From 2849752f36848359034616eb70dfc7fb14eb3cd4 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Thu, 6 Oct 2022 10:50:28 +0200 Subject: [PATCH] xen/pcifront: move xenstore config scanning into sub-function pcifront_try_connect() and pcifront_attach_devices() share a large chunk of duplicated code for reading the config information from Xenstore, which only differs regarding calling pcifront_rescan_root() or pcifront_scan_root(). Put that code into a new sub-function. It is fine to always call pcifront_rescan_root() from that common function, as it will fallback to pcifront_scan_root() if the domain/bus combination isn't known yet (and pcifront_scan_root() should never be called for an already known domain/bus combination anyway). In order to avoid duplicate messages for the fallback case move the check for domain/bus not known to the beginning of pcifront_rescan_root(). While at it fix the error reporting in case the root-xx node had the wrong format. As the return value of pcifront_try_connect() and pcifront_attach_devices() are not used anywhere make those functions return void. As an additional bonus this removes the dubious return of -EFAULT in case of an unexpected driver state. Signed-off-by: Juergen Gross Reviewed-by: Jason Andryuk Signed-off-by: Juergen Gross --- drivers/pci/xen-pcifront.c | 143 ++++++++++--------------------------- 1 file changed, 37 insertions(+), 106 deletions(-) diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c index 77e61b470121..7378e2f3e525 100644 --- a/drivers/pci/xen-pcifront.c +++ b/drivers/pci/xen-pcifront.c @@ -521,24 +521,14 @@ static int pcifront_rescan_root(struct pcifront_device *pdev, int err; struct pci_bus *b; -#ifndef CONFIG_PCI_DOMAINS - if (domain != 0) { - dev_err(&pdev->xdev->dev, - "PCI Root in non-zero PCI Domain! domain=%d\n", domain); - dev_err(&pdev->xdev->dev, - "Please compile with CONFIG_PCI_DOMAINS\n"); - return -EINVAL; - } -#endif - - dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n", - domain, bus); - b = pci_find_bus(domain, bus); if (!b) /* If the bus is unknown, create it. */ return pcifront_scan_root(pdev, domain, bus); + dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n", + domain, bus); + err = pcifront_scan_bus(pdev, domain, bus, b); /* Claim resources before going "live" with our devices */ @@ -819,76 +809,73 @@ out: return err; } -static int pcifront_try_connect(struct pcifront_device *pdev) +static void pcifront_connect(struct pcifront_device *pdev) { - int err = -EFAULT; + int err; int i, num_roots, len; char str[64]; unsigned int domain, bus; - - /* Only connect once */ - if (xenbus_read_driver_state(pdev->xdev->nodename) != - XenbusStateInitialised) - goto out; - - err = pcifront_connect_and_init_dma(pdev); - if (err && err != -EEXIST) { - xenbus_dev_fatal(pdev->xdev, err, - "Error setting up PCI Frontend"); - goto out; - } - err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "root_num", "%d", &num_roots); if (err == -ENOENT) { xenbus_dev_error(pdev->xdev, err, "No PCI Roots found, trying 0000:00"); - err = pcifront_scan_root(pdev, 0, 0); + err = pcifront_rescan_root(pdev, 0, 0); if (err) { xenbus_dev_fatal(pdev->xdev, err, "Error scanning PCI root 0000:00"); - goto out; + return; } num_roots = 0; } else if (err != 1) { - if (err == 0) - err = -EINVAL; - xenbus_dev_fatal(pdev->xdev, err, + xenbus_dev_fatal(pdev->xdev, err >= 0 ? -EINVAL : err, "Error reading number of PCI roots"); - goto out; + return; } for (i = 0; i < num_roots; i++) { len = snprintf(str, sizeof(str), "root-%d", i); - if (unlikely(len >= (sizeof(str) - 1))) { - err = -ENOMEM; - goto out; - } + if (unlikely(len >= (sizeof(str) - 1))) + return; err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, "%x:%x", &domain, &bus); if (err != 2) { - if (err >= 0) - err = -EINVAL; - xenbus_dev_fatal(pdev->xdev, err, + xenbus_dev_fatal(pdev->xdev, err >= 0 ? -EINVAL : err, "Error reading PCI root %d", i); - goto out; + return; } - err = pcifront_scan_root(pdev, domain, bus); + err = pcifront_rescan_root(pdev, domain, bus); if (err) { xenbus_dev_fatal(pdev->xdev, err, "Error scanning PCI root %04x:%02x", domain, bus); - goto out; + return; } } - err = xenbus_switch_state(pdev->xdev, XenbusStateConnected); + xenbus_switch_state(pdev->xdev, XenbusStateConnected); +} -out: - return err; +static void pcifront_try_connect(struct pcifront_device *pdev) +{ + int err; + + /* Only connect once */ + if (xenbus_read_driver_state(pdev->xdev->nodename) != + XenbusStateInitialised) + return; + + err = pcifront_connect_and_init_dma(pdev); + if (err && err != -EEXIST) { + xenbus_dev_fatal(pdev->xdev, err, + "Error setting up PCI Frontend"); + return; + } + + pcifront_connect(pdev); } static int pcifront_try_disconnect(struct pcifront_device *pdev) @@ -914,67 +901,11 @@ out: return err; } -static int pcifront_attach_devices(struct pcifront_device *pdev) +static void pcifront_attach_devices(struct pcifront_device *pdev) { - int err = -EFAULT; - int i, num_roots, len; - unsigned int domain, bus; - char str[64]; - - if (xenbus_read_driver_state(pdev->xdev->nodename) != + if (xenbus_read_driver_state(pdev->xdev->nodename) == XenbusStateReconfiguring) - goto out; - - err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, - "root_num", "%d", &num_roots); - if (err == -ENOENT) { - xenbus_dev_error(pdev->xdev, err, - "No PCI Roots found, trying 0000:00"); - err = pcifront_rescan_root(pdev, 0, 0); - if (err) { - xenbus_dev_fatal(pdev->xdev, err, - "Error scanning PCI root 0000:00"); - goto out; - } - num_roots = 0; - } else if (err != 1) { - if (err == 0) - err = -EINVAL; - xenbus_dev_fatal(pdev->xdev, err, - "Error reading number of PCI roots"); - goto out; - } - - for (i = 0; i < num_roots; i++) { - len = snprintf(str, sizeof(str), "root-%d", i); - if (unlikely(len >= (sizeof(str) - 1))) { - err = -ENOMEM; - goto out; - } - - err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, - "%x:%x", &domain, &bus); - if (err != 2) { - if (err >= 0) - err = -EINVAL; - xenbus_dev_fatal(pdev->xdev, err, - "Error reading PCI root %d", i); - goto out; - } - - err = pcifront_rescan_root(pdev, domain, bus); - if (err) { - xenbus_dev_fatal(pdev->xdev, err, - "Error scanning PCI root %04x:%02x", - domain, bus); - goto out; - } - } - - xenbus_switch_state(pdev->xdev, XenbusStateConnected); - -out: - return err; + pcifront_connect(pdev); } static int pcifront_detach_devices(struct pcifront_device *pdev)