ARCv2: IOC: use @ioc_enable not @ioc_exist where intended

if user disables IOC from debugger at startup (by clearing @ioc_enable),
@ioc_exists is cleared too. This means boot prints don't capture the
fact that IOC was present but disabled which could be misleading.

So invert how we use @ioc_enable and @ioc_exists and make it more
canonical. @ioc_exists represent whether hardware is present or not and
stays same whether enabled or not. @ioc_enable is still user driven,
but will be auto-disabled if IOC hardware is not present, i.e. if
@ioc_exist=0. This is opposite to what we were doing before, but much
clearer.

This means @ioc_enable is now the "exported" toggle in rest of code such
as dma mapping API.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 20afc65e22dc..60aab5a7522b 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -45,7 +45,7 @@ static void *arc_dma_alloc(struct device *dev, size_t size,
 	 *   -For coherent data, Read/Write to buffers terminate early in cache
 	 *   (vs. always going to memory - thus are faster)
 	 */
-	if ((is_isa_arcv2() && ioc_exists) ||
+	if ((is_isa_arcv2() && ioc_enable) ||
 	    (attrs & DMA_ATTR_NON_CONSISTENT))
 		need_coh = 0;
 
@@ -97,7 +97,7 @@ static void arc_dma_free(struct device *dev, size_t size, void *vaddr,
 	int is_non_coh = 1;
 
 	is_non_coh = (attrs & DMA_ATTR_NON_CONSISTENT) ||
-			(is_isa_arcv2() && ioc_exists);
+			(is_isa_arcv2() && ioc_enable);
 
 	if (PageHighMem(page) || !is_non_coh)
 		iounmap((void __force __iomem *)vaddr);