[PATCH v6 3/8] PCI: vmd: Add vmd_configure_membar() and vmd_configure_membar1_membar2()

[Szymon Durawa <szymon.durawa@linux.intel.com>]

Move the MEMBAR1 and MEMBAR2 registry initialization code to new helpers
vmd_configure_membar() and vmd_configure_membar1_membar2().
The refactor preserves MEMBAR address/offset/flags programming, but
resource name construction is now generated in the helper ("VMD MEMBAR%d")
instead of using two separate string literals.

Suggested-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Signed-off-by: Szymon Durawa <szymon.durawa@linux.intel.com>
---
 drivers/pci/controller/vmd.c | 98 +++++++++++++++++++++++++-----------
 1 file changed, 68 insertions(+), 30 deletions(-)

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 2c824660cabd..62bc9b91300b 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -783,6 +783,69 @@ static void vmd_configure_cfgbar(struct vmd_dev *vmd)
 	};
 }
 
+/*
+ * vmd_configure_membar - Configure VMD MemBAR register, which points
+ * to MMIO address assigned by the OS or BIOS.
+ * @vmd: the VMD device
+ * @resource_number: resource buffer number to be filled in
+ * @membar_number: number of the MemBAR
+ * @start_offset: 4K aligned offset applied to start of VMD’s MEMBAR MMIO space
+ * @end_offset: 4K aligned offset applied to end of VMD’s MEMBAR MMIO space
+ *
+ * Function fills resource buffer inside the VMD structure.
+ *
+ * Return: 0 on success, -ENOMEM on allocation failure.
+ */
+static int vmd_configure_membar(struct vmd_dev *vmd, u8 resource_number,
+				u8 membar_number, resource_size_t start_offset,
+				resource_size_t end_offset)
+{
+	char *name;
+	u32 upper_bits;
+	unsigned long flags;
+
+	struct resource *res = &vmd->dev->resource[membar_number];
+
+	upper_bits = upper_32_bits(res->end);
+	flags = res->flags & ~IORESOURCE_SIZEALIGN;
+	if (!upper_bits)
+		flags &= ~IORESOURCE_MEM_64;
+
+	name = devm_kasprintf(&vmd->dev->dev, GFP_KERNEL, "VMD MEMBAR%d",
+			      resource_number);
+	if (!name)
+		return -ENOMEM;
+
+	vmd->resources[resource_number] = (struct resource){
+		.name = name,
+		.start = res->start + start_offset,
+		.end = res->end - end_offset,
+		.flags = flags,
+		.parent = res,
+	};
+
+	return 0;
+}
+
+static int vmd_configure_membar1_membar2(struct vmd_dev *vmd,
+					 resource_size_t mbar2_ofs)
+{
+	int ret;
+
+	ret = vmd_configure_membar(vmd, 1, VMD_MEMBAR1, 0, 0);
+	if (ret)
+		return ret;
+
+	ret = vmd_configure_membar(vmd, 2, VMD_MEMBAR2, mbar2_ofs, 0);
+	if (ret) {
+		devm_kfree(&vmd->dev->dev, (void *)vmd->resources[1].name);
+		memset(&vmd->resources[1], 0, sizeof(vmd->resources[1]));
+		return ret;
+	}
+
+	return 0;
+}
+
 static void vmd_bus_enumeration(struct pci_bus *bus, unsigned long features)
 {
 	struct pci_bus *child;
@@ -834,9 +897,6 @@ static void vmd_bus_enumeration(struct pci_bus *bus, unsigned long features)
 static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 {
 	struct pci_sysdata *sd = &vmd->sysdata;
-	struct resource *res;
-	u32 upper_bits;
-	unsigned long flags;
 	LIST_HEAD(resources);
 	resource_size_t offset[2] = {0};
 	resource_size_t membar2_offset = 0x2000;
@@ -883,36 +943,14 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 	 *
 	 * The only way we could use a 64-bit non-prefetchable MEMBAR is
 	 * if its address is <4GB so that we can convert it to a 32-bit
-	 * resource.  To be visible to the host OS, all VMD endpoints must
+	 * resource. To be visible to the host OS, all VMD endpoints must
 	 * be initially configured by platform BIOS, which includes setting
-	 * up these resources.  We can assume the device is configured
+	 * up these resources. We can assume the device is configured
 	 * according to the platform needs.
 	 */
-	res = &vmd->dev->resource[VMD_MEMBAR1];
-	upper_bits = upper_32_bits(res->end);
-	flags = res->flags & ~IORESOURCE_SIZEALIGN;
-	if (!upper_bits)
-		flags &= ~IORESOURCE_MEM_64;
-	vmd->resources[1] = (struct resource) {
-		.name  = "VMD MEMBAR1",
-		.start = res->start,
-		.end   = res->end,
-		.flags = flags,
-		.parent = res,
-	};
-
-	res = &vmd->dev->resource[VMD_MEMBAR2];
-	upper_bits = upper_32_bits(res->end);
-	flags = res->flags & ~IORESOURCE_SIZEALIGN;
-	if (!upper_bits)
-		flags &= ~IORESOURCE_MEM_64;
-	vmd->resources[2] = (struct resource) {
-		.name  = "VMD MEMBAR2",
-		.start = res->start + membar2_offset,
-		.end   = res->end,
-		.flags = flags,
-		.parent = res,
-	};
+	ret = vmd_configure_membar1_membar2(vmd, membar2_offset);
+	if (ret)
+		return ret;
 
 	/*
 	 * Currently MSI remapping must be enabled in guest passthrough mode
-- 
2.43.0