[Patch v3 04/12] iommu/amd: add copy_irq_table function

[Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

If irq table exists in old kernel create a new one and copy the content
of old irq table to the newly created.

Signed-off-by: Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 drivers/iommu/amd_iommu.c       |  2 +-
 drivers/iommu/amd_iommu_init.c  | 43 +++++++++++++++++++++++++++++++++++++++++
 drivers/iommu/amd_iommu_proto.h |  1 +
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index aeae07a..63f4c6b 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3628,7 +3628,7 @@ struct amd_ir_data {
 static struct irq_chip amd_ir_chip;
 
 
-static void set_dte_irq_entry(u16 devid, struct irq_remap_table *table)
+void set_dte_irq_entry(u16 devid, struct irq_remap_table *table)
 {
 	u64 dte;
 
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 91659d8..450adad 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -660,6 +660,49 @@ static int get_dev_entry_bit(u16 devid, u8 bit)
 	return (amd_iommu_dev_table[devid].data[i] & (1UL << _bit)) >> _bit;
 }
 
+static void copy_irq_table(u16 devid)
+{
+	struct irq_remap_table *table = NULL;
+	u16 alias;
+	u64 dte;
+	u64 *old_intr_virt;
+
+	alias = amd_iommu_alias_table[devid];
+	table = irq_lookup_table[alias];
+	if (table) {
+	        irq_lookup_table[devid] = table;
+		set_dte_irq_entry(devid, table);
+	        return;
+	}
+	dte     = amd_iommu_dev_table[devid].data[2];
+	dte &= DTE_IRQ_PHYS_ADDR_MASK;
+	if( (!dte&DTE_IRQ_REMAP_ENABLE) || ( dte == 0) )
+	        return;
+
+	table = kzalloc(sizeof(*table), GFP_ATOMIC);
+	if (!table){
+	        pr_warn("AMD-Vi: amd irq table allocation failed\n");
+	        return;
+	}
+
+	table->table = kmem_cache_alloc(amd_iommu_irq_cache, GFP_ATOMIC);
+        if (!table->table) {
+                kfree(table);
+                table = NULL;
+		return;
+        }
+	memset(table->table, 0, MAX_IRQS_PER_TABLE * sizeof(u32));
+
+	old_intr_virt = memremap(dte, MAX_IRQS_PER_TABLE * sizeof(u32), MEMREMAP_WB);
+	memcpy(table->table, old_intr_virt, MAX_IRQS_PER_TABLE * sizeof(u32));
+	irq_lookup_table[devid] = table;
+	set_dte_irq_entry(devid, table);
+	if (devid != alias) {
+                irq_lookup_table[alias] = table;
+		set_dte_irq_entry(alias, table);
+        }
+	memunmap(old_intr_virt);
+}
 
 void amd_iommu_apply_erratum_63(u16 devid)
 {
diff --git a/drivers/iommu/amd_iommu_proto.h b/drivers/iommu/amd_iommu_proto.h
index 743e209..ab562e0 100644
--- a/drivers/iommu/amd_iommu_proto.h
+++ b/drivers/iommu/amd_iommu_proto.h
@@ -101,5 +101,6 @@ static inline bool iommu_feature(struct amd_iommu *iommu, u64 f)
 /* kdump checking  */
 extern bool translation_pre_enabled(void);
 extern void clear_translation_pre_enabled(void);
+extern void set_dte_irq_entry(u16 devid, struct irq_remap_table *table);
 
 #endif /* _ASM_X86_AMD_IOMMU_PROTO_H  */
-- 
2.1.0