Introduce the helper function pci_epf_align_addr() to adjust addresses
according to PCI BAR alignment requirements, converting addresses into base
and offset values.
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
change from v6 to v7
- new patch
---
drivers/pci/endpoint/pci-epf-core.c | 39 +++++++++++++++++++++++++++++++++++++
include/linux/pci-epf.h | 13 +++++++++++++
2 files changed, 52 insertions(+)
diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
index 8fa2797d4169a..a3f172cc786e9 100644
--- a/drivers/pci/endpoint/pci-epf-core.c
+++ b/drivers/pci/endpoint/pci-epf-core.c
@@ -464,6 +464,45 @@ struct pci_epf *pci_epf_create(const char *name)
}
EXPORT_SYMBOL_GPL(pci_epf_create);
+/**
+ * pci_epf_align_addr() - Get base address and offset that match bar's
+ * alignment requirement
+ * @epf: the EPF device
+ * @addr: the address of the memory
+ * @bar: the BAR number corresponding to map addr
+ * @base: return base address, which match BAR's alignment requirement, nothing
+ * return if NULL
+ * @off: return offset, nothing return if NULL
+ *
+ * Helper function to convert input 'addr' to base and offset, which match
+ * BAR's alignment requirement.
+ */
+int pci_epf_align_addr(struct pci_epf *epf, enum pci_barno bar, u64 addr, u64 *base, size_t *off)
+{
+ const struct pci_epc_features *epc_features;
+ u64 align;
+
+ epc_features = pci_epc_get_features(epf->epc, epf->func_no, epf->vfunc_no);
+ if (!epc_features) {
+ dev_err(&epf->dev, "epc_features not implemented\n");
+ return -EOPNOTSUPP;
+ }
+
+ align = epc_features->align;
+ align = align ? align : 128;
+ if (epc_features->bar[bar].type == BAR_FIXED)
+ align = max(epc_features->bar[bar].fixed_size, align);
+
+ if (base)
+ *base = round_down(addr, align);
+
+ if (off)
+ *off = addr & (align - 1);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_epf_align_addr);
+
static void pci_epf_dev_release(struct device *dev)
{
struct pci_epf *epf = to_pci_epf(dev);
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 5374e6515ffa0..20f4f31ba9b36 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -238,6 +238,19 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
enum pci_epc_interface_type type);
void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar,
enum pci_epc_interface_type type);
+
+int pci_epf_align_addr(struct pci_epf *epf, enum pci_barno bar, u64 addr, u64 *base, size_t *off);
+static inline int pci_epf_align_addr_lo_hi(struct pci_epf *epf, enum pci_barno bar,
+ u32 low, u32 high, u64 *base, size_t *off)
+{
+ u64 addr = high;
+
+ addr <<= 32;
+ addr |= low;
+
+ return pci_epf_align_addr(epf, bar, addr, base, off);
+}
+
int pci_epf_bind(struct pci_epf *epf);
void pci_epf_unbind(struct pci_epf *epf);
int pci_epf_add_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf);
--
2.34.1
