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c42e2f0767
RISCV_HWPROBE_KEY_CPUPERF_0 was mistakenly flagged as a bitmask in
hwprobe_key_is_bitmask(), when in reality it was an enum value. This
causes problems when used in conjunction with RISCV_HWPROBE_WHICH_CPUS,
since SLOW, FAST, and EMULATED have values whose bits overlap with
each other. If the caller asked for the set of CPUs that was SLOW or
EMULATED, the returned set would also include CPUs that were FAST.
Introduce a new hwprobe key, RISCV_HWPROBE_KEY_MISALIGNED_PERF, which
returns the same values in response to a direct query (with no flags),
but is properly handled as an enumerated value. As a result, SLOW,
FAST, and EMULATED are all correctly treated as distinct values under
the new key when queried with the WHICH_CPUS flag.
Leave the old key in place to avoid disturbing applications which may
have already come to rely on the key, with or without its broken
behavior with respect to the WHICH_CPUS flag.
Fixes: e178bf146e ("RISC-V: hwprobe: Introduce which-cpus flag")
Signed-off-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240809214444.3257596-2-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
43 lines
863 B
C
43 lines
863 B
C
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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/*
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* Copyright 2023 Rivos, Inc
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*/
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#ifndef _ASM_HWPROBE_H
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#define _ASM_HWPROBE_H
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#include <uapi/asm/hwprobe.h>
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#define RISCV_HWPROBE_MAX_KEY 9
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static inline bool riscv_hwprobe_key_is_valid(__s64 key)
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{
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return key >= 0 && key <= RISCV_HWPROBE_MAX_KEY;
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}
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static inline bool hwprobe_key_is_bitmask(__s64 key)
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{
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switch (key) {
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case RISCV_HWPROBE_KEY_BASE_BEHAVIOR:
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case RISCV_HWPROBE_KEY_IMA_EXT_0:
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case RISCV_HWPROBE_KEY_CPUPERF_0:
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return true;
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}
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return false;
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}
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static inline bool riscv_hwprobe_pair_cmp(struct riscv_hwprobe *pair,
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struct riscv_hwprobe *other_pair)
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{
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if (pair->key != other_pair->key)
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return false;
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if (hwprobe_key_is_bitmask(pair->key))
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return (pair->value & other_pair->value) == other_pair->value;
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return pair->value == other_pair->value;
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}
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#endif
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