cxl/pci: Reserve individual register block regions

Some hardware implementations mix component and device registers into
the same BAR and the driver stack is going to need independent mapping
implementations for those 2 cases.  Furthermore, it will be nice to have
finer grained mappings should user space want to map some register
blocks.

Now that individual register blocks are mapped; those blocks regions
should be reserved individually to fully separate the register blocks.

Release the 'global' memory reservation and create individual register
block region reservations through devm.

NOTE: pci_release_mem_regions() is still compatible with
pcim_enable_device() because it removes the automatic region release
when called.  So preserve the pcim_enable_device() so that the pcim
interface can be called if needed.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20210604005316.4187340-1-ira.weiny@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c
index f836aaa..c1efa11 100644 (file)
--- a/drivers/cxl/core.c
+++ b/drivers/cxl/core.c
@@ -79,11 +79,33 @@ void cxl_probe_device_regs(struct device *dev, void __iomem *base,
 }
 EXPORT_SYMBOL_GPL(cxl_probe_device_regs);
 
+static void __iomem *devm_cxl_iomap_block(struct pci_dev *pdev,
+                                         resource_size_t addr,
+                                         resource_size_t length)
+{
+       struct device *dev = &pdev->dev;
+       void __iomem *ret_val;
+       struct resource *res;
+
+       res = devm_request_mem_region(dev, addr, length, pci_name(pdev));
+       if (!res) {
+               resource_size_t end = addr + length - 1;
+
+               dev_err(dev, "Failed to request region %pa-%pa\n", &addr, &end);
+               return NULL;
+       }
+
+       ret_val = devm_ioremap(dev, addr, length);
+       if (!ret_val)
+               dev_err(dev, "Failed to map region %pr\n", res);
+
+       return ret_val;
+}
+
 int cxl_map_device_regs(struct pci_dev *pdev,
                        struct cxl_device_regs *regs,
                        struct cxl_register_map *map)
 {
-       struct device *dev = &pdev->dev;
        resource_size_t phys_addr;
 
        phys_addr = pci_resource_start(pdev, map->barno);
@@ -95,7 +117,9 @@ int cxl_map_device_regs(struct pci_dev *pdev,
 
                addr = phys_addr + map->device_map.status.offset;
                length = map->device_map.status.size;
-               regs->status = devm_ioremap(dev, addr, length);
+               regs->status = devm_cxl_iomap_block(pdev, addr, length);
+               if (!regs->status)
+                       return -ENOMEM;
        }
 
        if (map->device_map.mbox.valid) {
@@ -104,7 +128,9 @@ int cxl_map_device_regs(struct pci_dev *pdev,
 
                addr = phys_addr + map->device_map.mbox.offset;
                length = map->device_map.mbox.size;
-               regs->mbox = devm_ioremap(dev, addr, length);
+               regs->mbox = devm_cxl_iomap_block(pdev, addr, length);
+               if (!regs->mbox)
+                       return -ENOMEM;
        }
 
        if (map->device_map.memdev.valid) {
@@ -113,7 +139,9 @@ int cxl_map_device_regs(struct pci_dev *pdev,
 
                addr = phys_addr + map->device_map.memdev.offset;
                length = map->device_map.memdev.size;
-               regs->memdev = devm_ioremap(dev, addr, length);
+               regs->memdev = devm_cxl_iomap_block(pdev, addr, length);
+               if (!regs->memdev)
+                       return -ENOMEM;
        }
 
        return 0;

diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 3ffd5fa..e1a2dbc 100644 (file)
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -1110,6 +1110,8 @@ static int cxl_mem_setup_regs(struct cxl_mem *cxlm)
                        goto free_maps;
        }
 
+       pci_release_mem_regions(pdev);
+
        list_for_each_entry(map, &register_maps, list) {
                ret = cxl_map_regs(cxlm, map);
                if (ret)