| Message ID | 20240721070601.88639-6-jamestiotio@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | riscv: sbi: Add support to test timer extension | expand |
On Sun, Jul 21, 2024 at 03:06:00PM GMT, James Raphael Tiovalen wrote: > Add a test for the set_timer function of the time extension. The test > checks that: > - The time extension is available > - The installed timer interrupt handler is called > - The timer interrupt is received within a reasonable time interval > - The timer interrupt pending bit is cleared after the set_timer SBI > call is made > - The timer interrupt can be cleared either by requesting a timer > interrupt infinitely far into the future or by masking the timer > interrupt > > The timer interrupt delay can be set using the TIMER_DELAY environment > variable in microseconds. The default delay value is 200 milliseconds. > Since the interrupt can arrive a little later than the specified delay, > allow some margin of error. This margin of error can be specified via > the TIMER_MARGIN environment variable in microseconds. The default > margin of error is 200 milliseconds. > > Signed-off-by: James Raphael Tiovalen <jamestiotio@gmail.com> > --- > lib/riscv/asm/csr.h | 8 +++ > lib/riscv/asm/sbi.h | 5 ++ > lib/riscv/asm/timer.h | 10 ++++ > riscv/sbi.c | 132 ++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 155 insertions(+) > > diff --git a/lib/riscv/asm/csr.h b/lib/riscv/asm/csr.h > index a9b1bd42..24b333e0 100644 > --- a/lib/riscv/asm/csr.h > +++ b/lib/riscv/asm/csr.h > @@ -4,11 +4,15 @@ > #include <linux/const.h> > > #define CSR_SSTATUS 0x100 > +#define CSR_SIE 0x104 > #define CSR_STVEC 0x105 > #define CSR_SSCRATCH 0x140 > #define CSR_SEPC 0x141 > #define CSR_SCAUSE 0x142 > #define CSR_STVAL 0x143 > +#define CSR_SIP 0x144 > +#define CSR_STIMECMP 0x14d > +#define CSR_STIMECMPH 0x15d > #define CSR_SATP 0x180 > #define CSR_TIME 0xc01 > > @@ -47,6 +51,10 @@ > #define IRQ_S_GEXT 12 > #define IRQ_PMU_OVF 13 > > +#define IE_TIE (_AC(0x1, UL) << IRQ_S_TIMER) > + > +#define IP_TIP IE_TIE > + > #ifndef __ASSEMBLY__ > > #define csr_swap(csr, val) \ > diff --git a/lib/riscv/asm/sbi.h b/lib/riscv/asm/sbi.h > index 5e1a674a..73ab5438 100644 > --- a/lib/riscv/asm/sbi.h > +++ b/lib/riscv/asm/sbi.h > @@ -16,6 +16,7 @@ > > enum sbi_ext_id { > SBI_EXT_BASE = 0x10, > + SBI_EXT_TIME = 0x54494d45, > SBI_EXT_HSM = 0x48534d, > SBI_EXT_SRST = 0x53525354, > }; > @@ -37,6 +38,10 @@ enum sbi_ext_hsm_fid { > SBI_EXT_HSM_HART_SUSPEND, > }; > > +enum sbi_ext_time_fid { > + SBI_EXT_TIME_SET_TIMER = 0, > +}; > + > struct sbiret { > long error; > long value; > diff --git a/lib/riscv/asm/timer.h b/lib/riscv/asm/timer.h > index f7504f84..b3514d3f 100644 > --- a/lib/riscv/asm/timer.h > +++ b/lib/riscv/asm/timer.h > @@ -11,4 +11,14 @@ static inline uint64_t timer_get_cycles(void) > return csr_read(CSR_TIME); > } > > +static inline void timer_irq_enable(void) > +{ > + csr_set(CSR_SIE, IE_TIE); > +} > + > +static inline void timer_irq_disable(void) > +{ > + csr_clear(CSR_SIE, IE_TIE); > +} > + > #endif /* _ASMRISCV_TIMER_H_ */ > diff --git a/riscv/sbi.c b/riscv/sbi.c > index 762e9711..fe2fe771 100644 > --- a/riscv/sbi.c > +++ b/riscv/sbi.c > @@ -6,7 +6,21 @@ > */ > #include <libcflat.h> > #include <stdlib.h> > +#include <limits.h> > +#include <asm/barrier.h> > +#include <asm/csr.h> > +#include <asm/delay.h> > +#include <asm/isa.h> > +#include <asm/processor.h> > #include <asm/sbi.h> > +#include <asm/smp.h> > +#include <asm/timer.h> > + > +static bool timer_works; > +static bool mask_timer_irq; > +static bool timer_irq_set; > +static bool timer_irq_cleared; > +static unsigned long timer_irq_count; > > static void help(void) > { > @@ -19,6 +33,34 @@ static struct sbiret __base_sbi_ecall(int fid, unsigned long arg0) > return sbi_ecall(SBI_EXT_BASE, fid, arg0, 0, 0, 0, 0, 0); > } > > +static struct sbiret __time_sbi_ecall(unsigned long stime_value) > +{ > + return sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value, 0, 0, 0, 0, 0); > +} > + > +static inline bool timer_irq_pending(void) 'inline' isn't useful in a source file. The compiler will do what it wants anyway. > +{ > + return csr_read(CSR_SIP) & IP_TIP; > +} > + > +static void timer_irq_handler(struct pt_regs *regs) > +{ > + if (timer_irq_count < ULONG_MAX) > + ++timer_irq_count; > + > + timer_works = true; > + if (timer_irq_pending()) > + timer_irq_set = true; > + > + if (mask_timer_irq) { > + timer_irq_disable(); > + } else { > + __time_sbi_ecall(ULONG_MAX); > + if (!timer_irq_pending()) > + timer_irq_cleared = true; > + } > +} > + > static bool env_or_skip(const char *env) > { > if (!getenv(env)) { > @@ -112,6 +154,95 @@ static void check_base(void) > report_prefix_pop(); > } > > +static void check_time(void) > +{ > + struct sbiret ret; > + unsigned long begin, end, duration; > + unsigned long d = getenv("TIMER_DELAY") ? strtol(getenv("TIMER_DELAY"), NULL, 0) > + : 200000; > + unsigned long margin = getenv("TIMER_MARGIN") ? strtol(getenv("TIMER_MARGIN"), NULL, 0) > + : 200000; > + > + d = usec_to_cycles(d); > + margin = usec_to_cycles(margin); > + > + report_prefix_push("time"); > + > + if (!sbi_probe(SBI_EXT_TIME)) { > + report_skip("time extension not available"); > + report_prefix_pop(); > + return; > + } > + > + report_prefix_push("set_timer"); > + > + install_irq_handler(IRQ_S_TIMER, timer_irq_handler); > + local_irq_enable(); > + if (cpu_has_extension(smp_processor_id(), ISA_SSTC)) { > + csr_write(CSR_STIMECMP, ULONG_MAX); > +#if __riscv_xlen == 32 > + csr_write(CSR_STIMECMPH, ULONG_MAX); > +#endif > + } > + timer_irq_enable(); > + > + begin = timer_get_cycles(); > + ret = __time_sbi_ecall(begin + d); > + > + report(!ret.error, "set timer"); > + if (ret.error) > + report_info("set timer failed with %ld\n", ret.error); > + > + report(!timer_irq_pending(), "pending timer interrupt bit cleared"); > + > + while ((end = timer_get_cycles()) <= (begin + d + margin) && !timer_works) > + cpu_relax(); > + > + report(timer_works, "timer interrupt received"); > + report(timer_irq_set, "pending timer interrupt bit set in irq handler"); > + report(timer_irq_cleared, "pending timer interrupt bit cleared by setting timer to -1"); timer_irq_cleared being true is only interesting if timer_irq_set is also true. This test should be 'timer_irq_set && timer_irq_cleared' > + > + if (timer_works) { > + duration = end - begin; > + report(duration >= d && duration <= (d + margin), "timer delay honored"); > + } > + > + if (timer_irq_count > 1) > + report_fail("timer interrupt received multiple times"); > + > + timer_works = false; > + timer_irq_set = false; > + timer_irq_count = 0; > + mask_timer_irq = true; nit: We could collect all these variables into one struct, i.e. struct timer_info { bool timer_works; bool mask_timer_irq; bool timer_irq_set; bool timer_irq_cleared; unsigned long timer_irq_count; }; Then it's easy to reset them to zero with something like timer_info = (struct timer_info){ .mask_timer_irq = true, }; > + begin = timer_get_cycles(); > + ret = __time_sbi_ecall(begin + d); > + > + report(!ret.error, "set timer for mask irq test"); > + if (ret.error) > + report_info("set timer for mask irq test failed with %ld\n", ret.error); > + > + while ((end = timer_get_cycles()) <= (begin + d + margin) && !timer_works) > + cpu_relax(); > + > + report(timer_works, "timer interrupt received for mask irq test"); > + report(timer_irq_set, "pending timer interrupt bit set in irq handler for mask irq test"); > + > + if (timer_works) { > + duration = end - begin; > + report(duration >= d && duration <= (d + margin), > + "timer delay honored for mask irq test"); > + } > + > + if (timer_irq_count > 1) > + report_fail("timer interrupt received multiple times for mask irq test"); > + > + local_irq_disable(); > + install_irq_handler(IRQ_S_TIMER, NULL); > + > + report_prefix_pop(); > + report_prefix_pop(); > +} > + > int main(int argc, char **argv) > { > > @@ -122,6 +253,7 @@ int main(int argc, char **argv) > > report_prefix_push("sbi"); > check_base(); > + check_time(); > > return report_summary(); > } > -- > 2.43.0 > Thanks, drew
diff --git a/lib/riscv/asm/csr.h b/lib/riscv/asm/csr.h index a9b1bd42..24b333e0 100644 --- a/lib/riscv/asm/csr.h +++ b/lib/riscv/asm/csr.h @@ -4,11 +4,15 @@ #include <linux/const.h> #define CSR_SSTATUS 0x100 +#define CSR_SIE 0x104 #define CSR_STVEC 0x105 #define CSR_SSCRATCH 0x140 #define CSR_SEPC 0x141 #define CSR_SCAUSE 0x142 #define CSR_STVAL 0x143 +#define CSR_SIP 0x144 +#define CSR_STIMECMP 0x14d +#define CSR_STIMECMPH 0x15d #define CSR_SATP 0x180 #define CSR_TIME 0xc01 @@ -47,6 +51,10 @@ #define IRQ_S_GEXT 12 #define IRQ_PMU_OVF 13 +#define IE_TIE (_AC(0x1, UL) << IRQ_S_TIMER) + +#define IP_TIP IE_TIE + #ifndef __ASSEMBLY__ #define csr_swap(csr, val) \ diff --git a/lib/riscv/asm/sbi.h b/lib/riscv/asm/sbi.h index 5e1a674a..73ab5438 100644 --- a/lib/riscv/asm/sbi.h +++ b/lib/riscv/asm/sbi.h @@ -16,6 +16,7 @@ enum sbi_ext_id { SBI_EXT_BASE = 0x10, + SBI_EXT_TIME = 0x54494d45, SBI_EXT_HSM = 0x48534d, SBI_EXT_SRST = 0x53525354, }; @@ -37,6 +38,10 @@ enum sbi_ext_hsm_fid { SBI_EXT_HSM_HART_SUSPEND, }; +enum sbi_ext_time_fid { + SBI_EXT_TIME_SET_TIMER = 0, +}; + struct sbiret { long error; long value; diff --git a/lib/riscv/asm/timer.h b/lib/riscv/asm/timer.h index f7504f84..b3514d3f 100644 --- a/lib/riscv/asm/timer.h +++ b/lib/riscv/asm/timer.h @@ -11,4 +11,14 @@ static inline uint64_t timer_get_cycles(void) return csr_read(CSR_TIME); } +static inline void timer_irq_enable(void) +{ + csr_set(CSR_SIE, IE_TIE); +} + +static inline void timer_irq_disable(void) +{ + csr_clear(CSR_SIE, IE_TIE); +} + #endif /* _ASMRISCV_TIMER_H_ */ diff --git a/riscv/sbi.c b/riscv/sbi.c index 762e9711..fe2fe771 100644 --- a/riscv/sbi.c +++ b/riscv/sbi.c @@ -6,7 +6,21 @@ */ #include <libcflat.h> #include <stdlib.h> +#include <limits.h> +#include <asm/barrier.h> +#include <asm/csr.h> +#include <asm/delay.h> +#include <asm/isa.h> +#include <asm/processor.h> #include <asm/sbi.h> +#include <asm/smp.h> +#include <asm/timer.h> + +static bool timer_works; +static bool mask_timer_irq; +static bool timer_irq_set; +static bool timer_irq_cleared; +static unsigned long timer_irq_count; static void help(void) { @@ -19,6 +33,34 @@ static struct sbiret __base_sbi_ecall(int fid, unsigned long arg0) return sbi_ecall(SBI_EXT_BASE, fid, arg0, 0, 0, 0, 0, 0); } +static struct sbiret __time_sbi_ecall(unsigned long stime_value) +{ + return sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value, 0, 0, 0, 0, 0); +} + +static inline bool timer_irq_pending(void) +{ + return csr_read(CSR_SIP) & IP_TIP; +} + +static void timer_irq_handler(struct pt_regs *regs) +{ + if (timer_irq_count < ULONG_MAX) + ++timer_irq_count; + + timer_works = true; + if (timer_irq_pending()) + timer_irq_set = true; + + if (mask_timer_irq) { + timer_irq_disable(); + } else { + __time_sbi_ecall(ULONG_MAX); + if (!timer_irq_pending()) + timer_irq_cleared = true; + } +} + static bool env_or_skip(const char *env) { if (!getenv(env)) { @@ -112,6 +154,95 @@ static void check_base(void) report_prefix_pop(); } +static void check_time(void) +{ + struct sbiret ret; + unsigned long begin, end, duration; + unsigned long d = getenv("TIMER_DELAY") ? strtol(getenv("TIMER_DELAY"), NULL, 0) + : 200000; + unsigned long margin = getenv("TIMER_MARGIN") ? strtol(getenv("TIMER_MARGIN"), NULL, 0) + : 200000; + + d = usec_to_cycles(d); + margin = usec_to_cycles(margin); + + report_prefix_push("time"); + + if (!sbi_probe(SBI_EXT_TIME)) { + report_skip("time extension not available"); + report_prefix_pop(); + return; + } + + report_prefix_push("set_timer"); + + install_irq_handler(IRQ_S_TIMER, timer_irq_handler); + local_irq_enable(); + if (cpu_has_extension(smp_processor_id(), ISA_SSTC)) { + csr_write(CSR_STIMECMP, ULONG_MAX); +#if __riscv_xlen == 32 + csr_write(CSR_STIMECMPH, ULONG_MAX); +#endif + } + timer_irq_enable(); + + begin = timer_get_cycles(); + ret = __time_sbi_ecall(begin + d); + + report(!ret.error, "set timer"); + if (ret.error) + report_info("set timer failed with %ld\n", ret.error); + + report(!timer_irq_pending(), "pending timer interrupt bit cleared"); + + while ((end = timer_get_cycles()) <= (begin + d + margin) && !timer_works) + cpu_relax(); + + report(timer_works, "timer interrupt received"); + report(timer_irq_set, "pending timer interrupt bit set in irq handler"); + report(timer_irq_cleared, "pending timer interrupt bit cleared by setting timer to -1"); + + if (timer_works) { + duration = end - begin; + report(duration >= d && duration <= (d + margin), "timer delay honored"); + } + + if (timer_irq_count > 1) + report_fail("timer interrupt received multiple times"); + + timer_works = false; + timer_irq_set = false; + timer_irq_count = 0; + mask_timer_irq = true; + begin = timer_get_cycles(); + ret = __time_sbi_ecall(begin + d); + + report(!ret.error, "set timer for mask irq test"); + if (ret.error) + report_info("set timer for mask irq test failed with %ld\n", ret.error); + + while ((end = timer_get_cycles()) <= (begin + d + margin) && !timer_works) + cpu_relax(); + + report(timer_works, "timer interrupt received for mask irq test"); + report(timer_irq_set, "pending timer interrupt bit set in irq handler for mask irq test"); + + if (timer_works) { + duration = end - begin; + report(duration >= d && duration <= (d + margin), + "timer delay honored for mask irq test"); + } + + if (timer_irq_count > 1) + report_fail("timer interrupt received multiple times for mask irq test"); + + local_irq_disable(); + install_irq_handler(IRQ_S_TIMER, NULL); + + report_prefix_pop(); + report_prefix_pop(); +} + int main(int argc, char **argv) { @@ -122,6 +253,7 @@ int main(int argc, char **argv) report_prefix_push("sbi"); check_base(); + check_time(); return report_summary(); }
Add a test for the set_timer function of the time extension. The test checks that: - The time extension is available - The installed timer interrupt handler is called - The timer interrupt is received within a reasonable time interval - The timer interrupt pending bit is cleared after the set_timer SBI call is made - The timer interrupt can be cleared either by requesting a timer interrupt infinitely far into the future or by masking the timer interrupt The timer interrupt delay can be set using the TIMER_DELAY environment variable in microseconds. The default delay value is 200 milliseconds. Since the interrupt can arrive a little later than the specified delay, allow some margin of error. This margin of error can be specified via the TIMER_MARGIN environment variable in microseconds. The default margin of error is 200 milliseconds. Signed-off-by: James Raphael Tiovalen <jamestiotio@gmail.com> --- lib/riscv/asm/csr.h | 8 +++ lib/riscv/asm/sbi.h | 5 ++ lib/riscv/asm/timer.h | 10 ++++ riscv/sbi.c | 132 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 155 insertions(+)