[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>

3 files changed, 65 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)
 {
diff --git a/include/asm-powerpc/iommu.h b/include/asm-powerpc/iommu.h
index b2e56b30306a..870967e47204 100644
--- a/include/asm-powerpc/iommu.h
+++ b/include/asm-powerpc/iommu.h
@@ -26,6 +26,7 @@
 #include <linux/spinlock.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
+#include <asm/machdep.h>
 #include <asm/types.h>
 #include <asm/bitops.h>
 
@@ -109,6 +110,19 @@ static inline void pci_iommu_init(void) { }
 #endif
 
 extern void alloc_dart_table(void);
+#if defined(CONFIG_PPC64) && defined(CONFIG_PM)
+static inline void iommu_save(void)
+{
+        if (ppc_md.iommu_save)
+                ppc_md.iommu_save();
+}
+
+static inline void iommu_restore(void)
+{
+        if (ppc_md.iommu_restore)
+                ppc_md.iommu_restore();
+}
+#endif
 
 #endif /* __KERNEL__ */
 #endif /* _ASM_IOMMU_H */
diff --git a/include/asm-powerpc/machdep.h b/include/asm-powerpc/machdep.h
index bbd17d0e170d..6fdabd6dfb3e 100644
--- a/include/asm-powerpc/machdep.h
+++ b/include/asm-powerpc/machdep.h
@@ -91,6 +91,11 @@ struct machdep_calls {
         void __iomem *  (*ioremap)(phys_addr_t addr, unsigned long size,
                                    unsigned long flags);
         void            (*iounmap)(volatile void __iomem *token);
+
+#ifdef CONFIG_PM
+        void            (*iommu_save)(void);
+        void            (*iommu_restore)(void);
+#endif
 #endif /* CONFIG_PPC64 */
 
         int             (*probe)(void);