[PATCH v11 03/17] PCI: endpoint: Add helper API to get the 'next' unreserved BAR
From: Kishon Vijay Abraham I <hidden>
Date: 2021-02-01 20:00:07
Also in:
linux-pci, lkml
Subsystem:
pci endpoint subsystem, pci subsystem, the rest · Maintainers:
Manivannan Sadhasivam, Krzysztof Wilczyński, Bjorn Helgaas, Linus Torvalds
Add an API to get the next unreserved BAR starting from a given BAR number that can be used by the endpoint function. Signed-off-by: Kishon Vijay Abraham I <redacted> --- drivers/pci/endpoint/pci-epc-core.c | 26 ++++++++++++++++++++++---- include/linux/pci-epc.h | 2 ++ 2 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 25e57672e1a1..1afe5d9afb0d 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c@@ -87,17 +87,36 @@ EXPORT_SYMBOL_GPL(pci_epc_get); * pci_epc_get_first_free_bar() - helper to get first unreserved BAR * @epc_features: pci_epc_features structure that holds the reserved bar bitmap * - * Invoke to get the first unreserved BAR that can be used for endpoint + * 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) +{ + return pci_epc_get_next_free_bar(epc_features, BAR_0); +} +EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar); + +/** + * pci_epc_get_next_free_bar() - helper to get unreserved BAR starting from @bar + * @epc_features: pci_epc_features structure that holds the reserved bar bitmap + * @bar: the starting BAR number from where unreserved BAR should be searched + * + * 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) { unsigned long free_bar; if (!epc_features) return 0; + /* If 'bar - 1' is a 64-bit BAR, move to the next BAR */ + if ((epc_features->bar_fixed_64bit << 1) & 1 << bar) + bar++; + /* Find if the reserved BAR is also a 64-bit BAR */ free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit;
@@ -105,14 +124,13 @@ unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features free_bar <<= 1; free_bar |= epc_features->reserved_bar; - /* Now find the free BAR */ - free_bar = ffz(free_bar); + free_bar = find_next_zero_bit(&free_bar, 6, bar); if (free_bar > 5) return 0; return free_bar; } -EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar); +EXPORT_SYMBOL_GPL(pci_epc_get_next_free_bar); /** * pci_epc_get_features() - get the features supported by EPC
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index cc66bec8be90..cfe9b427e6b7 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h@@ -203,6 +203,8 @@ 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); struct pci_epc *pci_epc_get(const char *epc_name); void pci_epc_put(struct pci_epc *epc);
--
2.17.1