Re: [Qemu-devel] [kvm-unit-tests PATCH v3 09/10] arm/arm64: gicv3: add an IPI test

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

Hi Drew,

On 15/07/2016 15:00, Andrew Jones wrote:
> Signed-off-by: Andrew Jones <drjones@redhat.com>
> 
> ---
> v2: use IRM for gicv3 broadcast
> ---
>  arm/gic.c         | 157 ++++++++++++++++++++++++++++++++++++++++++++++++++----
>  arm/unittests.cfg |   6 +++
>  2 files changed, 154 insertions(+), 9 deletions(-)
> 
> diff --git a/arm/gic.c b/arm/gic.c
> index cf7ec1c90413c..fc7ef241de3e2 100644
> --- a/arm/gic.c
> +++ b/arm/gic.c
> @@ -3,6 +3,8 @@
>   *
>   * GICv2
>   *   . test sending/receiving IPIs
> + * GICv3
> + *   . test sending/receiving IPIs
>   *
>   * Copyright (C) 2016, Red Hat Inc, Andrew Jones <drjones@redhat.com>
>   *
> @@ -16,6 +18,18 @@
>  #include <asm/barrier.h>
>  #include <asm/io.h>
>  
> +struct gic {
> +	struct {
> +		void (*enable)(void);
> +		void (*send_self)(void);
> +		void (*send_tlist)(cpumask_t *);
> +		void (*send_broadcast)(void);
> +	} ipi;
> +	u32 (*read_iar)(void);
> +	void (*write_eoi)(u32);
> +};
> +
> +static struct gic *gic;
>  static int gic_version;
>  static int acked[NR_CPUS], spurious[NR_CPUS];
>  static cpumask_t ready;
> @@ -69,12 +83,22 @@ static void check_acked(cpumask_t *mask)
>  	       false, missing, extra, unexpected);
>  }
>  
> +static u32 gicv2_read_iar(void)
> +{
> +	return readl(gicv2_cpu_base() + GIC_CPU_INTACK);
> +}
> +
> +static void gicv2_write_eoi(u32 irq)
> +{
> +	writel(irq, gicv2_cpu_base() + GIC_CPU_EOI);
> +}
> +
>  static void ipi_handler(struct pt_regs *regs __unused)
>  {
> -	u32 iar = readl(gicv2_cpu_base() + GIC_CPU_INTACK);
> +	u32 iar = gic->read_iar();
>  
>  	if (iar != GICC_INT_SPURIOUS) {
> -		writel(iar, gicv2_cpu_base() + GIC_CPU_EOI);
> +		gic->write_eoi(iar);
>  		smp_rmb(); /* pairs with wmb in ipi_test functions */
>  		++acked[smp_processor_id()];
>  		smp_wmb(); /* pairs with rmb in check_acked */
> @@ -84,6 +108,89 @@ static void ipi_handler(struct pt_regs *regs __unused)
>  	}
>  }
>  
> +static void gicv2_ipi_send_self(void)
> +{
> +	writel(2 << 24, gicv2_dist_base() + GIC_DIST_SOFTINT);
> +}
> +
> +static void gicv2_ipi_send_tlist(cpumask_t *mask)
> +{
> +	u8 tlist = (u8)cpumask_bits(mask)[0];
> +
> +	writel(tlist << 16, gicv2_dist_base() + GIC_DIST_SOFTINT);
> +}
> +
> +static void gicv2_ipi_send_broadcast(void)
> +{
> +	writel(1 << 24, gicv2_dist_base() + GIC_DIST_SOFTINT);
> +}
> +
> +#define ICC_SGI1R_AFFINITY_1_SHIFT	16
> +#define ICC_SGI1R_AFFINITY_2_SHIFT	32
> +#define ICC_SGI1R_AFFINITY_3_SHIFT	48
> +#define MPIDR_TO_SGI_AFFINITY(cluster_id, level) \
> +	(MPIDR_AFFINITY_LEVEL(cluster_id, level) << ICC_SGI1R_AFFINITY_## level ## _SHIFT)
> +
> +static void gicv3_ipi_send_tlist(cpumask_t *mask)
> +{
This function really is indigestible to me. Can't we reuse the linux
kernel gic_compute_target_list routine. Since the code looks similar why
not trying to be as close as possible to the kernel?

Thanks

Eric
> +	u16 tlist;
> +	int cpu;
> +
> +	for_each_cpu(cpu, mask) {
> +		u64 mpidr = cpus[cpu], sgi1r;
> +		u64 cluster_id = mpidr & ~0xffUL;
> +
> +		tlist = 0;
> +
> +		while (cpu < nr_cpus) {
> +			if ((mpidr & 0xff) >= 16) {
> +				printf("cpu%d MPIDR:aff0 is %d (>= 16)!\n",
> +					cpu, (int)(mpidr & 0xff));
> +				break;
> +			}
> +
> +			tlist |= 1 << (mpidr & 0xf);
> +
> +			cpu = cpumask_next(cpu, mask);
> +			if (cpu >= nr_cpus)
> +				break;
> +
> +			mpidr = cpus[cpu];
> +
> +			if (cluster_id != (mpidr & ~0xffUL)) {
> +				--cpu;
> +				break;
> +			}
> +		}
> +
> +		sgi1r = (MPIDR_TO_SGI_AFFINITY(cluster_id, 3)	|
> +			 MPIDR_TO_SGI_AFFINITY(cluster_id, 2)	|
> +			 /* irq << 24				| */
> +			 MPIDR_TO_SGI_AFFINITY(cluster_id, 1)	|
> +			 tlist);
> +
> +		gicv3_write_sgi1r(sgi1r);
> +	}
> +
> +	/* Force the above writes to ICC_SGI1R_EL1 to be executed */
> +	isb();
> +}
> +
> +static void gicv3_ipi_send_self(void)
> +{
> +	cpumask_t mask;
> +
> +	cpumask_clear(&mask);
> +	cpumask_set_cpu(smp_processor_id(), &mask);
> +	gicv3_ipi_send_tlist(&mask);
> +}
> +
> +static void gicv3_ipi_send_broadcast(void)
> +{
> +	gicv3_write_sgi1r(1ULL << 40);
> +	isb();
> +}
> +
>  static void ipi_test_self(void)
>  {
>  	cpumask_t mask;
> @@ -93,7 +200,7 @@ static void ipi_test_self(void)
>  	smp_wmb();
>  	cpumask_clear(&mask);
>  	cpumask_set_cpu(0, &mask);
> -	writel(2 << 24, gicv2_dist_base() + GIC_DIST_SOFTINT);
> +	gic->ipi.send_self();
>  	check_acked(&mask);
>  	report_prefix_pop();
>  }
> @@ -101,14 +208,15 @@ static void ipi_test_self(void)
>  static void ipi_test_smp(void)
>  {
>  	cpumask_t mask;
> -	unsigned long tlist;
> +	int i;
>  
>  	report_prefix_push("target-list");
>  	memset(acked, 0, sizeof(acked));
>  	smp_wmb();
> -	tlist = cpumask_bits(&cpu_present_mask)[0] & 0xaa;
> -	cpumask_bits(&mask)[0] = tlist;
> -	writel((u8)tlist << 16, gicv2_dist_base() + GIC_DIST_SOFTINT);
> +	cpumask_copy(&mask, &cpu_present_mask);
> +	for (i = 0; i < nr_cpus; i += 2)
> +		cpumask_clear_cpu(i, &mask);
> +	gic->ipi.send_tlist(&mask);
>  	check_acked(&mask);
>  	report_prefix_pop();
>  
> @@ -117,14 +225,14 @@ static void ipi_test_smp(void)
>  	smp_wmb();
>  	cpumask_copy(&mask, &cpu_present_mask);
>  	cpumask_clear_cpu(0, &mask);
> -	writel(1 << 24, gicv2_dist_base() + GIC_DIST_SOFTINT);
> +	gic->ipi.send_broadcast();
>  	check_acked(&mask);
>  	report_prefix_pop();
>  }
>  
>  static void ipi_enable(void)
>  {
> -	gicv2_enable_defaults();
> +	gic->ipi.enable();
>  #ifdef __arm__
>  	install_exception_handler(EXCPTN_IRQ, ipi_handler);
>  #else
> @@ -141,6 +249,28 @@ static void ipi_recv(void)
>  		wfi();
>  }
>  
> +struct gic gicv2 = {
> +	.ipi = {
> +		.enable = gicv2_enable_defaults,
> +		.send_self = gicv2_ipi_send_self,
> +		.send_tlist = gicv2_ipi_send_tlist,
> +		.send_broadcast = gicv2_ipi_send_broadcast,
> +	},
> +	.read_iar = gicv2_read_iar,
> +	.write_eoi = gicv2_write_eoi,
> +};
> +
> +struct gic gicv3 = {
> +	.ipi = {
> +		.enable = gicv3_enable_defaults,
> +		.send_self = gicv3_ipi_send_self,
> +		.send_tlist = gicv3_ipi_send_tlist,
> +		.send_broadcast = gicv3_ipi_send_broadcast,
> +	},
> +	.read_iar = gicv3_read_iar,
> +	.write_eoi = gicv3_write_eoir,
> +};
> +
>  int main(int argc, char **argv)
>  {
>  	char pfx[8];
> @@ -153,6 +283,15 @@ int main(int argc, char **argv)
>  	snprintf(pfx, 8, "gicv%d", gic_version);
>  	report_prefix_push(pfx);
>  
> +	switch (gic_version) {
> +	case 2:
> +		gic = &gicv2;
> +		break;
> +	case 3:
> +		gic = &gicv3;
> +		break;
> +	}
> +
>  	if (argc < 2) {
>  
>  		report_prefix_push("ipi");
> diff --git a/arm/unittests.cfg b/arm/unittests.cfg
> index bb364675043f0..043a20e26e98c 100644
> --- a/arm/unittests.cfg
> +++ b/arm/unittests.cfg
> @@ -58,3 +58,9 @@ file = gic.flat
>  smp = $((($MAX_SMP < 8)?$MAX_SMP:8))
>  extra_params = -machine gic-version=2 -append 'ipi'
>  groups = gic
> +
> +[gicv3-ipi]
> +file = gic.flat
> +smp = $MAX_SMP
> +extra_params = -machine gic-version=3 -append 'ipi'
> +groups = gic
>