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RISC-V: selftests: cbo: Ensure asm operands match constraints

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The 'i' constraint expects a constant operand, which fn and its
constant derivative MK_CBO(fn) are, but passing fn through a function
as a parameter and using a local variable for MK_CBO(fn) allow the
compiler to lose sight of that when no optimization is done. Use
a macro instead of a function and skip the local variable to ensure
the compiler uses constants, matching the asm constraints.

Reported-by: Yunhui Cui <cuiyunhui@bytedance.com>
Closes: https://lore.kernel.org/all/20240117082514.42967-1-cuiyunhui@bytedance.com
Fixes: a29e2a48afe3 ("RISC-V: selftests: Add CBO tests")
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240117130933.57514-2-ajones@ventanamicro.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Andrew Jones 2024-01-17 14:09:34 +01:00 committed by Palmer Dabbelt
parent a894e8ed09
commit 0de65288d7
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1 changed files with 8 additions and 10 deletions
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18
tools/testing/selftests/riscv/hwprobe/cbo.c
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@ -36,16 +36,14 @@ static void sigill_handler(int sig, siginfo_t *info, void *context)
regs[0] += 4;
}
static void cbo_insn(char *base, int fn)
{
uint32_t insn = MK_CBO(fn);
asm volatile(
"mv a0, %0\n"
"li a1, %1\n"
".4byte %2\n"
: : "r" (base), "i" (fn), "i" (insn) : "a0", "a1", "memory");
}
#define cbo_insn(base, fn) \
({ \
asm volatile( \
"mv a0, %0\n" \
"li a1, %1\n" \
".4byte %2\n" \
: : "r" (base), "i" (fn), "i" (MK_CBO(fn)) : "a0", "a1", "memory"); \
})
static void cbo_inval(char *base) { cbo_insn(base, 0); }
static void cbo_clean(char *base) { cbo_insn(base, 1); }