From 7d75bbb4bc1ad90386776459d37e4ddfe605671e Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 20 Dec 2016 13:55:54 +0000 Subject: [PATCH] irqchip/gic-v3-its: Add VPE irq domain allocation/teardown When creating a VM, the low level GICv4 code is responsible for: - allocating each VPE a unique VPEID - allocating a doorbell interrupt for each VPE - allocating the pending tables for each VPE - allocating the property table for the VM This of course has to be reversed when the VM is brought down. All of this is wired into the irq domain alloc/free methods. Signed-off-by: Marc Zyngier --- drivers/irqchip/irq-gic-v3-its.c | 169 +++++++++++++++++++++++++++++++ 1 file changed, 169 insertions(+) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 0de4a54485e8..06ec47f004f9 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -148,6 +148,7 @@ static struct irq_domain *its_parent; #define ITS_LIST_MAX 16 static unsigned long its_list_map; +static DEFINE_IDA(its_vpeid_ida); #define gic_data_rdist() (raw_cpu_ptr(gic_rdists->rdist)) #define gic_data_rdist_rd_base() (gic_data_rdist()->rd_base) @@ -1255,6 +1256,11 @@ static struct page *its_allocate_prop_table(gfp_t gfp_flags) return prop_page; } +static void its_free_prop_table(struct page *prop_page) +{ + free_pages((unsigned long)page_address(prop_page), + get_order(LPI_PROPBASE_SZ)); +} static int __init its_alloc_lpi_tables(void) { @@ -1557,6 +1563,12 @@ static struct page *its_allocate_pending_table(gfp_t gfp_flags) return pend_page; } +static void its_free_pending_table(struct page *pt) +{ + free_pages((unsigned long)page_address(pt), + get_order(max_t(u32, LPI_PENDBASE_SZ, SZ_64K))); +} + static void its_cpu_init_lpis(void) { void __iomem *rbase = gic_data_rdist_rd_base(); @@ -1779,6 +1791,34 @@ static bool its_alloc_device_table(struct its_node *its, u32 dev_id) return its_alloc_table_entry(baser, dev_id); } +static bool its_alloc_vpe_table(u32 vpe_id) +{ + struct its_node *its; + + /* + * Make sure the L2 tables are allocated on *all* v4 ITSs. We + * could try and only do it on ITSs corresponding to devices + * that have interrupts targeted at this VPE, but the + * complexity becomes crazy (and you have tons of memory + * anyway, right?). + */ + list_for_each_entry(its, &its_nodes, entry) { + struct its_baser *baser; + + if (!its->is_v4) + continue; + + baser = its_get_baser(its, GITS_BASER_TYPE_VCPU); + if (!baser) + return false; + + if (!its_alloc_table_entry(baser, vpe_id)) + return false; + } + + return true; +} + static struct its_device *its_create_device(struct its_node *its, u32 dev_id, int nvecs) { @@ -2036,7 +2076,136 @@ static struct irq_chip its_vpe_irq_chip = { .name = "GICv4-vpe", }; +static int its_vpe_id_alloc(void) +{ + return ida_simple_get(&its_vpeid_ida, 0, 1 << 16, GFP_KERNEL); +} + +static void its_vpe_id_free(u16 id) +{ + ida_simple_remove(&its_vpeid_ida, id); +} + +static int its_vpe_init(struct its_vpe *vpe) +{ + struct page *vpt_page; + int vpe_id; + + /* Allocate vpe_id */ + vpe_id = its_vpe_id_alloc(); + if (vpe_id < 0) + return vpe_id; + + /* Allocate VPT */ + vpt_page = its_allocate_pending_table(GFP_KERNEL); + if (!vpt_page) { + its_vpe_id_free(vpe_id); + return -ENOMEM; + } + + if (!its_alloc_vpe_table(vpe_id)) { + its_vpe_id_free(vpe_id); + its_free_pending_table(vpe->vpt_page); + return -ENOMEM; + } + + vpe->vpe_id = vpe_id; + vpe->vpt_page = vpt_page; + + return 0; +} + +static void its_vpe_teardown(struct its_vpe *vpe) +{ + its_vpe_id_free(vpe->vpe_id); + its_free_pending_table(vpe->vpt_page); +} + +static void its_vpe_irq_domain_free(struct irq_domain *domain, + unsigned int virq, + unsigned int nr_irqs) +{ + struct its_vm *vm = domain->host_data; + int i; + + irq_domain_free_irqs_parent(domain, virq, nr_irqs); + + for (i = 0; i < nr_irqs; i++) { + struct irq_data *data = irq_domain_get_irq_data(domain, + virq + i); + struct its_vpe *vpe = irq_data_get_irq_chip_data(data); + + BUG_ON(vm != vpe->its_vm); + + clear_bit(data->hwirq, vm->db_bitmap); + its_vpe_teardown(vpe); + irq_domain_reset_irq_data(data); + } + + if (bitmap_empty(vm->db_bitmap, vm->nr_db_lpis)) { + its_lpi_free_chunks(vm->db_bitmap, vm->db_lpi_base, vm->nr_db_lpis); + its_free_prop_table(vm->vprop_page); + } +} + +static int its_vpe_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *args) +{ + struct its_vm *vm = args; + unsigned long *bitmap; + struct page *vprop_page; + int base, nr_ids, i, err = 0; + + BUG_ON(!vm); + + bitmap = its_lpi_alloc_chunks(nr_irqs, &base, &nr_ids); + if (!bitmap) + return -ENOMEM; + + if (nr_ids < nr_irqs) { + its_lpi_free_chunks(bitmap, base, nr_ids); + return -ENOMEM; + } + + vprop_page = its_allocate_prop_table(GFP_KERNEL); + if (!vprop_page) { + its_lpi_free_chunks(bitmap, base, nr_ids); + return -ENOMEM; + } + + vm->db_bitmap = bitmap; + vm->db_lpi_base = base; + vm->nr_db_lpis = nr_ids; + vm->vprop_page = vprop_page; + + for (i = 0; i < nr_irqs; i++) { + vm->vpes[i]->vpe_db_lpi = base + i; + err = its_vpe_init(vm->vpes[i]); + if (err) + break; + err = its_irq_gic_domain_alloc(domain, virq + i, + vm->vpes[i]->vpe_db_lpi); + if (err) + break; + irq_domain_set_hwirq_and_chip(domain, virq + i, i, + &its_vpe_irq_chip, vm->vpes[i]); + set_bit(i, bitmap); + } + + if (err) { + if (i > 0) + its_vpe_irq_domain_free(domain, virq, i - 1); + + its_lpi_free_chunks(bitmap, base, nr_ids); + its_free_prop_table(vprop_page); + } + + return err; +} + static const struct irq_domain_ops its_vpe_domain_ops = { + .alloc = its_vpe_irq_domain_alloc, + .free = its_vpe_irq_domain_free, }; static int its_force_quiescent(void __iomem *base) -- 2.20.1