diff options
| author | Akinobu Mita <akinobu.mita@gmail.com> | 2014-06-04 16:06:54 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-04 16:53:57 -0700 |
| commit | 5ea3b1b2f8ad9162684431ce6188102ca4c64b7a (patch) | |
| tree | fe87b74396be16d20025673adf39ed607d7e3b92 /arch | |
| parent | 2bfc2862c4fe38379a2fb2cfba33fad32ccb4ff4 (diff) | |
cma: add placement specifier for "cma=" kernel parameter
Currently, "cma=" kernel parameter is used to specify the size of CMA,
but we can't specify where it is located. We want to locate CMA below
4GB for devices only supporting 32-bit addressing on 64-bit systems
without iommu.
This enables to specify the placement of CMA by extending "cma=" kernel
parameter.
Examples:
1. locate 64MB CMA below 4GB by "cma=64M@0-4G"
2. locate 64MB CMA exact at 512MB by "cma=64M@512M"
Note that the DMA contiguous memory allocator on x86 assumes that
page_address() works for the pages to allocate. So this change requires
to limit end address of contiguous memory area upto max_pfn_mapped to
prevent from locating it on highmem area by the argument of
dma_contiguous_reserve().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/setup.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 09c76d26555..78a0e629892 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1119,7 +1119,7 @@ void __init setup_arch(char **cmdline_p) setup_real_mode(); memblock_set_current_limit(get_max_mapped()); - dma_contiguous_reserve(0); + dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT); /* * NOTE: On x86-32, only from this point on, fixmaps are ready for use. |