diff options
| author | Christoph Hellwig <hch@lst.de> | 2023-10-17 16:04:42 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2023-10-22 16:38:54 +0200 |
| commit | 9e28bf8bdf2177a88bd6648fc741bc0280e08af8 (patch) | |
| tree | 48d0dcc3c9d4d37994651d2a78bdc076a4c1f1cd /arch/m68k | |
| parent | 63f067e33c996a6e4d9a34d138116a43105182f1 (diff) | |
m68k: use the coherent DMA code for coldfire without data cache
Coldfire cores configured without a data cache are DMA coherent and
should thus simply use the simple coherent version of dma-direct.
Introduce a new COLDFIRE_COHERENT_DMA Kconfig symbol as a convenient
short hand for such configurations, and a M68K_NONCOHERENT_DMA symbol
for all cases where we need to build non-coherent DMA infrastructure
to simplify the Kconfig and code conditionals.
Not building the non-coherent DMA code slightly reduces the code
size for such configurations.
Numers for m5249evb_defconfig below:
text data bss dec hex filename
2896158 401052 65392 3362602 334f2a vmlinux.before
2895166 400988 65392 3361546 334b0a vmlinux.after
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Greg Ungerer <gerg@linux-m68k.org>
Diffstat (limited to 'arch/m68k')
| -rw-r--r-- | arch/m68k/Kconfig | 8 | ||||
| -rw-r--r-- | arch/m68k/Kconfig.cpu | 12 | ||||
| -rw-r--r-- | arch/m68k/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/m68k/kernel/dma.c | 2 |
4 files changed, 18 insertions, 6 deletions
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index 4f3e7dec2171..50ada24dfbba 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -6,16 +6,16 @@ config M68K select ARCH_HAS_BINFMT_FLAT select ARCH_HAS_CPU_FINALIZE_INIT if MMU select ARCH_HAS_CURRENT_STACK_POINTER - select ARCH_HAS_DMA_ALLOC if !MMU || COLDFIRE - select ARCH_HAS_DMA_PREP_COHERENT if HAS_DMA && MMU && !COLDFIRE - select ARCH_HAS_SYNC_DMA_FOR_DEVICE if HAS_DMA + select ARCH_HAS_DMA_ALLOC if M68K_NONCOHERENT_DMA && COLDFIRE + select ARCH_HAS_DMA_PREP_COHERENT if M68K_NONCOHERENT_DMA && !COLDFIRE + select ARCH_HAS_SYNC_DMA_FOR_DEVICE if M68K_NONCOHERENT_DMA select ARCH_HAVE_NMI_SAFE_CMPXCHG if RMW_INSNS select ARCH_MIGHT_HAVE_PC_PARPORT if ISA select ARCH_NO_PREEMPT if !COLDFIRE select ARCH_USE_MEMTEST if MMU_MOTOROLA select ARCH_WANT_IPC_PARSE_VERSION select BINFMT_FLAT_ARGVP_ENVP_ON_STACK - select DMA_DIRECT_REMAP if HAS_DMA && MMU && !COLDFIRE + select DMA_DIRECT_REMAP if M68K_NONCOHERENT_DMA && !COLDFIRE select GENERIC_ATOMIC64 select GENERIC_CPU_DEVICES select GENERIC_IOMAP diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu index b826e9c677b2..ad69b466a08b 100644 --- a/arch/m68k/Kconfig.cpu +++ b/arch/m68k/Kconfig.cpu @@ -535,3 +535,15 @@ config CACHE_COPYBACK The ColdFire CPU cache is set into Copy-back mode. endchoice endif # HAVE_CACHE_CB + +# Coldfire cores that do not have a data cache configured can do coherent DMA. +config COLDFIRE_COHERENT_DMA + bool + default y + depends on COLDFIRE + depends on !HAVE_CACHE_CB && !CACHE_D && !CACHE_BOTH + +config M68K_NONCOHERENT_DMA + bool + default y + depends on HAS_DMA && !COLDFIRE_COHERENT_DMA diff --git a/arch/m68k/kernel/Makefile b/arch/m68k/kernel/Makefile index af015447dfb4..01fb69a5095f 100644 --- a/arch/m68k/kernel/Makefile +++ b/arch/m68k/kernel/Makefile @@ -23,7 +23,7 @@ obj-$(CONFIG_MMU_MOTOROLA) += ints.o vectors.o obj-$(CONFIG_MMU_SUN3) += ints.o vectors.o obj-$(CONFIG_PCI) += pcibios.o -obj-$(CONFIG_HAS_DMA) += dma.o +obj-$(CONFIG_M68K_NONCOHERENT_DMA) += dma.o obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o obj-$(CONFIG_BOOTINFO_PROC) += bootinfo_proc.o diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c index 2e192a5df949..f83870cfa79b 100644 --- a/arch/m68k/kernel/dma.c +++ b/arch/m68k/kernel/dma.c @@ -17,7 +17,7 @@ #include <asm/cacheflush.h> -#if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE) +#ifndef CONFIG_COLDFIRE void arch_dma_prep_coherent(struct page *page, size_t size) { cache_push(page_to_phys(page), size); |