| Message ID | 20221006092929.30041-1-jgross@suse.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xen/pcifront: move xenstore config scanning into sub-function | expand |
On Thu, Oct 6, 2022 at 5:29 AM Juergen Gross <jgross@suse.com> wrote: > > 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 a function call. > > Put that code into a new sub-function. 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 <jgross@suse.com> > --- > drivers/pci/xen-pcifront.c | 133 +++++++++++-------------------------- > 1 file changed, 40 insertions(+), 93 deletions(-) > > diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c > index 689271c4245c..a68e47dcdd7e 100644 > --- a/drivers/pci/xen-pcifront.c > +++ b/drivers/pci/xen-pcifront.c > @@ -819,76 +819,79 @@ static int pcifront_publish_info(struct pcifront_device *pdev) > 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); > + if (rescan) > + err = pcifront_rescan_root(pdev, 0, 0); > + else > + err = pcifront_scan_root(pdev, 0, 0); Early in pcifront_rescan_root(), we have: b = pci_find_bus(domain, bus); if (!b) /* If the bus is unknown, create it. */ return pcifront_scan_root(pdev, domain, bus); pcifront_scan_root() does some allocation, but the later scanning matches that of pcifront_rescan_root(). So I think we can just always call pcifront_rescan_root() and it should do the right thing. That drops the need for the rescan boolean. Regardless of the above idea: Reviewed-by: Jason Andryuk <jandryuk@gmail.com> Regards, Jason
On 06.10.22 15:29, Jason Andryuk wrote: > On Thu, Oct 6, 2022 at 5:29 AM Juergen Gross <jgross@suse.com> wrote: >> >> 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 a function call. >> >> Put that code into a new sub-function. 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 <jgross@suse.com> >> --- >> drivers/pci/xen-pcifront.c | 133 +++++++++++-------------------------- >> 1 file changed, 40 insertions(+), 93 deletions(-) >> >> diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c >> index 689271c4245c..a68e47dcdd7e 100644 >> --- a/drivers/pci/xen-pcifront.c >> +++ b/drivers/pci/xen-pcifront.c >> @@ -819,76 +819,79 @@ static int pcifront_publish_info(struct pcifront_device *pdev) > >> 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); >> + if (rescan) >> + err = pcifront_rescan_root(pdev, 0, 0); >> + else >> + err = pcifront_scan_root(pdev, 0, 0); > > Early in pcifront_rescan_root(), we have: > > b = pci_find_bus(domain, bus); > if (!b) > /* If the bus is unknown, create it. */ > return pcifront_scan_root(pdev, domain, bus); > > pcifront_scan_root() does some allocation, but the later scanning > matches that of pcifront_rescan_root(). So I think we can just always > call pcifront_rescan_root() and it should do the right thing. That > drops the need for the rescan boolean. Hmm, with some more pcifront_rescan_root() adaption this will make it possible to drop even more code (i.e. the CONFIG_PCI_DOMAINS check in pcifront_rescan_root(), as the one in pcifront_scan_root() would be enough then). I'll send out V2 soon. > > Regardless of the above idea: > > Reviewed-by: Jason Andryuk <jandryuk@gmail.com> Thanks. As I'm about to change the patch, I'll drop the R-b. Juergen
diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c index 689271c4245c..a68e47dcdd7e 100644 --- a/drivers/pci/xen-pcifront.c +++ b/drivers/pci/xen-pcifront.c @@ -819,76 +819,79 @@ static int pcifront_publish_info(struct pcifront_device *pdev) return err; } -static int pcifront_try_connect(struct pcifront_device *pdev) +static void pcifront_connect(struct pcifront_device *pdev, bool rescan) { - 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); + if (rescan) + err = pcifront_rescan_root(pdev, 0, 0); + else + err = pcifront_scan_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); + if (rescan) + err = pcifront_rescan_root(pdev, domain, bus); + else + err = pcifront_scan_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, false); } static int pcifront_try_disconnect(struct pcifront_device *pdev) @@ -914,67 +917,11 @@ static int pcifront_try_disconnect(struct pcifront_device *pdev) 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, true); } static int pcifront_detach_devices(struct pcifront_device *pdev)
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 a function call. Put that code into a new sub-function. 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 <jgross@suse.com> --- drivers/pci/xen-pcifront.c | 133 +++++++++++-------------------------- 1 file changed, 40 insertions(+), 93 deletions(-)