137 lines
3.1 KiB
C
137 lines
3.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2002 Russell King
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*
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* Commonly used functions by the ARM SCSI-II drivers.
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*/
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#include <linux/scatterlist.h>
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#define BELT_AND_BRACES
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struct arm_cmd_priv {
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struct scsi_pointer scsi_pointer;
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};
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static inline struct scsi_pointer *arm_scsi_pointer(struct scsi_cmnd *cmd)
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{
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struct arm_cmd_priv *acmd = scsi_cmd_priv(cmd);
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return &acmd->scsi_pointer;
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}
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/*
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* The scatter-gather list handling. This contains all
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* the yucky stuff that needs to be fixed properly.
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*/
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/*
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* copy_SCp_to_sg() Assumes contiguous allocation at @sg of at-most @max
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* entries of uninitialized memory. SCp is from scsi-ml and has a valid
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* (possibly chained) sg-list
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*/
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static inline int copy_SCp_to_sg(struct scatterlist *sg, struct scsi_pointer *SCp, int max)
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{
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int bufs = SCp->buffers_residual;
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/* FIXME: It should be easy for drivers to loop on copy_SCp_to_sg().
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* and to remove this BUG_ON. Use min() in-its-place
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*/
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BUG_ON(bufs + 1 > max);
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sg_set_buf(sg, SCp->ptr, SCp->this_residual);
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if (bufs) {
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struct scatterlist *src_sg;
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unsigned i;
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for_each_sg(sg_next(SCp->buffer), src_sg, bufs, i)
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*(++sg) = *src_sg;
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sg_mark_end(sg);
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}
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return bufs + 1;
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}
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static inline int next_SCp(struct scsi_pointer *SCp)
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{
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int ret = SCp->buffers_residual;
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if (ret) {
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SCp->buffer = sg_next(SCp->buffer);
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SCp->buffers_residual--;
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SCp->ptr = sg_virt(SCp->buffer);
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SCp->this_residual = SCp->buffer->length;
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} else {
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SCp->ptr = NULL;
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SCp->this_residual = 0;
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}
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return ret;
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}
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static inline unsigned char get_next_SCp_byte(struct scsi_pointer *SCp)
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{
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char c = *SCp->ptr;
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SCp->ptr += 1;
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SCp->this_residual -= 1;
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return c;
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}
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static inline void put_next_SCp_byte(struct scsi_pointer *SCp, unsigned char c)
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{
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*SCp->ptr = c;
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SCp->ptr += 1;
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SCp->this_residual -= 1;
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}
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static inline void init_SCp(struct scsi_cmnd *SCpnt)
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{
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struct scsi_pointer *scsi_pointer = arm_scsi_pointer(SCpnt);
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memset(scsi_pointer, 0, sizeof(struct scsi_pointer));
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if (scsi_bufflen(SCpnt)) {
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unsigned long len = 0;
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scsi_pointer->buffer = scsi_sglist(SCpnt);
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scsi_pointer->buffers_residual = scsi_sg_count(SCpnt) - 1;
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scsi_pointer->ptr = sg_virt(scsi_pointer->buffer);
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scsi_pointer->this_residual = scsi_pointer->buffer->length;
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scsi_pointer->phase = scsi_bufflen(SCpnt);
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#ifdef BELT_AND_BRACES
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{ /*
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* Calculate correct buffer length. Some commands
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* come in with the wrong scsi_bufflen.
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*/
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struct scatterlist *sg;
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unsigned i, sg_count = scsi_sg_count(SCpnt);
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scsi_for_each_sg(SCpnt, sg, sg_count, i)
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len += sg->length;
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if (scsi_bufflen(SCpnt) != len) {
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printk(KERN_WARNING
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"scsi%d.%c: bad request buffer "
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"length %d, should be %ld\n",
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SCpnt->device->host->host_no,
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'0' + SCpnt->device->id,
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scsi_bufflen(SCpnt), len);
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/*
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* FIXME: Totaly naive fixup. We should abort
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* with error
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*/
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scsi_pointer->phase =
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min_t(unsigned long, len,
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scsi_bufflen(SCpnt));
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}
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}
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#endif
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} else {
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scsi_pointer->ptr = NULL;
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scsi_pointer->this_residual = 0;
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scsi_pointer->phase = 0;
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}
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}
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