1#ifndef _ASM_X86_IOMMU_TABLE_H 2#define _ASM_X86_IOMMU_TABLE_H 3 4#include <asm/swiotlb.h> 5 6/* 7 * History lesson: 8 * The execution chain of IOMMUs in 2.6.36 looks as so: 9 * 10 * [xen-swiotlb] 11 * | 12 * +----[swiotlb *]--+ 13 * / | \ 14 * / | \ 15 * [GART] [Calgary] [Intel VT-d] 16 * / 17 * / 18 * [AMD-Vi] 19 * 20 * *: if SWIOTLB detected 'iommu=soft'/'swiotlb=force' it would skip 21 * over the rest of IOMMUs and unconditionally initialize the SWIOTLB. 22 * Also it would surreptitiously initialize set the swiotlb=1 if there were 23 * more than 4GB and if the user did not pass in 'iommu=off'. The swiotlb 24 * flag would be turned off by all IOMMUs except the Calgary one. 25 * 26 * The IOMMU_INIT* macros allow a similar tree (or more complex if desired) 27 * to be built by defining who we depend on. 28 * 29 * And all that needs to be done is to use one of the macros in the IOMMU 30 * and the pci-dma.c will take care of the rest. 31 */ 32 33struct iommu_table_entry { 34 initcall_t detect; 35 initcall_t depend; 36 void (*early_init)(void); /* No memory allocate available. */ 37 void (*late_init)(void); /* Yes, can allocate memory. */ 38#define IOMMU_FINISH_IF_DETECTED (1<<0) 39#define IOMMU_DETECTED (1<<1) 40 int flags; 41}; 42/* 43 * Macro fills out an entry in the .iommu_table that is equivalent 44 * to the fields that 'struct iommu_table_entry' has. The entries 45 * that are put in the .iommu_table section are not put in any order 46 * hence during boot-time we will have to resort them based on 47 * dependency. */ 48 49 50#define __IOMMU_INIT(_detect, _depend, _early_init, _late_init, _finish)\ 51 static const struct iommu_table_entry const \ 52 __iommu_entry_##_detect __used \ 53 __attribute__ ((unused, __section__(".iommu_table"), \ 54 aligned((sizeof(void *))))) \ 55 = {_detect, _depend, _early_init, _late_init, \ 56 _finish ? IOMMU_FINISH_IF_DETECTED : 0} 57/* 58 * The simplest IOMMU definition. Provide the detection routine 59 * and it will be run after the SWIOTLB and the other IOMMUs 60 * that utilize this macro. If the IOMMU is detected (ie, the 61 * detect routine returns a positive value), the other IOMMUs 62 * are also checked. You can use IOMMU_INIT_POST_FINISH if you prefer 63 * to stop detecting the other IOMMUs after yours has been detected. 64 */ 65#define IOMMU_INIT_POST(_detect) \ 66 __IOMMU_INIT(_detect, pci_swiotlb_detect_4gb, 0, 0, 0) 67 68#define IOMMU_INIT_POST_FINISH(detect) \ 69 __IOMMU_INIT(_detect, pci_swiotlb_detect_4gb, 0, 0, 1) 70 71/* 72 * A more sophisticated version of IOMMU_INIT. This variant requires: 73 * a). A detection routine function. 74 * b). The name of the detection routine we depend on to get called 75 * before us. 76 * c). The init routine which gets called if the detection routine 77 * returns a positive value from the pci_iommu_alloc. This means 78 * no presence of a memory allocator. 79 * d). Similar to the 'init', except that this gets called from pci_iommu_init 80 * where we do have a memory allocator. 81 * 82 * The standard vs the _FINISH differs in that the _FINISH variant will 83 * continue detecting other IOMMUs in the call list after the 84 * the detection routine returns a positive number. The _FINISH will 85 * stop the execution chain. Both will still call the 'init' and 86 * 'late_init' functions if they are set. 87 */ 88#define IOMMU_INIT_FINISH(_detect, _depend, _init, _late_init) \ 89 __IOMMU_INIT(_detect, _depend, _init, _late_init, 1) 90 91#define IOMMU_INIT(_detect, _depend, _init, _late_init) \ 92 __IOMMU_INIT(_detect, _depend, _init, _late_init, 0) 93 94void sort_iommu_table(struct iommu_table_entry *start, 95 struct iommu_table_entry *finish); 96 97void check_iommu_entries(struct iommu_table_entry *start, 98 struct iommu_table_entry *finish); 99 100#endif /* _ASM_X86_IOMMU_TABLE_H */ 101