[PATCH v5 12/12] xen/arm: Suspend/resume IOMMU on Xen suspend/resume

[Mykola Kvach <xakep.amatop@xxxxxxxxx>]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

This is done using generic iommu_suspend/resume functions that cause
IOMMU driver specific suspend/resume handlers to be called for enabled
IOMMU (if one has suspend/resume driver handlers implemented).

These handlers work only when IPMMU-VMSA is used; otherwise,
we return an error during system suspend requests.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
Signed-off-by: Mykola Kvach <mykola_kvach@xxxxxxxx>
Tested-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
---
 xen/arch/arm/suspend.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/xen/arch/arm/suspend.c b/xen/arch/arm/suspend.c
index b5398e5ca6..cb86426ebd 100644
--- a/xen/arch/arm/suspend.c
+++ b/xen/arch/arm/suspend.c
@@ -4,6 +4,7 @@
 #include <asm/suspend.h>
 #include <xen/console.h>
 #include <xen/cpu.h>
+#include <xen/iommu.h>
 #include <xen/llc-coloring.h>
 #include <xen/sched.h>
 
@@ -49,6 +50,13 @@ static long system_suspend(void *data)
 
     time_suspend();
 
+    status = iommu_suspend();
+    if ( status )
+    {
+        system_state = SYS_STATE_resume;
+        goto resume_time;
+    }
+
     local_irq_save(flags);
     status = gic_suspend();
     if ( status )
@@ -105,6 +113,10 @@ static long system_suspend(void *data)
 
  resume_irqs:
     local_irq_restore(flags);
+
+    iommu_resume();
+
+ resume_time:
     time_resume();
 
  resume_nonboot_cpus:
@@ -140,6 +152,15 @@ int host_system_suspend(void)
         return -ENOSYS;
     }
 
+    /* TODO: drop check once suspend/resume support for SMMU is implemented */
+#ifndef CONFIG_IPMMU_VMSA
+    if ( iommu_enabled )
+    {
+        dprintk(XENLOG_ERR, "IOMMU is enabled, suspend not supported yet\n");
+        return -ENOSYS;
+    }
+#endif
+
     /*
      * system_suspend should be called when Dom0 finalizes the suspend
      * procedure from its boot core (VCPU#0). However, Dom0's VCPU#0 could
-- 
2.48.1