[PATCH v2 2/3] docs: riscv: hwprobe: Clarify misaligned keys are values not bitmasks

From: Yangyu Chen
Date: Thu May 23 2024 - 23:36:42 EST


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@xxxxxxxxxxxx>
---
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