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: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Koichiro Den <den@valinux.co.jp>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260130113038.2143947-2-cassel@kernel.org
This commit is contained in:
Niklas Cassel 2026-01-30 12:30:39 +01:00 committed by Bjorn Helgaas
parent c17b9046fa
commit ffcc4850a1
2 changed files with 116 additions and 2 deletions

View file

@ -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
--------------------------------------------

View file

@ -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 = {