[PATCH v1 1/2] x86/pci: Improve pci_mmcfg_{read,write} error handling

["Teddy Astie" <teddy.astie@xxxxxxxxxx>]

Return -ENODEV in case no mmcfg information is available instead of -EINVAL,
that is also returned when the parameters are incorrect.

It helps us distinguish between incorrect usage and no MMCFG support.

Signed-off-by: Teddy Astie <teddy.astie@xxxxxxxxxx>
---
 xen/arch/x86/x86_64/mmconfig_64.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/xen/arch/x86/x86_64/mmconfig_64.c 
b/xen/arch/x86/x86_64/mmconfig_64.c
index ffdc62700d..1a2803d2a3 100644
--- a/xen/arch/x86/x86_64/mmconfig_64.c
+++ b/xen/arch/x86/x86_64/mmconfig_64.c
@@ -60,15 +60,15 @@ int pci_mmcfg_read(unsigned int seg, unsigned int bus,
 {
     char __iomem *addr;
 
+    *value = -1;
+
     /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
-    if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {
-err:        *value = -1;
+    if ( unlikely((bus > 255) || (devfn > 255) || (reg > 4095)) )
         return -EINVAL;
-    }
 
     addr = pci_dev_base(seg, bus, devfn);
     if (!addr)
-        goto err;
+        return -ENODEV;
 
     switch (len) {
     case 1:
@@ -96,7 +96,7 @@ int pci_mmcfg_write(unsigned int seg, unsigned int bus,
 
     addr = pci_dev_base(seg, bus, devfn);
     if (!addr)
-        return -EINVAL;
+        return -ENODEV;
 
     switch (len) {
     case 1:
-- 
2.52.0



--
Teddy Astie | Vates XCP-ng Developer

XCP-ng & Xen Orchestra - Vates solutions

web: https://vates.tech