Re: [Qemu-devel] [kvm-unit-tests PATCH v7 11/11] arm/arm64: gic: don't just use zero

[Auger Eric <eric.auger@redhat.com>]

Hi,

On 23/11/2016 17:54, Andrew Jones wrote:
> Allow user to select who sends ipis and with which irq,
> rather than just always sending irq=0 from cpu0.
> 
> Signed-off-by: Andrew Jones <drjones@redhat.com>

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

Eric


> 
> ---
> v7: cleanup cmdline parsing and add complain on bad args [Eric]
> 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 | 143 ++++++++++++++++++++++++++++++++++++++++++++++++++++----------
>  1 file changed, 120 insertions(+), 23 deletions(-)
> 
> diff --git a/arm/gic.c b/arm/gic.c
> index 23c1860a49d9..88c5f49d807d 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>
> @@ -27,6 +28,8 @@ 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)
> @@ -42,10 +45,23 @@ 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) {
> @@ -55,9 +71,21 @@ 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;
>  		}
>  	}
> @@ -90,6 +118,22 @@ 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();
> @@ -97,8 +141,10 @@ 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()];
> @@ -108,22 +154,22 @@ 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_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)
>  {
> -	gic_ipi_send_single(0, smp_processor_id());
> +	gic_ipi_send_single(cmdl_irq, smp_processor_id());
>  }
>  
>  static void gicv3_ipi_send_broadcast(void)
>  {
> -	gicv3_write_sgi1r(1ULL << 40);
> +	gicv3_write_sgi1r(1ULL << 40 | cmdl_irq << 24);
>  	isb();
>  }
>  
> @@ -132,10 +178,9 @@ 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();
> @@ -147,20 +192,18 @@ 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_mask(0, &mask);
> +	gic_ipi_send_mask(cmdl_irq, &mask);
>  	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();
> @@ -177,6 +220,16 @@ 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();
> @@ -185,6 +238,54 @@ static void ipi_recv(void)
>  		wfi();
>  }
>  
> +static void ipi_test(void)
> +{
> +	if (smp_processor_id() == cmdl_sender)
> +		ipi_send();
> +	else
> +		ipi_recv();
> +}
> +
> +#define CMDL_IPI_USAGE "usage: gic ipi [sender=<cpu#>] [irq=<sgi#>]"
> +
> +static void cmdl_ipi_set_sender(int sender)
> +{
> +	if (sender < nr_cpus) {
> +		cmdl_sender = sender;
> +		return;
> +	}
> +	report_abort("invalid sender %d, nr_cpus=%d", sender, nr_cpus);
> +}
> +
> +static void cmdl_ipi_set_irq(int irq)
> +{
> +	if (irq < 16) {
> +		cmdl_irq = irq;
> +		return;
> +	}
> +	report_abort("invalid irq %d, SGI must be < 16", irq);
> +}
> +
> +static void cmdl_ipi_get_inputs(int argc, char **argv)
> +{
> +	int off, i = 1;
> +	long val;
> +
> +	while (--argc != 1) {
> +		off = parse_keyval(argv[++i], &val);
> +		if (off == -1)
> +			report_abort(CMDL_IPI_USAGE);
> +		argv[i][off] = '\0';
> +
> +		if (strcmp(argv[i], "sender") == 0)
> +			cmdl_ipi_set_sender(val);
> +		else if (strcmp(argv[i], "irq") == 0)
> +			cmdl_ipi_set_irq(val);
> +		else
> +			report_abort(CMDL_IPI_USAGE);
> +	}
> +}
> +
>  static struct gic gicv2 = {
>  	.ipi = {
>  		.send_self = gicv2_ipi_send_self,
> @@ -230,19 +331,15 @@ int main(int argc, char **argv)
>  	} else if (strcmp(argv[1], "ipi") == 0) {
>  
>  		report_prefix_push(argv[1]);
> +		cmdl_ipi_get_inputs(argc, argv);
>  		nr_cpu_check(2);
>  
>  		for_each_present_cpu(cpu) {
>  			if (cpu == 0)
>  				continue;
> -			smp_boot_secondary(cpu, ipi_recv);
> +			smp_boot_secondary(cpu, ipi_test);
>  		}
> -		ipi_enable();
> -		wait_on_ready();
> -		ipi_test_self();
> -		ipi_test_smp();
> -		check_spurious();
> -		report_prefix_pop();
> +		ipi_test();
>  
>  	} else {
>  		report_abort("Unknown subtest '%s'", argv[1]);
>