diff options
| -rw-r--r-- | arch/x86/include/asm/iommu_table.h | 95 | ||||
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 7 |
2 files changed, 102 insertions, 0 deletions
diff --git a/arch/x86/include/asm/iommu_table.h b/arch/x86/include/asm/iommu_table.h new file mode 100644 index 000000000000..435176f96a56 --- /dev/null +++ b/arch/x86/include/asm/iommu_table.h @@ -0,0 +1,95 @@ + +#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 */ diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index d0bb52296fa3..b92e040466c1 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -260,6 +260,13 @@ SECTIONS *(.altinstr_replacement) } + .iommu_table : AT(ADDR(.iommu_table) - LOAD_OFFSET) { + __iommu_table = .; + *(.iommu_table) + . = ALIGN(8); + __iommu_table_end = .; + } + /* * .exit.text is discard at runtime, not link time, to deal with * references from .altinstructions and .eh_frame |