[RFC 08/10] powerpc: dart iommu suspend

Johannes Berg
2007-02-05T18:30:35Z

[-- Attachment #1: dart-suspend.patch --]
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This implements suspend and resume code for the dart iommu.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>

---
Just come to think of it, I made it conditional on
CONFIG_SOFTWARE_SUSPEND but could imagine that it should
instead depend on CONFIG_PM... There is no lowlevel suspend
to RAM code yet which would call this so for now it's
probably fine.

--- mb-wireless.orig/arch/powerpc/sysdev/dart_iommu.c 2007-02-05 14:24:04.834526864 +0100
+++ mb-wireless/arch/powerpc/sysdev/dart_iommu.c 2007-02-05 14:24:40.684526864 +0100
@@ -54,6 +54,9 @@ static unsigned long dart_tablesize;

/* Virtual base address of the DART table */
static u32 *dart_vbase;
+#ifdef CONFIG_SOFTWARE_SUSPEND
+static u32 *dart_copy;
+#endif

/* Mapped base address for the dart */
static unsigned int __iomem *dart;
@@ -346,6 +349,52 @@ void iommu_init_early_dart(void)
pci_dma_ops = &dma_direct_ops;
}

+#ifdef CONFIG_SOFTWARE_SUSPEND
+static int iommu_init_late_dart(void)
+{
+ unsigned long i;
+ 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*)((unsigned long)dart_tablebase + 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);
+
+ return 0;
+}
+
+late_initcall(iommu_init_late_dart);
+
+void iommu_dart_save(void)
+{
+ if (!dart_tablebase)
+ return;
+
+ memcpy(dart_copy, dart_vbase, 2*1024*1024);
+}
+
+void iommu_dart_restore(void)
+{
+ if (!dart_tablebase)
+ return;
+
+ memcpy(dart_vbase, dart_copy, 2*1024*1024);
+ dart_tlb_invalidate_all();
+}
+#endif

void __init alloc_dart_table(void)
{
--- mb-wireless.orig/include/asm-powerpc/iommu.h 2007-02-05 14:24:05.014526864 +0100
+++ mb-wireless/include/asm-powerpc/iommu.h 2007-02-05 14:24:40.684526864 +0100
@@ -108,6 +108,10 @@ static inline void pci_iommu_init(void)
#endif

extern void alloc_dart_table(void);
+#if defined(CONFIG_SOFTWARE_SUSPEND) && defined(CONFIG_U3_DART)
+extern void iommu_dart_save(void);
+extern void iommu_dart_restore(void);
+#endif

#endif /* __KERNEL__ */
#endif /* _ASM_IOMMU_H */

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