Mykola Kvach <xakep.ama...@gmail.com> writes:
> From: Mirela Simonovic <mirela.simono...@aggios.com>
>
> System suspend may lead to a state where GIC would be powered down.
> Therefore, Xen should save/restore the context of GIC on suspend/resume.
>
> Note that the context consists of states of registers which are
> controlled by the hypervisor. Other GIC registers which are accessible
> by guests are saved/restored on context switch.
>
> Signed-off-by: Mirela Simonovic <mirela.simono...@aggios.com>
> Signed-off-by: Saeed Nowshadi <saeed.nowsh...@xilinx.com>
> Signed-off-by: Mykyta Poturai <mykyta_potu...@epam.com>
> Signed-off-by: Mykola Kvach <mykola_kv...@epam.com>
Reviewed-by: Volodymyr Babchuk <volodymyr_babc...@epam.com>
> ---
> Changes in v6:
> - drop extra func/line printing from dprintk
> - drop checking context allocation from resume handler
> - merge some loops where it is possible
>
> Changes in v4:
> - Add error logging for allocation failures
>
> Changes in v3:
> - Drop asserts and return error codes instead.
> - Wrap code with CONFIG_SYSTEM_SUSPEND.
>
> Changes in v2:
> - Minor fixes after review.
> ---
> xen/arch/arm/gic-v2.c | 143 +++++++++++++++++++++++++++++++++
> xen/arch/arm/gic.c | 29 +++++++
> xen/arch/arm/include/asm/gic.h | 12 +++
> 3 files changed, 184 insertions(+)
>
> diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c
> index b23e72a3d0..6373599e69 100644
> --- a/xen/arch/arm/gic-v2.c
> +++ b/xen/arch/arm/gic-v2.c
> @@ -1098,6 +1098,140 @@ static int gicv2_iomem_deny_access(struct domain *d)
> return iomem_deny_access(d, mfn, mfn + nr);
> }
>
> +#ifdef CONFIG_SYSTEM_SUSPEND
> +
> +/* GICv2 registers to be saved/restored on system suspend/resume */
> +struct gicv2_context {
> + /* GICC context */
> + uint32_t gicc_ctlr;
> + uint32_t gicc_pmr;
> + uint32_t gicc_bpr;
> + /* GICD context */
> + uint32_t gicd_ctlr;
> + uint32_t *gicd_isenabler;
> + uint32_t *gicd_isactiver;
> + uint32_t *gicd_ipriorityr;
> + uint32_t *gicd_itargetsr;
> + uint32_t *gicd_icfgr;
> +};
> +
> +static struct gicv2_context gicv2_context;
> +
> +static int gicv2_suspend(void)
> +{
> + unsigned int i;
> +
> + if ( !gicv2_context.gicd_isenabler )
> + {
> + dprintk(XENLOG_WARNING, "GICv2 suspend context not allocated!\n");
> + return -ENOMEM;
> + }
> +
> + /* Save GICC configuration */
> + gicv2_context.gicc_ctlr = readl_gicc(GICC_CTLR);
> + gicv2_context.gicc_pmr = readl_gicc(GICC_PMR);
> + gicv2_context.gicc_bpr = readl_gicc(GICC_BPR);
> +
> + /* Save GICD configuration */
> + gicv2_context.gicd_ctlr = readl_gicd(GICD_CTLR);
> +
> + for ( i = 0; i < DIV_ROUND_UP(gicv2_info.nr_lines, 32); i++ )
> + {
> + gicv2_context.gicd_isenabler[i] = readl_gicd(GICD_ISENABLER + i * 4);
> + gicv2_context.gicd_isactiver[i] = readl_gicd(GICD_ISACTIVER + i * 4);
> + }
> +
> + for ( i = 0; i < DIV_ROUND_UP(gicv2_info.nr_lines, 4); i++ )
> + {
> + gicv2_context.gicd_ipriorityr[i] = readl_gicd(GICD_IPRIORITYR + i *
> 4);
> + gicv2_context.gicd_itargetsr[i] = readl_gicd(GICD_ITARGETSR + i * 4);
> + }
> +
> + for ( i = 0; i < DIV_ROUND_UP(gicv2_info.nr_lines, 16); i++ )
> + gicv2_context.gicd_icfgr[i] = readl_gicd(GICD_ICFGR + i * 4);
> +
> + return 0;
> +}
> +
> +static void gicv2_resume(void)
> +{
> + unsigned int i;
> +
> + gicv2_cpu_disable();
> + /* Disable distributor */
> + writel_gicd(0, GICD_CTLR);
> +
> + /* Restore GICD configuration */
> + for ( i = 0; i < DIV_ROUND_UP(gicv2_info.nr_lines, 32); i++ )
> + {
> + writel_gicd(0xffffffff, GICD_ICENABLER + i * 4);
> + writel_gicd(gicv2_context.gicd_isenabler[i], GICD_ISENABLER + i * 4);
> +
> + writel_gicd(0xffffffff, GICD_ICACTIVER + i * 4);
> + writel_gicd(gicv2_context.gicd_isactiver[i], GICD_ISACTIVER + i * 4);
> + }
> +
> + for ( i = 0; i < DIV_ROUND_UP(gicv2_info.nr_lines, 4); i++ )
> + {
> + writel_gicd(gicv2_context.gicd_ipriorityr[i], GICD_IPRIORITYR + i *
> 4);
> + writel_gicd(gicv2_context.gicd_itargetsr[i], GICD_ITARGETSR + i * 4);
> + }
> +
> + for ( i = 0; i < DIV_ROUND_UP(gicv2_info.nr_lines, 16); i++ )
> + writel_gicd(gicv2_context.gicd_icfgr[i], GICD_ICFGR + i * 4);
> +
> + /* Make sure all registers are restored and enable distributor */
> + writel_gicd(gicv2_context.gicd_ctlr | GICD_CTL_ENABLE, GICD_CTLR);
> +
> + /* Restore GIC CPU interface configuration */
> + writel_gicc(gicv2_context.gicc_pmr, GICC_PMR);
> + writel_gicc(gicv2_context.gicc_bpr, GICC_BPR);
> +
> + /* Enable GIC CPU interface */
> + writel_gicc(gicv2_context.gicc_ctlr | GICC_CTL_ENABLE | GICC_CTL_EOI,
> + GICC_CTLR);
> +}
> +
> +static void gicv2_alloc_context(struct gicv2_context *gc)
> +{
> + uint32_t n = gicv2_info.nr_lines;
> +
> + gc->gicd_isenabler = xzalloc_array(uint32_t, DIV_ROUND_UP(n, 32));
> + if ( !gc->gicd_isenabler )
> + goto err_free;
> +
> + gc->gicd_isactiver = xzalloc_array(uint32_t, DIV_ROUND_UP(n, 32));
> + if ( !gc->gicd_isactiver )
> + goto err_free;
> +
> + gc->gicd_itargetsr = xzalloc_array(uint32_t, DIV_ROUND_UP(n, 4));
> + if ( !gc->gicd_itargetsr )
> + goto err_free;
> +
> + gc->gicd_ipriorityr = xzalloc_array(uint32_t, DIV_ROUND_UP(n, 4));
> + if ( !gc->gicd_ipriorityr )
> + goto err_free;
> +
> + gc->gicd_icfgr = xzalloc_array(uint32_t, DIV_ROUND_UP(n, 16));
> + if ( !gc->gicd_icfgr )
> + goto err_free;
> +
> + return;
> +
> + err_free:
> + printk(XENLOG_ERR "Failed to allocate memory for GICv2 suspend
> context\n");
> +
> + xfree(gc->gicd_icfgr);
> + xfree(gc->gicd_ipriorityr);
> + xfree(gc->gicd_itargetsr);
> + xfree(gc->gicd_isactiver);
> + xfree(gc->gicd_isenabler);
> +
> + memset(gc, 0, sizeof(*gc));
> +}
> +
> +#endif /* CONFIG_SYSTEM_SUSPEND */
> +
> #ifdef CONFIG_ACPI
> static unsigned long gicv2_get_hwdom_extra_madt_size(const struct domain *d)
> {
> @@ -1302,6 +1436,11 @@ static int __init gicv2_init(void)
>
> spin_unlock(&gicv2.lock);
>
> +#ifdef CONFIG_SYSTEM_SUSPEND
> + /* Allocate memory to be used for saving GIC context during the suspend
> */
> + gicv2_alloc_context(&gicv2_context);
> +#endif /* CONFIG_SYSTEM_SUSPEND */
> +
> return 0;
> }
>
> @@ -1345,6 +1484,10 @@ static const struct gic_hw_operations gicv2_ops = {
> .map_hwdom_extra_mappings = gicv2_map_hwdom_extra_mappings,
> .iomem_deny_access = gicv2_iomem_deny_access,
> .do_LPI = gicv2_do_LPI,
> +#ifdef CONFIG_SYSTEM_SUSPEND
> + .suspend = gicv2_suspend,
> + .resume = gicv2_resume,
> +#endif /* CONFIG_SYSTEM_SUSPEND */
> };
>
> /* Set up the GIC */
> diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
> index e80fe0ca24..a018bd7715 100644
> --- a/xen/arch/arm/gic.c
> +++ b/xen/arch/arm/gic.c
> @@ -425,6 +425,35 @@ int gic_iomem_deny_access(struct domain *d)
> return gic_hw_ops->iomem_deny_access(d);
> }
>
> +#ifdef CONFIG_SYSTEM_SUSPEND
> +
> +int gic_suspend(void)
> +{
> + /* Must be called by boot CPU#0 with interrupts disabled */
> + ASSERT(!local_irq_is_enabled());
> + ASSERT(!smp_processor_id());
> +
> + if ( !gic_hw_ops->suspend || !gic_hw_ops->resume )
> + return -ENOSYS;
> +
> + return gic_hw_ops->suspend();
> +}
> +
> +void gic_resume(void)
> +{
> + /*
> + * Must be called by boot CPU#0 with interrupts disabled after
> gic_suspend
> + * has returned successfully.
> + */
> + ASSERT(!local_irq_is_enabled());
> + ASSERT(!smp_processor_id());
> + ASSERT(gic_hw_ops->resume);
> +
> + gic_hw_ops->resume();
> +}
> +
> +#endif /* CONFIG_SYSTEM_SUSPEND */
> +
> static int cpu_gic_callback(struct notifier_block *nfb,
> unsigned long action,
> void *hcpu)
> diff --git a/xen/arch/arm/include/asm/gic.h b/xen/arch/arm/include/asm/gic.h
> index 541f0eeb80..a706303008 100644
> --- a/xen/arch/arm/include/asm/gic.h
> +++ b/xen/arch/arm/include/asm/gic.h
> @@ -280,6 +280,12 @@ extern int gicv_setup(struct domain *d);
> extern void gic_save_state(struct vcpu *v);
> extern void gic_restore_state(struct vcpu *v);
>
> +#ifdef CONFIG_SYSTEM_SUSPEND
> +/* Suspend/resume */
> +extern int gic_suspend(void);
> +extern void gic_resume(void);
> +#endif /* CONFIG_SYSTEM_SUSPEND */
> +
> /* SGI (AKA IPIs) */
> enum gic_sgi {
> GIC_SGI_EVENT_CHECK,
> @@ -395,6 +401,12 @@ struct gic_hw_operations {
> int (*iomem_deny_access)(struct domain *d);
> /* Handle LPIs, which require special handling */
> void (*do_LPI)(unsigned int lpi);
> +#ifdef CONFIG_SYSTEM_SUSPEND
> + /* Save GIC configuration due to the system suspend */
> + int (*suspend)(void);
> + /* Restore GIC configuration due to the system resume */
> + void (*resume)(void);
> +#endif /* CONFIG_SYSTEM_SUSPEND */
> };
>
> extern const struct gic_hw_operations *gic_hw_ops;
--
WBR, Volodymyr
