[PATCH 5.10 109/289] PCI: endpoint: Make *_free_bar() to return error codes on failure

From: Greg Kroah-Hartman
Date: Mon May 17 2021 - 11:36:21 EST


From: Kishon Vijay Abraham I <kishon@xxxxxx>

[ Upstream commit 0e27aeccfa3d1bab7c6a29fb8e6fcedbad7b09a8 ]

Modify pci_epc_get_next_free_bar() and pci_epc_get_first_free_bar() to
return error values if there are no free BARs available.

Link: https://lore.kernel.org/r/20210201195809.7342-5-kishon@xxxxxx
Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/pci/endpoint/functions/pci-epf-test.c | 2 ++
drivers/pci/endpoint/pci-epc-core.c | 12 ++++++------
include/linux/pci-epc.h | 8 ++++----
include/linux/pci-epf.h | 1 +
4 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index e4e51d884553..7a1f3abfde48 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -834,6 +834,8 @@ static int pci_epf_test_bind(struct pci_epf *epf)
linkup_notifier = epc_features->linkup_notifier;
core_init_notifier = epc_features->core_init_notifier;
test_reg_bar = pci_epc_get_first_free_bar(epc_features);
+ if (test_reg_bar < 0)
+ return -EINVAL;
pci_epf_configure_bar(epf, epc_features);
}

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 1afe5d9afb0d..ea7e7465ce7a 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -90,8 +90,8 @@ EXPORT_SYMBOL_GPL(pci_epc_get);
* Invoke to get the first unreserved BAR that can be used by the endpoint
* function. For any incorrect value in reserved_bar return '0'.
*/
-unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
- *epc_features)
+enum pci_barno
+pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features)
{
return pci_epc_get_next_free_bar(epc_features, BAR_0);
}
@@ -105,13 +105,13 @@ EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
* Invoke to get the next unreserved BAR starting from @bar that can be used
* for endpoint function. For any incorrect value in reserved_bar return '0'.
*/
-unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
- *epc_features, enum pci_barno bar)
+enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
+ *epc_features, enum pci_barno bar)
{
unsigned long free_bar;

if (!epc_features)
- return 0;
+ return BAR_0;

/* If 'bar - 1' is a 64-bit BAR, move to the next BAR */
if ((epc_features->bar_fixed_64bit << 1) & 1 << bar)
@@ -126,7 +126,7 @@ unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features

free_bar = find_next_zero_bit(&free_bar, 6, bar);
if (free_bar > 5)
- return 0;
+ return NO_BAR;

return free_bar;
}
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index cfe9b427e6b7..88d311bad984 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -201,10 +201,10 @@ int pci_epc_start(struct pci_epc *epc);
void pci_epc_stop(struct pci_epc *epc);
const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
u8 func_no);
-unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
- *epc_features);
-unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
- *epc_features, enum pci_barno bar);
+enum pci_barno
+pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features);
+enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
+ *epc_features, enum pci_barno bar);
struct pci_epc *pci_epc_get(const char *epc_name);
void pci_epc_put(struct pci_epc *epc);

diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 6644ff3b0702..fa3aca43eb19 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -21,6 +21,7 @@ enum pci_notify_event {
};

enum pci_barno {
+ NO_BAR = -1,
BAR_0,
BAR_1,
BAR_2,
--
2.30.2