| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <device/pci.h> |
| #include <device/pci_ops.h> |
| #include <delay.h> |
| |
| void pci_s_assert_secondary_reset(pci_devfn_t p2p_bridge) |
| { |
| u16 reg16; |
| reg16 = pci_s_read_config16(p2p_bridge, PCI_BRIDGE_CONTROL); |
| reg16 |= PCI_BRIDGE_CTL_BUS_RESET; |
| pci_s_write_config16(p2p_bridge, PCI_BRIDGE_CONTROL, reg16); |
| } |
| |
| void pci_s_deassert_secondary_reset(pci_devfn_t p2p_bridge) |
| { |
| u16 reg16; |
| reg16 = pci_s_read_config16(p2p_bridge, PCI_BRIDGE_CONTROL); |
| reg16 &= ~PCI_BRIDGE_CTL_BUS_RESET; |
| pci_s_write_config16(p2p_bridge, PCI_BRIDGE_CONTROL, reg16); |
| } |
| |
| void pci_s_bridge_set_secondary(pci_devfn_t p2p_bridge, u8 secondary) |
| { |
| /* Disable config transaction forwarding. */ |
| pci_s_write_config8(p2p_bridge, PCI_SECONDARY_BUS, 0x00); |
| pci_s_write_config8(p2p_bridge, PCI_SUBORDINATE_BUS, 0x00); |
| /* Enable config transaction forwarding. */ |
| pci_s_write_config8(p2p_bridge, PCI_SECONDARY_BUS, secondary); |
| pci_s_write_config8(p2p_bridge, PCI_SUBORDINATE_BUS, secondary); |
| } |
| |
| static void pci_s_bridge_set_mmio(pci_devfn_t p2p_bridge, u32 base, u32 size) |
| { |
| u16 reg16; |
| |
| /* Disable MMIO window behind the bridge. */ |
| reg16 = pci_s_read_config16(p2p_bridge, PCI_COMMAND); |
| reg16 &= ~PCI_COMMAND_MEMORY; |
| pci_s_write_config16(p2p_bridge, PCI_COMMAND, reg16); |
| pci_s_write_config32(p2p_bridge, PCI_MEMORY_BASE, 0x10); |
| |
| if (!size) |
| return; |
| |
| /* Enable MMIO window behind the bridge. */ |
| pci_s_write_config32(p2p_bridge, PCI_MEMORY_BASE, |
| ((base + size - 1) & 0xfff00000) | ((base >> 16) & 0xfff0)); |
| |
| reg16 = pci_s_read_config16(p2p_bridge, PCI_COMMAND); |
| reg16 |= PCI_COMMAND_MEMORY; |
| pci_s_write_config16(p2p_bridge, PCI_COMMAND, reg16); |
| } |
| |
| static void pci_s_early_mmio_window(pci_devfn_t p2p_bridge, u32 mmio_base, u32 mmio_size) |
| { |
| int timeout, ret = -1; |
| |
| /* Secondary bus number is mostly irrelevant as we disable |
| * configuration transactions right after the probe. |
| */ |
| u8 secondary = 15; |
| u8 dev = 0; |
| |
| /* Enable configuration and MMIO over bridge. */ |
| pci_s_assert_secondary_reset(p2p_bridge); |
| pci_s_deassert_secondary_reset(p2p_bridge); |
| pci_s_bridge_set_secondary(p2p_bridge, secondary); |
| pci_s_bridge_set_mmio(p2p_bridge, mmio_base, mmio_size); |
| |
| for (timeout = 20000; timeout; timeout--) { |
| pci_devfn_t dbg_dev = PCI_DEV(secondary, dev, 0); |
| u32 id = pci_s_read_config32(dbg_dev, PCI_VENDOR_ID); |
| if (id != 0 && id != 0xffffffff && id != 0xffff0001) |
| break; |
| udelay(10); |
| } |
| |
| if (timeout != 0) |
| ret = pci_early_device_probe(secondary, dev, mmio_base); |
| |
| /* Disable MMIO window if we found no suitable device. */ |
| if (ret) |
| pci_s_bridge_set_mmio(p2p_bridge, 0, 0); |
| |
| /* Resource allocator will reconfigure bridges and secondary bus |
| * number may change. Thus early device cannot reliably use config |
| * transactions from here on, so we may as well disable them. |
| */ |
| pci_s_bridge_set_secondary(p2p_bridge, 0); |
| } |
| |
| void pci_early_bridge_init(void) |
| { |
| /* No PCI-to-PCI bridges are enabled yet, so the one we try to |
| * configure must have its primary on bus 0. |
| */ |
| pci_devfn_t p2p_bridge = PCI_DEV(0, CONFIG_EARLY_PCI_BRIDGE_DEVICE, |
| CONFIG_EARLY_PCI_BRIDGE_FUNCTION); |
| |
| pci_s_early_mmio_window(p2p_bridge, CONFIG_EARLY_PCI_MMIO_BASE, 0x4000); |
| } |
| |
| /* FIXME: A lot of issues using the following, please avoid. |
| * Assumes 256 PCI buses, scans them all even when PCI bridges are still |
| * disabled. Probes all functions even if 0 is not present. |
| */ |
| pci_devfn_t pci_locate_device(unsigned int pci_id, pci_devfn_t dev) |
| { |
| for (; dev <= PCI_DEV(255, 31, 7); dev += PCI_DEV(0, 0, 1)) { |
| unsigned int id; |
| id = pci_s_read_config32(dev, 0); |
| if (id == pci_id) |
| return dev; |
| } |
| return PCI_DEV_INVALID; |
| } |
| |
| pci_devfn_t pci_locate_device_on_bus(unsigned int pci_id, unsigned int bus) |
| { |
| pci_devfn_t dev, last; |
| |
| dev = PCI_DEV(bus, 0, 0); |
| last = PCI_DEV(bus, 31, 7); |
| |
| for (; dev <= last; dev += PCI_DEV(0, 0, 1)) { |
| unsigned int id; |
| id = pci_s_read_config32(dev, 0); |
| if (id == pci_id) |
| return dev; |
| } |
| return PCI_DEV_INVALID; |
| } |