[PATCH v5 14/19] irqchip: gicv3-its: Make the PCI/MSI code standalone

Marc Zyngier
2015-07-23T09:28:06Z

We can now lookup the base ITS domain, making it possible to
initialize the PCI/MSI code independently from the main ITS
subsystem.

This allows us to remove all the previously add hooks.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
drivers/irqchip/irq-gic-v3-its-pci-msi.c | 47 +++++++++++++++++++++++++++----
drivers/irqchip/irq-gic-v3-its.c | 48 +++++++++++++++++++++-----------
include/linux/irqchip/arm-gic-v3.h | 5 ----
3 files changed, 73 insertions(+), 27 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index 7614721..cf351c6 100644
--- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
@@ -20,8 +20,6 @@
#include <linux/of_irq.h>
#include <linux/of_pci.h>

-#include <linux/irqchip/arm-gic-v3.h>
-
static void its_mask_msi_irq(struct irq_data *d)
{
pci_msi_mask_irq(d);
@@ -74,17 +72,24 @@ static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
{
struct pci_dev *pdev;
struct its_pci_alias dev_alias;
+ struct msi_domain_info *msi_info;

if (!dev_is_pci(dev))
return -EINVAL;

+ msi_info = msi_get_domain_info(domain->parent);
+
pdev = to_pci_dev(dev);
dev_alias.pdev = pdev;
dev_alias.count = nvec;

pci_for_each_dma_alias(pdev, its_get_pci_alias, &dev_alias);

- return its_msi_prepare(domain, dev_alias.dev_id, dev_alias.count, info);
+ /* ITS specific DeviceID, as the core ITS ignores dev. */
+ info->scratchpad[0].ul = dev_alias.dev_id;
+
+ return msi_info->ops->msi_prepare(domain->parent,
+ dev, dev_alias.count, info);
}

static struct msi_domain_ops its_pci_msi_ops = {
@@ -98,8 +103,38 @@ static struct msi_domain_info its_pci_msi_domain_info = {
.chip = &its_msi_irq_chip,
};

-struct irq_domain *its_pci_msi_alloc_domain(struct device_node *np,
- struct irq_domain *parent)
+static struct of_device_id its_device_id[] = {
+ { .compatible = "arm,gic-v3-its", },
+ {},
+};
+
+static int __init its_pci_msi_init(void)
{
- return pci_msi_create_irq_domain(np, &its_pci_msi_domain_info, parent);
+ struct device_node *np;
+ struct irq_domain *parent;
+
+ for (np = of_find_matching_node(NULL, its_device_id); np;
+ np = of_find_matching_node(np, its_device_id)) {
+ if (!of_property_read_bool(np, "msi-controller"))
+ continue;
+
+ parent = irq_find_matching_host(np, DOMAIN_BUS_NEXUS);
+ if (!parent || !msi_get_domain_info(parent)) {
+ pr_err("%s: unable to locate ITS domain\n",
+ np->full_name);
+ continue;
+ }
+
+ if (!pci_msi_create_irq_domain(np, &its_pci_msi_domain_info,
+ parent)) {
+ pr_err("%s: unable to create PCI domain\n",
+ np->full_name);
+ continue;
+ }
+
+ pr_info("PCI/MSI: %s domain created\n", np->full_name);
+ }
+
+ return 0;
}
+early_initcall(its_pci_msi_init);
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index ca8b1cc..21b002f 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -60,7 +60,6 @@ struct its_collection {
struct its_node {
raw_spinlock_t lock;
struct list_head entry;
- struct irq_domain *domain;
void __iomem *base;
unsigned long phys_base;
struct its_cmd_block *cmd_base;
@@ -1152,13 +1151,25 @@ static int its_alloc_device_irq(struct its_device *dev, irq_hw_number_t *hwirq)
return 0;
}

-int its_msi_prepare(struct irq_domain *domain, u32 dev_id,
- int nvec, msi_alloc_info_t *info)
+static int its_msi_prepare(struct irq_domain *domain, struct device *dev,
+ int nvec, msi_alloc_info_t *info)
{
struct its_node *its;
struct its_device *its_dev;
+ struct msi_domain_info *msi_info;
+ u32 dev_id;
+
+ /*
+ * We ignore "dev" entierely, and rely on the dev_id that has
+ * been passed via the scratchpad. This limits this domain's
+ * usefulness to upper layers that definitely know that they
+ * are built on top of the ITS.
+ */
+ dev_id = info->scratchpad[0].ul;
+
+ msi_info = msi_get_domain_info(domain);
+ its = msi_info->data;

- its = domain->parent->host_data;
its_dev = its_find_device(its, dev_id);
if (its_dev) {
/*
@@ -1180,6 +1191,10 @@ out:
return 0;
}

+static struct msi_domain_ops its_msi_domain_ops = {
+ .msi_prepare = its_msi_prepare,
+};
+
static int its_irq_gic_domain_alloc(struct irq_domain *domain,
unsigned int virq,
irq_hw_number_t hwirq)
@@ -1316,7 +1331,7 @@ static int its_probe(struct device_node *node, struct irq_domain *parent)
struct resource res;
struct its_node *its;
void __iomem *its_base;
- struct irq_domain *inner_domain = NULL;
+ struct irq_domain *inner_domain;
u32 val;
u64 baser, tmp;
int err;
@@ -1406,20 +1421,26 @@ static int its_probe(struct device_node *node, struct irq_domain *parent)
writel_relaxed(GITS_CTLR_ENABLE, its->base + GITS_CTLR);

if (of_property_read_bool(node, "msi-controller")) {
+ struct msi_domain_info *info;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info) {
+ err = -ENOMEM;
+ goto out_free_tables;
+ }
+
inner_domain = irq_domain_add_tree(node, &its_domain_ops, its);
if (!inner_domain) {
err = -ENOMEM;
+ kfree(info);
goto out_free_tables;
}

inner_domain->parent = parent;
inner_domain->bus_token = DOMAIN_BUS_NEXUS;
-
- its->domain = its_pci_msi_alloc_domain(node, inner_domain);
- if (!its->domain) {
- err = -ENOMEM;
- goto out_free_domains;
- }
+ info->ops = &its_msi_domain_ops;
+ info->data = its;
+ inner_domain->host_data = info;
}

spin_lock(&its_lock);
@@ -1428,11 +1449,6 @@ static int its_probe(struct device_node *node, struct irq_domain *parent)

return 0;

-out_free_domains:
- if (its->domain)
- irq_domain_remove(its->domain);
- if (inner_domain)
- irq_domain_remove(inner_domain);
out_free_tables:
its_free_tables(its);
out_free_cmd:
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index d6149ba..bf982e0 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -389,11 +389,6 @@ struct irq_domain;
int its_cpu_init(void);
int its_init(struct device_node *node, struct rdists *rdists,
struct irq_domain *domain);
-int its_msi_prepare(struct irq_domain *domain, u32 dev_id,
- int nvec, msi_alloc_info_t *info);
-
-struct irq_domain *its_pci_msi_alloc_domain(struct device_node *node,
- struct irq_domain *parent);

#endif

--
2.1.4