dma, mm/pat: Rename dma_*_writecombine() to dma_*_wc()

Rename dma_*_writecombine() to dma_*_wc(), so that the naming
is coherent across the various write-combining APIs. Keep the
old names for compatibility for a while, these can be removed
at a later time. A guard is left to enable backporting of the
rename, and later remove of the old mapping defines seemlessly.

Build tested successfully with allmodconfig.

The following Coccinelle SmPL patch was used for this simple
transformation:

@ rename_dma_alloc_writecombine @
expression dev, size, dma_addr, gfp;
@@

-dma_alloc_writecombine(dev, size, dma_addr, gfp)
+dma_alloc_wc(dev, size, dma_addr, gfp)

@ rename_dma_free_writecombine @
expression dev, size, cpu_addr, dma_addr;
@@

-dma_free_writecombine(dev, size, cpu_addr, dma_addr)
+dma_free_wc(dev, size, cpu_addr, dma_addr)

@ rename_dma_mmap_writecombine @
expression dev, vma, cpu_addr, dma_addr, size;
@@

-dma_mmap_writecombine(dev, vma, cpu_addr, dma_addr, size)
+dma_mmap_wc(dev, vma, cpu_addr, dma_addr, size)

We also keep the old names as compatibility helpers, and
guard against their definition to make backporting easier.

Generated-by: Coccinelle SmPL
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bhelgaas@google.com
Cc: bp@suse.de
Cc: dan.j.williams@intel.com
Cc: daniel.vetter@ffwll.ch
Cc: dhowells@redhat.com
Cc: julia.lawall@lip6.fr
Cc: konrad.wilk@oracle.com
Cc: linux-fbdev@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: luto@amacapital.net
Cc: mst@redhat.com
Cc: tomi.valkeinen@ti.com
Cc: toshi.kani@hp.com
Cc: vinod.koul@intel.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1453516462-4844-1-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/arm/mach-nspire/clcd.c

@@ -90,8 +90,8 @@ int nspire_clcd_setup(struct clcd_fb *fb)
 	panel_size = ((panel->mode.xres * panel->mode.yres) * panel->bpp) / 8;
 	panel_size = ALIGN(panel_size, PAGE_SIZE);
 
-	fb->fb.screen_base = dma_alloc_writecombine(&fb->dev->dev,
-		panel_size, &dma, GFP_KERNEL);
+	fb->fb.screen_base = dma_alloc_wc(&fb->dev->dev, panel_size, &dma,
+					  GFP_KERNEL);
 
 	if (!fb->fb.screen_base) {
 		pr_err("CLCD: unable to map framebuffer\n");
@@ -107,13 +107,12 @@ int nspire_clcd_setup(struct clcd_fb *fb)
 
 int nspire_clcd_mmap(struct clcd_fb *fb, struct vm_area_struct *vma)
 {
-	return dma_mmap_writecombine(&fb->dev->dev, vma,
-		fb->fb.screen_base, fb->fb.fix.smem_start,
-		fb->fb.fix.smem_len);
+	return dma_mmap_wc(&fb->dev->dev, vma, fb->fb.screen_base,
+			   fb->fb.fix.smem_start, fb->fb.fix.smem_len);
 }
 
 void nspire_clcd_remove(struct clcd_fb *fb)
 {
-	dma_free_writecombine(&fb->dev->dev, fb->fb.fix.smem_len,
-		fb->fb.screen_base, fb->fb.fix.smem_start);
+	dma_free_wc(&fb->dev->dev, fb->fb.fix.smem_len, fb->fb.screen_base,
+		    fb->fb.fix.smem_start);
 }