PCI: tegra: Track bus -> CPU mapping

Track the offsets of the bus -> CPU mapping for I/O and memory.  This is
cosmetic for current Tegra chips because the offset is always 0.  But to
properly support legacy use-cases, like VGA, this would be needed so that
PCI bus addresses can be relocated.

While at it, also request the I/O resource both in physical memory and I/O
space to make /proc/iomem consistent, as well as add the I/O region to the
list of host bridge resources.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 0ca1dae166037937e2a974d989278a5671ced331..7bda73bf7c5e08639a855a41c1e9cadc7ace4df4 100644 (file)
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -281,6 +281,11 @@ struct tegra_pcie {
        struct resource prefetch;
        struct resource busn;
 
+       struct {
+               resource_size_t mem;
+               resource_size_t io;
+       } offset;
+
        struct clk *pex_clk;
        struct clk *afi_clk;
        struct clk *pll_e;
@@ -611,6 +616,17 @@ static int tegra_pcie_setup(int nr, struct pci_sys_data *sys)
        struct tegra_pcie *pcie = sys_to_pcie(sys);
        int err;
 
+       sys->mem_offset = pcie->offset.mem;
+       sys->io_offset = pcie->offset.io;
+
+       err = devm_request_resource(pcie->dev, &pcie->all, &pcie->io);
+       if (err < 0)
+               return err;
+
+       err = devm_request_resource(pcie->dev, &ioport_resource, &pcie->pio);
+       if (err < 0)
+               return err;
+
        err = devm_request_resource(pcie->dev, &pcie->all, &pcie->mem);
        if (err < 0)
                return err;
@@ -619,6 +635,7 @@ static int tegra_pcie_setup(int nr, struct pci_sys_data *sys)
        if (err)
                return err;
 
+       pci_add_resource_offset(&sys->resources, &pcie->pio, sys->io_offset);
        pci_add_resource_offset(&sys->resources, &pcie->mem, sys->mem_offset);
        pci_add_resource_offset(&sys->resources, &pcie->prefetch,
                                sys->mem_offset);
@@ -1614,6 +1631,9 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
 
                switch (res.flags & IORESOURCE_TYPE_BITS) {
                case IORESOURCE_IO:
+                       /* Track the bus -> CPU I/O mapping offset. */
+                       pcie->offset.io = res.start - range.pci_addr;
+
                        memcpy(&pcie->pio, &res, sizeof(res));
                        pcie->pio.name = np->full_name;
 
@@ -1634,6 +1654,14 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
                        break;
 
                case IORESOURCE_MEM:
+                       /*
+                        * Track the bus -> CPU memory mapping offset. This
+                        * assumes that the prefetchable and non-prefetchable
+                        * regions will be the last of type IORESOURCE_MEM in
+                        * the ranges property.
+                        * */
+                       pcie->offset.mem = res.start - range.pci_addr;
+
                        if (res.flags & IORESOURCE_PREFETCH) {
                                memcpy(&pcie->prefetch, &res, sizeof(res));
                                pcie->prefetch.name = "prefetchable";