x86: Use x86_platform for iommu_shutdown

This patch cleans up pci_iommu_shutdown() a bit to use
x86_platform (similar to how IA64 initializes an IOMMU driver).

This adds iommu_shutdown() to x86_platform to avoid calling
every IOMMUs' shutdown functions in pci_iommu_shutdown() in
order. The IOMMU shutdown functions are platform specific (we
don't have multiple different IOMMU hardware) so the current way
is pointless.

An IOMMU driver sets x86_platform.iommu_shutdown to the shutdown
function if necessary.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: joerg.roedel@amd.com
LKML-Reference: <20091027163358F.fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/amd_iommu.h

@@ -30,12 +30,10 @@ extern void amd_iommu_detect(void);
 extern irqreturn_t amd_iommu_int_handler(int irq, void *data);
 extern void amd_iommu_flush_all_domains(void);
 extern void amd_iommu_flush_all_devices(void);
-extern void amd_iommu_shutdown(void);
 extern void amd_iommu_apply_erratum_63(u16 devid);
 #else
 static inline int amd_iommu_init(void) { return -ENODEV; }
 static inline void amd_iommu_detect(void) { }
-static inline void amd_iommu_shutdown(void) { }
 #endif
 
 #endif /* _ASM_X86_AMD_IOMMU_H */

arch/x86/include/asm/gart.h

@@ -36,7 +36,6 @@ extern int gart_iommu_aperture_disabled;
 
 extern void early_gart_iommu_check(void);
 extern void gart_iommu_init(void);
-extern void gart_iommu_shutdown(void);
 extern void __init gart_parse_options(char *);
 extern void gart_iommu_hole_init(void);
 
@@ -51,9 +50,6 @@ static inline void early_gart_iommu_check(void)
 static inline void gart_iommu_init(void)
 {
 }
-static inline void gart_iommu_shutdown(void)
-{
-}
 static inline void gart_parse_options(char *options)
 {
 }

arch/x86/include/asm/iommu.h

@@ -1,7 +1,7 @@
 #ifndef _ASM_X86_IOMMU_H
 #define _ASM_X86_IOMMU_H
 
-extern void pci_iommu_shutdown(void);
+static inline void iommu_shutdown_noop(void) {}
 extern void no_iommu_init(void);
 extern struct dma_map_ops nommu_dma_ops;
 extern int force_iommu, no_iommu;

arch/x86/include/asm/x86_init.h

@@ -121,6 +121,7 @@ struct x86_platform_ops {
 	unsigned long (*calibrate_tsc)(void);
 	unsigned long (*get_wallclock)(void);
 	int (*set_wallclock)(unsigned long nowtime);
+	void (*iommu_shutdown)(void);
 };
 
 extern struct x86_init_ops x86_init;

arch/x86/kernel/amd_iommu_init.c

@@ -1297,6 +1297,7 @@ int __init amd_iommu_init(void)
 	else
 		printk(KERN_INFO "AMD-Vi: Lazy IO/TLB flushing enabled\n");
 
+	x86_platform.iommu_shutdown = disable_iommus;
 out:
 	return ret;
 
@@ -1323,11 +1324,6 @@ free:
 	goto out;
 }
 
-void amd_iommu_shutdown(void)
-{
-	disable_iommus();
-}
-
 /****************************************************************************
  *
  * Early detect code. This code runs at IOMMU detection time in the DMA

arch/x86/kernel/crash.c

@@ -27,8 +27,7 @@
 #include <asm/cpu.h>
 #include <asm/reboot.h>
 #include <asm/virtext.h>
-#include <asm/iommu.h>
-
+#include <asm/x86_init.h>
 
 #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
 
@@ -106,7 +105,7 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
 #endif
 
 #ifdef CONFIG_X86_64
-	pci_iommu_shutdown();
+	x86_platform.iommu_shutdown();
 #endif
 
 	crash_save_cpu(regs, safe_smp_processor_id());

arch/x86/kernel/pci-dma.c

@@ -303,13 +303,6 @@ static int __init pci_iommu_init(void)
 	no_iommu_init();
 	return 0;
 }
-
-void pci_iommu_shutdown(void)
-{
-	gart_iommu_shutdown();
-
-	amd_iommu_shutdown();
-}
 /* Must execute after PCI subsystem */
 rootfs_initcall(pci_iommu_init);
 

arch/x86/kernel/pci-gart_64.c

@@ -39,6 +39,7 @@
 #include <asm/swiotlb.h>
 #include <asm/dma.h>
 #include <asm/k8.h>
+#include <asm/x86_init.h>
 
 static unsigned long iommu_bus_base;	/* GART remapping area (physical) */
 static unsigned long iommu_size;	/* size of remapping area bytes */
@@ -688,12 +689,12 @@ static struct dma_map_ops gart_dma_ops = {
 	.free_coherent			= gart_free_coherent,
 };
 
-void gart_iommu_shutdown(void)
+static void gart_iommu_shutdown(void)
 {
 	struct pci_dev *dev;
 	int i;
 
-	if (no_agp && (dma_ops != &gart_dma_ops))
+	if (no_agp)
 		return;
 
 	for (i = 0; i < num_k8_northbridges; i++) {
@@ -838,6 +839,7 @@ void __init gart_iommu_init(void)
 
 	flush_gart();
 	dma_ops = &gart_dma_ops;
+	x86_platform.iommu_shutdown = gart_iommu_shutdown;
 }
 
 void __init gart_parse_options(char *p)

arch/x86/kernel/reboot.c

@@ -23,7 +23,7 @@
 # include <linux/ctype.h>
 # include <linux/mc146818rtc.h>
 #else
-# include <asm/iommu.h>
+# include <asm/x86_init.h>
 #endif
 
 /*
@@ -622,7 +622,7 @@ void native_machine_shutdown(void)
 #endif
 
 #ifdef CONFIG_X86_64
-	pci_iommu_shutdown();
+	x86_platform.iommu_shutdown();
 #endif
 }
 

arch/x86/kernel/x86_init.c

@@ -14,6 +14,7 @@
 #include <asm/time.h>
 #include <asm/irq.h>
 #include <asm/tsc.h>
+#include <asm/iommu.h>
 
 void __cpuinit x86_init_noop(void) { }
 void __init x86_init_uint_noop(unsigned int unused) { }
@@ -72,4 +73,5 @@ struct x86_platform_ops x86_platform = {
 	.calibrate_tsc			= native_calibrate_tsc,
 	.get_wallclock			= mach_get_cmos_time,
 	.set_wallclock			= mach_set_rtc_mmss,
+	.iommu_shutdown			= iommu_shutdown_noop,
 };