[RFC PATCH 5/9] lib:sbi: Support sscof extension in OpenSBI
Atish Patra
atish.patra at wdc.com
Thu Sep 9 13:40:27 PDT 2021
This patch adds sscof extension in pmu module which includes
following things.
1. Enable overflow irq when starting a counter.
2. Setting the correct event filters passed from supervisor.
3. Delegating the overflow interrupt to the supervisor.
4. Add RV32 support for sscof.
Signed-off-by: Atish Patra <atish.patra at wdc.com>
---
include/sbi/riscv_encoding.h | 19 ++++++++
lib/sbi/sbi_pmu.c | 85 ++++++++++++++++++++++++++++++------
2 files changed, 90 insertions(+), 14 deletions(-)
diff --git a/include/sbi/riscv_encoding.h b/include/sbi/riscv_encoding.h
index c2cf0f4d69f4..f71412eae563 100644
--- a/include/sbi/riscv_encoding.h
+++ b/include/sbi/riscv_encoding.h
@@ -173,6 +173,25 @@
#define HGATP_MODE_SHIFT HGATP32_MODE_SHIFT
#endif
+#if __riscv_xlen == 64
+#define MHPMEVENT_OF (_UL(1) << 63)
+#define MHPMEVENT_MINH (_UL(1) << 62)
+#define MHPMEVENT_SINH (_UL(1) << 61)
+#define MHPMEVENT_UINH (_UL(1) << 60)
+#define MHPMEVENT_VSINH (_UL(1) << 59)
+#define MHPMEVENT_VUINH (_UL(1) << 58)
+#else
+#define MHPMEVENT_OF (_ULL(1) << 63)
+#define MHPMEVENT_MINH (_ULL(1) << 62)
+#define MHPMEVENT_SINH (_ULL(1) << 61)
+#define MHPMEVENT_UINH (_ULL(1) << 60)
+#define MHPMEVENT_VSINH (_ULL(1) << 59)
+#define MHPMEVENT_VUINH (_ULL(1) << 58)
+
+#define MHPMEVENTH_OF (_UL(1) << 31)
+#endif
+
+#define MHPMEVENT_SSCOF_MASK _ULL(0xFFFF000000000000)
/* ===== User-level CSRs ===== */
/* User Trap Setup (N-extension) */
diff --git a/lib/sbi/sbi_pmu.c b/lib/sbi/sbi_pmu.c
index c276a46e2876..bbbd033b4cfe 100644
--- a/lib/sbi/sbi_pmu.c
+++ b/lib/sbi/sbi_pmu.c
@@ -226,11 +226,47 @@ int sbi_pmu_add_raw_event_counter_map(uint64_t select, u32 cmap)
SBI_PMU_EVENT_RAW_IDX, cmap, select);
}
+static int pmu_ctr_enable_irq_hw(int ctr_idx)
+{
+ unsigned long mhpmevent_csr;
+ unsigned long mhpmevent_curr;
+ unsigned long mip_val;
+ unsigned long of_mask;
+
+ if (ctr_idx < 3 || ctr_idx >= SBI_PMU_HW_CTR_MAX)
+ return SBI_EFAIL;
+
+#if __riscv_xlen == 32
+ mhpmevent_csr = CSR_MHPMEVENT3H + ctr_idx - 3;
+ of_mask = ~MHPMEVENTH_OF;
+#else
+ mhpmevent_csr = CSR_MCOUNTINHIBIT + ctr_idx;
+ of_mask = ~MHPMEVENT_OF;
+#endif
+
+ mhpmevent_curr = csr_read_num(mhpmevent_csr);
+ mip_val = csr_read(CSR_MIP);
+ /**
+ * Clear out the OF bit so that next interrupt can be enabled.
+ * This should be done only when the corresponding overflow interrupt
+ * bit is cleared. That indicates that software has already handled the
+ * previous interrupts or the hardware yet to set an overflow interrupt.
+ * Otherwise, there will be race conditions where we may clear the bit
+ * the software is yet to handle the interrupt.
+ */
+ if (!(mip_val & MIP_LCOFIP)) {
+ mhpmevent_curr &= of_mask;
+ csr_write_num(mhpmevent_csr, mhpmevent_curr);
+ }
+
+ return 0;
+}
+
static void pmu_ctr_write_hw(uint32_t cidx, uint64_t ival)
{
#if __riscv_xlen == 32
csr_write_num(CSR_MCYCLE + cidx, 0);
- csr_write_num(CSR_MCYCLE + cidx, ival & 0xFFFF);
+ csr_write_num(CSR_MCYCLE + cidx, ival & 0xFFFFFFFF);
csr_write_num(CSR_MCYCLEH + cidx, ival >> BITS_PER_LONG);
#else
csr_write_num(CSR_MCYCLE + cidx, ival);
@@ -252,12 +288,14 @@ static int pmu_ctr_start_hw(uint32_t cidx, uint64_t ival, bool ival_update)
__set_bit(cidx, &mctr_en);
__clear_bit(cidx, &mctr_inhbt);
- if (ival_update)
- pmu_ctr_write_hw(cidx, ival);
-
+ if (sbi_hart_has_feature(scratch, SBI_HART_HAS_SSCOF))
+ pmu_ctr_enable_irq_hw(cidx);
csr_write(CSR_MCOUNTEREN, mctr_en);
csr_write(CSR_MCOUNTINHIBIT, mctr_inhbt);
+ if (ival_update)
+ pmu_ctr_write_hw(cidx, ival);
+
return 0;
}
@@ -326,7 +364,6 @@ static int pmu_ctr_stop_hw(uint32_t cidx)
static int pmu_ctr_stop_fw(uint32_t cidx, uint32_t fw_evt_code)
{
u32 hartid = current_hartid();
-
fw_event_map[hartid][fw_evt_code].bStarted = FALSE;
return 0;
@@ -362,8 +399,21 @@ int sbi_pmu_ctr_stop(unsigned long cbase, unsigned long cmask,
return ret;
}
+static void pmu_update_inhibit_flags(unsigned long flags, uint64_t *mhpmevent_val)
+{
+ if (flags & SBI_PMU_CFG_FLAG_SET_VUINH)
+ *mhpmevent_val |= MHPMEVENT_VUINH;
+ if (flags & SBI_PMU_CFG_FLAG_SET_VSINH)
+ *mhpmevent_val |= MHPMEVENT_VSINH;
+ if (flags & SBI_PMU_CFG_FLAG_SET_UINH)
+ *mhpmevent_val |= MHPMEVENT_UINH;
+ if (flags & SBI_PMU_CFG_FLAG_SET_SINH)
+ *mhpmevent_val |= MHPMEVENT_SINH;
+}
+
static int pmu_update_hw_mhpmevent(struct sbi_pmu_hw_event *hw_evt, int ctr_idx,
- unsigned long eindex, uint64_t data)
+ unsigned long flags, unsigned long eindex,
+ uint64_t data)
{
struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
const struct sbi_platform *plat = sbi_platform_ptr(scratch);
@@ -375,17 +425,23 @@ static int pmu_update_hw_mhpmevent(struct sbi_pmu_hw_event *hw_evt, int ctr_idx,
if (!mhpmevent_val || ctr_idx < 3 || ctr_idx >= SBI_PMU_HW_CTR_MAX)
return SBI_EFAIL;
- /* TODO: The upper 16 bits of mhpmevent is reserved by sscofpmf extension.
- * Update those bits based on the flags received from supervisor.
- * The OVF bit also should be cleared here in case it was not cleared
- * during event stop.
- */
+ /* Always clear the OVF bit and inhibit countin of events in M-mode */
+ mhpmevent_val = (mhpmevent_val & ~MHPMEVENT_SSCOF_MASK) | MHPMEVENT_MINH;
+
+ /* Update the inhibit flags based on inhibit flags received from supervisor */
+ pmu_update_inhibit_flags(flags, &mhpmevent_val);
+
+#if __riscv_xlen == 32
+ csr_write_num(CSR_MCOUNTINHIBIT + ctr_idx, mhpmevent_val & 0xFFFFFFFF);
+ csr_write_num(CSR_MHPMEVENT3H + ctr_idx - 3, mhpmevent_val >> BITS_PER_LONG);
+#else
csr_write_num(CSR_MCOUNTINHIBIT + ctr_idx, mhpmevent_val);
+#endif
return 0;
}
-static int pmu_ctr_find_hw(unsigned long cbase, unsigned long cmask,
+static int pmu_ctr_find_hw(unsigned long cbase, unsigned long cmask, unsigned long flags,
unsigned long event_idx, uint64_t data)
{
unsigned long ctr_mask;
@@ -427,7 +483,7 @@ static int pmu_ctr_find_hw(unsigned long cbase, unsigned long cmask,
if (ctr_idx == SBI_ENOTSUPP)
return SBI_EFAIL;
- ret = pmu_update_hw_mhpmevent(temp, ctr_idx, event_idx, data);
+ ret = pmu_update_hw_mhpmevent(temp, ctr_idx, flags, event_idx, data);
if (!ret)
ret = ctr_idx;
@@ -490,7 +546,8 @@ int sbi_pmu_ctr_cfg_match(unsigned long cidx_base, unsigned long cidx_mask,
/* Any firmware counter can be used track any firmware event */
ctr_idx = pmu_ctr_find_fw(cidx_base, cidx_mask, hartid);
} else {
- ctr_idx = pmu_ctr_find_hw(cidx_base, cidx_mask, event_idx, event_data);
+ ctr_idx = pmu_ctr_find_hw(cidx_base, cidx_mask, flags, event_idx,
+ event_data);
}
if (ctr_idx < 0)
--
2.31.1
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