IOMMU: add crash_shutdown iommu_op

The kdump kernel has problems booting with interrupt/dma
remapping enabled, so we need a new iommu_ops called
crash_shutdown which is basically suspend but doesn't
need to bother saving state.

We make sure that crash_shutdown is called on the kexec
path.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

diff -r 09344e4f7cde xen/arch/x86/crash.c
--- a/xen/arch/x86/crash.c	Thu May 26 16:51:35 2011 +0100
+++ b/xen/arch/x86/crash.c	Thu May 26 17:00:40 2011 +0100
@@ -89,6 +89,10 @@ void machine_crash_shutdown(void)
 
     nmi_shootdown_cpus();
 
+    /* Crash shutdown any IOMMU functionality as the crashdump kernel is not
+     * happy when booting if interrupt/dma remapping is still enabled */
+    iommu_crash_shutdown();
+
     info = kexec_crash_save_info();
     info->xen_phys_start = xen_phys_start;
     info->dom0_pfn_to_mfn_frame_list_list =
diff -r 09344e4f7cde xen/drivers/passthrough/amd/iommu_init.c
--- a/xen/drivers/passthrough/amd/iommu_init.c	Thu May 26 16:51:35 2011 +0100
+++ b/xen/drivers/passthrough/amd/iommu_init.c	Thu May 26 17:00:40 2011 +0100
@@ -923,6 +923,14 @@ void amd_iommu_suspend(void)
         disable_iommu(iommu);
 }
 
+void amd_iommu_crash_shutdown(void)
+{
+    struct amd_iommu *iommu;
+
+    for_each_amd_iommu ( iommu )
+        disable_iommu(iommu);
+}
+
 void amd_iommu_resume(void)
 {
     struct amd_iommu *iommu;
diff -r 09344e4f7cde xen/drivers/passthrough/amd/pci_amd_iommu.c
--- a/xen/drivers/passthrough/amd/pci_amd_iommu.c	Thu May 26 16:51:35 2011 +0100
+++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c	Thu May 26 17:00:40 2011 +0100
@@ -455,4 +455,5 @@ const struct iommu_ops amd_iommu_ops = {
     .read_msi_from_ire = amd_iommu_read_msi_from_ire,
     .suspend = amd_iommu_suspend,
     .resume = amd_iommu_resume,
+    .crash_shutdown = amd_iommu_crash_shutdown,
 };
diff -r 09344e4f7cde xen/drivers/passthrough/iommu.c
--- a/xen/drivers/passthrough/iommu.c	Thu May 26 16:51:35 2011 +0100
+++ b/xen/drivers/passthrough/iommu.c	Thu May 26 17:00:40 2011 +0100
@@ -419,6 +419,15 @@ void iommu_suspend(void)
         ops->suspend();
 }
 
+void iommu_crash_shutdown(void)
+{
+    const struct iommu_ops *ops = iommu_get_ops();
+    if ( ops && ops->crash_shutdown )
+        ops->crash_shutdown();
+}
+
+
+
 /*
  * Local variables:
  * mode: C
diff -r 09344e4f7cde xen/drivers/passthrough/vtd/iommu.c
--- a/xen/drivers/passthrough/vtd/iommu.c	Thu May 26 16:51:35 2011 +0100
+++ b/xen/drivers/passthrough/vtd/iommu.c	Thu May 26 17:00:40 2011 +0100
@@ -2261,6 +2261,25 @@ static void vtd_suspend(void)
     }
 }
 
+static void vtd_crash_shutdown(void)
+{
+    struct acpi_drhd_unit *drhd;
+    struct iommu *iommu;
+
+    if ( !iommu_enabled )
+        return;
+
+    iommu_flush_all();
+
+    for_each_drhd_unit ( drhd )
+    {
+        iommu = drhd->iommu;
+        iommu_disable_translation(iommu);
+    }
+
+    iommu_disable_IR();
+}
+
 static void vtd_resume(void)
 {
     struct acpi_drhd_unit *drhd;
@@ -2311,6 +2330,7 @@ const struct iommu_ops intel_iommu_ops =
     .read_msi_from_ire = msi_msg_read_remap_rte,
     .suspend = vtd_suspend,
     .resume = vtd_resume,
+    .crash_shutdown = vtd_crash_shutdown,
 };
 
 /*
diff -r 09344e4f7cde xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
--- a/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h	Thu May 26 16:51:35 2011 +0100
+++ b/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h	Thu May 26 17:00:40 2011 +0100
@@ -91,6 +91,7 @@ unsigned int amd_iommu_read_ioapic_from_
 /* power management support */
 void amd_iommu_resume(void);
 void amd_iommu_suspend(void);
+void amd_iommu_crash_shutdown(void);
 
 static inline u32 get_field_from_reg_u32(u32 reg_value, u32 mask, u32 shift)
 {
diff -r 09344e4f7cde xen/include/xen/iommu.h
--- a/xen/include/xen/iommu.h	Thu May 26 16:51:35 2011 +0100
+++ b/xen/include/xen/iommu.h	Thu May 26 17:00:40 2011 +0100
@@ -133,6 +133,7 @@ struct iommu_ops {
     unsigned int (*read_apic_from_ire)(unsigned int apic, unsigned int reg);
     void (*suspend)(void);
     void (*resume)(void);
+    void (*crash_shutdown)(void);
 };
 
 void iommu_update_ire_from_apic(unsigned int apic, unsigned int reg, unsigned int value);
@@ -142,6 +143,7 @@ unsigned int iommu_read_apic_from_ire(un
 
 void iommu_suspend(void);
 void iommu_resume(void);
+void iommu_crash_shutdown(void);
 
 void iommu_set_dom0_mapping(struct domain *d);