[PATCH 1/2] PCI: hisi: Avoid invalid address space conversions

Bjorn Helgaas
2021-12-23T21:38:01Z

The sparse checker complains about converting pointers between address
spaces. The pci_config_window.priv pointer is a generic void *, but
hisi_pcie_map_bus() needs a void __iomem *.

This isn't a problem in other drivers because they store the __iomem
pointer in a driver struct. Add a trivial struct hisi_pcie to avoid the
warning.

The sparse warning looks like this:

$ make C=2 drivers/pci/controller/
drivers/pci/controller/dwc/pcie-hisi.c:61:37: warning: incorrect type in initializer (different address spaces)
drivers/pci/controller/dwc/pcie-hisi.c:61:37: expected void [noderef] __iomem *reg_base
drivers/pci/controller/dwc/pcie-hisi.c:61:37: got void *priv

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Zhou Wang <wangzhou1@hisilicon.com>
---
drivers/pci/controller/dwc/pcie-hisi.c | 32 ++++++++++++++++++--------
1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-hisi.c b/drivers/pci/controller/dwc/pcie-hisi.c
index 8fc5960faf28..8904b5b85ee5 100644
--- a/drivers/pci/controller/dwc/pcie-hisi.c
+++ b/drivers/pci/controller/dwc/pcie-hisi.c
@@ -18,6 +18,10 @@

#if defined(CONFIG_PCI_HISI) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))

+struct hisi_pcie {
+ void __iomem *reg_base;
+};
+
static int hisi_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
int size, u32 *val)
{
@@ -58,10 +62,10 @@ static void __iomem *hisi_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
int where)
{
struct pci_config_window *cfg = bus->sysdata;
- void __iomem *reg_base = cfg->priv;
+ struct hisi_pcie *pcie = cfg->priv;

if (bus->number == cfg->busr.start)
- return reg_base + where;
+ return pcie->reg_base + where;
else
return pci_ecam_map_bus(bus, devfn, where);
}
@@ -71,12 +75,16 @@ static void __iomem *hisi_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
static int hisi_pcie_init(struct pci_config_window *cfg)
{
struct device *dev = cfg->parent;
+ struct hisi_pcie *pcie;
struct acpi_device *adev = to_acpi_device(dev);
struct acpi_pci_root *root = acpi_driver_data(adev);
struct resource *res;
- void __iomem *reg_base;
int ret;

+ pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+ if (!pcie)
+ return -ENOMEM;
+
/*
* Retrieve RC base and size from a HISI0081 device with _UID
* matching our segment.
@@ -91,11 +99,11 @@ static int hisi_pcie_init(struct pci_config_window *cfg)
return -ENOMEM;
}

- reg_base = devm_pci_remap_cfgspace(dev, res->start, resource_size(res));
- if (!reg_base)
+ pcie->reg_base = devm_pci_remap_cfgspace(dev, res->start, resource_size(res));
+ if (!pcie->reg_base)
return -ENOMEM;

- cfg->priv = reg_base;
+ cfg->priv = pcie;
return 0;
}

@@ -115,9 +123,13 @@ const struct pci_ecam_ops hisi_pcie_ops = {
static int hisi_pcie_platform_init(struct pci_config_window *cfg)
{
struct device *dev = cfg->parent;
+ struct hisi_pcie *pcie;
struct platform_device *pdev = to_platform_device(dev);
struct resource *res;
- void __iomem *reg_base;
+
+ pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+ if (!pcie)
+ return -ENOMEM;

res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!res) {
@@ -125,11 +137,11 @@ static int hisi_pcie_platform_init(struct pci_config_window *cfg)
return -EINVAL;
}

- reg_base = devm_pci_remap_cfgspace(dev, res->start, resource_size(res));
- if (!reg_base)
+ pcie->reg_base = devm_pci_remap_cfgspace(dev, res->start, resource_size(res));
+ if (!pcie->reg_base)
return -ENOMEM;

- cfg->priv = reg_base;
+ cfg->priv = pcie;
return 0;
}

--
2.25.1