From 9739ab7eda459f0669ec9807e0d9be5020bab88c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 13 Jun 2019 10:24:46 +0200 Subject: [PATCH] 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 Signed-off-by: Christoph Hellwig Tested-by: Larry Finger Acked-by: Larry Finger Tested-by: Aaro Koskinen Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/page.h | 7 +++++++ arch/powerpc/mm/mem.c | 3 ++- arch/powerpc/platforms/powermac/Kconfig | 1 + 3 files changed, 10 insertions(+), 1 deletion(-) 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 +/* + * 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 -- 2.30.2