x86/PCI: use RCU list to protect mmconfig list
Use RCU list to protect mmconfig list from dynamic change
when supporting PCI host bridge hotplug.
Reviewed-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
index 915a493..acc48c5 100644
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -9,6 +9,7 @@
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/bitmap.h>
+#include <linux/rcupdate.h>
#include <asm/e820.h>
#include <asm/pci_x86.h>
@@ -34,9 +35,12 @@
return -EINVAL;
}
+ rcu_read_lock();
addr = pci_dev_base(seg, bus, devfn);
- if (!addr)
+ if (!addr) {
+ rcu_read_unlock();
goto err;
+ }
switch (len) {
case 1:
@@ -49,6 +53,7 @@
*value = mmio_config_readl(addr + reg);
break;
}
+ rcu_read_unlock();
return 0;
}
@@ -62,9 +67,12 @@
if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
return -EINVAL;
+ rcu_read_lock();
addr = pci_dev_base(seg, bus, devfn);
- if (!addr)
+ if (!addr) {
+ rcu_read_unlock();
return -EINVAL;
+ }
switch (len) {
case 1:
@@ -77,6 +85,7 @@
mmio_config_writel(addr + reg, value);
break;
}
+ rcu_read_unlock();
return 0;
}