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Add support for 64bit event selectors.
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New API to get supported no. of HPM counters.
New API to assign user values to event selector register.
Add metal_cpureg_t as a cpu register-size dependent type.
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@NandkumarJoshi
NandkumarJoshi committed Jul 15, 2020
1 parent 5f32db1 commit 0427278
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Showing 3 changed files with 120 additions and 26 deletions.
9 changes: 9 additions & 0 deletions metal/cpu.h
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,15 @@

struct metal_cpu;

/*!
* @brief Typedef for CPU register-size datatype.
*/
#if __riscv_xlen == 32
typedef uint32_t metal_cpureg_t;
#else
typedef uint64_t metal_cpureg_t;
#endif

/*!
* @brief Function signature for exception handlers
*/
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71 changes: 64 additions & 7 deletions metal/hpm.h
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Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,38 @@
#define METAL_HPM_EVENTID_29 (1UL << 29)
#define METAL_HPM_EVENTID_30 (1UL << 30)
#define METAL_HPM_EVENTID_31 (1UL << 31)
#define METAL_HPM_EVENTID_32 (1UL << 32)
#define METAL_HPM_EVENTID_33 (1UL << 33)
#define METAL_HPM_EVENTID_34 (1UL << 34)
#define METAL_HPM_EVENTID_35 (1UL << 35)
#define METAL_HPM_EVENTID_36 (1UL << 36)
#define METAL_HPM_EVENTID_37 (1UL << 37)
#define METAL_HPM_EVENTID_38 (1UL << 38)
#define METAL_HPM_EVENTID_39 (1UL << 39)
#define METAL_HPM_EVENTID_40 (1UL << 40)
#define METAL_HPM_EVENTID_41 (1UL << 41)
#define METAL_HPM_EVENTID_42 (1UL << 42)
#define METAL_HPM_EVENTID_43 (1UL << 43)
#define METAL_HPM_EVENTID_44 (1UL << 44)
#define METAL_HPM_EVENTID_45 (1UL << 45)
#define METAL_HPM_EVENTID_46 (1UL << 46)
#define METAL_HPM_EVENTID_47 (1UL << 47)
#define METAL_HPM_EVENTID_48 (1UL << 48)
#define METAL_HPM_EVENTID_49 (1UL << 49)
#define METAL_HPM_EVENTID_50 (1UL << 50)
#define METAL_HPM_EVENTID_51 (1UL << 51)
#define METAL_HPM_EVENTID_52 (1UL << 52)
#define METAL_HPM_EVENTID_53 (1UL << 53)
#define METAL_HPM_EVENTID_54 (1UL << 54)
#define METAL_HPM_EVENTID_55 (1UL << 55)
#define METAL_HPM_EVENTID_56 (1UL << 56)
#define METAL_HPM_EVENTID_57 (1UL << 57)
#define METAL_HPM_EVENTID_58 (1UL << 58)
#define METAL_HPM_EVENTID_59 (1UL << 59)
#define METAL_HPM_EVENTID_60 (1UL << 60)
#define METAL_HPM_EVENTID_61 (1UL << 61)
#define METAL_HPM_EVENTID_62 (1UL << 62)
#define METAL_HPM_EVENTID_63 (1UL << 63)

/*! @brief Macros for valid Event Class */
#define METAL_HPM_EVENTCLASS_0 (0UL)
Expand All @@ -43,6 +75,10 @@
#define METAL_HPM_EVENTCLASS_7 (7UL)
#define METAL_HPM_EVENTCLASS_8 (8UL)

/* Return codes */
#define METAL_HPM_RET_OK 0
#define METAL_HPM_RET_NOK -1

/*! @brief Enums for available HPM counters */
typedef enum {
METAL_HPM_CYCLE = 0,
Expand Down Expand Up @@ -84,13 +120,18 @@ typedef enum {
* @return 0 If no error.*/
int metal_hpm_init(struct metal_cpu *cpu);

/*! @brief Get count of supported hardware performance monitor counters.
* @param cpu The CPU device handle.
* @return Number of supported HPM counters.*/
unsigned int metal_hpm_get_count(struct metal_cpu *cpu);

/*! @brief Disables hardware performance monitor counters.
* Note - Disabled HPM counters may reduce power consumption.
* @param cpu The CPU device handle.
* @return 0 If no error.*/
int metal_hpm_disable(struct metal_cpu *cpu);

/*! @brief Set events which will cause the specified counter to increment.
/*! @brief Set bits in event selector register as specified in the bit-mask.
* Counter will start incrementing from the moment events are set.
* @param cpu The CPU device handle.
* @param counter Hardware counter to be incremented by selected events.
Expand All @@ -100,21 +141,37 @@ int metal_hpm_disable(struct metal_cpu *cpu);
* [XLEN-1:8] - Event selection mask [7:0] - Event class
* @return 0 If no error.*/
int metal_hpm_set_event(struct metal_cpu *cpu, metal_hpm_counter counter,
unsigned int bitmask);
metal_cpureg_t bitmask);

/*! @brief Writes specified value into event selector register.
* Counter will start incrementing from the moment events are set.
* @param cpu The CPU device handle.
* @param counter Hardware counter to be incremented by selected events.
* @param regval Bit pattern to select events for a particular counter,
* refer core reference manual for selection of events.
* Event bit mask is partitioned as follows:
* [XLEN-1:8] - Event selection mask [7:0] - Event class
* @return 0 If no error.*/
int metal_hpm_assign_event(struct metal_cpu *cpu, metal_hpm_counter counter,
metal_cpureg_t regval);

/*! @brief Get events selection mask set for specified counter.
/*! @brief Get events selection bit-mask set for specified counter.
* @param cpu The CPU device handle.
* @param counter Hardware counter.
* @return Event selection bit mask. refer core reference manual for details.*/
unsigned int metal_hpm_get_event(struct metal_cpu *cpu,
metal_hpm_counter counter);
* @param bitmask Event selection bit mask.
* refer core reference manual for details.
* @return 0 If no error.*/
int metal_hpm_get_event(struct metal_cpu *cpu, metal_hpm_counter counter,
metal_cpureg_t *bitmask);

/*! @brief Clear event selector bits as per specified bit-mask.
* @param cpu The CPU device handle.
* @param counter Hardware counter.
* @param bitmask Event selection bit mask.
* refer core reference manual for details.
* @return 0 If no error.*/
int metal_hpm_clr_event(struct metal_cpu *cpu, metal_hpm_counter counter,
unsigned int bitmask);
metal_cpureg_t bitmask);

/*! @brief Enable counter access to next lower privilege mode.
* @param cpu The CPU device handle.
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66 changes: 47 additions & 19 deletions src/hpm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,12 @@
__asm__ __volatile__("csrw mhpmevent" #x ", %0" : : "r"(val)); \
break;

/* Macro to assign values into event selector register */
#define METAL_HPM_ASSIGN_EVENT_REG(x) \
case METAL_HPM_COUNTER_##x: \
__asm__ __volatile__("csrw mhpmevent" #x ", %0" : : "r"(regval)); \
break;

/* Macro to set values into event selector register */
#define METAL_HPM_CLR_EVENT_REG(x) \
case METAL_HPM_COUNTER_##x: \
Expand Down Expand Up @@ -72,25 +78,21 @@
/* Macro to check for instruction trap */
#define MCAUSE_ILLEGAL_INST 0x02

/* Return codes */
#define METAL_HPM_RET_OK 0
#define METAL_HPM_RET_NOK 1

int metal_hpm_init(struct metal_cpu *gcpu) {
struct __metal_driver_cpu *cpu = (void *)gcpu;

/* Check if counters are initialized or pointer is NULL */
if ((gcpu) && (cpu->hpm_count == 0)) {
metal_hpm_counter n;

metal_cpureg_t bitmask;
/* Count number of available hardware performance counters */
cpu->hpm_count = METAL_HPM_COUNT_MAX;

/* mcycle, mtime and minstret counters are always available */
for (n = METAL_HPM_COUNTER_3; n < METAL_HPM_COUNTER_31; n++) {
metal_hpm_set_event(gcpu, n, 0xFFFFFFFF);

if (metal_hpm_get_event(gcpu, n) == 0) {
metal_hpm_get_event(gcpu, n, &bitmask);
if (bitmask == 0) {
break;
}
}
Expand All @@ -115,9 +117,15 @@ int metal_hpm_init(struct metal_cpu *gcpu) {
return METAL_HPM_RET_OK;
}

unsigned int metal_hpm_get_count(struct metal_cpu *gcpu) {
struct __metal_driver_cpu *cpu = (void *)gcpu;
/* Return Number of supported HPM counters */
return cpu->hpm_count;
}

int metal_hpm_disable(struct metal_cpu *gcpu) {
struct __metal_driver_cpu *cpu = (void *)gcpu;
uintptr_t temp = 0, val = 0;
metal_cpureg_t temp = 0, val = 0;

/* Check if pointer is NULL */
if (gcpu) {
Expand All @@ -143,9 +151,9 @@ int metal_hpm_disable(struct metal_cpu *gcpu) {
}

int metal_hpm_set_event(struct metal_cpu *gcpu, metal_hpm_counter counter,
unsigned int bitmask) {
metal_cpureg_t bitmask) {
struct __metal_driver_cpu *cpu = (void *)gcpu;
unsigned int val;
metal_cpureg_t val;

/* Return error if counter is out of range or pointer is NULL */
if ((gcpu) && (counter >= cpu->hpm_count))
Expand All @@ -162,30 +170,50 @@ int metal_hpm_set_event(struct metal_cpu *gcpu, metal_hpm_counter counter,
return METAL_HPM_RET_OK;
}

unsigned int metal_hpm_get_event(struct metal_cpu *gcpu,
metal_hpm_counter counter) {
int metal_hpm_assign_event(struct metal_cpu *gcpu, metal_hpm_counter counter,
metal_cpureg_t regval) {
struct __metal_driver_cpu *cpu = (void *)gcpu;
unsigned int val = 0;

/* Return error if counter is out of range or pointer is NULL */
if ((gcpu) && (counter >= cpu->hpm_count))
return METAL_HPM_RET_NOK;

switch (counter) {
/* Assign event register bit mask as requested */
METAL_HPM_HANDLE_SWITCH(METAL_HPM_ASSIGN_EVENT_REG)

default:
break;
}

return METAL_HPM_RET_OK;
}

int metal_hpm_get_event(struct metal_cpu *gcpu, metal_hpm_counter counter,
metal_cpureg_t *bitmask) {
struct __metal_driver_cpu *cpu = (void *)gcpu;
metal_cpureg_t val = 0;

/* Return error if counter is out of range or pointer is NULL */
if ((gcpu) && (bitmask) && (counter >= cpu->hpm_count))
return METAL_HPM_RET_NOK;

switch (counter) {
/* Read event registers */
METAL_HPM_HANDLE_SWITCH(METAL_HPM_GET_EVENT_REG)

default:
break;
}
*bitmask = val;

return val;
return METAL_HPM_RET_OK;
}

int metal_hpm_clr_event(struct metal_cpu *gcpu, metal_hpm_counter counter,
unsigned int bitmask) {
metal_cpureg_t bitmask) {
struct __metal_driver_cpu *cpu = (void *)gcpu;
unsigned int val;
metal_cpureg_t val = 0;

/* Return error if counter is out of range or pointer is NULL */
if ((gcpu) && (counter >= cpu->hpm_count))
Expand All @@ -204,7 +232,7 @@ int metal_hpm_clr_event(struct metal_cpu *gcpu, metal_hpm_counter counter,

int metal_hpm_enable_access(struct metal_cpu *gcpu, metal_hpm_counter counter) {
struct __metal_driver_cpu *cpu = (void *)gcpu;
uintptr_t temp = 0, val = 0;
metal_cpureg_t temp = 0, val = 0;

/* Return error if counter is out of range or pointer is NULL */
if ((gcpu) && (counter >= cpu->hpm_count))
Expand All @@ -229,7 +257,7 @@ int metal_hpm_enable_access(struct metal_cpu *gcpu, metal_hpm_counter counter) {
int metal_hpm_disable_access(struct metal_cpu *gcpu,
metal_hpm_counter counter) {
struct __metal_driver_cpu *cpu = (void *)gcpu;
uintptr_t temp = 0, val = 0;
metal_cpureg_t temp = 0, val = 0;

/* Return error if counter is out of range or pointer is NULL */
if ((gcpu) && (counter >= cpu->hpm_count))
Expand Down Expand Up @@ -262,7 +290,7 @@ unsigned long long metal_hpm_read_counter(struct metal_cpu *gcpu,

/* Return error if counter is out of range or pointer is NULL */
if ((gcpu) && (counter >= cpu->hpm_count))
return METAL_HPM_RET_NOK;
return 0;

switch (counter) {
case METAL_HPM_CYCLE:
Expand Down

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