[PATCH 1/2] drivers: dma-mapping: allow dma_common_mmap() for NOMMU
From: Vladimir Murzin <hidden>
Date: 2017-06-28 09:17:57
Also in:
lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, m68k architecture, microblaze architecture, superh, tensilica xtensa port (xtensa), the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Geert Uytterhoeven, Michal Simek, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Chris Zankel, Max Filippov, Linus Torvalds
Currently, internals of dma_common_mmap() is compiled out if build is done for either NOMMU or target which explicitly says it does not have/want coherent DMA mmap. It turned out that dma_common_mmap() can be handy in NOMMU setup (at least for ARM). This patch converts exitent NOMMU targets to use ARCH_NO_COHERENT_DMA_MMAP, thus when CONFIG_MMU is gone from dma_common_mmap() their behaviour stays unchanged. ARM is not converted to ARCH_NO_COHERENT_DMA_MMAP because it 1) already has mmap callback which can handle (at some extent) NOMMU 2) already defines dummy pgprot_noncached() for NOMMU build. c6x and frv stay untouched since they already have ARCH_NO_COHERENT_DMA_MMAP. Cc: Steven Miao <redacted> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Vladimir Murzin <redacted> --- arch/blackfin/Kconfig | 1 + arch/m32r/Kconfig | 1 + arch/m68k/Kconfig | 1 + arch/microblaze/Kconfig | 1 + arch/sh/Kconfig | 1 + arch/xtensa/Kconfig | 1 + drivers/base/dma-mapping.c | 4 ++-- 7 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 3c1bd64..89bdb82 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig@@ -41,6 +41,7 @@ config BLACKFIN select MODULES_USE_ELF_RELA select HAVE_DEBUG_STACKOVERFLOW select HAVE_NMI + select ARCH_NO_COHERENT_DMA_MMAP config GENERIC_CSUM def_bool y
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index 9547446..87cde1e 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig@@ -19,6 +19,7 @@ config M32R select HAVE_DEBUG_STACKOVERFLOW select CPU_NO_EFFICIENT_FFS select DMA_NOOP_OPS + select ARCH_NO_COHERENT_DMA_MMAP if !MMU config SBUS bool
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index d140206..5abb548 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig@@ -2,6 +2,7 @@ config M68K bool default y select ARCH_MIGHT_HAVE_PC_PARPORT if ISA + select ARCH_NO_COHERENT_DMA_MMAP if !MMU select HAVE_IDE select HAVE_AOUT if MMU select HAVE_DEBUG_BUGVERBOSE
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 85885a5..8ba7b7c 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig@@ -2,6 +2,7 @@ config MICROBLAZE def_bool y select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_MIGHT_HAVE_PC_PARPORT + select ARCH_NO_COHERENT_DMA_MMAP if !MMU select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT select CLKSRC_OF
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index ee08695..640a859 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig@@ -2,6 +2,7 @@ config SUPERH def_bool y select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_MIGHT_HAVE_PC_PARPORT + select ARCH_NO_COHERENT_DMA_MMAP if !MMU select HAVE_PATA_PLATFORM select CLKDEV_LOOKUP select HAVE_IDE if HAS_IOPORT_MAP
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index f4126cf..7ad6d77 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig@@ -3,6 +3,7 @@ config ZONE_DMA config XTENSA def_bool y + select ARCH_NO_COHERENT_DMA_MMAP if !MMU select ARCH_WANT_FRAME_POINTERS select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 10e7c02..ce1e02b 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c@@ -227,7 +227,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size) { int ret = -ENXIO; -#if defined(CONFIG_MMU) && !defined(CONFIG_ARCH_NO_COHERENT_DMA_MMAP) +#ifndef CONFIG_ARCH_NO_COHERENT_DMA_MMAP unsigned long user_count = vma_pages(vma); unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
@@ -244,7 +244,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, user_count << PAGE_SHIFT, vma->vm_page_prot); } -#endif /* CONFIG_MMU && !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */ +#endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */ return ret; }
--
2.0.0