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authorChristoph Hellwig <hch@lst.de>2019-06-13 11:24:46 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2019-06-19 15:31:20 +0300
commit9739ab7eda459f0669ec9807e0d9be5020bab88c (patch)
tree8c47ef74097699cd4dd4d53bebf10a8ccbb7610d /arch
parent84b028243ef07a3f65c1857343ada2b1022f8bed (diff)
downloadlinux-9739ab7eda459f0669ec9807e0d9be5020bab88c.tar.xz
powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac
With the strict dma mask checking introduced with the switch to the generic DMA direct code common wifi chips on 32-bit powerbooks stopped working. Add a 30-bit ZONE_DMA to the 32-bit pmac builds to allow them to reliably allocate dma coherent memory. Fixes: 65a21b71f948 ("powerpc/dma: remove dma_nommu_dma_supported") Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Larry Finger <Larry.Finger@lwfinger.net> Acked-by: Larry Finger <Larry.Finger@lwfinger.net> Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/include/asm/page.h7
-rw-r--r--arch/powerpc/mm/mem.c3
-rw-r--r--arch/powerpc/platforms/powermac/Kconfig1
3 files changed, 10 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index dbc8c0679480..3d013e4696e9 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -323,6 +323,13 @@ struct vm_area_struct;
#endif /* __ASSEMBLY__ */
#include <asm/slice.h>
+/*
+ * Allow 30-bit DMA for very limited Broadcom wifi chips on many powerbooks.
+ */
+#ifdef CONFIG_PPC32
+#define ARCH_ZONE_DMA_BITS 30
+#else
#define ARCH_ZONE_DMA_BITS 31
+#endif
#endif /* _ASM_POWERPC_PAGE_H */
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index e885fe2aafcc..40bd4153ab09 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -253,7 +253,8 @@ void __init paging_init(void)
(long int)((top_of_ram - total_ram) >> 20));
#ifdef CONFIG_ZONE_DMA
- max_zone_pfns[ZONE_DMA] = min(max_low_pfn, 0x7fffffffUL >> PAGE_SHIFT);
+ max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
+ ((1UL << ARCH_ZONE_DMA_BITS) - 1) >> PAGE_SHIFT);
#endif
max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
#ifdef CONFIG_HIGHMEM
diff --git a/arch/powerpc/platforms/powermac/Kconfig b/arch/powerpc/platforms/powermac/Kconfig
index f834a19ed772..c02d8c503b29 100644
--- a/arch/powerpc/platforms/powermac/Kconfig
+++ b/arch/powerpc/platforms/powermac/Kconfig
@@ -7,6 +7,7 @@ config PPC_PMAC
select PPC_INDIRECT_PCI if PPC32
select PPC_MPC106 if PPC32
select PPC_NATIVE
+ select ZONE_DMA if PPC32
default y
config PPC_PMAC64