cxl/pci: Add @base to cxl_register_map

In addition to carrying @barno, @block_offset, and @reg_type, add @base
to keep all map/unmap parameters in one object. The helpers
cxl_{map,unmap}_regblock() handle adjusting @base to the @block_offset
at map and unmap time.

Document that @base incorporates @block_offset so that downstream
consumers of a mapped cxl_register_map instance do not need perform any
fixups / can use @base directly.

Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/163433497228.889435.11271988238496181536.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index a6687e7fd5988477d690396fb259453f9e902122..5e2e934519286f97dd6129007bf7ccc3104d50ab 100644 (file)
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -139,7 +139,17 @@ struct cxl_device_reg_map {
        struct cxl_reg_map memdev;
 };
 
+/**
+ * struct cxl_register_map - DVSEC harvested register block mapping parameters
+ * @base: virtual base of the register-block-BAR + @block_offset
+ * @block_offset: offset to start of register block in @barno
+ * @reg_type: see enum cxl_regloc_type
+ * @barno: PCI BAR number containing the register block
+ * @component_map: cxl_reg_map for component registers
+ * @device_map: cxl_reg_maps for device registers
+ */
 struct cxl_register_map {
+       void __iomem *base;
        u64 block_offset;
        u8 reg_type;
        u8 barno;

diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index eb0c2f1b9e658fa837f51ec2c16812a4799f3dad..7d5e5548b31677fb880610554e9c3e8bfc6cf6aa 100644 (file)
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -306,8 +306,7 @@ static int cxl_pci_setup_mailbox(struct cxl_mem *cxlm)
        return 0;
 }
 
-static void __iomem *cxl_pci_map_regblock(struct pci_dev *pdev,
-                                         struct cxl_register_map *map)
+static int cxl_map_regblock(struct pci_dev *pdev, struct cxl_register_map *map)
 {
        void __iomem *addr;
        int bar = map->barno;
@@ -318,24 +317,27 @@ static void __iomem *cxl_pci_map_regblock(struct pci_dev *pdev,
        if (pci_resource_len(pdev, bar) < offset) {
                dev_err(dev, "BAR%d: %pr: too small (offset: %pa)\n", bar,
                        &pdev->resource[bar], &offset);
-               return NULL;
+               return -ENXIO;
        }
 
        addr = pci_iomap(pdev, bar, 0);
        if (!addr) {
                dev_err(dev, "failed to map registers\n");
-               return addr;
+               return -ENOMEM;
        }
 
        dev_dbg(dev, "Mapped CXL Memory Device resource bar %u @ %pa\n",
                bar, &offset);
 
-       return addr;
+       map->base = addr + map->block_offset;
+       return 0;
 }
 
-static void cxl_pci_unmap_regblock(struct pci_dev *pdev, void __iomem *base)
+static void cxl_unmap_regblock(struct pci_dev *pdev,
+                              struct cxl_register_map *map)
 {
-       pci_iounmap(pdev, base);
+       pci_iounmap(pdev, map->base - map->block_offset);
+       map->base = NULL;
 }
 
 static int cxl_pci_dvsec(struct pci_dev *pdev, int dvsec)
@@ -361,12 +363,12 @@ static int cxl_pci_dvsec(struct pci_dev *pdev, int dvsec)
        return 0;
 }
 
-static int cxl_probe_regs(struct pci_dev *pdev, void __iomem *base,
-                         struct cxl_register_map *map)
+static int cxl_probe_regs(struct pci_dev *pdev, struct cxl_register_map *map)
 {
        struct cxl_component_reg_map *comp_map;
        struct cxl_device_reg_map *dev_map;
        struct device *dev = &pdev->dev;
+       void __iomem *base = map->base;
 
        switch (map->reg_type) {
        case CXL_REGLOC_RBI_COMPONENT:
@@ -442,7 +444,6 @@ static void cxl_decode_regblock(u32 reg_lo, u32 reg_hi,
  */
 static int cxl_pci_setup_regs(struct cxl_mem *cxlm)
 {
-       void __iomem *base;
        u32 regloc_size, regblocks;
        int regloc, i, n_maps, ret = 0;
        struct device *dev = cxlm->dev;
@@ -475,12 +476,12 @@ static int cxl_pci_setup_regs(struct cxl_mem *cxlm)
                if (map->reg_type > CXL_REGLOC_RBI_MEMDEV)
                        continue;
 
-               base = cxl_pci_map_regblock(pdev, map);
-               if (!base)
-                       return -ENOMEM;
+               ret = cxl_map_regblock(pdev, map);
+               if (ret)
+                       return ret;
 
-               ret = cxl_probe_regs(pdev, base + map->block_offset, map);
-               cxl_pci_unmap_regblock(pdev, base);
+               ret = cxl_probe_regs(pdev, map);
+               cxl_unmap_regblock(pdev, map);
                if (ret)
                        return ret;