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/Kconfig.cpu | |
| 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/Kconfig.cpu')
| -rw-r--r-- | arch/m68k/Kconfig.cpu | 12 |
1 files changed, 12 insertions, 0 deletions
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 |