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#ifndef _ASM_X86_IOMMU_TABLE_H
#define _ASM_X86_IOMMU_TABLE_H
#include <asm/swiotlb.h>
/*
* History lesson:
* The execution chain of IOMMUs in 2.6.36 looks as so:
*
* [xen-swiotlb]
* |
* +----[swiotlb *]--+
* / | \
* / | \
* [GART] [Calgary] [Intel VT-d]
* /
* /
* [AMD-Vi]
*
* *: if SWIOTLB detected 'iommu=soft'/'swiotlb=force' it would skip
* over the rest of IOMMUs and unconditionally initialize the SWIOTLB.
* Also it would surreptitiously initialize set the swiotlb=1 if there were
* more than 4GB and if the user did not pass in 'iommu=off'. The swiotlb
* flag would be turned off by all IOMMUs except the Calgary one.
*
* The IOMMU_INIT* macros allow a similar tree (or more complex if desired)
* to be built by defining who we depend on.
*
* And all that needs to be done is to use one of the macros in the IOMMU
* and the pci-dma.c will take care of the rest.
*/
struct iommu_table_entry {
initcall_t detect;
initcall_t depend;
void (*early_init)(void); /* No memory allocate available. */
void (*late_init)(void); /* Yes, can allocate memory. */
#define IOMMU_FINISH_IF_DETECTED (1<<0)
#define IOMMU_DETECTED (1<<1)
int flags;
};
/*
* Macro fills out an entry in the .iommu_table that is equivalent
* to the fields that 'struct iommu_table_entry' has. The entries
* that are put in the .iommu_table section are not put in any order
* hence during boot-time we will have to resort them based on
* dependency. */
#define __IOMMU_INIT(_detect, _depend, _early_init, _late_init, _finish)\
static const struct iommu_table_entry const \
__iommu_entry_##_detect __used \
__attribute__ ((unused, __section__(".iommu_table"), \
aligned((sizeof(void *))))) \
= {_detect, _depend, _early_init, _late_init, \
_finish ? IOMMU_FINISH_IF_DETECTED : 0}
/*
* The simplest IOMMU definition. Provide the detection routine
* and it will be run after the SWIOTLB and the other IOMMUs
* that utilize this macro. If the IOMMU is detected (ie, the
* detect routine returns a positive value), the other IOMMUs
* are also checked. You can use IOMMU_INIT_FINISH if you prefer
* to stop detecting the other IOMMUs after yours has been detected.
*/
#define IOMMU_INIT_POST(_detect) \
__IOMMU_INIT(_detect, pci_swiotlb_detect, 0, 0, 0)
#define IOMMU_INIT_POST_FINISH(detect) \
__IOMMU_INIT(_detect, pci_swiotlb_detect, 0, 0, 1)
/*
* A more sophisticated version of IOMMU_INIT. This variant requires:
* a). A detection routine function.
* b). The name of the detection routine we depend on to get called
* before us.
* c). The init routine which gets called if the detection routine
* returns a positive value from the pci_iommu_alloc. This means
* no presence of a memory allocator.
* d). Similar to the 'init', except that this gets called from pci_iommu_init
* where we do have a memory allocator.
*
* The _CONT vs the _EXIT differs in that the _CONT variant will
* continue detecting other IOMMUs in the call list after the
* the detection routine returns a positive number. The _EXIT will
* stop the execution chain. Both will still call the 'init' and
* 'late_init' functions if they are set.
*/
#define IOMMU_INIT_FINISH(_detect, _depend, _init, _late_init) \
__IOMMU_INIT(_detect, _depend, _init, _late_init, 1)
#define IOMMU_INIT(_detect, _depend, _init, _late_init) \
__IOMMU_INIT(_detect, _depend, _init, _late_init, 0)
#endif /* _ASM_X86_IOMMU_TABLE_H */
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