diff options
author | Jens Axboe <jens.axboe@oracle.com> | 2007-10-16 12:29:34 +0200 |
---|---|---|
committer | Jens Axboe <jens.axboe@oracle.com> | 2007-10-16 12:29:34 +0200 |
commit | 3eed13fd933dbb81db12f7cdec6de9268c4443b5 (patch) | |
tree | c16913706acffd4a0b29ec12cd68906b708c9a8a /include/linux | |
parent | a39d113936370ba524fa9e34d6954c3625c8aa64 (diff) | |
parent | 2c941a204070ab32d92d40318a3196a7fb994c00 (diff) |
Merge branch 'sglist-arch' into for-linus
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/i2o.h | 3 | ||||
-rw-r--r-- | include/linux/ide.h | 2 | ||||
-rw-r--r-- | include/linux/libata.h | 16 | ||||
-rw-r--r-- | include/linux/scatterlist.h | 84 |
4 files changed, 97 insertions, 8 deletions
diff --git a/include/linux/i2o.h b/include/linux/i2o.h index 9752307d16b..7da5b98d90e 100644 --- a/include/linux/i2o.h +++ b/include/linux/i2o.h @@ -32,6 +32,7 @@ #include <linux/workqueue.h> /* work_struct */ #include <linux/mempool.h> #include <linux/mutex.h> +#include <linux/scatterlist.h> #include <asm/io.h> #include <asm/semaphore.h> /* Needed for MUTEX init macros */ @@ -837,7 +838,7 @@ static inline int i2o_dma_map_sg(struct i2o_controller *c, if ((sizeof(dma_addr_t) > 4) && c->pae_support) *mptr++ = cpu_to_le32(i2o_dma_high(sg_dma_address(sg))); #endif - sg++; + sg = sg_next(sg); } *sg_ptr = mptr; diff --git a/include/linux/ide.h b/include/linux/ide.h index 234fa3df24f..30a1931466a 100644 --- a/include/linux/ide.h +++ b/include/linux/ide.h @@ -772,7 +772,7 @@ typedef struct hwif_s { unsigned int nsect; unsigned int nleft; - unsigned int cursg; + struct scatterlist *cursg; unsigned int cursg_ofs; int rqsize; /* max sectors per request */ diff --git a/include/linux/libata.h b/include/linux/libata.h index 229a9ff9f92..377e6d4d9be 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -29,7 +29,7 @@ #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/dma-mapping.h> -#include <asm/scatterlist.h> +#include <linux/scatterlist.h> #include <linux/io.h> #include <linux/ata.h> #include <linux/workqueue.h> @@ -416,6 +416,7 @@ struct ata_queued_cmd { unsigned long flags; /* ATA_QCFLAG_xxx */ unsigned int tag; unsigned int n_elem; + unsigned int n_iter; unsigned int orig_n_elem; int dma_dir; @@ -426,7 +427,7 @@ struct ata_queued_cmd { unsigned int nbytes; unsigned int curbytes; - unsigned int cursg; + struct scatterlist *cursg; unsigned int cursg_ofs; struct scatterlist sgent; @@ -1043,7 +1044,7 @@ ata_sg_is_last(struct scatterlist *sg, struct ata_queued_cmd *qc) return 1; if (qc->pad_len) return 0; - if (((sg - qc->__sg) + 1) == qc->n_elem) + if (qc->n_iter == qc->n_elem) return 1; return 0; } @@ -1051,6 +1052,7 @@ ata_sg_is_last(struct scatterlist *sg, struct ata_queued_cmd *qc) static inline struct scatterlist * ata_qc_first_sg(struct ata_queued_cmd *qc) { + qc->n_iter = 0; if (qc->n_elem) return qc->__sg; if (qc->pad_len) @@ -1063,8 +1065,8 @@ ata_qc_next_sg(struct scatterlist *sg, struct ata_queued_cmd *qc) { if (sg == &qc->pad_sgent) return NULL; - if (++sg - qc->__sg < qc->n_elem) - return sg; + if (++qc->n_iter < qc->n_elem) + return sg_next(sg); if (qc->pad_len) return &qc->pad_sgent; return NULL; @@ -1309,9 +1311,11 @@ static inline void ata_qc_reinit(struct ata_queued_cmd *qc) qc->dma_dir = DMA_NONE; qc->__sg = NULL; qc->flags = 0; - qc->cursg = qc->cursg_ofs = 0; + qc->cursg = NULL; + qc->cursg_ofs = 0; qc->nbytes = qc->curbytes = 0; qc->n_elem = 0; + qc->n_iter = 0; qc->err_mask = 0; qc->pad_len = 0; qc->sect_size = ATA_SECT_SIZE; diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 4efbd9c445f..2dc7464cce5 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -20,4 +20,88 @@ static inline void sg_init_one(struct scatterlist *sg, const void *buf, sg_set_buf(sg, buf, buflen); } +/* + * We overload the LSB of the page pointer to indicate whether it's + * a valid sg entry, or whether it points to the start of a new scatterlist. + * Those low bits are there for everyone! (thanks mason :-) + */ +#define sg_is_chain(sg) ((unsigned long) (sg)->page & 0x01) +#define sg_chain_ptr(sg) \ + ((struct scatterlist *) ((unsigned long) (sg)->page & ~0x01)) + +/** + * sg_next - return the next scatterlist entry in a list + * @sg: The current sg entry + * + * Usually the next entry will be @sg@ + 1, but if this sg element is part + * of a chained scatterlist, it could jump to the start of a new + * scatterlist array. + * + * Note that the caller must ensure that there are further entries after + * the current entry, this function will NOT return NULL for an end-of-list. + * + */ +static inline struct scatterlist *sg_next(struct scatterlist *sg) +{ + sg++; + + if (unlikely(sg_is_chain(sg))) + sg = sg_chain_ptr(sg); + + return sg; +} + +/* + * Loop over each sg element, following the pointer to a new list if necessary + */ +#define for_each_sg(sglist, sg, nr, __i) \ + for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg)) + +/** + * sg_last - return the last scatterlist entry in a list + * @sgl: First entry in the scatterlist + * @nents: Number of entries in the scatterlist + * + * Should only be used casually, it (currently) scan the entire list + * to get the last entry. + * + * Note that the @sgl@ pointer passed in need not be the first one, + * the important bit is that @nents@ denotes the number of entries that + * exist from @sgl@. + * + */ +static inline struct scatterlist *sg_last(struct scatterlist *sgl, + unsigned int nents) +{ +#ifndef ARCH_HAS_SG_CHAIN + struct scatterlist *ret = &sgl[nents - 1]; +#else + struct scatterlist *sg, *ret = NULL; + int i; + + for_each_sg(sgl, sg, nents, i) + ret = sg; + +#endif + return ret; +} + +/** + * sg_chain - Chain two sglists together + * @prv: First scatterlist + * @prv_nents: Number of entries in prv + * @sgl: Second scatterlist + * + * Links @prv@ and @sgl@ together, to form a longer scatterlist. + * + */ +static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents, + struct scatterlist *sgl) +{ +#ifndef ARCH_HAS_SG_CHAIN + BUG(); +#endif + prv[prv_nents - 1].page = (struct page *) ((unsigned long) sgl | 0x01); +} + #endif /* _LINUX_SCATTERLIST_H */ |