From ef9e41df680a494dec92fe8d166cb2bc531b29a4 Mon Sep 17 00:00:00 2001 From: Michael Clark Date: Fri, 14 Dec 2018 00:18:39 +0000 Subject: [PATCH] RISC-V: Fix CLINT timecmp low 32-bit writes A missing shift made updates to the low order bits of timecmp erroneously copy the old low order bits into the high order bits of the 64-bit timecmp register. Add the missing shift and rename timecmp local variables to timecmp_hi and timecmp_lo. This bug didn't show up as the low order bits are usually written first followed by the high order bits meaning the high order bits contained an invalid value between the timecmp_lo and timecmp_hi update. Cc: Palmer Dabbelt Cc: Sagar Karandikar Cc: Bastian Koppelmann Cc: Alistair Francis Co-Authored-by: Johannes Haring Signed-off-by: Michael Clark Reviewed-by: Alistair Francis Signed-off-by: Alistair Francis Signed-off-by: Palmer Dabbelt --- hw/riscv/sifive_clint.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/hw/riscv/sifive_clint.c b/hw/riscv/sifive_clint.c index 0d2fd52487..d4c159e937 100644 --- a/hw/riscv/sifive_clint.c +++ b/hw/riscv/sifive_clint.c @@ -146,15 +146,15 @@ static void sifive_clint_write(void *opaque, hwaddr addr, uint64_t value, error_report("clint: invalid timecmp hartid: %zu", hartid); } else if ((addr & 0x7) == 0) { /* timecmp_lo */ - uint64_t timecmp = env->timecmp; + uint64_t timecmp_hi = env->timecmp >> 32; sifive_clint_write_timecmp(RISCV_CPU(cpu), - timecmp << 32 | (value & 0xFFFFFFFF)); + timecmp_hi << 32 | (value & 0xFFFFFFFF)); return; } else if ((addr & 0x7) == 4) { /* timecmp_hi */ - uint64_t timecmp = env->timecmp; + uint64_t timecmp_lo = env->timecmp; sifive_clint_write_timecmp(RISCV_CPU(cpu), - value << 32 | (timecmp & 0xFFFFFFFF)); + value << 32 | (timecmp_lo & 0xFFFFFFFF)); } else { error_report("clint: invalid timecmp write: %08x", (uint32_t)addr); }