/* SPDX-License-Identifier: GPL-2.0 */ #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 \ __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_POST_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_4gb, NULL, NULL, 0) #define IOMMU_INIT_POST_FINISH(detect) \ __IOMMU_INIT(_detect, pci_swiotlb_detect_4gb, NULL, NULL, 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 standard IOMMU_INIT differs from the IOMMU_INIT_FINISH variant * in that the former will continue detecting other IOMMUs in the call * list after the detection routine returns a positive number, while the * latter will stop the execution chain upon first successful detection. * Both variants 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) void sort_iommu_table(struct iommu_table_entry *start, struct iommu_table_entry *finish); void check_iommu_entries(struct iommu_table_entry *start, struct iommu_table_entry *finish); #endif /* _ASM_X86_IOMMU_TABLE_H */ |