PCI: Separate VF BAR updates from standard BAR updates

From: Bjorn Helgaas <bhelgaas@google.com>

[ Upstream commit 6ffa2489c51da77564a0881a73765ea2169f955d ]

Previously pci_update_resource() used the same code path for updating
standard BARs and VF BARs in SR-IOV capabilities.

Split the VF BAR update into a new pci_iov_update_resource() internal
interface, which makes it simpler to compute the BAR address (we can get
rid of pci_resource_bar() and pci_iov_resource_bar()).

This patch:

  - Renames pci_update_resource() to pci_std_update_resource(),
  - Adds pci_iov_update_resource(),
  - Makes pci_update_resource() a wrapper that calls the appropriate one,

No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: sumitsemwal

drivers/pci/iov.c

@@ -572,6 +572,56 @@ int pci_iov_resource_bar(struct pci_dev *dev, int resno)
 		4 * (resno - PCI_IOV_RESOURCES);
 }
 
+/**
+ * pci_iov_update_resource - update a VF BAR
+ * @dev: the PCI device
+ * @resno: the resource number
+ *
+ * Update a VF BAR in the SR-IOV capability of a PF.
+ */
+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;
+	struct pci_bus_region region;
+	u32 new;
+	int reg;
+
+	/*
+	 * The generic pci_restore_bars() path calls this for all devices,
+	 * including VFs and non-SR-IOV devices.  If this is not a PF, we
+	 * have nothing to do.
+	 */
+	if (!iov)
+		return;
+
+	/*
+	 * Ignore unimplemented BARs, unused resource slots for 64-bit
+	 * BARs, and non-movable resources, e.g., those described via
+	 * Enhanced Allocation.
+	 */
+	if (!res->flags)
+		return;
+
+	if (res->flags & IORESOURCE_UNSET)
+		return;
+
+	if (res->flags & IORESOURCE_PCI_FIXED)
+		return;
+
+	pcibios_resource_to_bus(dev->bus, &region, res);
+	new = region.start;
+	new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
+
+	reg = iov->pos + PCI_SRIOV_BAR + 4 * vf_bar;
+	pci_write_config_dword(dev, reg, new);
+	if (res->flags & IORESOURCE_MEM_64) {
+		new = region.start >> 16 >> 16;
+		pci_write_config_dword(dev, reg + 4, new);
+	}
+}
+
 resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
 						      int resno)
 {

drivers/pci/pci.h

@@ -277,6 +277,7 @@ static inline void pci_restore_ats_state(struct pci_dev *dev)
 int pci_iov_init(struct pci_dev *dev);
 void pci_iov_release(struct pci_dev *dev);
 int pci_iov_resource_bar(struct pci_dev *dev, int resno);
+void pci_iov_update_resource(struct pci_dev *dev, int resno);
 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno);
 void pci_restore_iov_state(struct pci_dev *dev);
 int pci_iov_bus_range(struct pci_bus *bus);

drivers/pci/setup-res.c

@@ -25,8 +25,7 @@
 #include <linux/slab.h>
 #include "pci.h"
 
-
-void pci_update_resource(struct pci_dev *dev, int resno)
+static void pci_std_update_resource(struct pci_dev *dev, int resno)
 {
 	struct pci_bus_region region;
 	bool disable;
@@ -110,6 +109,16 @@ void pci_update_resource(struct pci_dev *dev, int resno)
 		pci_write_config_word(dev, PCI_COMMAND, cmd);
 }
 
+void pci_update_resource(struct pci_dev *dev, int resno)
+{
+	if (resno <= PCI_ROM_RESOURCE)
+		pci_std_update_resource(dev, resno);
+#ifdef CONFIG_PCI_IOV
+	else if (resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END)
+		pci_iov_update_resource(dev, resno);
+#endif
+}
+
 int pci_claim_resource(struct pci_dev *dev, int resource)
 {
 	struct resource *res = &dev->resource[resource];