/* SPDX-License-Identifier: GPL-2.0-only */ #include #include #include #include #include #include #include struct ht_link { struct device *dev; unsigned int pos; unsigned char ctrl_off, config_off, freq_off, freq_cap_off; }; static struct device *ht_scan_get_devs(struct device **old_devices) { struct device *first, *last; first = *old_devices; last = first; /* * Extract the chain of devices to (first through last) for the next * hypertransport device. */ while (last && last->sibling && (last->sibling->path.type == DEVICE_PATH_PCI) && (last->sibling->path.pci.devfn > last->path.pci.devfn)) { last = last->sibling; } if (first) { struct device *child; /* Unlink the chain from the list of old devices. */ *old_devices = last->sibling; last->sibling = 0; /* Now add the device to the list of devices on the bus. */ /* Find the last child of our parent. */ for (child = first->bus->children; child && child->sibling;) child = child->sibling; /* Place the chain on the list of children of their parent. */ if (child) child->sibling = first; else first->bus->children = first; } return first; } static int ht_setup_link(struct ht_link *prev, struct device *dev, unsigned int pos) { struct ht_link cur[1]; int linkb_to_host; /* Set the hypertransport link width and frequency. */ /* * See which side of the device our previous write to set the unitid * came from. */ cur->dev = dev; cur->pos = pos; linkb_to_host = (pci_read_config16(cur->dev, cur->pos + PCI_CAP_FLAGS) >> 10) & 1; if (!linkb_to_host) { cur->ctrl_off = PCI_HT_CAP_SLAVE_CTRL0; cur->config_off = PCI_HT_CAP_SLAVE_WIDTH0; cur->freq_off = PCI_HT_CAP_SLAVE_FREQ0; cur->freq_cap_off = PCI_HT_CAP_SLAVE_FREQ_CAP0; } else { cur->ctrl_off = PCI_HT_CAP_SLAVE_CTRL1; cur->config_off = PCI_HT_CAP_SLAVE_WIDTH1; cur->freq_off = PCI_HT_CAP_SLAVE_FREQ1; cur->freq_cap_off = PCI_HT_CAP_SLAVE_FREQ_CAP1; } /* * Remember the current link as the previous link, but look at the * other offsets. */ prev->dev = cur->dev; prev->pos = cur->pos; if (cur->ctrl_off == PCI_HT_CAP_SLAVE_CTRL0) { prev->ctrl_off = PCI_HT_CAP_SLAVE_CTRL1; prev->config_off = PCI_HT_CAP_SLAVE_WIDTH1; prev->freq_off = PCI_HT_CAP_SLAVE_FREQ1; prev->freq_cap_off = PCI_HT_CAP_SLAVE_FREQ_CAP1; } else { prev->ctrl_off = PCI_HT_CAP_SLAVE_CTRL0; prev->config_off = PCI_HT_CAP_SLAVE_WIDTH0; prev->freq_off = PCI_HT_CAP_SLAVE_FREQ0; prev->freq_cap_off = PCI_HT_CAP_SLAVE_FREQ_CAP0; } return 0; } static unsigned int ht_lookup_slave_capability(struct device *dev) { unsigned int pos; pos = 0; do { pos = pci_find_next_capability(dev, PCI_CAP_ID_HT, pos); if (pos) { u16 flags; flags = pci_read_config16(dev, pos + PCI_CAP_FLAGS); printk(BIOS_SPEW, "flags: 0x%04x\n", flags); if ((flags >> 13) == 0) { /* Entry is a slave secondary, success... */ break; } } } while (pos); return pos; } static void ht_collapse_early_enumeration(struct bus *bus, unsigned int offset_unitid) { unsigned int devfn; struct ht_link prev; u16 ctrl; /* Initialize the hypertransport enumeration state. */ prev.dev = bus->dev; prev.pos = bus->cap; prev.ctrl_off = PCI_HT_CAP_HOST_CTRL; prev.config_off = PCI_HT_CAP_HOST_WIDTH; prev.freq_off = PCI_HT_CAP_HOST_FREQ; prev.freq_cap_off = PCI_HT_CAP_HOST_FREQ_CAP; /* Wait until the link initialization is complete. */ do { ctrl = pci_read_config16(prev.dev, prev.pos + prev.ctrl_off); /* Is this the end of the hypertransport chain? */ if (ctrl & (1 << 6)) return; /* Has the link failed? */ if (ctrl & (1 << 4)) { /* * Either the link has failed, or we have a CRC error. * Sometimes this can happen due to link retrain, so * lets knock it down and see if its transient. */ ctrl |= ((1 << 4) | (1 << 8)); /* Link fail + CRC */ pci_write_config16(prev.dev, prev.pos + prev.ctrl_off, ctrl); ctrl = pci_read_config16(prev.dev, prev.pos + prev.ctrl_off); if (ctrl & ((1 << 4) | (1 << 8))) { printk(BIOS_ALERT, "Detected error on " "Hypertransport link\n"); return; } } } while ((ctrl & (1 << 5)) == 0); /* Actually, only for one HT device HT chain, and unitid is 0. */ #if !CONFIG_HT_CHAIN_UNITID_BASE if (offset_unitid) return; #endif /* Check if is already collapsed. */ if ((!offset_unitid) || (offset_unitid && (!((CONFIG_HT_CHAIN_END_UNITID_BASE == 0) && (CONFIG_HT_CHAIN_END_UNITID_BASE < CONFIG_HT_CHAIN_UNITID_BASE))))) { struct device dummy; u32 id; dummy.bus = bus; dummy.path.type = DEVICE_PATH_PCI; dummy.path.pci.devfn = PCI_DEVFN(0, 0); id = pci_read_config32(&dummy, PCI_VENDOR_ID); if (!((id == 0xffffffff) || (id == 0x00000000) || (id == 0x0000ffff) || (id == 0xffff0000))) { return; } } /* Spin through the devices and collapse any early HT enumeration. */ for (devfn = PCI_DEVFN(1, 0); devfn <= 0xff; devfn += 8) { struct device dummy; u32 id; unsigned int pos, flags; dummy.bus = bus; dummy.path.type = DEVICE_PATH_PCI; dummy.path.pci.devfn = devfn; id = pci_read_config32(&dummy, PCI_VENDOR_ID); if ((id == 0xffffffff) || (id == 0x00000000) || (id == 0x0000ffff) || (id == 0xffff0000)) { continue; } dummy.vendor = id & 0xffff; dummy.device = (id >> 16) & 0xffff; dummy.hdr_type = pci_read_config8(&dummy, PCI_HEADER_TYPE); pos = ht_lookup_slave_capability(&dummy); if (!pos) continue; /* Clear the unitid. */ flags = pci_read_config16(&dummy, pos + PCI_CAP_FLAGS); flags &= ~0x1f; pci_write_config16(&dummy, pos + PCI_CAP_FLAGS, flags); printk(BIOS_SPEW, "Collapsing %s [%04x/%04x]\n", dev_path(&dummy), dummy.vendor, dummy.device); } } static unsigned int do_hypertransport_scan_chain(struct bus *bus, unsigned int min_devfn, unsigned int max_devfn, unsigned int *ht_unitid_base, unsigned int offset_unitid) { /* * Even CONFIG_HT_CHAIN_UNITID_BASE == 0, we still can go through this * function, because of end_of_chain check. Also, we need it to * optimize link. */ unsigned int next_unitid, last_unitid, min_unitid, max_unitid; struct device *old_devices, *dev, *func, *last_func = NULL; struct ht_link prev; int ht_dev_num = 0; printk(BIOS_SPEW, "%s for bus %02x\n", __func__, bus->secondary); min_unitid = (offset_unitid) ? CONFIG_HT_CHAIN_UNITID_BASE : 1; #if CONFIG_HT_CHAIN_END_UNITID_BASE != 0x20 /* * Let's record the device of last HT device, so we can set the unitid * to CONFIG_HT_CHAIN_END_UNITID_BASE. */ unsigned int real_last_unitid = 0, end_used = 0; u8 real_last_pos = 0; struct device *real_last_dev = NULL; #endif /* Restore the hypertransport chain to it's uninitialized state. */ ht_collapse_early_enumeration(bus, offset_unitid); /* See which static device nodes I have. */ old_devices = bus->children; bus->children = 0; /* Initialize the hypertransport enumeration state. */ prev.dev = bus->dev; prev.pos = bus->cap; prev.ctrl_off = PCI_HT_CAP_HOST_CTRL; prev.config_off = PCI_HT_CAP_HOST_WIDTH; prev.freq_off = PCI_HT_CAP_HOST_FREQ; prev.freq_cap_off = PCI_HT_CAP_HOST_FREQ_CAP; /* If present, assign unitid to a hypertransport chain. */ max_unitid = next_unitid = min_unitid; do { u8 pos; u16 flags, ctrl; unsigned int count, static_count; last_unitid = next_unitid; /* Wait until the link initialization is complete. */ do { ctrl = pci_read_config16(prev.dev, prev.pos + prev.ctrl_off); /* End of chain? */ if (ctrl & (1 << 6)) goto end_of_chain; if (ctrl & ((1 << 4) | (1 << 8))) { /* * Either the link has failed, or we have a CRC * error. Sometimes this can happen due to link * retrain, so lets knock it down and see if * it's transient. */ ctrl |= ((1 << 4) | (1 <<8)); // Link fail + CRC pci_write_config16(prev.dev, prev.pos + prev.ctrl_off, ctrl); ctrl = pci_read_config16(prev.dev, prev.pos + prev.ctrl_off); if (ctrl & ((1 << 4) | (1 << 8))) { printk(BIOS_ALERT, "Detected error on " "hypertransport link\n"); goto end_of_chain; } } } while ((ctrl & (1 << 5)) == 0); /* Get and setup the device_structure. */ dev = ht_scan_get_devs(&old_devices); /* See if a device is present and setup the device structure. */ dev = pci_probe_dev(dev, bus, 0); if (!dev || !dev->enabled) break; /* Find the hypertransport link capability. */ pos = ht_lookup_slave_capability(dev); if (pos == 0) { printk(BIOS_ERR, "%s Hypertransport link capability " "not found", dev_path(dev)); break; } /* Update the unitid of the current device. */ flags = pci_read_config16(dev, pos + PCI_CAP_FLAGS); /* * If the device has a unitid set and is at devfn 0 we are * done. This can happen with shadow hypertransport devices, * or if we have reached the bottom of a HT device chain. */ if (flags & 0x1f) break; flags &= ~0x1f; /* Mask out base Unit ID. */ count = (flags >> 5) & 0x1f; /* Het unit count. */ #if CONFIG_HT_CHAIN_END_UNITID_BASE != 0x20 if (offset_unitid) { /* max_devfn will be (0x17<<3)|7 or (0x1f<<3)|7. */ if (next_unitid > (max_devfn >> 3)) { if (!end_used) { next_unitid = CONFIG_HT_CHAIN_END_UNITID_BASE; end_used = 1; } else { goto end_of_chain; } } } #endif flags |= next_unitid & 0x1f; pci_write_config16(dev, pos + PCI_CAP_FLAGS, flags); /* Update the unitid in the device structure. */ static_count = 1; for (func = dev; func; func = func->sibling) { func->path.pci.devfn += (next_unitid << 3); static_count = (func->path.pci.devfn >> 3) - (dev->path.pci.devfn >> 3) + 1; last_func = func; } /* Compute the number of unitids consumed. */ printk(BIOS_SPEW, "%s count: %04x static_count: %04x\n", dev_path(dev), count, static_count); if (count < static_count) count = static_count; /* Update the unitid of the next device. */ ht_unitid_base[ht_dev_num] = next_unitid; ht_dev_num++; #if CONFIG_HT_CHAIN_END_UNITID_BASE != 0x20 if (offset_unitid) { real_last_pos = pos; real_last_unitid = next_unitid; real_last_dev = dev; } #endif next_unitid += count; if (next_unitid > max_unitid) max_unitid = next_unitid; /* Setup the hypertransport link. */ bus->reset_needed |= ht_setup_link(&prev, dev, pos); printk(BIOS_DEBUG, "%s [%04x/%04x] %s next_unitid: %04x\n", dev_path(dev), dev->vendor, dev->device, (dev->enabled? "enabled" : "disabled"), next_unitid); } while (last_unitid != next_unitid); end_of_chain: #if CONFIG_HT_CHAIN_END_UNITID_BASE != 0x20 if (offset_unitid && (ht_dev_num > 1) && (real_last_unitid != CONFIG_HT_CHAIN_END_UNITID_BASE) && !end_used) { u16 flags; flags = pci_read_config16(real_last_dev, real_last_pos + PCI_CAP_FLAGS); flags &= ~0x1f; flags |= CONFIG_HT_CHAIN_END_UNITID_BASE & 0x1f; pci_write_config16(real_last_dev, real_last_pos + PCI_CAP_FLAGS, flags); for (func = real_last_dev; func; func = func->sibling) { func->path.pci.devfn -= ((real_last_unitid - CONFIG_HT_CHAIN_END_UNITID_BASE) << 3); last_func = func; } /* Update last one. */ ht_unitid_base[ht_dev_num-1] = CONFIG_HT_CHAIN_END_UNITID_BASE; printk(BIOS_DEBUG, " unitid: %04x --> %04x\n", real_last_unitid, CONFIG_HT_CHAIN_END_UNITID_BASE); } #endif next_unitid = max_unitid; if (next_unitid > 0x20) next_unitid = 0x20; if ((bus->secondary == 0) && (next_unitid > 0x18)) next_unitid = 0x18; /* Avoid K8 on bus 0. */ /* * Die if any leftover static devices are are found. There's probably * a problem in devicetree.cb. */ if (old_devices) { struct device *left; for (left = old_devices; left; left = left->sibling) printk(BIOS_DEBUG, "%s\n", dev_path(left)); printk(BIOS_ERR, "HT: Leftover static devices. " "Check your devicetree.cb\n"); /* * Put back the leftover static device, and let pci_scan_bus() * disable it. */ if (last_func && !last_func->sibling) last_func->sibling = old_devices; } return next_unitid; } /** * Scan a PCI bridge and the buses behind the bridge. * * Determine the existence of buses behind the bridge. Set up the bridge * according to the result of the scan. * * This function is the default scan_bus() method for PCI bridge devices. * * @param bus TODO * @param min_devfn TODO * @param max_devfn TODO */ static void hypertransport_scan_chain_x(struct bus *bus, unsigned int min_devfn, unsigned int max_devfn) { unsigned int ht_unitid_base[4]; unsigned int offset_unitid = 1; unsigned int next_unitid = do_hypertransport_scan_chain(bus, min_devfn, max_devfn, ht_unitid_base, offset_unitid); /* Now that nothing is overlapping it is safe to scan the children. */ pci_scan_bus(bus, 0x00, ((next_unitid - 1) << 3) | 7); } static void ht_scan_bridge(struct device *dev) { do_pci_scan_bridge(dev, hypertransport_scan_chain_x); } /** Default device operations for hypertransport bridges */ static struct pci_operations ht_bus_ops_pci = { .set_subsystem = 0, }; struct device_operations default_ht_ops_bus = { .read_resources = pci_bus_read_resources, .set_resources = pci_dev_set_resources, .enable_resources = pci_bus_enable_resources, .scan_bus = ht_scan_bridge, .reset_bus = pci_bus_reset, .ops_pci = &ht_bus_ops_pci, };