kernel-fxtec-pro1x/arch/x86/include/asm/iommu_table.h
Konrad Rzeszutek Wilk 5bef80a4b8 x86, iommu: Add proper dependency sort routine (and sanity check).
We are using a very simple sort routine which sorts the .iommu_table
array in the order of dependencies. Specifically each structure
of iommu_table_entry has a field 'depend' which contains the function
pointer to the IOMMU that MUST be run before us. We sort the array
of structures so that the struct iommu_table_entry with no
'depend' field are first, and then the subsequent ones are the
ones for which the 'depend' function has been already invoked
(in other words, precede us).

Using the kernel's version 'sort', which is a mergeheap is
feasible, but would require making the comparison operator
scan recursivly the array to satisfy the "heapify" process: setting the
levels properly. The end result would much more complex than it should
be an it is just much simpler to utilize this simple sort routine.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
LKML-Reference: <1282845485-8991-4-git-send-email-konrad.wilk@oracle.com>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Fujita Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-08-26 15:13:19 -07:00

101 lines
3.7 KiB
C

#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)
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 */