Re: [PATCH v2 2/2] irqchip/ti-sci-inta: Add support for unmapped event handling

From: Marc Zyngier
Date: Wed Sep 30 2020 - 04:33:45 EST


On 2020-09-30 08:45, Peter Ujfalusi wrote:
The DMA (BCDMA/PKTDMA and their rings/flows) events are under the INTA's
supervision as unmapped events in AM64.

What does "unmapped event" mean? An event that doesn't require a mapping?
Or an internally generated event? Or a proxy event?


In order to keep the current SW stack working, the INTA driver must replace
the dev_id with it's own when a request comes for BCDMA or PKTDMA
resources.

This seems to support my second option. Please clarify what you mean exactly.


Implement parsing of the optional "ti,unmapped-event-sources" phandle array
to get the sci-dev-ids of the devices where the unmapped events originate.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
---
drivers/irqchip/irq-ti-sci-inta.c | 72 +++++++++++++++++++++++++++++--
1 file changed, 68 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/irq-ti-sci-inta.c
b/drivers/irqchip/irq-ti-sci-inta.c
index bc863ef7998d..00f5b34863c5 100644
--- a/drivers/irqchip/irq-ti-sci-inta.c
+++ b/drivers/irqchip/irq-ti-sci-inta.c
@@ -85,6 +85,8 @@ struct ti_sci_inta_vint_desc {
* @base: Base address of the memory mapped IO registers
* @pdev: Pointer to platform device.
* @ti_sci_id: TI-SCI device identifier
+ * @difu_cnt: Number of TI-SCI device identifiers for unmapped events
+ * @dev_ids_for_unmapped: Pointer to an array of TI-SCI device identifiers
*/
struct ti_sci_inta_irq_domain {
const struct ti_sci_handle *sci;
@@ -96,11 +98,33 @@ struct ti_sci_inta_irq_domain {
void __iomem *base;
struct platform_device *pdev;
u32 ti_sci_id;
+
+ int difu_cnt;

I like silly acronyms as much as the next man, but please adopt
sensible names. unmapped_cnt, or something.

+ u32 *dev_ids_for_unmapped;

unmapped_dev_ids?

};

#define to_vint_desc(e, i) container_of(e, struct ti_sci_inta_vint_desc, \
events[i])

+static u16 ti_sci_inta_get_dev_id(struct ti_sci_inta_irq_domain *inta,
+ u32 hwirq)
+{
+ u16 dev_id = HWIRQ_TO_DEVID(hwirq);
+ int i;
+
+ if (inta->difu_cnt == 0)
+ return dev_id;
+
+ for (i = 0; i < inta->difu_cnt; i++) {
+ if (dev_id == inta->dev_ids_for_unmapped[i]) {
+ dev_id = inta->ti_sci_id;

ti_sci_id is a u32, and you are implicitly casting it as u16.
One of the two is wrong.

+ break;
+ }
+ }
+
+ return dev_id;
+}
+
/**
* ti_sci_inta_irq_handler() - Chained IRQ handler for the vint irqs
* @desc: Pointer to irq_desc corresponding to the irq
@@ -251,7 +275,7 @@ static struct ti_sci_inta_event_desc
*ti_sci_inta_alloc_event(struct ti_sci_inta
u16 dev_id, dev_index;
int err;

- dev_id = HWIRQ_TO_DEVID(hwirq);
+ dev_id = ti_sci_inta_get_dev_id(inta, hwirq);
dev_index = HWIRQ_TO_IRQID(hwirq);

event_desc = &vint_desc->events[free_bit];
@@ -352,14 +376,15 @@ static void ti_sci_inta_free_irq(struct
ti_sci_inta_event_desc *event_desc,
{
struct ti_sci_inta_vint_desc *vint_desc;
struct ti_sci_inta_irq_domain *inta;
+ u16 dev_id;

vint_desc = to_vint_desc(event_desc, event_desc->vint_bit);
inta = vint_desc->domain->host_data;
+ dev_id = ti_sci_inta_get_dev_id(inta, hwirq);
/* free event irq */
mutex_lock(&inta->vint_mutex);
inta->sci->ops.rm_irq_ops.free_event_map(inta->sci,
- HWIRQ_TO_DEVID(hwirq),
- HWIRQ_TO_IRQID(hwirq),
+ dev_id, HWIRQ_TO_IRQID(hwirq),
inta->ti_sci_id,
vint_desc->vint_id,
event_desc->global_event,
@@ -562,7 +587,6 @@ static void ti_sci_inta_msi_set_desc(msi_alloc_info_t *arg,
arg->desc = desc;
arg->hwirq = TO_HWIRQ(pdev->id, desc->inta.dev_index);
}
-
static struct msi_domain_ops ti_sci_inta_msi_ops = {
.set_desc = ti_sci_inta_msi_set_desc,
};
@@ -574,6 +598,42 @@ static struct msi_domain_info
ti_sci_inta_msi_domain_info = {
.chip = &ti_sci_inta_msi_irq_chip,
};

+static int ti_sci_inta_get_unmapped_sources(struct
ti_sci_inta_irq_domain *inta)
+{
+ struct device *dev = &inta->pdev->dev;
+ struct device_node *node = dev_of_node(dev);
+ struct of_phandle_iterator it;
+ int count, err, ret, i;
+
+ count = of_count_phandle_with_args(node, "ti,unmapped-event-sources",
+ NULL);
+ if (count <= 0)
+ return 0;
+
+ inta->dev_ids_for_unmapped = devm_kcalloc(dev, count,
+ sizeof(*inta->dev_ids_for_unmapped),
+ GFP_KERNEL);
+ if (!inta->dev_ids_for_unmapped)
+ return -ENOMEM;
+
+ i = 0;
+ of_for_each_phandle(&it, err, node, "ti,unmapped-event-sources",
+ NULL, 0) {
+ ret = of_property_read_u32(it.node, "ti,sci-dev-id",
+ &inta->dev_ids_for_unmapped[i++]);
+ if (ret) {
+ dev_err(dev, "ti,sci-dev-id read failure for %s\n",
+ of_node_full_name(it.node));

Use the printk format specifier instead of of_node_full_name.

+ of_node_put(it.node);
+ return ret;
+ }
+ }
+
+ inta->difu_cnt = count;
+
+ return 0;
+}
+
static int ti_sci_inta_irq_domain_probe(struct platform_device *pdev)
{
struct irq_domain *parent_domain, *domain, *msi_domain;
@@ -629,6 +689,10 @@ static int ti_sci_inta_irq_domain_probe(struct
platform_device *pdev)
if (IS_ERR(inta->base))
return PTR_ERR(inta->base);

+ ret = ti_sci_inta_get_unmapped_sources(inta);
+ if (ret)
+ return ret;
+
domain = irq_domain_add_linear(dev_of_node(dev),
ti_sci_get_num_resources(inta->vint),
&ti_sci_inta_irq_domain_ops, inta);

M.
--
Jazz is not dead. It just smells funny...