From d45033ef56fa9b09b73a6eb2a0f280fa7c1bab09 Mon Sep 17 00:00:00 2001 From: "Stephen M. Cameron" Date: Fri, 26 Feb 2010 16:01:37 -0600 Subject: cciss: factor out scatter gather chain block mapping code cciss: factor out scatter gather chain block mapping code Rationale is I want to use this code from the scsi half of the driver. Signed-off-by: Stephen M. Cameron Signed-off-by: Jens Axboe --- drivers/block/cciss.c | 63 +++++++++++++++++++++++++++------------------------ 1 file changed, 34 insertions(+), 29 deletions(-) diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c index c0d794ce69c..9e3af307aae 100644 --- a/drivers/block/cciss.c +++ b/drivers/block/cciss.c @@ -301,6 +301,35 @@ clean: return NULL; } +static void cciss_unmap_sg_chain_block(ctlr_info_t *h, CommandList_struct *c) +{ + SGDescriptor_struct *chain_sg; + u64bit temp64; + + if (c->Header.SGTotal <= h->max_cmd_sgentries) + return; + + chain_sg = &c->SG[h->max_cmd_sgentries - 1]; + temp64.val32.lower = chain_sg->Addr.lower; + temp64.val32.upper = chain_sg->Addr.upper; + pci_unmap_single(h->pdev, temp64.val, chain_sg->Len, PCI_DMA_TODEVICE); +} + +static void cciss_map_sg_chain_block(ctlr_info_t *h, CommandList_struct *c, + SGDescriptor_struct *chain_block, int len) +{ + SGDescriptor_struct *chain_sg; + u64bit temp64; + + chain_sg = &c->SG[h->max_cmd_sgentries - 1]; + chain_sg->Ext = CCISS_SG_CHAIN; + chain_sg->Len = len; + temp64.val = pci_map_single(h->pdev, chain_block, len, + PCI_DMA_TODEVICE); + chain_sg->Addr.lower = temp64.val32.lower; + chain_sg->Addr.upper = temp64.val32.upper; +} + #include "cciss_scsi.c" /* For SCSI tape support */ static const char *raid_label[] = { "0", "4", "1(1+0)", "5", "5+1", "ADG", @@ -1715,10 +1744,7 @@ static void cciss_softirq_done(struct request *rq) /* unmap the DMA mapping for all the scatter gather elements */ for (i = 0; i < cmd->Header.SGList; i++) { if (curr_sg[sg_index].Ext == CCISS_SG_CHAIN) { - temp64.val32.lower = cmd->SG[i].Addr.lower; - temp64.val32.upper = cmd->SG[i].Addr.upper; - pci_unmap_single(h->pdev, temp64.val, - cmd->SG[i].Len, PCI_DMA_TODEVICE); + cciss_unmap_sg_chain_block(h, cmd); /* Point to the next block */ curr_sg = h->cmd_sg_list[cmd->cmdindex]; sg_index = 0; @@ -3122,7 +3148,6 @@ static void do_cciss_request(struct request_queue *q) SGDescriptor_struct *curr_sg; drive_info_struct *drv; int i, dir; - int nseg = 0; int sg_index = 0; int chained = 0; @@ -3189,11 +3214,6 @@ static void do_cciss_request(struct request_queue *q) for (i = 0; i < seg; i++) { if (((sg_index+1) == (h->max_cmd_sgentries)) && !chained && ((seg - i) > 1)) { - nseg = seg - i; - curr_sg[sg_index].Len = (nseg) * - sizeof(SGDescriptor_struct); - curr_sg[sg_index].Ext = CCISS_SG_CHAIN; - /* Point to next chain block. */ curr_sg = h->cmd_sg_list[c->cmdindex]; sg_index = 0; @@ -3206,27 +3226,12 @@ static void do_cciss_request(struct request_queue *q) curr_sg[sg_index].Addr.lower = temp64.val32.lower; curr_sg[sg_index].Addr.upper = temp64.val32.upper; curr_sg[sg_index].Ext = 0; /* we are not chaining */ - ++sg_index; } - - if (chained) { - int len; - dma_addr_t dma_addr; - curr_sg = c->SG; - sg_index = h->max_cmd_sgentries - 1; - len = curr_sg[sg_index].Len; - /* Setup pointer to next chain block. - * Fill out last element in current chain - * block with address of next chain block. - */ - temp64.val = pci_map_single(h->pdev, - h->cmd_sg_list[c->cmdindex], len, - PCI_DMA_TODEVICE); - dma_addr = temp64.val; - curr_sg[sg_index].Addr.lower = temp64.val32.lower; - curr_sg[sg_index].Addr.upper = temp64.val32.upper; - } + if (chained) + cciss_map_sg_chain_block(h, c, h->cmd_sg_list[c->cmdindex], + (seg - (h->max_cmd_sgentries - 1)) * + sizeof(SGDescriptor_struct)); /* track how many SG entries we are using */ if (seg > h->maxSG) -- cgit v1.2.3