diff options
Diffstat (limited to 'drivers/pci/controller/dwc/pcie-designware-host.c')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware-host.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 94e0fe11a0b0..20c9333bcb1c 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -8,6 +8,7 @@ * Author: Jingoo Han <jg1.han@samsung.com> */ +#include <linux/align.h> #include <linux/iopoll.h> #include <linux/irqchip/chained_irq.h> #include <linux/irqchip/irq-msi-lib.h> @@ -32,6 +33,8 @@ static struct pci_ops dw_child_pcie_ops; MSI_FLAG_PCI_MSIX | \ MSI_GENERIC_FLAGS_MASK) +#define IS_256MB_ALIGNED(x) IS_ALIGNED(x, SZ_256M) + static const struct msi_parent_ops dw_pcie_msi_parent_ops = { .required_flags = DW_PCIE_MSI_FLAGS_REQUIRED, .supported_flags = DW_PCIE_MSI_FLAGS_SUPPORTED, @@ -474,6 +477,34 @@ static int dw_pcie_create_ecam_window(struct dw_pcie_rp *pp, struct resource *re return 0; } +static bool dw_pcie_ecam_enabled(struct dw_pcie_rp *pp, struct resource *config_res) +{ + struct resource *bus_range; + u64 nr_buses; + + /* Vendor glue drivers may implement their own ECAM mechanism */ + if (pp->native_ecam) + return false; + + /* + * PCIe spec r6.0, sec 7.2.2 mandates the base address used for ECAM to + * be aligned on a 2^(n+20) byte boundary, where n is the number of bits + * used for representing 'bus' in BDF. Since the DWC cores always use 8 + * bits for representing 'bus', the base address has to be aligned to + * 2^28 byte boundary, which is 256 MiB. + */ + if (!IS_256MB_ALIGNED(config_res->start)) + return false; + + bus_range = resource_list_first_type(&pp->bridge->windows, IORESOURCE_BUS)->res; + if (!bus_range) + return false; + + nr_buses = resource_size(config_res) >> PCIE_ECAM_BUS_SHIFT; + + return nr_buses >= resource_size(bus_range); +} + static int dw_pcie_host_get_resources(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); @@ -492,6 +523,7 @@ static int dw_pcie_host_get_resources(struct dw_pcie_rp *pp) pp->cfg0_size = resource_size(res); pp->cfg0_base = res->start; + pp->ecam_enabled = dw_pcie_ecam_enabled(pp, res); if (pp->ecam_enabled) { ret = dw_pcie_create_ecam_window(pp, res); if (ret) |