2023-05-23 17:46:33

by Davidlohr Bueso

Subject: [PATCH 3/4] cxl/pci: Introduce cxl_request_irq()

Factor out common functionality/semantics for cxl shared interrupts
into a new helper on top of devm_request_irq().

Suggested-by: Dan Williams <[email protected]>
Signed-off-by: Davidlohr Bueso <[email protected]>
---
drivers/cxl/pci.c | 39 +++++++++++++++++++++++----------------
1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index f2039fe0805d..18b8f3ce680c 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -84,6 +84,27 @@ static int cxl_pci_mbox_wait_for_doorbell(struct cxl_dev_state *cxlds)
status & CXLMDEV_DEV_FATAL ? " fatal" : "", \
status & CXLMDEV_FW_HALT ? " firmware-halt" : "")

+struct cxl_dev_id {
+ struct cxl_dev_state *cxlds;
+};
+
+static int cxl_request_irq(struct cxl_dev_state *cxlds, int irq,
+ irq_handler_t handler, irq_handler_t thread_fn)
+{
+ struct device *dev = cxlds->dev;
+ struct cxl_dev_id *dev_id;
+
+ /* dev_id must be globally unique and must contain the cxlds */
+ dev_id = devm_kzalloc(dev, sizeof(*dev_id), GFP_KERNEL);
+ if (!dev_id)
+ return -ENOMEM;
+ dev_id->cxlds = cxlds;
+
+ return devm_request_threaded_irq(dev, irq, handler, thread_fn,
+ IRQF_SHARED | IRQF_ONESHOT,
+ NULL, dev_id);
+}
+
/**
* __cxl_pci_mbox_send_cmd() - Execute a mailbox command
* @cxlds: The device state to communicate with.
@@ -469,10 +490,6 @@ static int cxl_alloc_irq_vectors(struct pci_dev *pdev)
return 0;
}

-struct cxl_dev_id {
- struct cxl_dev_state *cxlds;
-};
-
static irqreturn_t cxl_event_thread(int irq, void *id)
{
struct cxl_dev_id *dev_id = id;
@@ -498,28 +515,18 @@ static irqreturn_t cxl_event_thread(int irq, void *id)

static int cxl_event_req_irq(struct cxl_dev_state *cxlds, u8 setting)
{
- struct device *dev = cxlds->dev;
- struct pci_dev *pdev = to_pci_dev(dev);
- struct cxl_dev_id *dev_id;
+ struct pci_dev *pdev = to_pci_dev(cxlds->dev);
int irq;

if (FIELD_GET(CXLDEV_EVENT_INT_MODE_MASK, setting) != CXL_INT_MSI_MSIX)
return -ENXIO;

- /* dev_id must be globally unique and must contain the cxlds */
- dev_id = devm_kzalloc(dev, sizeof(*dev_id), GFP_KERNEL);
- if (!dev_id)
- return -ENOMEM;
- dev_id->cxlds = cxlds;
-
irq = pci_irq_vector(pdev,
FIELD_GET(CXLDEV_EVENT_INT_MSGNUM_MASK, setting));
if (irq < 0)
return irq;

- return devm_request_threaded_irq(dev, irq, NULL, cxl_event_thread,
- IRQF_SHARED | IRQF_ONESHOT, NULL,
- dev_id);
+ return cxl_request_irq(cxlds, irq, NULL, cxl_event_thread);
}

static int cxl_event_get_int_policy(struct cxl_dev_state *cxlds,
--
2.40.1

2023-05-23 18:54:24

by Dan Williams

Subject: RE: [PATCH 3/4] cxl/pci: Introduce cxl_request_irq()

Davidlohr Bueso wrote:
> Factor out common functionality/semantics for cxl shared interrupts
> into a new helper on top of devm_request_irq().
>
> Suggested-by: Dan Williams <[email protected]>
> Signed-off-by: Davidlohr Bueso <[email protected]>
> ---
> drivers/cxl/pci.c | 39 +++++++++++++++++++++++----------------
> 1 file changed, 23 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index f2039fe0805d..18b8f3ce680c 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -84,6 +84,27 @@ static int cxl_pci_mbox_wait_for_doorbell(struct cxl_dev_state *cxlds)
> status & CXLMDEV_DEV_FATAL ? " fatal" : "", \
> status & CXLMDEV_FW_HALT ? " firmware-halt" : "")
>
> +struct cxl_dev_id {
> + struct cxl_dev_state *cxlds;
> +};
> +
> +static int cxl_request_irq(struct cxl_dev_state *cxlds, int irq,
> + irq_handler_t handler, irq_handler_t thread_fn)
> +{
> + struct device *dev = cxlds->dev;
> + struct cxl_dev_id *dev_id;
> +
> + /* dev_id must be globally unique and must contain the cxlds */
> + dev_id = devm_kzalloc(dev, sizeof(*dev_id), GFP_KERNEL);
> + if (!dev_id)
> + return -ENOMEM;
> + dev_id->cxlds = cxlds;
> +
> + return devm_request_threaded_irq(dev, irq, handler, thread_fn,
> + IRQF_SHARED | IRQF_ONESHOT,
> + NULL, dev_id);

I was going to say drop the IRQF_ONESHOT in the case where @thread_fn is
NULL, but I could not convince myself that was safe. I assume that
pci_request_irq() gets away with that because most drivers are not
mixing combinations of @handler and @thread_fn being set to NULL.

So, with that, this looks good to me.