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lib: sbi: Allow programmable counters to monitor cycle/instret events

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A platform may use programmable counters for cycle/instret events.
The priv spec allows that provided that cycle/instret also report those
events in addition to the programmable counters. We should allow that
functionality in OpenSBI.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
This commit is contained in:
Atish Patra
2021-11-08 10:53:02 -08:00
committed by Anup Patel
parent 2363f950bc
commit 0c304b6619
2 changed files with 49 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
include/sbi/sbi_pmu.h
View File

@@ -26,6 +26,7 @@
#define SBI_PMU_FW_CTR_MAX 16
#define SBI_PMU_HW_CTR_MAX 32
#define SBI_PMU_CTR_MAX (SBI_PMU_HW_CTR_MAX + SBI_PMU_FW_CTR_MAX)
#define SBI_PMU_FIXED_CTR_MASK 0x07
/** Initialize PMU */
int sbi_pmu_init(struct sbi_scratch *scratch, bool cold_boot);

68
lib/sbi/sbi_pmu.c
View File

@@ -175,9 +175,7 @@ static int pmu_add_hw_event_map(u32 eidx_start, u32 eidx_end, u32 cmap,
struct sbi_pmu_hw_event *event = &hw_event_map[num_hw_events];
/* The first two counters are reserved by priv spec */
if ((eidx_start == SBI_PMU_HW_CPU_CYCLES && cmap != 0x1) ||
(eidx_start == SBI_PMU_HW_INSTRUCTIONS && cmap != 0x4) ||
(eidx_start > SBI_PMU_HW_INSTRUCTIONS && (cmap & 0x07)))
if (eidx_start > SBI_PMU_HW_INSTRUCTIONS && (cmap & SBI_PMU_FIXED_CTR_MASK))
return SBI_EDENIED;
if (num_hw_events >= SBI_PMU_HW_EVENT_MAX - 1) {
@@ -188,8 +186,6 @@ static int pmu_add_hw_event_map(u32 eidx_start, u32 eidx_end, u32 cmap,
event->start_idx = eidx_start;
event->end_idx = eidx_end;
event->counters = cmap;
event->select = select;
/* Sanity check */
for (i = 0; i < num_hw_events; i++) {
@@ -199,11 +195,19 @@ static int pmu_add_hw_event_map(u32 eidx_start, u32 eidx_end, u32 cmap,
else
is_overlap = pmu_event_range_overlap(&hw_event_map[i], event);
if (is_overlap)
return SBI_EINVALID_ADDR;
goto reset_event;
}
event->counters = cmap;
event->select = select;
num_hw_events++;
return 0;
reset_event:
event->start_idx = 0;
event->end_idx = 0;
return SBI_EINVAL;
}
/**
@@ -437,23 +441,37 @@ static int pmu_update_hw_mhpmevent(struct sbi_pmu_hw_event *hw_evt, int ctr_idx,
return 0;
}
static int pmu_ctr_find_hw(unsigned long cbase, unsigned long cmask, unsigned long flags,
unsigned long event_idx, uint64_t data)
static int pmu_ctr_find_fixed_fw(unsigned long evt_idx_code)
{
unsigned long ctr_mask;
int i, ret = 0, ctr_idx = SBI_ENOTSUPP;
struct sbi_pmu_hw_event *temp;
unsigned long mctr_inhbt = csr_read(CSR_MCOUNTINHIBIT);
int evt_idx_code = get_cidx_code(event_idx);
if (cbase > num_hw_ctrs)
return SBI_EINVAL;
/* Non-programmables counters are enabled always. No need to do lookup */
if (evt_idx_code == SBI_PMU_HW_CPU_CYCLES)
return 0;
else if (evt_idx_code == SBI_PMU_HW_INSTRUCTIONS)
return 2;
else
return SBI_EINVAL;
}
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;
int i, ret = 0, fixed_ctr, ctr_idx = SBI_ENOTSUPP;
struct sbi_pmu_hw_event *temp;
unsigned long mctr_inhbt = csr_read(CSR_MCOUNTINHIBIT);
struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
if (cbase > num_hw_ctrs)
return SBI_EINVAL;
/**
* If Sscof is present try to find the programmable counter for
* cycle/instret as well.
*/
fixed_ctr = pmu_ctr_find_fixed_fw(event_idx);
if (fixed_ctr >= 0 &&
!sbi_hart_has_feature(scratch, SBI_HART_HAS_SSCOFPMF))
return fixed_ctr;
for (i = 0; i < num_hw_events; i++) {
temp = &hw_event_map[i];
@@ -465,7 +483,9 @@ static int pmu_ctr_find_hw(unsigned long cbase, unsigned long cmask, unsigned lo
if ((event_idx == SBI_PMU_EVENT_RAW_IDX) && temp->select != data)
continue;
ctr_mask = temp->counters & (cmask << cbase);
/* Fixed counters should not be part of the search */
ctr_mask = temp->counters & (cmask << cbase) &
(~SBI_PMU_FIXED_CTR_MASK);
for_each_set_bit_from(cbase, &ctr_mask, SBI_PMU_HW_CTR_MAX) {
if (__test_bit(cbase, &mctr_inhbt)) {
ctr_idx = cbase;
@@ -474,8 +494,16 @@ static int pmu_ctr_find_hw(unsigned long cbase, unsigned long cmask, unsigned lo
}
}
if (ctr_idx == SBI_ENOTSUPP)
return SBI_EFAIL;
if (ctr_idx == SBI_ENOTSUPP) {
/**
* We can't find any programmable counters for cycle/instret.
* Return the fixed counter as they are mandatory anyways.
*/
if (fixed_ctr >= 0)
return fixed_ctr;
else
return SBI_EFAIL;
}
ret = pmu_update_hw_mhpmevent(temp, ctr_idx, flags, event_idx, data);