobe keys are bitmasks, but actually,
they are values. This patch clarifies this to avoid confusion.
Signed-off-by: Yangyu Chen <cyy@cyyself.name>
---
Documentation/arch/riscv/hwprobe.rst | 31 ++++++++++++++++------------
1 file changed, 18 insertions(+), 13 deletions(-)
diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
index d720712e9734..2e212956185d 100644
--- a/Documentation/arch/riscv/hwprobe.rst
+++ b/Documentation/arch/riscv/hwprobe.rst
@@ -192,25 +192,30 @@ The following keys are defined:
supported as defined in the RISC-V ISA manual starting from commit
d8ab5c78c207 ("Zihintpause is ratified").
-* :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: A bitmask that contains performance
+* :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: A value that contains performance
information about the selected set of processors.
- * :c:macro:`RISCV_HWPROBE_MISALIGNED_UNKNOWN`: The performance of misaligned
- scalar accesses is unknown.
+ * :c:macro:`RISCV_HWPROBE_MISALIGNED_MASK`: The bitmask of the misaligned
+ access performance field in the value of key `RISCV_HWPROBE_KEY_CPUPERF_0`.
- * :c:macro:`RISCV_HWPROBE_MISALIGNED_EMULATED`: Misaligned scalar accesses are
- emulated via software, either in or below the kernel. These accesses are
- always extremely slow.
+ The following values (not bitmasks) in this field are defined:
- * :c:macro:`RISCV_HWPROBE_MISALIGNED_SLOW`: Misaligned scalar accesses are
- slower than equivalent byte accesses. Misaligned accesses may be supported
- directly in hardware, or trapped and emulated by software.
+ * :c:macro:`RISCV_HWPROBE_MISALIGNED_UNKNOWN`: The performance of misaligned
+ scalar accesses is unknown.
- * :c:macro:`RISCV_HWPROBE_MISALIGNED_FAST`: Misaligned scalar accesses are
- faster than equivalent byte accesses.
+ * :c:macro:`RISCV_HWPROBE_MISALIGNED_EMULATED`: Misaligned scalar accesses are
+ emulated via software, either in or below the kernel. These accesses are
+ always extremely slow.
- * :c:macro:`RISCV_HWPROBE_MISALIGNED_UNSUPPORTED`: Misaligned scalar accesses
- are not supported at all and will generate a misaligned address fault.
+ * :c:macro:`RISCV_HWPROBE_MISALIGNED_SLOW`: Misaligned scalar accesses are
+ slower than equivalent byte accesses. Misaligned accesses may be supported
+ directly in hardware, or trapped and emulated by software.
+
+ * :c:macro:`RISCV_HWPROBE_MISALIGNED_FAST`: Misaligned scalar accesses are
+ faster than equivalent byte accesses.
+
+ * :c:macro:`RISCV_HWPROBE_MISALIGNED_UNSUPPORTED`: Misaligned scalar accesses
+ are not supported at all and will generate a misaligned address fault.
* :c:macro:`RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE`: An unsigned int which
represents the size of the Zicboz block in bytes.
--
2.45.1
next prev parent reply other threads:[~2024-05-24 3:36 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-24 3:34 [PATCH v2 0/3] docs: riscv: Some clarifies on hwprobe misaligned performance Yangyu Chen
2024-05-24 3:35 ` [PATCH v2 1/3] docs: riscv: Clarify risc-v hwprobe RISCV_HWPROBE_MISALIGNED_* docs Yangyu Chen
2024-05-24 3:35 ` Yangyu Chen [this message]
2024-05-24 3:35 ` [PATCH v2 3/3] RISC-V: hwprobe: not treat KEY_CPUPERF_0 as bitmask Yangyu Chen
2024-05-29 18:33 ` Evan Green
2024-06-26 14:43 ` Palmer Dabbelt
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