Re: [kvm-unit-tests PATCH v6 11/11] arm/arm64: gic: don't just use zero

[Andrew Jones <drjones@redhat.com>]

On Wed, Nov 23, 2016 at 12:28:34PM +0100, Auger Eric wrote:
> Hi,
> 
> On 14/11/2016 22:08, Andrew Jones wrote:
> > Allow user to select who sends ipis and with which irq,
> > rather than just always sending irq=0 from cpu0.
> From a user point of view is there a way to know the list of available
> tests and their arg?

Not at the moment. I could change the arg-less run and/or add
a '-h' though that would provide a usage. So far unit tests
have never had -h's, but it's not a bad idea.

> > 
> > Signed-off-by: Andrew Jones <drjones@redhat.com>
> > 
> > ---
> > v6:
> >  - make sender/irq names more future-proof [drew]
> >  - sanity check inputs [drew]
> >  - introduce check_sender/irq and bad_sender/irq to more
> >    cleanly do checks [drew]
> >  - default sender and irq to 1, instead of still zero [drew]
> > v4: improve structure and make sure spurious checking is
> >     done even when the sender isn't cpu0
> > v2: actually check that the irq received was the irq sent,
> >     and (for gicv2) that the sender is the expected one.
> > ---
> >  arm/gic.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++-------------
> >  1 file changed, 99 insertions(+), 25 deletions(-)
> > 
> > diff --git a/arm/gic.c b/arm/gic.c
> > index d954a3775c26..638b8b140c96 100644
> > --- a/arm/gic.c
> > +++ b/arm/gic.c
> > @@ -11,6 +11,7 @@
> >   * This work is licensed under the terms of the GNU LGPL, version 2.
> >   */
> >  #include <libcflat.h>
> > +#include <util.h>
> >  #include <asm/setup.h>
> >  #include <asm/processor.h>
> >  #include <asm/gic.h>
> > @@ -28,6 +29,8 @@ struct gic {
> >  
> >  static struct gic *gic;
> >  static int acked[NR_CPUS], spurious[NR_CPUS];
> > +static int bad_sender[NR_CPUS], bad_irq[NR_CPUS];
> > +static int cmdl_sender = 1, cmdl_irq = 1;
> >  static cpumask_t ready;
> >  
> >  static void nr_cpu_check(int nr)
> > @@ -43,10 +46,23 @@ static void wait_on_ready(void)
> >  		cpu_relax();
> >  }
> >  
> > +static void stats_reset(void)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < nr_cpus; ++i) {
> > +		acked[i] = 0;
> > +		bad_sender[i] = -1;
> > +		bad_irq[i] = -1;
> > +	}
> > +	smp_wmb();
> > +}
> > +
> >  static void check_acked(cpumask_t *mask)
> >  {
> >  	int missing = 0, extra = 0, unexpected = 0;
> >  	int nr_pass, cpu, i;
> > +	bool bad = false;
> >  
> >  	/* Wait up to 5s for all interrupts to be delivered */
> >  	for (i = 0; i < 50; ++i) {
> > @@ -56,9 +72,21 @@ static void check_acked(cpumask_t *mask)
> >  			smp_rmb();
> >  			nr_pass += cpumask_test_cpu(cpu, mask) ?
> >  				acked[cpu] == 1 : acked[cpu] == 0;
> > +
> > +			if (bad_sender[cpu] != -1) {
> > +				printf("cpu%d received IPI from wrong sender %d\n",
> > +					cpu, bad_sender[cpu]);
> > +				bad = true;
> > +			}
> > +
> > +			if (bad_irq[cpu] != -1) {
> > +				printf("cpu%d received wrong irq %d\n",
> > +					cpu, bad_irq[cpu]);
> > +				bad = true;
> > +			}
> >  		}
> >  		if (nr_pass == nr_cpus) {
> > -			report("Completed in %d ms", true, ++i * 100);
> > +			report("Completed in %d ms", !bad, ++i * 100);
> >  			return;
> >  		}
> >  	}
> > @@ -91,6 +119,22 @@ static void check_spurious(void)
> >  	}
> >  }
> >  
> > +static void check_ipi_sender(u32 irqstat)
> > +{
> > +	if (gic_version() == 2) {
> > +		int src = (irqstat >> 10) & 7;
> > +
> > +		if (src != cmdl_sender)
> > +			bad_sender[smp_processor_id()] = src;
> > +	}
> > +}
> > +
> > +static void check_irqnr(u32 irqnr)
> > +{
> > +	if (irqnr != (u32)cmdl_irq)
> > +		bad_irq[smp_processor_id()] = irqnr;
> > +}
> > +
> >  static void ipi_handler(struct pt_regs *regs __unused)
> >  {
> >  	u32 irqstat = gic_read_iar();
> > @@ -98,8 +142,10 @@ static void ipi_handler(struct pt_regs *regs __unused)
> >  
> >  	if (irqnr != GICC_INT_SPURIOUS) {
> >  		gic_write_eoir(irqstat);
> > -		smp_rmb(); /* pairs with wmb in ipi_test functions */
> > +		smp_rmb(); /* pairs with wmb in stats_reset */
> >  		++acked[smp_processor_id()];
> > +		check_ipi_sender(irqstat);
> > +		check_irqnr(irqnr);
> >  		smp_wmb(); /* pairs with rmb in check_acked */
> >  	} else {
> >  		++spurious[smp_processor_id()];
> > @@ -109,19 +155,19 @@ static void ipi_handler(struct pt_regs *regs __unused)
> >  
> >  static void gicv2_ipi_send_self(void)
> >  {
> > -	writel(2 << 24, gicv2_dist_base() + GICD_SGIR);
> > +	writel(2 << 24 | cmdl_irq, gicv2_dist_base() + GICD_SGIR);
> >  }
> >  
> > -static void gicv2_ipi_send_tlist(cpumask_t *mask, int irq __unused)
> > +static void gicv2_ipi_send_tlist(cpumask_t *mask, int irq)
> >  {
> >  	u8 tlist = (u8)cpumask_bits(mask)[0];
> >  
> > -	writel(tlist << 16, gicv2_dist_base() + GICD_SGIR);
> > +	writel(tlist << 16 | irq, gicv2_dist_base() + GICD_SGIR);
> >  }
> >  
> >  static void gicv2_ipi_send_broadcast(void)
> >  {
> > -	writel(1 << 24, gicv2_dist_base() + GICD_SGIR);
> > +	writel(1 << 24 | cmdl_irq, gicv2_dist_base() + GICD_SGIR);
> >  }
> >  
> >  static void gicv3_ipi_send_self(void)
> > @@ -130,12 +176,12 @@ static void gicv3_ipi_send_self(void)
> >  
> >  	cpumask_clear(&mask);
> >  	cpumask_set_cpu(smp_processor_id(), &mask);
> > -	gicv3_ipi_send_tlist(&mask, 0);
> > +	gicv3_ipi_send_tlist(&mask, cmdl_irq);
> >  }
> >  
> >  static void gicv3_ipi_send_broadcast(void)
> >  {
> > -	gicv3_write_sgi1r(1ULL << 40);
> > +	gicv3_write_sgi1r(1ULL << 40 | cmdl_irq << 24);
> >  	isb();
> >  }
> >  
> > @@ -144,10 +190,9 @@ static void ipi_test_self(void)
> >  	cpumask_t mask;
> >  
> >  	report_prefix_push("self");
> > -	memset(acked, 0, sizeof(acked));
> > -	smp_wmb();
> > +	stats_reset();
> >  	cpumask_clear(&mask);
> > -	cpumask_set_cpu(0, &mask);
> > +	cpumask_set_cpu(smp_processor_id(), &mask);
> >  	gic->ipi.send_self();
> >  	check_acked(&mask);
> >  	report_prefix_pop();
> > @@ -159,20 +204,18 @@ static void ipi_test_smp(void)
> >  	int i;
> >  
> >  	report_prefix_push("target-list");
> > -	memset(acked, 0, sizeof(acked));
> > -	smp_wmb();
> > +	stats_reset();
> >  	cpumask_copy(&mask, &cpu_present_mask);
> > -	for (i = 0; i < nr_cpus; i += 2)
> > +	for (i = smp_processor_id() & 1; i < nr_cpus; i += 2)
> >  		cpumask_clear_cpu(i, &mask);
> > -	gic->ipi.send_tlist(&mask, 0);
> > +	gic->ipi.send_tlist(&mask, cmdl_irq);
> >  	check_acked(&mask);
> >  	report_prefix_pop();
> >  
> >  	report_prefix_push("broadcast");
> > -	memset(acked, 0, sizeof(acked));
> > -	smp_wmb();
> > +	stats_reset();
> >  	cpumask_copy(&mask, &cpu_present_mask);
> > -	cpumask_clear_cpu(0, &mask);
> > +	cpumask_clear_cpu(smp_processor_id(), &mask);
> >  	gic->ipi.send_broadcast();
> >  	check_acked(&mask);
> >  	report_prefix_pop();
> > @@ -189,6 +232,16 @@ static void ipi_enable(void)
> >  	local_irq_enable();
> >  }
> >  
> > +static void ipi_send(void)
> > +{
> > +	ipi_enable();
> > +	wait_on_ready();
> > +	ipi_test_self();
> > +	ipi_test_smp();
> > +	check_spurious();
> > +	exit(report_summary());
> > +}
> > +
> >  static void ipi_recv(void)
> >  {
> >  	ipi_enable();
> > @@ -197,6 +250,14 @@ static void ipi_recv(void)
> >  		wfi();
> >  }
> >  
> > +static void ipi_test(void)
> > +{
> > +	if (smp_processor_id() == cmdl_sender)
> > +		ipi_send();
> > +	else
> > +		ipi_recv();
> > +}
> > +
> >  static struct gic gicv2 = {
> >  	.ipi = {
> >  		.send_self = gicv2_ipi_send_self,
> > @@ -242,21 +303,34 @@ int main(int argc, char **argv)
> >  		report_prefix_pop();
> >  
> >  	} else if (strcmp(argv[1], "ipi") == 0) {
> > +		int off, i = 1;
> > +		long val;
> >  
> >  		report_prefix_push(argv[1]);
> >  		nr_cpu_check(2);
> >  
> > +		while (--argc != 1) {
> > +			off = parse_keyval(argv[++i], &val);
> > +			if (off == -1)
> > +				continue;
> > +			argv[i][off] = '\0';
> > +			if (strcmp(argv[i], "sender") == 0) {
> > +				if (val >= nr_cpus)
> > +					report_abort("invalid sender %d, nr_cpus=%d", val, nr_cpus);
> > +				cmdl_sender = val;
> > +			} else if (strcmp(argv[i], "irq") == 0) {
> > +				if (val > 15)
> > +					report_abort("irq (SGI) must be < 16");
> > +				cmdl_irq = val;
> > +			}
> wrong arg could potentially be tested.

What do you mean by 'wrong arg'? Can you give me an example?

> 
> Besides
> Reviewed-by: Eric Auger <eric.auger@redhat.com>

Thanks!

drew