x86: Add iommu_init to x86_init_ops

We call the detections functions of all the IOMMUs then all
their initialization functions. The latter is pointless since we
don't detect multiple different IOMMUs. What we need to do is
calling the initialization function of the detected IOMMU.

This adds iommu_init hook to x86_init_ops so if an IOMMU
detection function can set its initialization function to the
hook.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: chrisw@sous-sol.org
Cc: dwmw2@infradead.org
Cc: joerg.roedel@amd.com
Cc: muli@il.ibm.com
LKML-Reference: <1257849980-22640-2-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/x86_init.h

@@ -90,6 +90,14 @@ struct x86_init_timers {
 	void (*timer_init)(void);
 };
 
+/**
+ * struct x86_init_iommu - platform specific iommu setup
+ * @iommu_init:			platform specific iommu setup
+ */
+struct x86_init_iommu {
+	int (*iommu_init)(void);
+};
+
 /**
  * struct x86_init_ops - functions for platform specific setup
  *
@@ -101,6 +109,7 @@ struct x86_init_ops {
 	struct x86_init_oem		oem;
 	struct x86_init_paging		paging;
 	struct x86_init_timers		timers;
+	struct x86_init_iommu		iommu;
 };
 
 /**

arch/x86/kernel/pci-dma.c

@@ -292,6 +292,8 @@ static int __init pci_iommu_init(void)
 	dma_debug_add_bus(&pci_bus_type);
 #endif
 
+	x86_init.iommu.iommu_init();
+
 	calgary_iommu_init();
 
 	intel_iommu_init();

arch/x86/kernel/x86_init.c

@@ -19,6 +19,7 @@
 void __cpuinit x86_init_noop(void) { }
 void __init x86_init_uint_noop(unsigned int unused) { }
 void __init x86_init_pgd_noop(pgd_t *unused) { }
+int __init iommu_init_noop(void) { return 0; }
 
 /*
  * The platform setup functions are preset with the default functions
@@ -63,6 +64,10 @@ struct x86_init_ops x86_init __initdata = {
 		.tsc_pre_init		= x86_init_noop,
 		.timer_init		= hpet_time_init,
 	},
+
+	.iommu = {
+		.iommu_init		= iommu_init_noop,
+	},
 };
 
 struct x86_cpuinit_ops x86_cpuinit __cpuinitdata = {