x86: Calgary: Convert detect_calgary() to use iommu_init hook

This changes detect_calgary() to set init_calgary() to
iommu_init hook if detect_calgary() finds the Calgary IOMMU.

We can kill the code to check if we found the IOMMU in
init_calgary() since detect_calgary() sets init_calgary() only
when it found the IOMMU.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: chrisw@sous-sol.org
Cc: dwmw2@infradead.org
Cc: joerg.roedel@amd.com
LKML-Reference: <1257849980-22640-3-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/calgary.h

@@ -62,10 +62,8 @@ struct cal_chipset_ops {
 extern int use_calgary;
 
 #ifdef CONFIG_CALGARY_IOMMU
-extern int calgary_iommu_init(void);
 extern void detect_calgary(void);
 #else
-static inline int calgary_iommu_init(void) { return 1; }
 static inline void detect_calgary(void) { return; }
 #endif
 

arch/x86/kernel/pci-calgary_64.c

@@ -46,6 +46,7 @@
 #include <asm/dma.h>
 #include <asm/rio.h>
 #include <asm/bios_ebda.h>
+#include <asm/x86_init.h>
 
 #ifdef CONFIG_CALGARY_IOMMU_ENABLED_BY_DEFAULT
 int use_calgary __read_mostly = 1;
@@ -1344,6 +1345,8 @@ static void __init get_tce_space_from_tar(void)
 	return;
 }
 
+int __init calgary_iommu_init(void);
+
 void __init detect_calgary(void)
 {
 	int bus;
@@ -1445,6 +1448,8 @@ void __init detect_calgary(void)
 		/* swiotlb for devices that aren't behind the Calgary. */
 		if (max_pfn > MAX_DMA32_PFN)
 			swiotlb = 1;
+
+		x86_init.iommu.iommu_init = calgary_iommu_init;
 	}
 	return;
 
@@ -1461,12 +1466,6 @@ int __init calgary_iommu_init(void)
 {
 	int ret;
 
-	if (no_iommu || (swiotlb && !calgary_detected))
-		return -ENODEV;
-
-	if (!calgary_detected)
-		return -ENODEV;
-
 	/* ok, we're trying to use Calgary - let's roll */
 	printk(KERN_INFO "PCI-DMA: Using Calgary IOMMU\n");
 

arch/x86/kernel/pci-dma.c

@@ -294,8 +294,6 @@ static int __init pci_iommu_init(void)
 
 	x86_init.iommu.iommu_init();
 
-	calgary_iommu_init();
-
 	intel_iommu_init();
 
 	amd_iommu_init();