Re: [RFC 08/10] powerpc: dart iommu suspend

Johannes Berg
2007-02-06T01:52:47Z

How's this? Needs to go along with the correct changes in the code that
uses it, of course.

I can't use a local void * as you suggested because it needs to be added
to as an unsigned long, but I can use a local unsigned long.

Not even compiled yet.

Btw. What does TCE stand for?

--- mb-wireless.orig/arch/powerpc/sysdev/dart_iommu.c 2007-02-06 02:45:34.464524763 +0100
+++ mb-wireless/arch/powerpc/sysdev/dart_iommu.c 2007-02-06 02:48:40.784524763 +0100
@@ -54,6 +54,9 @@ 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 +349,49 @@ void iommu_init_early_dart(void)
pci_dma_ops = &dma_direct_ops;
}

+#ifdef CONFIG_PM
+static void iommu_dart_suspend(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 iommu_init_late_dart(void)
+{
+ unsigned long i, tbase = (unsigned long) dart_tablebase;
+ struct page *p;
+
+ /* this 16MB area is left unmapped because of caching
+ * considerations. that happens early so we can't mark
+ * it there, do it now instead */
+ for (i = 0; i < (1<<24); i+= PAGE_SIZE)
+ SetPageNosave(virt_to_page((void*)(tbase + i)));
+
+ /* if no dart table exists then we don't need to save it */
+ if (!dart_tablebase)
+ return 0;
+
+ /* 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_suspend = iommu_dart_suspend;
+ ppc_md.iommu_resume = iommu_dart_resume;
+
+ return 0;
+}
+
+late_initcall(iommu_init_late_dart);
+#endif

void __init alloc_dart_table(void)
{
--- mb-wireless.orig/include/asm-powerpc/iommu.h 2007-02-06 02:45:34.524524763 +0100
+++ mb-wireless/include/asm-powerpc/iommu.h 2007-02-06 02:46:28.964524763 +0100
@@ -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>

@@ -108,6 +109,19 @@ static inline void pci_iommu_init(void)
#endif

extern void alloc_dart_table(void);
+#ifdef CONFIG_PM
+static inline void iommu_suspend(void)
+{
+ if (ppc_md.iommu_suspend)
+ ppc_md.iommu_suspend();
+}
+
+static inline void iommu_restore(void)
+{
+ if (ppc_md.iommu_resume)
+ ppc_md.iommu_resume();
+}
+#endif

#endif /* __KERNEL__ */
#endif /* _ASM_IOMMU_H */
--- mb-wireless.orig/include/asm-powerpc/machdep.h 2007-02-06 02:45:34.584524763 +0100
+++ mb-wireless/include/asm-powerpc/machdep.h 2007-02-06 02:46:10.834524763 +0100
@@ -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_suspend)(void);
+ void (*iommu_resume)(void);
+#endif
#endif /* CONFIG_PPC64 */

int (*probe)(void);