From d42df0ea5dd58cfda5e1466487f93b5b90a67594 Mon Sep 17 00:00:00 2001 From: Frank Chang Date: Wed, 20 Apr 2022 16:08:58 +0800 Subject: [PATCH] hw/intc: Support 32/64-bit mtimecmp and mtime accesses in RISC-V ACLINT RISC-V privilege spec defines that: * In RV32, memory-mapped writes to mtimecmp modify only one 32-bit part of the register. * For RV64, naturally aligned 64-bit memory accesses to the mtime and mtimecmp registers are additionally supported and are atomic. It's possible to perform both 32/64-bit read/write accesses to both mtimecmp and mtime registers. Signed-off-by: Frank Chang Reviewed-by: Alistair Francis Reviewed-by: Jim Shu Message-Id: <20220420080901.14655-3-frank.chang@sifive.com> Signed-off-by: Alistair Francis --- hw/intc/riscv_aclint.c | 42 +++++++++++++++++++++++++++--------------- 1 file changed, 27 insertions(+), 15 deletions(-) diff --git a/hw/intc/riscv_aclint.c b/hw/intc/riscv_aclint.c index 37e9ace801..ff082090fe 100644 --- a/hw/intc/riscv_aclint.c +++ b/hw/intc/riscv_aclint.c @@ -126,9 +126,9 @@ static uint64_t riscv_aclint_mtimer_read(void *opaque, hwaddr addr, qemu_log_mask(LOG_GUEST_ERROR, "aclint-mtimer: invalid hartid: %zu", hartid); } else if ((addr & 0x7) == 0) { - /* timecmp_lo */ + /* timecmp_lo for RV32/RV64 or timecmp for RV64 */ uint64_t timecmp = env->timecmp; - return timecmp & 0xFFFFFFFF; + return (size == 4) ? (timecmp & 0xFFFFFFFF) : timecmp; } else if ((addr & 0x7) == 4) { /* timecmp_hi */ uint64_t timecmp = env->timecmp; @@ -139,8 +139,9 @@ static uint64_t riscv_aclint_mtimer_read(void *opaque, hwaddr addr, return 0; } } else if (addr == mtimer->time_base) { - /* time_lo */ - return cpu_riscv_read_rtc(mtimer->timebase_freq) & 0xFFFFFFFF; + /* time_lo for RV32/RV64 or timecmp for RV64 */ + uint64_t rtc = cpu_riscv_read_rtc(mtimer->timebase_freq); + return (size == 4) ? (rtc & 0xFFFFFFFF) : rtc; } else if (addr == mtimer->time_base + 4) { /* time_hi */ return (cpu_riscv_read_rtc(mtimer->timebase_freq) >> 32) & 0xFFFFFFFF; @@ -167,18 +168,29 @@ static void riscv_aclint_mtimer_write(void *opaque, hwaddr addr, qemu_log_mask(LOG_GUEST_ERROR, "aclint-mtimer: invalid hartid: %zu", hartid); } else if ((addr & 0x7) == 0) { - /* timecmp_lo */ - uint64_t timecmp_hi = env->timecmp >> 32; - riscv_aclint_mtimer_write_timecmp(mtimer, RISCV_CPU(cpu), hartid, - timecmp_hi << 32 | (value & 0xFFFFFFFF), - mtimer->timebase_freq); - return; + if (size == 4) { + /* timecmp_lo for RV32/RV64 */ + uint64_t timecmp_hi = env->timecmp >> 32; + riscv_aclint_mtimer_write_timecmp(mtimer, RISCV_CPU(cpu), hartid, + timecmp_hi << 32 | (value & 0xFFFFFFFF), + mtimer->timebase_freq); + } else { + /* timecmp for RV64 */ + riscv_aclint_mtimer_write_timecmp(mtimer, RISCV_CPU(cpu), hartid, + value, mtimer->timebase_freq); + } } else if ((addr & 0x7) == 4) { - /* timecmp_hi */ - uint64_t timecmp_lo = env->timecmp; - riscv_aclint_mtimer_write_timecmp(mtimer, RISCV_CPU(cpu), hartid, - value << 32 | (timecmp_lo & 0xFFFFFFFF), - mtimer->timebase_freq); + if (size == 4) { + /* timecmp_hi for RV32/RV64 */ + uint64_t timecmp_lo = env->timecmp; + riscv_aclint_mtimer_write_timecmp(mtimer, RISCV_CPU(cpu), hartid, + value << 32 | (timecmp_lo & 0xFFFFFFFF), + mtimer->timebase_freq); + } else { + qemu_log_mask(LOG_GUEST_ERROR, + "aclint-mtimer: invalid timecmp_hi write: %08x", + (uint32_t)addr); + } } else { qemu_log_mask(LOG_UNIMP, "aclint-mtimer: invalid timecmp write: %08x", -- 2.11.0