[SCSI] arcmsr: simplify assumptions in dma_alloc_coherent()
authorTomas Henzl <thenzl@redhat.com>
Fri, 29 Apr 2011 14:28:30 +0000 (16:28 +0200)
committerJames Bottomley <James.Bottomley@suse.de>
Sun, 1 May 2011 21:32:23 +0000 (16:32 -0500)
The code currently computes an offset into a dma_alloc_coherent() area
on the assumption that the alignment is imprecise.  In fact, the API
guarantees PAGE_SIZE alignment, so the offset calculation is always
zero: remove it.

[jejb: make description actually descriptive]
Signed-off-by: Tomas henzl <thenzl@redhat.com>
Acked-by: Nick Cheng<nick.cheng@areca.com.tw>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
drivers/scsi/arcmsr/arcmsr_hba.c

index a47327f..f980600 100644 (file)
@@ -441,10 +441,11 @@ static int arcmsr_alloc_ccb_pool(struct AdapterControlBlock *acb)
        struct CommandControlBlock *ccb_tmp;
        int i = 0, j = 0;
        dma_addr_t cdb_phyaddr;
-       unsigned long roundup_ccbsize = 0, offset;
+       unsigned long roundup_ccbsize;
        unsigned long max_xfer_len;
        unsigned long max_sg_entrys;
        uint32_t  firm_config_version;
+
        for (i = 0; i < ARCMSR_MAX_TARGETID; i++)
                for (j = 0; j < ARCMSR_MAX_TARGETLUN; j++)
                        acb->devstate[i][j] = ARECA_RAID_GONE;
@@ -454,23 +455,20 @@ static int arcmsr_alloc_ccb_pool(struct AdapterControlBlock *acb)
        firm_config_version = acb->firm_cfg_version;
        if((firm_config_version & 0xFF) >= 3){
                max_xfer_len = (ARCMSR_CDB_SG_PAGE_LENGTH << ((firm_config_version >> 8) & 0xFF)) * 1024;/* max 4M byte */
-               max_sg_entrys = (max_xfer_len/4096);    
+               max_sg_entrys = (max_xfer_len/4096);
        }
        acb->host->max_sectors = max_xfer_len/512;
        acb->host->sg_tablesize = max_sg_entrys;
        roundup_ccbsize = roundup(sizeof(struct CommandControlBlock) + (max_sg_entrys - 1) * sizeof(struct SG64ENTRY), 32);
-       acb->uncache_size = roundup_ccbsize * ARCMSR_MAX_FREECCB_NUM + 32;
+       acb->uncache_size = roundup_ccbsize * ARCMSR_MAX_FREECCB_NUM;
        dma_coherent = dma_alloc_coherent(&pdev->dev, acb->uncache_size, &dma_coherent_handle, GFP_KERNEL);
        if(!dma_coherent){
-               printk(KERN_NOTICE "arcmsr%d: dma_alloc_coherent got error \n", acb->host->host_no);
+               printk(KERN_NOTICE "arcmsr%d: dma_alloc_coherent got error\n", acb->host->host_no);
                return -ENOMEM;
        }
        acb->dma_coherent = dma_coherent;
        acb->dma_coherent_handle = dma_coherent_handle;
        memset(dma_coherent, 0, acb->uncache_size);
-       offset = roundup((unsigned long)dma_coherent, 32) - (unsigned long)dma_coherent;
-       dma_coherent_handle = dma_coherent_handle + offset;
-       dma_coherent = (struct CommandControlBlock *)dma_coherent + offset;
        ccb_tmp = dma_coherent;
        acb->vir2phy_offset = (unsigned long)dma_coherent - (unsigned long)dma_coherent_handle;
        for(i = 0; i < ARCMSR_MAX_FREECCB_NUM; i++){