From 3171a47a22eedfb6e97803fb193fc98cdb61d90f Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 20 Dec 2016 15:17:28 +0000 Subject: [PATCH] irqchip/gic-v3-its: Add VPE affinity changes When we're about to run a vcpu, it is crucial that the redistributor associated with the physical CPU is being told about the new residency. This is abstracted by hijacking the irq_set_affinity method for the doorbell interrupt associated with the VPE. It is expected that the hypervisor will call this method before scheduling the VPE. Reviewed-by: Thomas Gleixner Signed-off-by: Marc Zyngier --- drivers/irqchip/irq-gic-v3-its.c | 96 ++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 21b728df7544..ab25b57866cd 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -148,6 +148,9 @@ static struct irq_domain *its_parent; #define ITS_LIST_MAX 16 static unsigned long its_list_map; +static u16 vmovp_seq_num; +static DEFINE_RAW_SPINLOCK(vmovp_lock); + static DEFINE_IDA(its_vpeid_ida); #define gic_data_rdist() (raw_cpu_ptr(gic_rdists->rdist)) @@ -238,6 +241,13 @@ struct its_cmd_desc { u32 event_id; bool db_enabled; } its_vmovi_cmd; + + struct { + struct its_vpe *vpe; + struct its_collection *col; + u16 seq_num; + u16 its_list; + } its_vmovp_cmd; }; }; @@ -329,6 +339,16 @@ static void its_encode_db_valid(struct its_cmd_block *cmd, bool db_valid) its_mask_encode(&cmd->raw_cmd[2], db_valid, 0, 0); } +static void its_encode_seq_num(struct its_cmd_block *cmd, u16 seq_num) +{ + its_mask_encode(&cmd->raw_cmd[0], seq_num, 47, 32); +} + +static void its_encode_its_list(struct its_cmd_block *cmd, u16 its_list) +{ + its_mask_encode(&cmd->raw_cmd[1], its_list, 15, 0); +} + static void its_encode_vpt_addr(struct its_cmd_block *cmd, u64 vpt_pa) { its_mask_encode(&cmd->raw_cmd[3], vpt_pa >> 16, 50, 16); @@ -571,6 +591,20 @@ static struct its_vpe *its_build_vmovi_cmd(struct its_cmd_block *cmd, return desc->its_vmovi_cmd.vpe; } +static struct its_vpe *its_build_vmovp_cmd(struct its_cmd_block *cmd, + struct its_cmd_desc *desc) +{ + its_encode_cmd(cmd, GITS_CMD_VMOVP); + its_encode_seq_num(cmd, desc->its_vmovp_cmd.seq_num); + its_encode_its_list(cmd, desc->its_vmovp_cmd.its_list); + its_encode_vpeid(cmd, desc->its_vmovp_cmd.vpe->vpe_id); + its_encode_target(cmd, desc->its_vmovp_cmd.col->target_address); + + its_fixup_cmd(cmd); + + return desc->its_vmovp_cmd.vpe; +} + static u64 its_cmd_ptr_to_offset(struct its_node *its, struct its_cmd_block *ptr) { @@ -871,6 +905,48 @@ static void its_send_vmapp(struct its_vpe *vpe, bool valid) } } +static void its_send_vmovp(struct its_vpe *vpe) +{ + struct its_cmd_desc desc; + struct its_node *its; + unsigned long flags; + int col_id = vpe->col_idx; + + desc.its_vmovp_cmd.vpe = vpe; + desc.its_vmovp_cmd.its_list = (u16)its_list_map; + + if (!its_list_map) { + its = list_first_entry(&its_nodes, struct its_node, entry); + desc.its_vmovp_cmd.seq_num = 0; + desc.its_vmovp_cmd.col = &its->collections[col_id]; + its_send_single_vcommand(its, its_build_vmovp_cmd, &desc); + return; + } + + /* + * Yet another marvel of the architecture. If using the + * its_list "feature", we need to make sure that all ITSs + * receive all VMOVP commands in the same order. The only way + * to guarantee this is to make vmovp a serialization point. + * + * Wall <-- Head. + */ + raw_spin_lock_irqsave(&vmovp_lock, flags); + + desc.its_vmovp_cmd.seq_num = vmovp_seq_num++; + + /* Emit VMOVPs */ + list_for_each_entry(its, &its_nodes, entry) { + if (!its->is_v4) + continue; + + desc.its_vmovp_cmd.col = &its->collections[col_id]; + its_send_single_vcommand(its, its_build_vmovp_cmd, &desc); + } + + raw_spin_unlock_irqrestore(&vmovp_lock, flags); +} + static void its_send_vinvall(struct its_vpe *vpe) { struct its_cmd_desc desc; @@ -2154,6 +2230,25 @@ static const struct irq_domain_ops its_domain_ops = { .deactivate = its_irq_domain_deactivate, }; +static int its_vpe_set_affinity(struct irq_data *d, + const struct cpumask *mask_val, + bool force) +{ + struct its_vpe *vpe = irq_data_get_irq_chip_data(d); + int cpu = cpumask_first(mask_val); + + /* + * Changing affinity is mega expensive, so let's be as lazy as + * we can and only do it if we really have to. + */ + if (vpe->col_idx != cpu) { + vpe->col_idx = cpu; + its_send_vmovp(vpe); + } + + return IRQ_SET_MASK_OK_DONE; +} + static void its_vpe_schedule(struct its_vpe *vpe) { void * __iomem vlpi_base = gic_data_rdist_vlpi_base(); @@ -2243,6 +2338,7 @@ static int its_vpe_set_vcpu_affinity(struct irq_data *d, void *vcpu_info) static struct irq_chip its_vpe_irq_chip = { .name = "GICv4-vpe", + .irq_set_affinity = its_vpe_set_affinity, .irq_set_vcpu_affinity = its_vpe_set_vcpu_affinity, }; -- 2.30.2