Commit ffcc4850 authored by Niklas Cassel's avatar Niklas Cassel Committed by Bjorn Helgaas
Browse files

PCI: endpoint: pci-epf-test: Allow overriding default BAR sizes 



Add bar{0,1,2,3,4,5}_size attributes in configfs, so that the user is not
restricted to run pci-epf-test with the hardcoded BAR size values defined
in pci-epf-test.c.

This code is shamelessly more or less copy pasted from pci-epf-vntb.c

Signed-off-by: default avatarNiklas Cassel <cassel@kernel.org>
Signed-off-by: default avatarManivannan Sadhasivam <mani@kernel.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Tested-by: default avatarKoichiro Den <den@valinux.co.jp>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarFrank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260130113038.2143947-2-cassel@kernel.org
parent c17b9046

Documentation/PCI/endpoint/pci-test-howto.rst

+19 −0
Original line number Diff line number Diff line
@@ -84,6 +84,25 @@ device, the following commands can be used:: 
	# echo 32 > functions/pci_epf_test/func1/msi_interrupts

	# echo 2048 > functions/pci_epf_test/func1/msix_interrupts



By default, pci-epf-test uses the following BAR sizes::



	# grep . functions/pci_epf_test/func1/pci_epf_test.0/bar?_size

	  functions/pci_epf_test/func1/pci_epf_test.0/bar0_size:131072

	  functions/pci_epf_test/func1/pci_epf_test.0/bar1_size:131072

	  functions/pci_epf_test/func1/pci_epf_test.0/bar2_size:131072

	  functions/pci_epf_test/func1/pci_epf_test.0/bar3_size:131072

	  functions/pci_epf_test/func1/pci_epf_test.0/bar4_size:131072

	  functions/pci_epf_test/func1/pci_epf_test.0/bar5_size:1048576



The user can override a default value using e.g.::

	# echo 1048576 > functions/pci_epf_test/func1/pci_epf_test.0/bar1_size



Overriding the default BAR sizes can only be done before binding the

pci-epf-test device to a PCI endpoint controller driver.



Note: Some endpoint controllers might have fixed-size BARs or reserved BARs;

for such controllers, the corresponding BAR size in configfs will be ignored.





Binding pci-epf-test Device to EP Controller

--------------------------------------------

drivers/pci/endpoint/functions/pci-epf-test.c

+97 −2
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ static struct workqueue_struct *kpcitest_workqueue; 
struct pci_epf_test {

	void			*reg[PCI_STD_NUM_BARS];

	struct pci_epf		*epf;

	struct config_group	group;

	enum pci_barno		test_reg_bar;

	size_t			msix_table_offset;

	struct delayed_work	cmd_handler;
@@ -85,6 +86,7 @@ struct pci_epf_test { 
	bool			dma_private;

	const struct pci_epc_features *epc_features;

	struct pci_epf_bar	db_bar;

	size_t			bar_size[PCI_STD_NUM_BARS];

};



struct pci_epf_test_reg {
@@ -111,7 +113,8 @@ static struct pci_epf_header test_header = { 
	.interrupt_pin	= PCI_INTERRUPT_INTA,

};



static size_t bar_size[] = { 131072, 131072, 131072, 131072, 131072, 1048576 };

/* default BAR sizes, can be overridden by the user using configfs */

static size_t default_bar_size[] = { 131072, 131072, 131072, 131072, 131072, 1048576 };



static void pci_epf_test_dma_callback(void *param)

{
@@ -1240,7 +1243,7 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) 
		if (epc_features->bar[bar].type == BAR_FIXED)

			test_reg_size = epc_features->bar[bar].fixed_size;

		else

			test_reg_size = bar_size[bar];

			test_reg_size = epf_test->bar_size[bar];



		base = pci_epf_alloc_space(epf, test_reg_size, bar,

					   epc_features, PRIMARY_INTERFACE);
@@ -1312,6 +1315,94 @@ static void pci_epf_test_unbind(struct pci_epf *epf) 
	pci_epf_test_free_space(epf);

}



#define PCI_EPF_TEST_BAR_SIZE_R(_name, _id)				\

static ssize_t pci_epf_test_##_name##_show(struct config_item *item,	\

					   char *page)			\

{									\

	struct config_group *group = to_config_group(item);		\

	struct pci_epf_test *epf_test =					\

		container_of(group, struct pci_epf_test, group);	\

									\

	return sysfs_emit(page, "%zu\n", epf_test->bar_size[_id]);	\

}



#define PCI_EPF_TEST_BAR_SIZE_W(_name, _id)				\

static ssize_t pci_epf_test_##_name##_store(struct config_item *item,	\

					    const char *page,		\

					    size_t len)			\

{									\

	struct config_group *group = to_config_group(item);		\

	struct pci_epf_test *epf_test =					\

		container_of(group, struct pci_epf_test, group);	\

	int val, ret;							\

									\

	/*								\

	 * BAR sizes can only be modified before binding to an EPC,	\

	 * because pci_epf_test_alloc_space() is called in .bind().	\

	 */								\

	if (epf_test->epf->epc)						\

		return -EOPNOTSUPP;					\

									\

	ret = kstrtouint(page, 0, &val);				\

	if (ret)							\

		return ret;						\

									\

	if (!is_power_of_2(val))					\

		return -EINVAL;						\

									\

	epf_test->bar_size[_id] = val;					\

									\

	return len;							\

}



PCI_EPF_TEST_BAR_SIZE_R(bar0_size, BAR_0)

PCI_EPF_TEST_BAR_SIZE_W(bar0_size, BAR_0)

PCI_EPF_TEST_BAR_SIZE_R(bar1_size, BAR_1)

PCI_EPF_TEST_BAR_SIZE_W(bar1_size, BAR_1)

PCI_EPF_TEST_BAR_SIZE_R(bar2_size, BAR_2)

PCI_EPF_TEST_BAR_SIZE_W(bar2_size, BAR_2)

PCI_EPF_TEST_BAR_SIZE_R(bar3_size, BAR_3)

PCI_EPF_TEST_BAR_SIZE_W(bar3_size, BAR_3)

PCI_EPF_TEST_BAR_SIZE_R(bar4_size, BAR_4)

PCI_EPF_TEST_BAR_SIZE_W(bar4_size, BAR_4)

PCI_EPF_TEST_BAR_SIZE_R(bar5_size, BAR_5)

PCI_EPF_TEST_BAR_SIZE_W(bar5_size, BAR_5)



CONFIGFS_ATTR(pci_epf_test_, bar0_size);

CONFIGFS_ATTR(pci_epf_test_, bar1_size);

CONFIGFS_ATTR(pci_epf_test_, bar2_size);

CONFIGFS_ATTR(pci_epf_test_, bar3_size);

CONFIGFS_ATTR(pci_epf_test_, bar4_size);

CONFIGFS_ATTR(pci_epf_test_, bar5_size);



static struct configfs_attribute *pci_epf_test_attrs[] = {

	&pci_epf_test_attr_bar0_size,

	&pci_epf_test_attr_bar1_size,

	&pci_epf_test_attr_bar2_size,

	&pci_epf_test_attr_bar3_size,

	&pci_epf_test_attr_bar4_size,

	&pci_epf_test_attr_bar5_size,

	NULL,

};



static const struct config_item_type pci_epf_test_group_type = {

	.ct_attrs	= pci_epf_test_attrs,

	.ct_owner	= THIS_MODULE,

};



static struct config_group *pci_epf_test_add_cfs(struct pci_epf *epf,

						 struct config_group *group)

{

	struct pci_epf_test *epf_test = epf_get_drvdata(epf);

	struct config_group *epf_group = &epf_test->group;

	struct device *dev = &epf->dev;



	config_group_init_type_name(epf_group, dev_name(dev),

				    &pci_epf_test_group_type);



	return epf_group;

}



static const struct pci_epf_device_id pci_epf_test_ids[] = {

	{

		.name = "pci_epf_test",
@@ -1324,6 +1415,7 @@ static int pci_epf_test_probe(struct pci_epf *epf, 
{

	struct pci_epf_test *epf_test;

	struct device *dev = &epf->dev;

	enum pci_barno bar;



	epf_test = devm_kzalloc(dev, sizeof(*epf_test), GFP_KERNEL);

	if (!epf_test)
@@ -1331,6 +1423,8 @@ static int pci_epf_test_probe(struct pci_epf *epf, 


	epf->header = &test_header;

	epf_test->epf = epf;

	for (bar = BAR_0; bar < PCI_STD_NUM_BARS; bar++)

		epf_test->bar_size[bar] = default_bar_size[bar];



	INIT_DELAYED_WORK(&epf_test->cmd_handler, pci_epf_test_cmd_handler);
@@ -1343,6 +1437,7 @@ static int pci_epf_test_probe(struct pci_epf *epf, 
static const struct pci_epf_ops ops = {

	.unbind	= pci_epf_test_unbind,

	.bind	= pci_epf_test_bind,

	.add_cfs = pci_epf_test_add_cfs,

};



static struct pci_epf_driver test_driver = {