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
kneon domain/bus combination anyway). In order to avoid duplicate
messages for the fallback case move the check for domain/bus not knwon
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 <[email protected]>
---
V2:
- always call pcifront_rescan_root() (Jason Andryuk)
---
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 689271c4245c..601efdceae63 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 @@ 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)
{
- 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 @@ 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);
}
static int pcifront_detach_devices(struct pcifront_device *pdev)
--
2.35.3
On Thu, Oct 6, 2022 at 11:35 AM Juergen Gross <[email protected]> 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 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
> kneon domain/bus combination anyway). In order to avoid duplicate
known
> messages for the fallback case move the check for domain/bus not knwon
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 <[email protected]>
Reviewed-by: Jason Andryuk <[email protected]>