[POWERPC] DART iommu suspend

This implements save and restore hooks for IOMMUs and implements
it the DART iommu.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
index 336186dd7f10..a1d2042bb304 100644
--- a/arch/powerpc/sysdev/dart_iommu.c
+++ b/arch/powerpc/sysdev/dart_iommu.c
@@ -36,6 +36,7 @@
 #include <linux/pci.h>
 #include <linux/dma-mapping.h>
 #include <linux/vmalloc.h>
+#include <linux/suspend.h>
 #include <asm/io.h>
 #include <asm/prom.h>
 #include <asm/iommu.h>
@@ -54,6 +55,9 @@ static unsigned long dart_tablesize;
 
 /* Virtual base address of the DART table */
 static u32 *dart_vbase;
+#ifdef CONFIG_PM
+static u32 *dart_copy;
+#endif
 
 /* Mapped base address for the dart */
 static unsigned int __iomem *dart;
@@ -346,6 +350,48 @@ void iommu_init_early_dart(void)
         set_pci_dma_ops(&dma_direct_ops);
 }
 
+#ifdef CONFIG_PM
+static void iommu_dart_save(void)
+{
+        memcpy(dart_copy, dart_vbase, 2*1024*1024);
+}
+
+static void iommu_dart_restore(void)
+{
+        memcpy(dart_vbase, dart_copy, 2*1024*1024);
+        dart_tlb_invalidate_all();
+}
+
+static int __init iommu_init_late_dart(void)
+{
+        unsigned long tbasepfn;
+        struct page *p;
+
+        /* if no dart table exists then we won't need to save it
+         * and the area has also not been reserved */
+        if (!dart_tablebase)
+                return 0;
+
+        tbasepfn = __pa(dart_tablebase) >> PAGE_SHIFT;
+        register_nosave_region_late(tbasepfn,
+                                    tbasepfn + ((1<<24) >> PAGE_SHIFT));
+
+        /* For suspend we need to copy the dart contents because
+         * it is not part of the regular mapping (see above) and
+         * thus not saved automatically. The memory for this copy
+         * must be allocated early because we need 2 MB. */
+        p = alloc_pages(GFP_KERNEL, 21 - PAGE_SHIFT);
+        BUG_ON(!p);
+        dart_copy = page_address(p);
+
+        ppc_md.iommu_save = iommu_dart_save;
+        ppc_md.iommu_restore = iommu_dart_restore;
+
+        return 0;
+}
+
+late_initcall(iommu_init_late_dart);
+#endif
 
 void __init alloc_dart_table(void)
 {