[PATCH v7 6/8] irqchip/gicv2m: implement msi_doorbell_info callback

From: Eric Auger
Date: Tue Apr 19 2016 - 13:14:24 EST


This patch implements the msi_doorbell_info callback in the
gicv2m driver.

The driver now is able to return its doorbell characteristics
(base, size, prot). A single doorbell is exposed.

This will allow the msi layer to iommu_map this doorbell when
requested.

Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>

---

v7: creation
---
drivers/irqchip/irq-gic-v2m.c | 32 +++++++++++++++++++++++++++++++-
1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
index 28f047c..54690b9 100644
--- a/drivers/irqchip/irq-gic-v2m.c
+++ b/drivers/irqchip/irq-gic-v2m.c
@@ -24,6 +24,8 @@
#include <linux/of_pci.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
+#include <linux/percpu.h>
+#include <linux/iommu.h>

/*
* MSI_TYPER:
@@ -64,6 +66,7 @@ struct v2m_data {
u32 nr_spis; /* The number of SPIs for MSIs */
unsigned long *bm; /* MSI vector bitmap */
u32 flags; /* v2m flags for specific implementation */
+ struct irq_chip_msi_doorbell_info doorbell_info;
};

static void gicv2m_mask_msi_irq(struct irq_data *d)
@@ -105,6 +108,16 @@ static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
msg->data -= v2m->spi_start;
}

+static const struct irq_chip_msi_doorbell_info *
+gicv2m_msi_doorbell_info(struct irq_data *data)
+{
+ struct v2m_data *v2m = irq_data_get_irq_chip_data(data);
+
+ if (!v2m)
+ return NULL;
+ return (const struct irq_chip_msi_doorbell_info *)(&v2m->doorbell_info);
+}
+
static struct irq_chip gicv2m_irq_chip = {
.name = "GICv2m",
.irq_mask = irq_chip_mask_parent,
@@ -112,6 +125,7 @@ static struct irq_chip gicv2m_irq_chip = {
.irq_eoi = irq_chip_eoi_parent,
.irq_set_affinity = irq_chip_set_affinity_parent,
.irq_compose_msi_msg = gicv2m_compose_msi_msg,
+ .msi_doorbell_info = gicv2m_msi_doorbell_info,
};

static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain,
@@ -247,6 +261,7 @@ static void gicv2m_teardown(void)

list_for_each_entry_safe(v2m, tmp, &v2m_nodes, entry) {
list_del(&v2m->entry);
+ free_percpu(v2m->doorbell_info.percpu_doorbells);
kfree(v2m->bm);
iounmap(v2m->base);
of_node_put(to_of_node(v2m->fwnode));
@@ -299,6 +314,7 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode,
{
int ret;
struct v2m_data *v2m;
+ struct irq_chip_msi_doorbell __percpu *doorbell;

v2m = kzalloc(sizeof(struct v2m_data), GFP_KERNEL);
if (!v2m) {
@@ -311,11 +327,23 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode,

memcpy(&v2m->res, res, sizeof(struct resource));

+ v2m->doorbell_info.percpu_doorbells =
+ alloc_percpu(struct irq_chip_msi_doorbell);
+ if (WARN_ON(!v2m->doorbell_info.percpu_doorbells)) {
+ ret = -ENOMEM;
+ goto err_free_v2m;
+ }
+ doorbell = per_cpu_ptr(v2m->doorbell_info.percpu_doorbells, 0);
+ doorbell->base = v2m->res.start;
+ doorbell->size = 4;
+ doorbell->prot = IOMMU_WRITE;
+ v2m->doorbell_info.nb_doorbells = 1;
+
v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res));
if (!v2m->base) {
pr_err("Failed to map GICv2m resource\n");
ret = -ENOMEM;
- goto err_free_v2m;
+ goto err_free_v2m_doorbells;
}

if (spi_start && nr_spis) {
@@ -359,6 +387,8 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode,

err_iounmap:
iounmap(v2m->base);
+err_free_v2m_doorbells:
+ free_percpu(v2m->doorbell_info.percpu_doorbells);
err_free_v2m:
kfree(v2m);
return ret;
--
1.9.1