powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac (9739ab7e) · Commits · 戴 / test

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: ("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>

arch/powerpc/include/asm/page.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -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 */

arch/powerpc/mm/mem.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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

arch/powerpc/platforms/powermac/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

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