VT-d: cleanup ATS code

Rather than having per-architecture stubs when ATS support is not
implemented, simply provide inline functions in the common header for
that case.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

xen/drivers/passthrough/vtd/extern.h

@@ -24,7 +24,6 @@
 #include "dmar.h"
 #include <xen/keyhandler.h>
 
-extern bool_t ats_enabled;
 extern bool_t rwbf_quirk;
 
 void print_iommu_regs(struct acpi_drhd_unit *drhd);
@@ -56,17 +55,50 @@ struct iommu * ioapic_to_iommu(unsigned int apic_id);
 struct acpi_drhd_unit * ioapic_to_drhd(unsigned int apic_id);
 struct acpi_drhd_unit * iommu_to_drhd(struct iommu *iommu);
 struct acpi_rhsa_unit * drhd_to_rhsa(struct acpi_drhd_unit *drhd);
+
+#ifdef CONFIG_X86_64
+extern bool_t ats_enabled;
+
 struct acpi_drhd_unit * find_ats_dev_drhd(struct iommu *iommu);
 
 int ats_device(int seg, int bus, int devfn);
 int enable_ats_device(int seg, int bus, int devfn);
-int disable_ats_device(int seg, int bus, int devfn);
+void disable_ats_device(int seg, int bus, int devfn);
 int invalidate_ats_tcs(struct iommu *iommu);
 
+int dev_invalidate_iotlb(struct iommu *iommu, u16 did,
+                         u64 addr, unsigned int size_order, u64 type);
+#else
+#define ats_enabled 0
+
+static inline struct acpi_drhd_unit *find_ats_dev_drhd(struct iommu *iommu)
+{
+    return NULL;
+}
+
+static inline int ats_device(int seg, int bus, int devfn)
+{
+    return 0;
+}
+static inline int enable_ats_device(int seg, int bus, int devfn)
+{
+    BUG();
+    return -ENOSYS;
+}
+static inline void disable_ats_device(int seg, int bus, int devfn)
+{
+    BUG();
+}
+
+static inline int dev_invalidate_iotlb(struct iommu *iommu, u16 did, u64 addr,
+                                       unsigned int size_order, u64 type)
+{
+    return 0;
+}
+#endif
+
 int qinval_device_iotlb(struct iommu *iommu,
                         u32 max_invs_pend, u16 sid, u16 size, u64 addr);
-int dev_invalidate_iotlb(struct iommu *iommu, u16 did,
-                         u64 addr, unsigned int size_order, u64 type);
 
 unsigned int get_cache_line_size(void);
 void cacheline_flush(char *);

xen/drivers/passthrough/vtd/ia64/Makefile

@@ -1,2 +1 @@
 obj-y += vtd.o
-obj-y += ats.o

xen/drivers/passthrough/vtd/ia64/ats.c

@@ -1,59 +0,0 @@
-/*
- * Copyright (c) 2006, Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
- * Place - Suite 330, Boston, MA 02111-1307 USA.
- *
- * Author: Allen Kay <allen.m.kay@intel.com>
- */
-
-#include <xen/sched.h>
-#include <xen/iommu.h>
-#include <xen/time.h>
-#include <xen/pci.h>
-#include <xen/pci_regs.h>
-#include <asm/msi.h>
-#include "../iommu.h"
-#include "../dmar.h"
-#include "../vtd.h"
-#include "../extern.h"
-
-struct pci_ats_dev;
-
-bool_t __read_mostly ats_enabled = 0;
-
-struct acpi_drhd_unit * find_ats_dev_drhd(struct iommu *iommu)
-{
-    return NULL;
-}
-
-int ats_device(int seg, int bus, int devfn)
-{
-    return 0;
-}
-
-int enable_ats_device(int seg, int bus, int devfn)
-{
-    return 0;
-}
-
-int disable_ats_device(int seg, int bus, int devfn)
-{
-    return 0;
-}
-
-int dev_invalidate_iotlb(struct iommu *iommu, u16 did,
-    u64 addr, unsigned int size_order, u64 type)
-{
-    return 0;
-}

xen/drivers/passthrough/vtd/x86/Makefile

@@ -1,2 +1,2 @@
 obj-y += vtd.o
-obj-y += ats.o
+obj-$(CONFIG_X86_64) += ats.o

xen/drivers/passthrough/vtd/x86/ats.c

@@ -127,23 +127,11 @@ int enable_ats_device(int seg, int bus, int devfn)
     u32 value;
     int pos;
 
-    if ( !acpi_find_matched_atsr_unit(bus, devfn) )
-    {
-        dprintk(XENLOG_WARNING VTDPREFIX,
-                "cannot find matched atsr for %x:%x.%x\n",
-                bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
-        return 0;
-    }
-
     pos = pci_find_ext_capability(seg, bus, devfn, PCI_EXT_CAP_ID_ATS);
-    if ( !pos )
-    {
-        dprintk(XENLOG_ERR VTDPREFIX, "ats capability not found %x:%x.%x\n",
-                bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
-        return 0;
-    }
-    else
-        dprintk(XENLOG_ERR VTDPREFIX, "ats capability found %x:%x.%x\n",
+    BUG_ON(!pos);
+
+    if ( iommu_verbose )
+        dprintk(XENLOG_INFO VTDPREFIX, "%x:%x.%x: ATS capability found\n",
                 bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
 
     /* BUGBUG: add back seg when multi-seg platform support is enabled */
@@ -189,16 +177,14 @@ int enable_ats_device(int seg, int bus, int devfn)
     return pos;
 }
 
-int disable_ats_device(int seg, int bus, int devfn)
+void disable_ats_device(int seg, int bus, int devfn)
 {
-    struct list_head *pdev_list, *tmp;
     struct pci_ats_dev *pdev;
     u32 value;
     int pos;
 
     pos = pci_find_ext_capability(seg, bus, devfn, PCI_EXT_CAP_ID_ATS);
-    if ( !pos )
-        return 0;
+    BUG_ON(!pos);
 
     /* BUGBUG: add back seg when multi-seg platform support is enabled */
     value = pci_conf_read16(bus, PCI_SLOT(devfn),
@@ -207,9 +193,8 @@ int disable_ats_device(int seg, int bus, int devfn)
     pci_conf_write16(bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
                      pos + ATS_REG_CTL, value);
 
-    list_for_each_safe( pdev_list, tmp, &ats_devices )
+    list_for_each_entry ( pdev, &ats_devices, list )
     {
-        pdev = list_entry(pdev_list, struct pci_ats_dev, list);
         if ( pdev->bus == bus && pdev->devfn == devfn )
         {
             list_del(&pdev->list);
@@ -221,8 +206,6 @@ int disable_ats_device(int seg, int bus, int devfn)
     if ( iommu_verbose )
         dprintk(XENLOG_INFO VTDPREFIX, "%x:%x.%x: ATS is disabled\n",
                 bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
-
-    return 0;
 }
 
 
@@ -257,10 +240,7 @@ out:
     if ( ctxt_entry )
         unmap_vtd_domain_page(ctxt_entry);
 
-    if ( found )
-        return 1;
-
-    return 0;
+    return found;
 }
 
 int dev_invalidate_iotlb(struct iommu *iommu, u16 did,