The global variable "irq_type" preserves the current value of
ioctl(GET_IRQTYPE), however, it's enough to use test->irq_type.
Remove the variable, and replace with test->irq_type.

The ioctl(GET_IRQTYPE) returns an error if test->irq_type has
IRQ_TYPE_UNDEFINED.

Suggested-by: Niklas Cassel <cassel@kernel.org>
Suggested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
---
 drivers/misc/pci_endpoint_test.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
index 6a0972e7674f..8d98cd18634d 100644
--- a/drivers/misc/pci_endpoint_test.c
+++ b/drivers/misc/pci_endpoint_test.c
@@ -100,10 +100,6 @@ static bool no_msi;
 module_param(no_msi, bool, 0444);
 MODULE_PARM_DESC(no_msi, "Disable MSI interrupt in pci_endpoint_test");
 
-static int irq_type = IRQ_TYPE_MSI;
-module_param(irq_type, int, 0444);
-MODULE_PARM_DESC(irq_type, "IRQ mode selection in pci_endpoint_test (0 - Legacy, 1 - MSI, 2 - MSI-X)");
-
 enum pci_barno {
 	BAR_0,
 	BAR_1,
@@ -829,7 +825,6 @@ static int pci_endpoint_test_set_irq(struct pci_endpoint_test *test,
 		return ret;
 	}
 
-	irq_type = test->irq_type;
 	return 0;
 }
 
@@ -878,7 +873,7 @@ static long pci_endpoint_test_ioctl(struct file *file, unsigned int cmd,
 		ret = pci_endpoint_test_set_irq(test, arg);
 		break;
 	case PCITEST_GET_IRQTYPE:
-		ret = irq_type;
+		ret = test->irq_type;
 		break;
 	case PCITEST_CLEAR_IRQ:
 		ret = pci_endpoint_test_clear_irq(test);
@@ -936,14 +931,14 @@ static int pci_endpoint_test_probe(struct pci_dev *pdev,
 	test->irq_type = IRQ_TYPE_UNDEFINED;
 
 	if (no_msi)
-		irq_type = IRQ_TYPE_INTX;
+		test->irq_type = IRQ_TYPE_INTX;
 
 	data = (struct pci_endpoint_test_data *)ent->driver_data;
 	if (data) {
 		test_reg_bar = data->test_reg_bar;
 		test->test_reg_bar = test_reg_bar;
 		test->alignment = data->alignment;
-		irq_type = data->irq_type;
+		test->irq_type = data->irq_type;
 	}
 
 	init_completion(&test->irq_raised);
@@ -965,7 +960,7 @@ static int pci_endpoint_test_probe(struct pci_dev *pdev,
 
 	pci_set_master(pdev);
 
-	ret = pci_endpoint_test_alloc_irq_vectors(test, irq_type);
+	ret = pci_endpoint_test_alloc_irq_vectors(test, test->irq_type);
 	if (ret)
 		goto err_disable_irq;
 
-- 
2.25.1

On Mon, Feb 10, 2025 at 04:58:11PM +0900, Kunihiko Hayashi wrote:
> The global variable "irq_type" preserves the current value of
> ioctl(GET_IRQTYPE), however, it's enough to use test->irq_type.
> Remove the variable, and replace with test->irq_type.

I think the commit message is missing the biggest point.

ioctl(SET_IRQTYPE) sets test->irq_type.
PCITEST_WRITE/PCITEST_READ/PCITEST_COPY all use test->irq_type when
writing the PCI_ENDPOINT_TEST_IRQ_TYPE register in test_reg_bar.

The endpoint function driver (pci-epf-test) will look at
PCI_ENDPOINT_TEST_IRQ_TYPE register in test_reg_bar when determining
which type of IRQ it should raise.

This means that the kernel module parameter is basically useless,
since it is unused if anyone has called ioctl(SET_IRQTYPE).

Both the old pcitest.sh and the new pci_endpoint_test kselftest call
ioctl(SET_IRQTYPE), so in practice the irq_type kernel module parameter
is dead code.


> 
> The ioctl(GET_IRQTYPE) returns an error if test->irq_type has
> IRQ_TYPE_UNDEFINED.
> 
> Suggested-by: Niklas Cassel <cassel@kernel.org>
> Suggested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> ---
>  drivers/misc/pci_endpoint_test.c | 13 ++++---------
>  1 file changed, 4 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
> index 6a0972e7674f..8d98cd18634d 100644
> --- a/drivers/misc/pci_endpoint_test.c
> +++ b/drivers/misc/pci_endpoint_test.c
> @@ -100,10 +100,6 @@ static bool no_msi;
>  module_param(no_msi, bool, 0444);
>  MODULE_PARM_DESC(no_msi, "Disable MSI interrupt in pci_endpoint_test");

Considering that you are removing the irq_type kernel module parameter,
it doesn't make sense to keep the no_msi kernel module parameter IMO.

The exact same argument for why we are removing irq_type, can be made for
no_msi.


Kind regards,
Niklas

On Mon, Feb 10, 2025 at 05:30:42PM +0100, Niklas Cassel wrote:
> On Mon, Feb 10, 2025 at 04:58:11PM +0900, Kunihiko Hayashi wrote:
> > The global variable "irq_type" preserves the current value of
> > ioctl(GET_IRQTYPE), however, it's enough to use test->irq_type.
> > Remove the variable, and replace with test->irq_type.
> 
> I think the commit message is missing the biggest point.
> 
> ioctl(SET_IRQTYPE) sets test->irq_type.
> PCITEST_WRITE/PCITEST_READ/PCITEST_COPY all use test->irq_type when
> writing the PCI_ENDPOINT_TEST_IRQ_TYPE register in test_reg_bar.
> 
> The endpoint function driver (pci-epf-test) will look at
> PCI_ENDPOINT_TEST_IRQ_TYPE register in test_reg_bar when determining
> which type of IRQ it should raise.
> 
> This means that the kernel module parameter is basically useless,
> since it is unused if anyone has called ioctl(SET_IRQTYPE).
> 
> Both the old pcitest.sh and the new pci_endpoint_test kselftest call
> ioctl(SET_IRQTYPE), so in practice the irq_type kernel module parameter
> is dead code.
> 

+1

> 
> > 
> > The ioctl(GET_IRQTYPE) returns an error if test->irq_type has
> > IRQ_TYPE_UNDEFINED.
> > 
> > Suggested-by: Niklas Cassel <cassel@kernel.org>
> > Suggested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> > ---
> >  drivers/misc/pci_endpoint_test.c | 13 ++++---------
> >  1 file changed, 4 insertions(+), 9 deletions(-)
> > 
> > diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
> > index 6a0972e7674f..8d98cd18634d 100644
> > --- a/drivers/misc/pci_endpoint_test.c
> > +++ b/drivers/misc/pci_endpoint_test.c
> > @@ -100,10 +100,6 @@ static bool no_msi;
> >  module_param(no_msi, bool, 0444);
> >  MODULE_PARM_DESC(no_msi, "Disable MSI interrupt in pci_endpoint_test");
> 
> Considering that you are removing the irq_type kernel module parameter,
> it doesn't make sense to keep the no_msi kernel module parameter IMO.
> 
> The exact same argument for why we are removing irq_type, can be made for
> no_msi.
> 

Right.

- Mani

-- 
மணிவண்ணன் சதாசிவம்

Hi Niklas,

On 2025/02/11 1:30, Niklas Cassel wrote:
> On Mon, Feb 10, 2025 at 04:58:11PM +0900, Kunihiko Hayashi wrote:
>> The global variable "irq_type" preserves the current value of
>> ioctl(GET_IRQTYPE), however, it's enough to use test->irq_type.
>> Remove the variable, and replace with test->irq_type.
> 
> I think the commit message is missing the biggest point.
> 
> ioctl(SET_IRQTYPE) sets test->irq_type.
> PCITEST_WRITE/PCITEST_READ/PCITEST_COPY all use test->irq_type when
> writing the PCI_ENDPOINT_TEST_IRQ_TYPE register in test_reg_bar.
> 
> The endpoint function driver (pci-epf-test) will look at
> PCI_ENDPOINT_TEST_IRQ_TYPE register in test_reg_bar when determining
> which type of IRQ it should raise.
> 
> This means that the kernel module parameter is basically useless,
> since it is unused if anyone has called ioctl(SET_IRQTYPE).
> 
> Both the old pcitest.sh and the new pci_endpoint_test kselftest call
> ioctl(SET_IRQTYPE), so in practice the irq_type kernel module parameter
> is dead code.

Thank you for pointing out.

Surely, global "irq_type" is only used for return value of ioctl(GET_IRQTYPE).
It isn't used in the test case, and the test is completed with test->irq_type
and the register.

I'll add this point to the explanation.

>>
>> The ioctl(GET_IRQTYPE) returns an error if test->irq_type has
>> IRQ_TYPE_UNDEFINED.
>>
>> Suggested-by: Niklas Cassel <cassel@kernel.org>
>> Suggested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
>> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
>> ---
>>   drivers/misc/pci_endpoint_test.c | 13 ++++---------
>>   1 file changed, 4 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/misc/pci_endpoint_test.c
> b/drivers/misc/pci_endpoint_test.c
>> index 6a0972e7674f..8d98cd18634d 100644
>> --- a/drivers/misc/pci_endpoint_test.c
>> +++ b/drivers/misc/pci_endpoint_test.c
>> @@ -100,10 +100,6 @@ static bool no_msi;
>>   module_param(no_msi, bool, 0444);
>>   MODULE_PARM_DESC(no_msi, "Disable MSI interrupt in pci_endpoint_test");
> 
> Considering that you are removing the irq_type kernel module parameter,
> it doesn't make sense to keep the no_msi kernel module parameter IMO.
> 
> The exact same argument for why we are removing irq_type, can be made for
> no_msi.

Agreed.
Even if chip doesn't have MSI, test->irq_type starts with IRQ_TYPE_UNDEFINED
and will be changed with ioctl(SET_IRQTYPE).
"no_msi" can also be removed.

Thank you,

---
Best Regards
Kunihiko Hayashi