Merge branch 'xtensa-dma-fixes' (early part) into xtensa-fixes

This switches xtensa arch to the generic noncoherent direct mapping
operations, adds support for DMA_ATTR_NO_KERNEL_MAPPING attribute and
allows for platform-specific handling of coherent memory.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

5 files changed, 36 insertions, 32 deletions

diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild
index e5e1e61c538c..82c756431b49 100644
--- a/arch/xtensa/include/asm/Kbuild
+++ b/arch/xtensa/include/asm/Kbuild
@@ -3,6 +3,7 @@ generic-y += compat.h
 generic-y += device.h
 generic-y += div64.h
 generic-y += dma-contiguous.h
+generic-y += dma-mapping.h
 generic-y += emergency-restart.h
 generic-y += exec.h
 generic-y += extable.h
diff --git a/arch/xtensa/include/asm/dma-mapping.h b/arch/xtensa/include/asm/dma-mapping.h
deleted file mode 100644
index 44098800dad7..000000000000
--- a/arch/xtensa/include/asm/dma-mapping.h
+++ /dev/null
@@ -1,26 +0,0 @@
-/*
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (C) 2003 - 2005 Tensilica Inc.
- * Copyright (C) 2015 Cadence Design Systems Inc.
- */
-
-#ifndef _XTENSA_DMA_MAPPING_H
-#define _XTENSA_DMA_MAPPING_H
-
-#include <asm/cache.h>
-#include <asm/io.h>
-
-#include <linux/mm.h>
-#include <linux/scatterlist.h>
-
-extern const struct dma_map_ops xtensa_dma_map_ops;
-
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
-{
-	return &xtensa_dma_map_ops;
-}
-
-#endif	/* _XTENSA_DMA_MAPPING_H */
diff --git a/arch/xtensa/include/asm/kmem_layout.h b/arch/xtensa/include/asm/kmem_layout.h
index 2317c835a4db..9c12babc016c 100644
--- a/arch/xtensa/include/asm/kmem_layout.h
+++ b/arch/xtensa/include/asm/kmem_layout.h
@@ -63,12 +63,6 @@
 #error XCHAL_KSEG_PADDR is not properly aligned to XCHAL_KSEG_ALIGNMENT
 #endif
 
-#else
-
-#define XCHAL_KSEG_CACHED_VADDR	__XTENSA_UL_CONST(0xd0000000)
-#define XCHAL_KSEG_BYPASS_VADDR	__XTENSA_UL_CONST(0xd8000000)
-#define XCHAL_KSEG_SIZE		__XTENSA_UL_CONST(0x08000000)
-
 #endif
 
 #ifndef CONFIG_KASAN
diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
index 38802259978f..29cfe421cf41 100644
--- a/arch/xtensa/include/asm/pgtable.h
+++ b/arch/xtensa/include/asm/pgtable.h
@@ -66,6 +66,7 @@
 #define FIRST_USER_ADDRESS	0UL
 #define FIRST_USER_PGD_NR	(FIRST_USER_ADDRESS >> PGDIR_SHIFT)
 
+#ifdef CONFIG_MMU
 /*
  * Virtual memory area. We keep a distance to other memory regions to be
  * on the safe side. We also use this area for cache aliasing.
@@ -80,6 +81,13 @@
 #define TLBTEMP_SIZE		ICACHE_WAY_SIZE
 #endif
 
+#else
+
+#define VMALLOC_START		__XTENSA_UL_CONST(0)
+#define VMALLOC_END		__XTENSA_UL_CONST(0xffffffff)
+
+#endif
+
 /*
  * For the Xtensa architecture, the PTE layout is as follows:
  *
diff --git a/arch/xtensa/include/asm/platform.h b/arch/xtensa/include/asm/platform.h
index f8fbef67bc5f..560483356a06 100644
--- a/arch/xtensa/include/asm/platform.h
+++ b/arch/xtensa/include/asm/platform.h
@@ -75,4 +75,31 @@ extern void platform_calibrate_ccount (void);
  */
 void cpu_reset(void) __attribute__((noreturn));
 
+/*
+ * Memory caching is platform-dependent in noMMU xtensa configurations.
+ * The following set of functions should be implemented in platform code
+ * in order to enable coherent DMA memory operations when CONFIG_MMU is not
+ * enabled. Default implementations do nothing and issue a warning.
+ */
+
+/*
+ * Check whether p points to a cached memory.
+ */
+bool platform_vaddr_cached(const void *p);
+
+/*
+ * Check whether p points to an uncached memory.
+ */
+bool platform_vaddr_uncached(const void *p);
+
+/*
+ * Return pointer to an uncached view of the cached sddress p.
+ */
+void *platform_vaddr_to_uncached(void *p);
+
+/*
+ * Return pointer to a cached view of the uncached sddress p.
+ */
+void *platform_vaddr_to_cached(void *p);
+
 #endif	/* _XTENSA_PLATFORM_H */