From e64fab1a1477dbf0c355691914511612ba312932 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 24 Dec 2019 11:10:35 +0000 Subject: irqchip/gic-v4.1: Add VPE eviction callback When descheduling a VPE, special care must be taken to tell the GIC about whether we want to receive a doorbell or not. This is a major improvement on GICv4.0, where the doorbell had to be separately enabled/disabled. Signed-off-by: Marc Zyngier Reviewed-by: Zenghui Yu Link: https://lore.kernel.org/r/20191224111055.11836-13-maz@kernel.org --- drivers/irqchip/irq-gic-v3-its.c | 53 +++++++++++++++++++++++++++++++--------- 1 file changed, 42 insertions(+), 11 deletions(-) (limited to 'drivers/irqchip') diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 3adc597e2a82..69b16e5da383 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -2630,7 +2630,7 @@ static int __init allocate_lpi_tables(void) return 0; } -static u64 its_clear_vpend_valid(void __iomem *vlpi_base) +static u64 its_clear_vpend_valid(void __iomem *vlpi_base, u64 clr, u64 set) { u32 count = 1000000; /* 1s! */ bool clean; @@ -2638,6 +2638,8 @@ static u64 its_clear_vpend_valid(void __iomem *vlpi_base) val = gits_read_vpendbaser(vlpi_base + GICR_VPENDBASER); val &= ~GICR_VPENDBASER_Valid; + val &= ~clr; + val |= set; gits_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER); do { @@ -2650,6 +2652,11 @@ static u64 its_clear_vpend_valid(void __iomem *vlpi_base) } } while (!clean && count); + if (unlikely(val & GICR_VPENDBASER_Dirty)) { + pr_err_ratelimited("ITS virtual pending table not cleaning\n"); + val |= GICR_VPENDBASER_PendingLast; + } + return val; } @@ -2758,7 +2765,7 @@ static void its_cpu_init_lpis(void) * ancient programming gets left in and has possibility of * corrupting memory. */ - val = its_clear_vpend_valid(vlpi_base); + val = its_clear_vpend_valid(vlpi_base, 0, 0); WARN_ON(val & GICR_VPENDBASER_Dirty); } @@ -3438,16 +3445,10 @@ static void its_vpe_deschedule(struct its_vpe *vpe) void __iomem *vlpi_base = gic_data_rdist_vlpi_base(); u64 val; - val = its_clear_vpend_valid(vlpi_base); + val = its_clear_vpend_valid(vlpi_base, 0, 0); - if (unlikely(val & GICR_VPENDBASER_Dirty)) { - pr_err_ratelimited("ITS virtual pending table not cleaning\n"); - vpe->idai = false; - vpe->pending_last = true; - } else { - vpe->idai = !!(val & GICR_VPENDBASER_IDAI); - vpe->pending_last = !!(val & GICR_VPENDBASER_PendingLast); - } + vpe->idai = !!(val & GICR_VPENDBASER_IDAI); + vpe->pending_last = !!(val & GICR_VPENDBASER_PendingLast); } static void its_vpe_invall(struct its_vpe *vpe) @@ -3639,6 +3640,35 @@ static void its_vpe_4_1_schedule(struct its_vpe *vpe, gits_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER); } +static void its_vpe_4_1_deschedule(struct its_vpe *vpe, + struct its_cmd_info *info) +{ + void __iomem *vlpi_base = gic_data_rdist_vlpi_base(); + u64 val; + + if (info->req_db) { + /* + * vPE is going to block: make the vPE non-resident with + * PendingLast clear and DB set. The GIC guarantees that if + * we read-back PendingLast clear, then a doorbell will be + * delivered when an interrupt comes. + */ + val = its_clear_vpend_valid(vlpi_base, + GICR_VPENDBASER_PendingLast, + GICR_VPENDBASER_4_1_DB); + vpe->pending_last = !!(val & GICR_VPENDBASER_PendingLast); + } else { + /* + * We're not blocking, so just make the vPE non-resident + * with PendingLast set, indicating that we'll be back. + */ + val = its_clear_vpend_valid(vlpi_base, + 0, + GICR_VPENDBASER_PendingLast); + vpe->pending_last = true; + } +} + static int its_vpe_4_1_set_vcpu_affinity(struct irq_data *d, void *vcpu_info) { struct its_vpe *vpe = irq_data_get_irq_chip_data(d); @@ -3650,6 +3680,7 @@ static int its_vpe_4_1_set_vcpu_affinity(struct irq_data *d, void *vcpu_info) return 0; case DESCHEDULE_VPE: + its_vpe_4_1_deschedule(vpe, info); return 0; case INVALL_VPE: -- cgit v1.2.3-59-g8ed1b