Merge branches 'iommu/fixes', 'dma-debug', 'x86/amd', 'x86/vt-d', 'ar…

…m/tegra' and 'arm/omap' into next

Documentation/DMA-API-HOWTO.txt

@@ -468,11 +468,46 @@ To map a single region, you do:
 	size_t size = buffer->len;
 
 	dma_handle = dma_map_single(dev, addr, size, direction);
+	if (dma_mapping_error(dma_handle)) {
+		/*
+		 * reduce current DMA mapping usage,
+		 * delay and try again later or
+		 * reset driver.
+		 */
+		goto map_error_handling;
+	}
 
 and to unmap it:
 
 	dma_unmap_single(dev, dma_handle, size, direction);
 
+You should call dma_mapping_error() as dma_map_single() could fail and return
+error. Not all dma implementations support dma_mapping_error() interface.
+However, it is a good practice to call dma_mapping_error() interface, which
+will invoke the generic mapping error check interface. Doing so will ensure
+that the mapping code will work correctly on all dma implementations without
+any dependency on the specifics of the underlying implementation. Using the
+returned address without checking for errors could result in failures ranging
+from panics to silent data corruption. Couple of example of incorrect ways to
+check for errors that make assumptions about the underlying dma implementation
+are as follows and these are applicable to dma_map_page() as well.
+
+Incorrect example 1:
+	dma_addr_t dma_handle;
+
+	dma_handle = dma_map_single(dev, addr, size, direction);
+	if ((dma_handle & 0xffff != 0) || (dma_handle >= 0x1000000)) {
+		goto map_error;
+	}
+
+Incorrect example 2:
+	dma_addr_t dma_handle;
+
+	dma_handle = dma_map_single(dev, addr, size, direction);
+	if (dma_handle == DMA_ERROR_CODE) {
+		goto map_error;
+	}
+
 You should call dma_unmap_single when the DMA activity is finished, e.g.
 from the interrupt which told you that the DMA transfer is done.
 
@@ -489,13 +524,27 @@ Specifically:
 	size_t size = buffer->len;
 
 	dma_handle = dma_map_page(dev, page, offset, size, direction);
+	if (dma_mapping_error(dma_handle)) {
+		/*
+		 * reduce current DMA mapping usage,
+		 * delay and try again later or
+		 * reset driver.
+		 */
+		goto map_error_handling;
+	}
 
 	...
 
 	dma_unmap_page(dev, dma_handle, size, direction);
 
 Here, "offset" means byte offset within the given page.
 
+You should call dma_mapping_error() as dma_map_page() could fail and return
+error as outlined under the dma_map_single() discussion.
+
+You should call dma_unmap_page when the DMA activity is finished, e.g.
+from the interrupt which told you that the DMA transfer is done.
+
 With scatterlists, you map a region gathered from several regions by:
 
 	int i, count = dma_map_sg(dev, sglist, nents, direction);
@@ -578,6 +627,14 @@ to use the dma_sync_*() interfaces.
 		dma_addr_t mapping;
 
 		mapping = dma_map_single(cp->dev, buffer, len, DMA_FROM_DEVICE);
+		if (dma_mapping_error(dma_handle)) {
+			/*
+			 * reduce current DMA mapping usage,
+			 * delay and try again later or
+			 * reset driver.
+			 */
+			goto map_error_handling;
+		}
 
 		cp->rx_buf = buffer;
 		cp->rx_len = len;
@@ -658,6 +715,75 @@ failure can be determined by:
 		 * delay and try again later or
 		 * reset driver.
 		 */
+		goto map_error_handling;
+	}
+
+- unmap pages that are already mapped, when mapping error occurs in the middle
+  of a multiple page mapping attempt. These example are applicable to
+  dma_map_page() as well.
+
+Example 1:
+	dma_addr_t dma_handle1;
+	dma_addr_t dma_handle2;
+
+	dma_handle1 = dma_map_single(dev, addr, size, direction);
+	if (dma_mapping_error(dev, dma_handle1)) {
+		/*
+		 * reduce current DMA mapping usage,
+		 * delay and try again later or
+		 * reset driver.
+		 */
+		goto map_error_handling1;
+	}
+	dma_handle2 = dma_map_single(dev, addr, size, direction);
+	if (dma_mapping_error(dev, dma_handle2)) {
+		/*
+		 * reduce current DMA mapping usage,
+		 * delay and try again later or
+		 * reset driver.
+		 */
+		goto map_error_handling2;
+	}
+
+	...
+
+	map_error_handling2:
+		dma_unmap_single(dma_handle1);
+	map_error_handling1:
+
+Example 2: (if buffers are allocated a loop, unmap all mapped buffers when
+	    mapping error is detected in the middle)
+
+	dma_addr_t dma_addr;
+	dma_addr_t array[DMA_BUFFERS];
+	int save_index = 0;
+
+	for (i = 0; i < DMA_BUFFERS; i++) {
+
+		...
+
+		dma_addr = dma_map_single(dev, addr, size, direction);
+		if (dma_mapping_error(dev, dma_addr)) {
+			/*
+			 * reduce current DMA mapping usage,
+			 * delay and try again later or
+			 * reset driver.
+			 */
+			goto map_error_handling;
+		}
+		array[i].dma_addr = dma_addr;
+		save_index++;
+	}
+
+	...
+
+	map_error_handling:
+
+	for (i = 0; i < save_index; i++) {
+
+		...
+
+		dma_unmap_single(array[i].dma_addr);
 	}
 
 Networking drivers must call dev_kfree_skb to free the socket buffer

Documentation/DMA-API.txt

@@ -678,3 +678,15 @@ out of dma_debug_entries. These entries are preallocated at boot. The number
 of preallocated entries is defined per architecture. If it is too low for you
 boot with 'dma_debug_entries=<your_desired_number>' to overwrite the
 architectural default.
+
+void debug_dmap_mapping_error(struct device *dev, dma_addr_t dma_addr);
+
+dma-debug interface debug_dma_mapping_error() to debug drivers that fail
+to check dma mapping errors on addresses returned by dma_map_single() and
+dma_map_page() interfaces. This interface clears a flag set by
+debug_dma_map_page() to indicate that dma_mapping_error() has been called by
+the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
+this flag is still set, prints warning message that includes call trace that
+leads up to the unmap. This interface can be called from dma_mapping_error()
+routines to enable dma mapping error check debugging.
+

arch/arm/include/asm/dma-mapping.h

@@ -91,6 +91,7 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  */
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
+	debug_dma_mapping_error(dev, dma_addr);
 	return dma_addr == DMA_ERROR_CODE;
 }
 

arch/arm/mach-omap2/Makefile

@@ -184,8 +184,6 @@ obj-$(CONFIG_HW_PERF_EVENTS)		+= pmu.o
 obj-$(CONFIG_OMAP_MBOX_FWK)		+= mailbox_mach.o
 mailbox_mach-objs			:= mailbox.o
 
-obj-$(CONFIG_OMAP_IOMMU)		+= iommu2.o
-
 iommu-$(CONFIG_OMAP_IOMMU)		:= omap-iommu.o
 obj-y					+= $(iommu-m) $(iommu-y)
 

arch/arm/mach-omap2/clock44xx_data.c

@@ -1316,16 +1316,6 @@ static struct clk dmic_fck = {
 	.clkdm_name	= "abe_clkdm",
 };
 
-static struct clk dsp_fck = {
-	.name		= "dsp_fck",
-	.ops		= &clkops_omap2_dflt,
-	.enable_reg	= OMAP4430_CM_TESLA_TESLA_CLKCTRL,
-	.enable_bit	= OMAP4430_MODULEMODE_HWCTRL,
-	.clkdm_name	= "tesla_clkdm",
-	.parent		= &dpll_iva_m4x2_ck,
-	.recalc		= &followparent_recalc,
-};
-
 static struct clk dss_sys_clk = {
 	.name		= "dss_sys_clk",
 	.ops		= &clkops_omap2_dflt,
@@ -1696,16 +1686,6 @@ static struct clk i2c4_fck = {
 	.recalc		= &followparent_recalc,
 };
 
-static struct clk ipu_fck = {
-	.name		= "ipu_fck",
-	.ops		= &clkops_omap2_dflt,
-	.enable_reg	= OMAP4430_CM_DUCATI_DUCATI_CLKCTRL,
-	.enable_bit	= OMAP4430_MODULEMODE_HWCTRL,
-	.clkdm_name	= "ducati_clkdm",
-	.parent		= &ducati_clk_mux_ck,
-	.recalc		= &followparent_recalc,
-};
-
 static struct clk iss_ctrlclk = {
 	.name		= "iss_ctrlclk",
 	.ops		= &clkops_omap2_dflt,
@@ -3151,7 +3131,6 @@ static struct omap_clk omap44xx_clks[] = {
 	CLK(NULL,	"div_ts_ck",			&div_ts_ck,	CK_446X),
 	CLK(NULL,	"dmic_sync_mux_ck",		&dmic_sync_mux_ck,	CK_443X),
 	CLK(NULL,	"dmic_fck",			&dmic_fck,	CK_443X),
-	CLK(NULL,	"dsp_fck",			&dsp_fck,	CK_443X),
 	CLK(NULL,	"dss_sys_clk",			&dss_sys_clk,	CK_443X),
 	CLK(NULL,	"dss_tv_clk",			&dss_tv_clk,	CK_443X),
 	CLK(NULL,	"dss_48mhz_clk",		&dss_48mhz_clk,	CK_443X),
@@ -3183,7 +3162,6 @@ static struct omap_clk omap44xx_clks[] = {
 	CLK(NULL,	"i2c2_fck",			&i2c2_fck,	CK_443X),
 	CLK(NULL,	"i2c3_fck",			&i2c3_fck,	CK_443X),
 	CLK(NULL,	"i2c4_fck",			&i2c4_fck,	CK_443X),
-	CLK(NULL,	"ipu_fck",			&ipu_fck,	CK_443X),
 	CLK(NULL,	"iss_ctrlclk",			&iss_ctrlclk,	CK_443X),
 	CLK(NULL,	"iss_fck",			&iss_fck,	CK_443X),
 	CLK(NULL,	"iva_fck",			&iva_fck,	CK_443X),

arch/arm/mach-omap2/devices.c

@@ -127,7 +127,7 @@ static struct platform_device omap2cam_device = {
 
 #if defined(CONFIG_IOMMU_API)
 
-#include <plat/iommu.h>
+#include <linux/platform_data/iommu-omap.h>
 
 static struct resource omap3isp_resources[] = {
 	{
@@ -214,7 +214,7 @@ static struct platform_device omap3isp_device = {
 };
 
 static struct omap_iommu_arch_data omap3_isp_iommu = {
-	.name = "isp",
+	.name = "mmu_isp",
 };
 
 int omap3_init_camera(struct isp_platform_data *pdata)