Re: FOR COMMENT: void __iomem * and similar casts are Bad News

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

On Wed, Sep 03, 2008 at 03:05:59PM -0700, David Brownell wrote:
> According to Mr. Grep, there are at least 10 ARMs that work
> like that in mainline.  Maybe Russell can recommend one of
> them as a preferred model.

As I've been trying to say, I see this as a separate issue for the near
future.  At the moment, I'm trying to concentrate on one aspect only.

That is, getting OMAP to the point that we're using the compiler to
warn us when we do something silly, like passing a virtual address
to a function which takes a physical address, and fixing the places
which are currently wrong.

Anything else like changing the ioremap behaviour is actually
completely orthogonal to that, and *is* a distraction.  Rather than
actually fixing the mcbsp.c issue, I've spent the last hour or so
composing various replies to Richard's emails, and then postponing
them, reading more of this thread, creating more replies, postponing
those as well, etc.

Anyway, what I've done now is committed the minimal set of fixes so
far to go into mainline for the current -rc so we can at least improve
the situation there.  That's not to say that the other patch won't be
going in - it will in some form or other.

It can also be applied to the omap tree by saving this message as
"whateverpatchfile", running:

sed -i 's,\[id\]\.,->,' whateverpatchfile

and then applying "whateverpatchfile".  Expect some offsets.

Arun - can you please test this patch on your 5912 OSK board to see if
it resolves your problem please?

diff --git a/arch/arm/mach-omap1/mcbsp.c b/arch/arm/mach-omap1/mcbsp.c
index 826010d..b6ffbab 100644
--- a/arch/arm/mach-omap1/mcbsp.c
+++ b/arch/arm/mach-omap1/mcbsp.c
@@ -184,7 +184,7 @@ static struct omap_mcbsp_platform_data omap730_mcbsp_pdata[] = {
 #ifdef CONFIG_ARCH_OMAP15XX
 static struct omap_mcbsp_platform_data omap15xx_mcbsp_pdata[] = {
 	{
-		.virt_base	= OMAP1510_MCBSP1_BASE,
+		.virt_base	= io_p2v(OMAP1510_MCBSP1_BASE),
 		.dma_rx_sync	= OMAP_DMA_MCBSP1_RX,
 		.dma_tx_sync	= OMAP_DMA_MCBSP1_TX,
 		.rx_irq		= INT_McBSP1RX,
@@ -201,7 +201,7 @@ static struct omap_mcbsp_platform_data omap15xx_mcbsp_pdata[] = {
 		.ops		= &omap1_mcbsp_ops,
 	},
 	{
-		.virt_base	= OMAP1510_MCBSP3_BASE,
+		.virt_base	= io_p2v(OMAP1510_MCBSP3_BASE),
 		.dma_rx_sync	= OMAP_DMA_MCBSP3_RX,
 		.dma_tx_sync	= OMAP_DMA_MCBSP3_TX,
 		.rx_irq		= INT_McBSP3RX,
@@ -219,7 +219,7 @@ static struct omap_mcbsp_platform_data omap15xx_mcbsp_pdata[] = {
 #ifdef CONFIG_ARCH_OMAP16XX
 static struct omap_mcbsp_platform_data omap16xx_mcbsp_pdata[] = {
 	{
-		.virt_base	= OMAP1610_MCBSP1_BASE,
+		.virt_base	= io_p2v(OMAP1610_MCBSP1_BASE),
 		.dma_rx_sync	= OMAP_DMA_MCBSP1_RX,
 		.dma_tx_sync	= OMAP_DMA_MCBSP1_TX,
 		.rx_irq		= INT_McBSP1RX,
@@ -236,7 +236,7 @@ static struct omap_mcbsp_platform_data omap16xx_mcbsp_pdata[] = {
 		.ops		= &omap1_mcbsp_ops,
 	},
 	{
-		.virt_base	= OMAP1610_MCBSP3_BASE,
+		.virt_base	= io_p2v(OMAP1610_MCBSP3_BASE),
 		.dma_rx_sync	= OMAP_DMA_MCBSP3_RX,
 		.dma_tx_sync	= OMAP_DMA_MCBSP3_TX,
 		.rx_irq		= INT_McBSP3RX,
diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c
index d084405..5245a2a 100644
--- a/arch/arm/plat-omap/mcbsp.c
+++ b/arch/arm/plat-omap/mcbsp.c
@@ -651,7 +651,7 @@ int omap_mcbsp_xmit_buffer(unsigned int id, dma_addr_t buffer,
 	omap_set_dma_dest_params(mcbsp[id].dma_tx_lch,
 				 src_port,
 				 OMAP_DMA_AMODE_CONSTANT,
-				 mcbsp[id].io_base + OMAP_MCBSP_REG_DXR1,
+				 io_v2p(mcbsp[id].io_base + OMAP_MCBSP_REG_DXR1),
 				 0, 0);
 
 	omap_set_dma_src_params(mcbsp[id].dma_tx_lch,
@@ -712,7 +712,7 @@ int omap_mcbsp_recv_buffer(unsigned int id, dma_addr_t buffer,
 	omap_set_dma_src_params(mcbsp[id].dma_rx_lch,
 				src_port,
 				OMAP_DMA_AMODE_CONSTANT,
-				mcbsp[id].io_base + OMAP_MCBSP_REG_DRR1,
+				io_v2p(mcbsp[id].io_base + OMAP_MCBSP_REG_DRR1),
 				0, 0);
 
 	omap_set_dma_dest_params(mcbsp[id].dma_rx_lch,