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-rw-r--r--arch/ia64/include/asm/io.h24
1 files changed, 0 insertions, 24 deletions
diff --git a/arch/ia64/include/asm/io.h b/arch/ia64/include/asm/io.h
index 7f257507cd86..0d9d16e2d949 100644
--- a/arch/ia64/include/asm/io.h
+++ b/arch/ia64/include/asm/io.h
@@ -434,28 +434,4 @@ extern void memset_io(volatile void __iomem *s, int c, long n);
434 434
435# endif /* __KERNEL__ */ 435# endif /* __KERNEL__ */
436 436
437/*
438 * Enabling BIO_VMERGE_BOUNDARY forces us to turn off I/O MMU bypassing. It is said that
439 * BIO-level virtual merging can give up to 4% performance boost (not verified for ia64).
440 * On the other hand, we know that I/O MMU bypassing gives ~8% performance improvement on
441 * SPECweb-like workloads on zx1-based machines. Thus, for now we favor I/O MMU bypassing
442 * over BIO-level virtual merging.
443 */
444extern unsigned long ia64_max_iommu_merge_mask;
445#if 1
446#define BIO_VMERGE_BOUNDARY 0
447#else
448/*
449 * It makes no sense at all to have this BIO_VMERGE_BOUNDARY macro here. Should be
450 * replaced by dma_merge_mask() or something of that sort. Note: the only way
451 * BIO_VMERGE_BOUNDARY is used is to mask off bits. Effectively, our definition gets
452 * expanded into:
453 *
454 * addr & ((ia64_max_iommu_merge_mask + 1) - 1) == (addr & ia64_max_iommu_vmerge_mask)
455 *
456 * which is precisely what we want.
457 */
458#define BIO_VMERGE_BOUNDARY (ia64_max_iommu_merge_mask + 1)
459#endif
460
461#endif /* _ASM_IA64_IO_H */ 437#endif /* _ASM_IA64_IO_H */