Commit 7d75bbb4 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

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: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 8fff27ae

drivers/irqchip/irq-gic-v3-its.c

+169 −0
Original line number Diff line number Diff line
@@ -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)

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