Merge tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from David Vrabel:
 "Features and fixes for 4.8-rc0:

   - ACPI support for guests on ARM platforms.
   - Generic steal time support for arm and x86.
   - Support cases where kernel cpu is not Xen VCPU number (e.g., if
     in-guest kexec is used).
   - Use the system workqueue instead of a custom workqueue in various
     places"

* tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (47 commits)
  xen: add static initialization of steal_clock op to xen_time_ops
  xen/pvhvm: run xen_vcpu_setup() for the boot CPU
  xen/evtchn: use xen_vcpu_id mapping
  xen/events: fifo: use xen_vcpu_id mapping
  xen/events: use xen_vcpu_id mapping in events_base
  x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to shared_info
  x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_op
  xen: introduce xen_vcpu_id mapping
  x86/acpi: store ACPI ids from MADT for future usage
  x86/xen: update cpuid.h from Xen-4.7
  xen/evtchn: add IOCTL_EVTCHN_RESTRICT
  xen-blkback: really don't leak mode property
  xen-blkback: constify instance of "struct attribute_group"
  xen-blkfront: prefer xenbus_scanf() over xenbus_gather()
  xen-blkback: prefer xenbus_scanf() over xenbus_gather()
  xen: support runqueue steal time on xen
  arm/xen: add support for vm_assist hypercall
  xen: update xen headers
  xen-pciback: drop superfluous variables
  xen-pciback: short-circuit read path used for merging write values
  ...

1 files changed, 8 insertions, 14 deletions

diff --git a/drivers/xen/xen-pciback/conf_space.c b/drivers/xen/xen-pciback/conf_space.c
index 6a25533da237..9e9286d0872e 100644
--- a/drivers/xen/xen-pciback/conf_space.c
+++ b/drivers/xen/xen-pciback/conf_space.c
@@ -148,7 +148,7 @@ int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size,
 	struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
 	const struct config_field_entry *cfg_entry;
 	const struct config_field *field;
-	int req_start, req_end, field_start, field_end;
+	int field_start, field_end;
 	/* if read fails for any reason, return 0
 	 * (as if device didn't respond) */
 	u32 value = 0, tmp_val;
@@ -178,12 +178,10 @@ int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size,
 	list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
 		field = cfg_entry->field;
 
-		req_start = offset;
-		req_end = offset + size;
 		field_start = OFFSET(cfg_entry);
 		field_end = OFFSET(cfg_entry) + field->size;
 
-		 if (req_end > field_start && field_end > req_start) {
+		if (offset + size > field_start && field_end > offset) {
 			err = conf_space_read(dev, cfg_entry, field_start,
 					      &tmp_val);
 			if (err)
@@ -191,7 +189,7 @@ int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size,
 
 			value = merge_value(value, tmp_val,
 					    get_mask(field->size),
-					    field_start - req_start);
+					    field_start - offset);
 		}
 	}
 
@@ -211,7 +209,7 @@ int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value)
 	const struct config_field_entry *cfg_entry;
 	const struct config_field *field;
 	u32 tmp_val;
-	int req_start, req_end, field_start, field_end;
+	int field_start, field_end;
 
 	if (unlikely(verbose_request))
 		printk(KERN_DEBUG
@@ -224,21 +222,17 @@ int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value)
 	list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
 		field = cfg_entry->field;
 
-		req_start = offset;
-		req_end = offset + size;
 		field_start = OFFSET(cfg_entry);
 		field_end = OFFSET(cfg_entry) + field->size;
 
-		 if (req_end > field_start && field_end > req_start) {
-			tmp_val = 0;
-
-			err = xen_pcibk_config_read(dev, field_start,
-						  field->size, &tmp_val);
+		if (offset + size > field_start && field_end > offset) {
+			err = conf_space_read(dev, cfg_entry, field_start,
+					      &tmp_val);
 			if (err)
 				break;
 
 			tmp_val = merge_value(tmp_val, value, get_mask(size),
-					      req_start - field_start);
+					      offset - field_start);
 
 			err = conf_space_write(dev, cfg_entry, field_start,
 					       tmp_val);