From abd9a20665496aa4f3680fbbd42b5c389ea53d1c Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Wed, 24 Aug 2022 15:17:00 -0700 Subject: [PATCH] hw/riscv: virt: Add PMU DT node to the device tree Qemu virt machine can support few cache events and cycle/instret counters. It also supports counter overflow for these events. Add a DT node so that OpenSBI/Linux kernel is aware of the virt machine capabilities. There are some dummy nodes added for testing as well. Acked-by: Alistair Francis Signed-off-by: Atish Patra Signed-off-by: Atish Patra Message-Id: <20220824221701.41932-5-atishp@rivosinc.com> Signed-off-by: Alistair Francis --- hw/riscv/virt.c | 16 +++++++++++++ target/riscv/pmu.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++ target/riscv/pmu.h | 1 + 3 files changed, 74 insertions(+) diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c index ff8c0df5cd..befa9d2c26 100644 --- a/hw/riscv/virt.c +++ b/hw/riscv/virt.c @@ -30,6 +30,7 @@ #include "hw/char/serial.h" #include "target/riscv/cpu.h" #include "hw/core/sysbus-fdt.h" +#include "target/riscv/pmu.h" #include "hw/riscv/riscv_hart.h" #include "hw/riscv/virt.h" #include "hw/riscv/boot.h" @@ -708,6 +709,20 @@ static void create_fdt_socket_aplic(RISCVVirtState *s, aplic_phandles[socket] = aplic_s_phandle; } +static void create_fdt_pmu(RISCVVirtState *s) +{ + char *pmu_name; + MachineState *mc = MACHINE(s); + RISCVCPU hart = s->soc[0].harts[0]; + + pmu_name = g_strdup_printf("/soc/pmu"); + qemu_fdt_add_subnode(mc->fdt, pmu_name); + qemu_fdt_setprop_string(mc->fdt, pmu_name, "compatible", "riscv,pmu"); + riscv_pmu_generate_fdt_node(mc->fdt, hart.cfg.pmu_num, pmu_name); + + g_free(pmu_name); +} + static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry *memmap, bool is_32_bit, uint32_t *phandle, uint32_t *irq_mmio_phandle, @@ -1036,6 +1051,7 @@ static void create_fdt(RISCVVirtState *s, const MemMapEntry *memmap, create_fdt_flash(s, memmap); create_fdt_fw_cfg(s, memmap); + create_fdt_pmu(s); update_bootargs: if (cmdline && *cmdline) { diff --git a/target/riscv/pmu.c b/target/riscv/pmu.c index a5f504e53c..b8e56d2b7b 100644 --- a/target/riscv/pmu.c +++ b/target/riscv/pmu.c @@ -20,11 +20,68 @@ #include "cpu.h" #include "pmu.h" #include "sysemu/cpu-timers.h" +#include "sysemu/device_tree.h" #define RISCV_TIMEBASE_FREQ 1000000000 /* 1Ghz */ #define MAKE_32BIT_MASK(shift, length) \ (((uint32_t)(~0UL) >> (32 - (length))) << (shift)) +/* + * To keep it simple, any event can be mapped to any programmable counters in + * QEMU. The generic cycle & instruction count events can also be monitored + * using programmable counters. In that case, mcycle & minstret must continue + * to provide the correct value as well. Heterogeneous PMU per hart is not + * supported yet. Thus, number of counters are same across all harts. + */ +void riscv_pmu_generate_fdt_node(void *fdt, int num_ctrs, char *pmu_name) +{ + uint32_t fdt_event_ctr_map[20] = {}; + uint32_t cmask; + + /* All the programmable counters can map to any event */ + cmask = MAKE_32BIT_MASK(3, num_ctrs); + + /* + * The event encoding is specified in the SBI specification + * Event idx is a 20bits wide number encoded as follows: + * event_idx[19:16] = type + * event_idx[15:0] = code + * The code field in cache events are encoded as follows: + * event_idx.code[15:3] = cache_id + * event_idx.code[2:1] = op_id + * event_idx.code[0:0] = result_id + */ + + /* SBI_PMU_HW_CPU_CYCLES: 0x01 : type(0x00) */ + fdt_event_ctr_map[0] = cpu_to_be32(0x00000001); + fdt_event_ctr_map[1] = cpu_to_be32(0x00000001); + fdt_event_ctr_map[2] = cpu_to_be32(cmask | 1 << 0); + + /* SBI_PMU_HW_INSTRUCTIONS: 0x02 : type(0x00) */ + fdt_event_ctr_map[3] = cpu_to_be32(0x00000002); + fdt_event_ctr_map[4] = cpu_to_be32(0x00000002); + fdt_event_ctr_map[5] = cpu_to_be32(cmask | 1 << 2); + + /* SBI_PMU_HW_CACHE_DTLB : 0x03 READ : 0x00 MISS : 0x00 type(0x01) */ + fdt_event_ctr_map[6] = cpu_to_be32(0x00010019); + fdt_event_ctr_map[7] = cpu_to_be32(0x00010019); + fdt_event_ctr_map[8] = cpu_to_be32(cmask); + + /* SBI_PMU_HW_CACHE_DTLB : 0x03 WRITE : 0x01 MISS : 0x00 type(0x01) */ + fdt_event_ctr_map[9] = cpu_to_be32(0x0001001B); + fdt_event_ctr_map[10] = cpu_to_be32(0x0001001B); + fdt_event_ctr_map[11] = cpu_to_be32(cmask); + + /* SBI_PMU_HW_CACHE_ITLB : 0x04 READ : 0x00 MISS : 0x00 type(0x01) */ + fdt_event_ctr_map[12] = cpu_to_be32(0x00010021); + fdt_event_ctr_map[13] = cpu_to_be32(0x00010021); + fdt_event_ctr_map[14] = cpu_to_be32(cmask); + + /* This a OpenSBI specific DT property documented in OpenSBI docs */ + qemu_fdt_setprop(fdt, pmu_name, "riscv,event-to-mhpmcounters", + fdt_event_ctr_map, sizeof(fdt_event_ctr_map)); +} + static bool riscv_pmu_counter_valid(RISCVCPU *cpu, uint32_t ctr_idx) { if (ctr_idx < 3 || ctr_idx >= RV_MAX_MHPMCOUNTERS || diff --git a/target/riscv/pmu.h b/target/riscv/pmu.h index 036653627f..3004ce37b6 100644 --- a/target/riscv/pmu.h +++ b/target/riscv/pmu.h @@ -31,5 +31,6 @@ int riscv_pmu_init(RISCVCPU *cpu, int num_counters); int riscv_pmu_update_event_map(CPURISCVState *env, uint64_t value, uint32_t ctr_idx); int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum riscv_pmu_event_idx event_idx); +void riscv_pmu_generate_fdt_node(void *fdt, int num_counters, char *pmu_name); int riscv_pmu_setup_timer(CPURISCVState *env, uint64_t value, uint32_t ctr_idx); -- 2.39.5