diff options
| author | shaohui xie <Shaohui.Xie@freescale.com> | 2012-09-27 11:44:32 (GMT) |
|---|---|---|
| committer | Emil Medve <Emilian.Medve@Freescale.com> | 2013-03-21 18:42:11 (GMT) |
| commit | 142229f7ecd8e302821fc6e3f81d934a834796af (patch) | |
| tree | dd3a715d926afd345a7ad0c9cee20bcd758b74bf /arch/powerpc/kernel/dma.c | |
| parent | 16e8de2280329ce5b1afd5f881ea1b434953f0e4 (diff) | |
| download | linux-fsl-qoriq-142229f7ecd8e302821fc6e3f81d934a834796af.tar.xz | |
powerpc/mm: add ZONE_NORMAL zone for 64 bit kernel
PowerPC platform only supports ZONE_DMA zone for 64bit kernel, so all the
memory will be put into this zone. If the memory size is greater than
the device's DMA capability and device uses dma_alloc_coherent to allocate
memory, it will get an address which is over the device's DMA addressing,
the device will fail.
So we split the memory to two zones by adding a zone ZONE_NORMAL, since
we already allocate PCICSRBAR/PEXCSRBAR right below the 4G boundary (if the
lowest PCI address is above 4G), so we constrain the DMA zone ZONE_DMA
to 2GB, also, we clear the flag __GFP_DMA and set it only if the device's
dma_mask < total memory size. By doing this, devices which cannot DMA all
the memory will be limited to ZONE_DMA, but devices which can DMA all the
memory will not be affected by this limitation.
Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Chen Yuanquan <B41889@freescale.com>
(cherry picked from commit 070f1ae0a48417888b6ad02b15baa384823c7591)
Diffstat (limited to 'arch/powerpc/kernel/dma.c')
| -rw-r--r-- | arch/powerpc/kernel/dma.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c index 8032b97..1a3dd00 100644 --- a/arch/powerpc/kernel/dma.c +++ b/arch/powerpc/kernel/dma.c @@ -31,6 +31,7 @@ void *dma_direct_alloc_coherent(struct device *dev, size_t size, struct dma_attrs *attrs) { void *ret; + phys_addr_t top_ram_pfn = memblock_end_of_DRAM(); #ifdef CONFIG_NOT_COHERENT_CACHE ret = __dma_alloc_coherent(dev, size, dma_handle, flag); if (ret == NULL) @@ -41,8 +42,18 @@ void *dma_direct_alloc_coherent(struct device *dev, size_t size, struct page *page; int node = dev_to_node(dev); + /* + * check for crappy device which has dma_mask < ZONE_DMA, and + * we are not going to support it, just warn and fail. + */ + if (*dev->dma_mask < DMA_BIT_MASK(31)) { + dev_err(dev, "Unsupported dma_mask 0x%llx\n", *dev->dma_mask); + return NULL; + } /* ignore region specifiers */ - flag &= ~(__GFP_HIGHMEM); + flag &= ~(__GFP_HIGHMEM | __GFP_DMA); + if (*dev->dma_mask < top_ram_pfn - 1) + flag |= GFP_DMA; page = alloc_pages_node(node, flag, get_order(size)); if (page == NULL) |