[SCSI] sym53c8xx: Simplify DAC DMA handling

By introducing the use_dac(), set_dac() and DMA_DAC_MASK macros, we can
eliminate a lot of ifdefs from the code.  We now rely on the compiler to
optimise away a few things that we'd formerly relied on the preprocessor
to do.  This makes sym_setup_bus_dma_mask() small enough to inline into
its only caller.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

4 files changed, 26 insertions, 42 deletions

diff --git a/drivers/scsi/sym53c8xx_2/sym_fw.c b/drivers/scsi/sym53c8xx_2/sym_fw.c
index 3d4db802c06f..aa230d23eda4 100644
--- a/drivers/scsi/sym53c8xx_2/sym_fw.c
+++ b/drivers/scsi/sym53c8xx_2/sym_fw.c
@@ -167,7 +167,7 @@ sym_fw2_patch(struct sym_hcb *np)
          *  Remove useless 64 bit DMA specific SCRIPTS, 
          *  when this feature is not available.
          */
-        if (!np->use_dac) {
+        if (!use_dac(np)) {
                 scripta0->is_dmap_dirty[0] = cpu_to_scr(SCR_NO_OP);
                 scripta0->is_dmap_dirty[1] = 0;
                 scripta0->is_dmap_dirty[2] = cpu_to_scr(SCR_NO_OP);
diff --git a/drivers/scsi/sym53c8xx_2/sym_glue.c b/drivers/scsi/sym53c8xx_2/sym_glue.c
index c1d9f6989664..55012970912b 100644
--- a/drivers/scsi/sym53c8xx_2/sym_glue.c
+++ b/drivers/scsi/sym53c8xx_2/sym_glue.c
@@ -1265,31 +1265,6 @@ static void sym_free_resources(struct sym_hcb *np, struct pci_dev *pdev)
 }
 
 /*
- *  Ask/tell the system about DMA addressing.
- */
-static int sym_setup_bus_dma_mask(struct sym_hcb *np)
-{
-#if SYM_CONF_DMA_ADDRESSING_MODE > 0
-#if   SYM_CONF_DMA_ADDRESSING_MODE == 1
-#define DMA_DAC_MASK    DMA_40BIT_MASK
-#elif SYM_CONF_DMA_ADDRESSING_MODE == 2
-#define DMA_DAC_MASK    DMA_64BIT_MASK
-#endif
-        if ((np->features & FE_DAC) &&
-                        !pci_set_dma_mask(np->s.device, DMA_DAC_MASK)) {
-                np->use_dac = 1;
-                return 0;
-        }
-#endif
-
-        if (!pci_set_dma_mask(np->s.device, DMA_32BIT_MASK))
-                return 0;
-
-        printf_warning("%s: No suitable DMA available\n", sym_name(np));
-        return -1;
-}
-
-/*
  *  Host attach and initialisations.
  *
  *  Allocate host data and ncb structure.
@@ -1362,8 +1337,13 @@ static struct Scsi_Host * __devinit sym_attach(struct scsi_host_template *tpnt,
         strlcpy(np->s.chip_name, dev->chip.name, sizeof(np->s.chip_name));
         sprintf(np->s.inst_name, "sym%d", np->s.unit);
 
-        if (sym_setup_bus_dma_mask(np))
+        if ((SYM_CONF_DMA_ADDRESSING_MODE > 0) && (np->features & FE_DAC) &&
+                        !pci_set_dma_mask(np->s.device, DMA_DAC_MASK)) {
+                set_dac(np);
+        } else if (pci_set_dma_mask(np->s.device, DMA_32BIT_MASK)) {
+                printf_warning("%s: No suitable DMA available\n", sym_name(np));
                 goto attach_failed;
+        }
 
         /*
          *  Try to map the controller chip to
diff --git a/drivers/scsi/sym53c8xx_2/sym_hipd.c b/drivers/scsi/sym53c8xx_2/sym_hipd.c
index 39f84bbe6856..5d0d356e1e74 100644
--- a/drivers/scsi/sym53c8xx_2/sym_hipd.c
+++ b/drivers/scsi/sym53c8xx_2/sym_hipd.c
@@ -778,19 +778,12 @@ static int sym_prepare_setting(struct Scsi_Host *shost, struct sym_hcb *np, stru
          *  64 bit addressing  (895A/896/1010) ?
          */
         if (np->features & FE_DAC) {
-#if   SYM_CONF_DMA_ADDRESSING_MODE == 0
-                np->rv_ccntl1   |= (DDAC);
-#elif SYM_CONF_DMA_ADDRESSING_MODE == 1
-                if (!np->use_dac)
-                        np->rv_ccntl1   |= (DDAC);
-                else
-                        np->rv_ccntl1   |= (XTIMOD | EXTIBMV);
-#elif SYM_CONF_DMA_ADDRESSING_MODE == 2
-                if (!np->use_dac)
-                        np->rv_ccntl1   |= (DDAC);
-                else
-                        np->rv_ccntl1   |= (0 | EXTIBMV);
-#endif
+                if (!use_dac(np))
+                        np->rv_ccntl1 |= (DDAC);
+                else if (SYM_CONF_DMA_ADDRESSING_MODE == 1)
+                        np->rv_ccntl1 |= (XTIMOD | EXTIBMV);
+                else if (SYM_CONF_DMA_ADDRESSING_MODE == 2)
+                        np->rv_ccntl1 |= (0 | EXTIBMV);
         }
 
         /*
@@ -1322,7 +1315,7 @@ int sym_lookup_dmap(struct sym_hcb *np, u32 h, int s)
 {
         int i;
 
-        if (!np->use_dac)
+        if (!use_dac(np))
                 goto weird;
 
         /* Look up existing mappings */
@@ -1837,7 +1830,7 @@ void sym_start_up (struct sym_hcb *np, int reason)
          *  Set up scratch C and DRS IO registers to map the 32 bit 
          *  DMA address range our data structures are located in.
          */
-        if (np->use_dac) {
+        if (use_dac(np)) {
                 np->dmap_bah[0] = 0;    /* ??? */
                 OUTL(np, nc_scrx[0], np->dmap_bah[0]);
                 OUTL(np, nc_drs, np->dmap_bah[0]);
diff --git a/drivers/scsi/sym53c8xx_2/sym_hipd.h b/drivers/scsi/sym53c8xx_2/sym_hipd.h
index f76b27f0aa2c..4354571a63ef 100644
--- a/drivers/scsi/sym53c8xx_2/sym_hipd.h
+++ b/drivers/scsi/sym53c8xx_2/sym_hipd.h
@@ -1026,6 +1026,14 @@ struct sym_hcb {
 #endif
 };
 
+#if SYM_CONF_DMA_ADDRESSING_MODE == 0
+#define use_dac(np)     0
+#define set_dac(np)     do { } while (0)
+#else
+#define use_dac(np)     (np)->use_dac
+#define set_dac(np)     (np)->use_dac = 1
+#endif
+
 #define HCB_BA(np, lbl) (np->hcb_ba + offsetof(struct sym_hcb, lbl))
 
 
@@ -1068,18 +1076,21 @@ int sym_hcb_attach(struct Scsi_Host *shost, struct sym_fw *fw, struct sym_nvram
  */
 
 #if   SYM_CONF_DMA_ADDRESSING_MODE == 0
+#define DMA_DAC_MASK    DMA_32BIT_MASK
 #define sym_build_sge(np, data, badd, len)      \
 do {                                            \
         (data)->addr = cpu_to_scr(badd);        \
         (data)->size = cpu_to_scr(len);         \
 } while (0)
 #elif SYM_CONF_DMA_ADDRESSING_MODE == 1
+#define DMA_DAC_MASK    DMA_40BIT_MASK
 #define sym_build_sge(np, data, badd, len)                              \
 do {                                                                    \
         (data)->addr = cpu_to_scr(badd);                                \
         (data)->size = cpu_to_scr((((badd) >> 8) & 0xff000000) + len);  \
 } while (0)
 #elif SYM_CONF_DMA_ADDRESSING_MODE == 2
+#define DMA_DAC_MASK    DMA_64BIT_MASK
 int sym_lookup_dmap(struct sym_hcb *np, u32 h, int s);
 static __inline void 
 sym_build_sge(struct sym_hcb *np, struct sym_tblmove *data, u64 badd, int len)