[PATCH v4 3/7] PCI: Add a helper to convert between standard and IOV resources

[Michał Winiarski]

There are multiple places where conversions between IOV resources and
standard resources are done.

Extract the logic to pci_resource_to_iov() and pci_resource_from_iov()
helpers.

Suggested-by: Ilpo Järvinen <ilpo.jarvinen at linux.intel.com>
Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
---
 drivers/pci/iov.c       | 20 ++++++++++----------
 drivers/pci/pci.h       | 18 ++++++++++++++++++
 drivers/pci/setup-bus.c |  2 +-
 3 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 6bdc9950b9787..eedc1df56c49e 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -151,7 +151,7 @@ resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
 	if (!dev->is_physfn)
 		return 0;
 
-	return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
+	return dev->sriov->barsz[pci_resource_from_iov(resno)];
 }
 
 static void pci_read_vf_config_common(struct pci_dev *virtfn)
@@ -322,12 +322,12 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
 	virtfn->multifunction = 0;
 
 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
-		res = &dev->resource[i + PCI_IOV_RESOURCES];
+		res = &dev->resource[pci_resource_to_iov(i)];
 		if (!res->parent)
 			continue;
 		virtfn->resource[i].name = pci_name(virtfn);
 		virtfn->resource[i].flags = res->flags;
-		size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
+		size = pci_iov_resource_size(dev, pci_resource_to_iov(i));
 		virtfn->resource[i].start = res->start + size * id;
 		virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
 		rc = request_resource(res, &virtfn->resource[i]);
@@ -624,8 +624,8 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 
 	nres = 0;
 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
-		bars |= (1 << (i + PCI_IOV_RESOURCES));
-		res = &dev->resource[i + PCI_IOV_RESOURCES];
+		bars |= (1 << pci_resource_to_iov(i));
+		res = &dev->resource[pci_resource_to_iov(i)];
 		if (res->parent)
 			nres++;
 	}
@@ -786,8 +786,8 @@ static int sriov_init(struct pci_dev *dev, int pos)
 
 	nres = 0;
 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
-		res = &dev->resource[i + PCI_IOV_RESOURCES];
-		res_name = pci_resource_name(dev, i + PCI_IOV_RESOURCES);
+		res = &dev->resource[pci_resource_to_iov(i)];
+		res_name = pci_resource_name(dev, pci_resource_to_iov(i));
 
 		/*
 		 * If it is already FIXED, don't change it, something
@@ -844,7 +844,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
 	dev->is_physfn = 0;
 failed:
 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
-		res = &dev->resource[i + PCI_IOV_RESOURCES];
+		res = &dev->resource[pci_resource_to_iov(i)];
 		res->flags = 0;
 	}
 
@@ -906,7 +906,7 @@ static void sriov_restore_state(struct pci_dev *dev)
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl);
 
 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++)
-		pci_update_resource(dev, i + PCI_IOV_RESOURCES);
+		pci_update_resource(dev, pci_resource_to_iov(i));
 
 	pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
 	pci_iov_set_numvfs(dev, iov->num_VFs);
@@ -972,7 +972,7 @@ void pci_iov_update_resource(struct pci_dev *dev, int resno)
 {
 	struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
 	struct resource *res = dev->resource + resno;
-	int vf_bar = resno - PCI_IOV_RESOURCES;
+	int vf_bar = pci_resource_from_iov(resno);
 	struct pci_bus_region region;
 	u16 cmd;
 	u32 new;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 48d345607e57e..1f8d88f0243b7 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -584,6 +584,15 @@ static inline bool pci_resource_is_iov(int resno)
 {
 	return resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END;
 }
+static inline int pci_resource_to_iov(int resno)
+{
+	return resno + PCI_IOV_RESOURCES;
+}
+
+static inline int pci_resource_from_iov(int resno)
+{
+	return resno - PCI_IOV_RESOURCES;
+}
 extern const struct attribute_group sriov_pf_dev_attr_group;
 extern const struct attribute_group sriov_vf_dev_attr_group;
 #else
@@ -608,6 +617,15 @@ static inline bool pci_resource_is_iov(int resno)
 {
 	return false;
 }
+static inline int pci_resource_to_iov(int resno)
+{
+	return -ENODEV;
+}
+
+static inline int pci_resource_from_iov(int resno)
+{
+	return -ENODEV;
+}
 #endif /* CONFIG_PCI_IOV */
 
 #ifdef CONFIG_PCIE_PTM
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index ba293df10c050..c5ad7c4ad6eb1 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1778,7 +1778,7 @@ static int iov_resources_unassigned(struct pci_dev *dev, void *data)
 	bool *unassigned = data;
 
 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
-		struct resource *r = &dev->resource[i + PCI_IOV_RESOURCES];
+		struct resource *r = &dev->resource[pci_resource_to_iov(i)];
 		struct pci_bus_region region;
 
 		/* Not assigned or rejected by kernel? */
-- 
2.47.0