From: Thierry Reding <treding@xxxxxxxxxx>
Commit 0b0b0893d49b ("of/pci: Fix the conversion of IO ranges into IO
resources") changed how I/O resources are parsed from DT. Rather than
containing the physical address of the I/O region, the addresses will
now be in I/O address space.
On Tegra the union of all ranges is used to expose a top-level memory-
mapped resource for the PCI host bridge. This helps to make /proc/iomem
more readable.
Combining both of the above, the union would now include the I/O space
region. This causes a regression on Tegra20, where the physical base
address of the PCIe controller (and therefore of the union) is located
at physical address 0x80000000. Since I/O space starts at 0, the union
will now include all of system RAM which starts at 0x00000000.
This commit fixes this by keeping two copies of the I/O range: one that
represents the range in the CPU's physical address space, the other for
the range in the I/O address space. This allows the translation setup
within the driver to reuse the physical addresses. The code registering
the I/O region with the PCI core uses both ranges to establish the
mapping.
Fixes: 0b0b0893d49b ("of/pci: Fix the conversion of IO ranges into IO resources")
Reported-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Suggested-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
Marc, any chance of getting a Tested-by from you on this? I think you
said you were seeing this on Harmony and I'm pretty sure this should fix
the issue for you as well.
Bjorn, this fixes a regression on Tegra20 (it's hidden on later Tegra
generations because the PCIe controller has moved to the first 1 GiB of
physical address space) that was introduced in 3.18-rc1, so it would be
good to get this in before the final 3.18 release.
Changes in v2:
- remove cleanup not essential to fix the regression (will be part of a
follow-up patch)
drivers/pci/host/pci-tegra.c | 28 ++++++++++++++++++++--------
1 file changed, 20 insertions(+), 8 deletions(-)
diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 3d43874319be..19bb19c7db4a 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -276,6 +276,7 @@ struct tegra_pcie {
struct resource all;
struct resource io;
+ struct resource pio;
struct resource mem;
struct resource prefetch;
struct resource busn;
@@ -658,7 +659,6 @@ static int tegra_pcie_setup(int nr, struct pci_sys_data *sys)
{
struct tegra_pcie *pcie = sys_to_pcie(sys);
int err;
- phys_addr_t io_start;
err = devm_request_resource(pcie->dev, &pcie->all, &pcie->mem);
if (err < 0)
@@ -668,14 +668,12 @@ static int tegra_pcie_setup(int nr, struct pci_sys_data *sys)
if (err)
return err;
- io_start = pci_pio_to_address(pcie->io.start);
-
pci_add_resource_offset(&sys->resources, &pcie->mem, sys->mem_offset);
pci_add_resource_offset(&sys->resources, &pcie->prefetch,
sys->mem_offset);
pci_add_resource(&sys->resources, &pcie->busn);
- pci_ioremap_io(nr * SZ_64K, io_start);
+ pci_ioremap_io(pcie->pio.start, pcie->io.start);
return 1;
}
@@ -786,7 +784,6 @@ static irqreturn_t tegra_pcie_isr(int irq, void *arg)
static void tegra_pcie_setup_translations(struct tegra_pcie *pcie)
{
u32 fpci_bar, size, axi_address;
- phys_addr_t io_start = pci_pio_to_address(pcie->io.start);
/* Bar 0: type 1 extended configuration space */
fpci_bar = 0xfe100000;
@@ -799,7 +796,7 @@ static void tegra_pcie_setup_translations(struct tegra_pcie *pcie)
/* Bar 1: downstream IO bar */
fpci_bar = 0xfdfc0000;
size = resource_size(&pcie->io);
- axi_address = io_start;
+ axi_address = pcie->io.start;
afi_writel(pcie, axi_address, AFI_AXI_BAR1_START);
afi_writel(pcie, size >> 12, AFI_AXI_BAR1_SZ);
afi_writel(pcie, fpci_bar, AFI_FPCI_BAR1);
@@ -1690,8 +1687,23 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
switch (res.flags & IORESOURCE_TYPE_BITS) {
case IORESOURCE_IO:
- memcpy(&pcie->io, &res, sizeof(res));
- pcie->io.name = np->full_name;
+ memcpy(&pcie->pio, &res, sizeof(res));
+ pcie->pio.name = np->full_name;
+
+ /*
+ * The Tegra PCIe host bridge uses this to program the
+ * mapping of the I/O space to the physical address,
+ * so we override the .start and .end fields here that
+ * of_pci_range_to_resource() converted to I/O space.
+ * We also set the IORESOURCE_MEM type to clarify that
+ * the resource is in the physical memory space.
+ */
+ pcie->io.start = range.cpu_addr;
+ pcie->io.end = range.cpu_addr + range.size - 1;
+ pcie->io.flags = IORESOURCE_MEM;
+ pcie->io.name = "I/O";
+
+ memcpy(&res, &pcie->io, sizeof(res));
break;
case IORESOURCE_MEM:
--
2.1.3
--
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