diff options
Diffstat (limited to 'hw/riscv/riscv-iommu-hpm.c')
| -rw-r--r-- | hw/riscv/riscv-iommu-hpm.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/hw/riscv/riscv-iommu-hpm.c b/hw/riscv/riscv-iommu-hpm.c new file mode 100644 index 0000000000..c5034bff79 --- /dev/null +++ b/hw/riscv/riscv-iommu-hpm.c @@ -0,0 +1,381 @@ +/* + * RISC-V IOMMU - Hardware Performance Monitor (HPM) helpers + * + * Copyright (C) 2022-2023 Rivos Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2 or later, as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "qemu/osdep.h" +#include "qemu/timer.h" +#include "cpu_bits.h" +#include "riscv-iommu-hpm.h" +#include "riscv-iommu.h" +#include "riscv-iommu-bits.h" +#include "trace.h" + +/* For now we assume IOMMU HPM frequency to be 1GHz so 1-cycle is of 1-ns. */ +static inline uint64_t get_cycles(void) +{ + return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); +} + +uint64_t riscv_iommu_hpmcycle_read(RISCVIOMMUState *s) +{ + const uint64_t cycle = riscv_iommu_reg_get64( + s, RISCV_IOMMU_REG_IOHPMCYCLES); + const uint32_t inhibit = riscv_iommu_reg_get32( + s, RISCV_IOMMU_REG_IOCOUNTINH); + const uint64_t ctr_prev = s->hpmcycle_prev; + const uint64_t ctr_val = s->hpmcycle_val; + + trace_riscv_iommu_hpm_read(cycle, inhibit, ctr_prev, ctr_val); + + if (get_field(inhibit, RISCV_IOMMU_IOCOUNTINH_CY)) { + /* + * Counter should not increment if inhibit bit is set. We can't really + * stop the QEMU_CLOCK_VIRTUAL, so we just return the last updated + * counter value to indicate that counter was not incremented. + */ + return (ctr_val & RISCV_IOMMU_IOHPMCYCLES_COUNTER) | + (cycle & RISCV_IOMMU_IOHPMCYCLES_OVF); + } + + return (ctr_val + get_cycles() - ctr_prev) | + (cycle & RISCV_IOMMU_IOHPMCYCLES_OVF); +} + +static void hpm_incr_ctr(RISCVIOMMUState *s, uint32_t ctr_idx) +{ + const uint32_t off = ctr_idx << 3; + uint64_t cntr_val; + + cntr_val = ldq_le_p(&s->regs_rw[RISCV_IOMMU_REG_IOHPMCTR_BASE + off]); + stq_le_p(&s->regs_rw[RISCV_IOMMU_REG_IOHPMCTR_BASE + off], cntr_val + 1); + + trace_riscv_iommu_hpm_incr_ctr(cntr_val); + + /* Handle the overflow scenario. */ + if (cntr_val == UINT64_MAX) { + /* + * Generate interrupt only if OF bit is clear. +1 to offset the cycle + * register OF bit. + */ + const uint32_t ovf = + riscv_iommu_reg_mod32(s, RISCV_IOMMU_REG_IOCOUNTOVF, + BIT(ctr_idx + 1), 0); + if (!get_field(ovf, BIT(ctr_idx + 1))) { + riscv_iommu_reg_mod64(s, + RISCV_IOMMU_REG_IOHPMEVT_BASE + off, + RISCV_IOMMU_IOHPMEVT_OF, + 0); + riscv_iommu_notify(s, RISCV_IOMMU_INTR_PM); + } + } +} + +void riscv_iommu_hpm_incr_ctr(RISCVIOMMUState *s, RISCVIOMMUContext *ctx, + unsigned event_id) +{ + const uint32_t inhibit = riscv_iommu_reg_get32( + s, RISCV_IOMMU_REG_IOCOUNTINH); + uint32_t did_gscid; + uint32_t pid_pscid; + uint32_t ctr_idx; + gpointer value; + uint32_t ctrs; + uint64_t evt; + + if (!(s->cap & RISCV_IOMMU_CAP_HPM)) { + return; + } + + value = g_hash_table_lookup(s->hpm_event_ctr_map, + GUINT_TO_POINTER(event_id)); + if (value == NULL) { + return; + } + + for (ctrs = GPOINTER_TO_UINT(value); ctrs != 0; ctrs &= ctrs - 1) { + ctr_idx = ctz32(ctrs); + if (get_field(inhibit, BIT(ctr_idx + 1))) { + continue; + } + + evt = riscv_iommu_reg_get64(s, + RISCV_IOMMU_REG_IOHPMEVT_BASE + (ctr_idx << 3)); + + /* + * It's quite possible that event ID has been changed in counter + * but hashtable hasn't been updated yet. We don't want to increment + * counter for the old event ID. + */ + if (event_id != get_field(evt, RISCV_IOMMU_IOHPMEVT_EVENT_ID)) { + continue; + } + + if (get_field(evt, RISCV_IOMMU_IOHPMEVT_IDT)) { + did_gscid = get_field(ctx->gatp, RISCV_IOMMU_DC_IOHGATP_GSCID); + pid_pscid = get_field(ctx->ta, RISCV_IOMMU_DC_TA_PSCID); + } else { + did_gscid = ctx->devid; + pid_pscid = ctx->process_id; + } + + if (get_field(evt, RISCV_IOMMU_IOHPMEVT_PV_PSCV)) { + /* + * If the transaction does not have a valid process_id, counter + * increments if device_id matches DID_GSCID. If the transaction + * has a valid process_id, counter increments if device_id + * matches DID_GSCID and process_id matches PID_PSCID. See + * IOMMU Specification, Chapter 5.23. Performance-monitoring + * event selector. + */ + if (ctx->process_id && + get_field(evt, RISCV_IOMMU_IOHPMEVT_PID_PSCID) != pid_pscid) { + continue; + } + } + + if (get_field(evt, RISCV_IOMMU_IOHPMEVT_DV_GSCV)) { + uint32_t mask = ~0; + + if (get_field(evt, RISCV_IOMMU_IOHPMEVT_DMASK)) { + /* + * 1001 1011 mask = GSCID + * 0000 0111 mask = mask ^ (mask + 1) + * 1111 1000 mask = ~mask; + */ + mask = get_field(evt, RISCV_IOMMU_IOHPMEVT_DID_GSCID); + mask = mask ^ (mask + 1); + mask = ~mask; + } + + if ((get_field(evt, RISCV_IOMMU_IOHPMEVT_DID_GSCID) & mask) != + (did_gscid & mask)) { + continue; + } + } + + hpm_incr_ctr(s, ctr_idx); + } +} + +/* Timer callback for cycle counter overflow. */ +void riscv_iommu_hpm_timer_cb(void *priv) +{ + RISCVIOMMUState *s = priv; + const uint32_t inhibit = riscv_iommu_reg_get32( + s, RISCV_IOMMU_REG_IOCOUNTINH); + uint32_t ovf; + + if (get_field(inhibit, RISCV_IOMMU_IOCOUNTINH_CY)) { + return; + } + + if (s->irq_overflow_left > 0) { + uint64_t irq_trigger_at = + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->irq_overflow_left; + timer_mod_anticipate_ns(s->hpm_timer, irq_trigger_at); + s->irq_overflow_left = 0; + return; + } + + ovf = riscv_iommu_reg_get32(s, RISCV_IOMMU_REG_IOCOUNTOVF); + if (!get_field(ovf, RISCV_IOMMU_IOCOUNTOVF_CY)) { + /* + * We don't need to set hpmcycle_val to zero and update hpmcycle_prev to + * current clock value. The way we calculate iohpmcycs will overflow + * and return the correct value. This avoids the need to synchronize + * timer callback and write callback. + */ + riscv_iommu_reg_mod32(s, RISCV_IOMMU_REG_IOCOUNTOVF, + RISCV_IOMMU_IOCOUNTOVF_CY, 0); + riscv_iommu_reg_mod64(s, RISCV_IOMMU_REG_IOHPMCYCLES, + RISCV_IOMMU_IOHPMCYCLES_OVF, 0); + riscv_iommu_notify(s, RISCV_IOMMU_INTR_PM); + } +} + +static void hpm_setup_timer(RISCVIOMMUState *s, uint64_t value) +{ + const uint32_t inhibit = riscv_iommu_reg_get32( + s, RISCV_IOMMU_REG_IOCOUNTINH); + uint64_t overflow_at, overflow_ns; + + if (get_field(inhibit, RISCV_IOMMU_IOCOUNTINH_CY)) { + return; + } + + /* + * We are using INT64_MAX here instead to UINT64_MAX because cycle counter + * has 63-bit precision and INT64_MAX is the maximum it can store. + */ + if (value) { + overflow_ns = INT64_MAX - value + 1; + } else { + overflow_ns = INT64_MAX; + } + + overflow_at = (uint64_t)qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + overflow_ns; + + if (overflow_at > INT64_MAX) { + s->irq_overflow_left = overflow_at - INT64_MAX; + overflow_at = INT64_MAX; + } + + timer_mod_anticipate_ns(s->hpm_timer, overflow_at); +} + +/* Updates the internal cycle counter state when iocntinh:CY is changed. */ +void riscv_iommu_process_iocntinh_cy(RISCVIOMMUState *s, bool prev_cy_inh) +{ + const uint32_t inhibit = riscv_iommu_reg_get32( + s, RISCV_IOMMU_REG_IOCOUNTINH); + + /* We only need to process CY bit toggle. */ + if (!(inhibit ^ prev_cy_inh)) { + return; + } + + trace_riscv_iommu_hpm_iocntinh_cy(prev_cy_inh); + + if (!(inhibit & RISCV_IOMMU_IOCOUNTINH_CY)) { + /* + * Cycle counter is enabled. Just start the timer again and update + * the clock snapshot value to point to the current time to make + * sure iohpmcycles read is correct. + */ + s->hpmcycle_prev = get_cycles(); + hpm_setup_timer(s, s->hpmcycle_val); + } else { + /* + * Cycle counter is disabled. Stop the timer and update the cycle + * counter to record the current value which is last programmed + * value + the cycles passed so far. + */ + s->hpmcycle_val = s->hpmcycle_val + (get_cycles() - s->hpmcycle_prev); + timer_del(s->hpm_timer); + } +} + +void riscv_iommu_process_hpmcycle_write(RISCVIOMMUState *s) +{ + const uint64_t val = riscv_iommu_reg_get64(s, RISCV_IOMMU_REG_IOHPMCYCLES); + const uint32_t ovf = riscv_iommu_reg_get32(s, RISCV_IOMMU_REG_IOCOUNTOVF); + + trace_riscv_iommu_hpm_cycle_write(ovf, val); + + /* + * Clear OF bit in IOCNTOVF if it's being cleared in IOHPMCYCLES register. + */ + if (get_field(ovf, RISCV_IOMMU_IOCOUNTOVF_CY) && + !get_field(val, RISCV_IOMMU_IOHPMCYCLES_OVF)) { + riscv_iommu_reg_mod32(s, RISCV_IOMMU_REG_IOCOUNTOVF, 0, + RISCV_IOMMU_IOCOUNTOVF_CY); + } + + s->hpmcycle_val = val & ~RISCV_IOMMU_IOHPMCYCLES_OVF; + s->hpmcycle_prev = get_cycles(); + hpm_setup_timer(s, s->hpmcycle_val); +} + +static inline bool check_valid_event_id(unsigned event_id) +{ + return event_id > RISCV_IOMMU_HPMEVENT_INVALID && + event_id < RISCV_IOMMU_HPMEVENT_MAX; +} + +static gboolean hpm_event_equal(gpointer key, gpointer value, gpointer udata) +{ + uint32_t *pair = udata; + + if (GPOINTER_TO_UINT(value) & (1 << pair[0])) { + pair[1] = GPOINTER_TO_UINT(key); + return true; + } + + return false; +} + +/* Caller must check ctr_idx against hpm_ctrs to see if its supported or not. */ +static void update_event_map(RISCVIOMMUState *s, uint64_t value, + uint32_t ctr_idx) +{ + unsigned event_id = get_field(value, RISCV_IOMMU_IOHPMEVT_EVENT_ID); + uint32_t pair[2] = { ctr_idx, RISCV_IOMMU_HPMEVENT_INVALID }; + uint32_t new_value = 1 << ctr_idx; + gpointer data; + + /* + * If EventID field is RISCV_IOMMU_HPMEVENT_INVALID + * remove the current mapping. + */ + if (event_id == RISCV_IOMMU_HPMEVENT_INVALID) { + data = g_hash_table_find(s->hpm_event_ctr_map, hpm_event_equal, pair); + + new_value = GPOINTER_TO_UINT(data) & ~(new_value); + if (new_value != 0) { + g_hash_table_replace(s->hpm_event_ctr_map, + GUINT_TO_POINTER(pair[1]), + GUINT_TO_POINTER(new_value)); + } else { + g_hash_table_remove(s->hpm_event_ctr_map, + GUINT_TO_POINTER(pair[1])); + } + + return; + } + + /* Update the counter mask if the event is already enabled. */ + if (g_hash_table_lookup_extended(s->hpm_event_ctr_map, + GUINT_TO_POINTER(event_id), + NULL, + &data)) { + new_value |= GPOINTER_TO_UINT(data); + } + + g_hash_table_insert(s->hpm_event_ctr_map, + GUINT_TO_POINTER(event_id), + GUINT_TO_POINTER(new_value)); +} + +void riscv_iommu_process_hpmevt_write(RISCVIOMMUState *s, uint32_t evt_reg) +{ + const uint32_t ctr_idx = (evt_reg - RISCV_IOMMU_REG_IOHPMEVT_BASE) >> 3; + const uint32_t ovf = riscv_iommu_reg_get32(s, RISCV_IOMMU_REG_IOCOUNTOVF); + uint64_t val = riscv_iommu_reg_get64(s, evt_reg); + + if (ctr_idx >= s->hpm_cntrs) { + return; + } + + trace_riscv_iommu_hpm_evt_write(ctr_idx, ovf, val); + + /* Clear OF bit in IOCNTOVF if it's being cleared in IOHPMEVT register. */ + if (get_field(ovf, BIT(ctr_idx + 1)) && + !get_field(val, RISCV_IOMMU_IOHPMEVT_OF)) { + /* +1 to offset CYCLE register OF bit. */ + riscv_iommu_reg_mod32( + s, RISCV_IOMMU_REG_IOCOUNTOVF, 0, BIT(ctr_idx + 1)); + } + + if (!check_valid_event_id(get_field(val, RISCV_IOMMU_IOHPMEVT_EVENT_ID))) { + /* Reset EventID (WARL) field to invalid. */ + val = set_field(val, RISCV_IOMMU_IOHPMEVT_EVENT_ID, + RISCV_IOMMU_HPMEVENT_INVALID); + riscv_iommu_reg_set64(s, evt_reg, val); + } + + update_event_map(s, val, ctr_idx); +} |