On Sun, Jan 9, 2022 at 11:55 PM Bin Meng <bmeng...@gmail.com> wrote: > > On Fri, Jan 7, 2022 at 10:27 AM Atish Patra <ati...@rivosinc.com> wrote: > > > > 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. > > > > Signed-off-by: Atish Patra <atish.pa...@wdc.com> > > Signed-off-by: Atish Patra <ati...@rivosinc.com> > > --- > > hw/riscv/virt.c | 38 ++++++++++++++++++++++++++++++++++++++ > > target/riscv/pmu.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ > > target/riscv/pmu.h | 1 + > > 3 files changed, 84 insertions(+) > > > > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c > > index 3af074148ef4..99154199091c 100644 > > --- a/hw/riscv/virt.c > > +++ b/hw/riscv/virt.c > > @@ -28,6 +28,7 @@ > > #include "hw/qdev-properties.h" > > #include "hw/char/serial.h" > > #include "target/riscv/cpu.h" > > +#include "target/riscv/pmu.h" > > #include "hw/riscv/riscv_hart.h" > > #include "hw/riscv/virt.h" > > #include "hw/riscv/boot.h" > > @@ -406,6 +407,33 @@ static void create_fdt_socket_plic(RISCVVirtState *s, > > g_free(plic_cells); > > } > > > > +static void create_fdt_socket_pmu(RISCVVirtState *s, > > + int socket, uint32_t *phandle, > > + uint32_t *intc_phandles) > > +{ > > + int cpu; > > + char *pmu_name; > > + uint32_t *pmu_cells; > > + MachineState *mc = MACHINE(s); > > + RISCVCPU hart = s->soc[socket].harts[0]; > > + > > + pmu_cells = g_new0(uint32_t, s->soc[socket].num_harts * 2); > > + > > + for (cpu = 0; cpu < s->soc[socket].num_harts; cpu++) { > > + pmu_cells[cpu * 2 + 0] = cpu_to_be32(intc_phandles[cpu]); > > + pmu_cells[cpu * 2 + 1] = cpu_to_be32(IRQ_PMU_OVF); > > + } > > + > > + 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); > > + g_free(pmu_cells); > > +} > > + > > + > > static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry > > *memmap, > > bool is_32_bit, uint32_t *phandle, > > uint32_t *irq_mmio_phandle, > > @@ -417,12 +445,20 @@ static void create_fdt_sockets(RISCVVirtState *s, > > const MemMapEntry *memmap, > > uint32_t *intc_phandles; > > MachineState *mc = MACHINE(s); > > uint32_t xplic_phandles[MAX_NODES]; > > + RISCVCPU hart; > > > > qemu_fdt_add_subnode(mc->fdt, "/cpus"); > > qemu_fdt_setprop_cell(mc->fdt, "/cpus", "timebase-frequency", > > RISCV_ACLINT_DEFAULT_TIMEBASE_FREQ); > > qemu_fdt_setprop_cell(mc->fdt, "/cpus", "#size-cells", 0x0); > > qemu_fdt_setprop_cell(mc->fdt, "/cpus", "#address-cells", 0x1); > > + > > + /* Add the node for isa extensions discovery */ > > + qemu_fdt_add_subnode(mc->fdt, "/cpus/riscv,isa-ext"); > > Looks like the ongoing discussion does not support this idea > https://lore.kernel.org/linux-riscv/20211224211632.1698523-1-ati...@rivosinc.com/ >
Yes. Palmer's comment arrived after I sent out the Qemu series. I will fix that in the next version once we have string parsing (riscv,isa) ready. > > + hart = s->soc[0].harts[0]; > > + if (hart.cfg.ext_sscof) { > > + qemu_fdt_setprop(mc->fdt, "/cpus/riscv,isa-ext", "sscofpmf", NULL, > > 0); > > + } > > qemu_fdt_add_subnode(mc->fdt, "/cpus/cpu-map"); > > > > for (socket = (riscv_socket_count(mc) - 1); socket >= 0; socket--) { > > @@ -445,6 +481,8 @@ static void create_fdt_sockets(RISCVVirtState *s, const > > MemMapEntry *memmap, > > create_fdt_socket_plic(s, memmap, socket, phandle, > > intc_phandles, xplic_phandles); > > > > + create_fdt_socket_pmu(s, socket, phandle, intc_phandles); > > + > > g_free(intc_phandles); > > g_free(clust_name); > > } > > diff --git a/target/riscv/pmu.c b/target/riscv/pmu.c > > index 15f161059fb7..b58a09c85616 100644 > > --- a/target/riscv/pmu.c > > +++ b/target/riscv/pmu.c > > @@ -19,11 +19,56 @@ > > #include "qemu/osdep.h" > > #include "cpu.h" > > #include "pmu.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. Hetergenous PMU per hart is not > > typo of Heterogeneous > > > + * 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); > > + > > + /* SBI_PMU_HW_CPU_CYCLES */ > > + 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 */ > > + 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 : READ : MISS */ > > + 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 : WRITE : MISS */ > > + 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 : READ : MISS */ > > + 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); > > + > > + qemu_fdt_setprop(fdt, pmu_name, "riscv,event-to-mhpmcounters", > > + fdt_event_ctr_map, sizeof(fdt_event_ctr_map)); > > Where is this documented? I can't find related discussion in the linux-riscv > ML. > These are OpenSBI specific DT bindings. OpenSBI will delete it during the dt fixup. https://github.com/riscv-software-src/opensbi/blob/master/docs/pmu_support.md Apologies for this confusion. I should have put a comment about this here. > Please add some comment blocks to explain where these magic numbers > (like 0x00010021) come from. > Sure. I will refer to the event encoding scheme and describe the details. > > +} > > + > > 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 9b400c3522f2..63c4b533b223 100644 > > --- a/target/riscv/pmu.h > > +++ b/target/riscv/pmu.h > > @@ -31,6 +31,7 @@ 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); > > target_ulong get_icount_ticks(bool brv32); > > int riscv_pmu_setup_timer(CPURISCVState *env, uint64_t value, > > uint32_t ctr_idx); > > -- > > Regards, > Bin