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Commit 25078dc1 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Michael Ellerman
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powerpc: use mm zones more sensibly 



Powerpc has somewhat odd usage where ZONE_DMA is used for all memory on
common 64-bit configfs, and ZONE_DMA32 is used for 31-bit schemes.

Move to a scheme closer to what other architectures use (and I dare to
say the intent of the system):

 - ZONE_DMA: optionally for memory < 31-bit (64-bit embedded only)
 - ZONE_NORMAL: everything addressable by the kernel
 - ZONE_HIGHMEM: memory > 32-bit for 32-bit kernels

Also provide information on how ZONE_DMA is used by defining
ARCH_ZONE_DMA_BITS.

Contains various fixes from Benjamin Herrenschmidt.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent f3e5a857

arch/powerpc/Kconfig

+2 −6
Original line number Diff line number Diff line
@@ -375,9 +375,9 @@ config PPC_ADV_DEBUG_DAC_RANGE 
	depends on PPC_ADV_DEBUG_REGS && 44x

	default y



config ZONE_DMA32

config ZONE_DMA

	bool

	default y if PPC64

	default y if PPC_BOOK3E_64



config PGTABLE_LEVELS

	int
@@ -870,10 +870,6 @@ config ISA 
	  have an IBM RS/6000 or pSeries machine, say Y.  If you have an

	  embedded board, consult your board documentation.



config ZONE_DMA

	bool

	default y



config GENERIC_ISA_DMA

	bool

	depends on ISA_DMA_API

arch/powerpc/include/asm/page.h

+2 −0
Original line number Diff line number Diff line
@@ -340,4 +340,6 @@ struct vm_area_struct; 
#endif /* __ASSEMBLY__ */

#include <asm/slice.h>



#define ARCH_ZONE_DMA_BITS 31



#endif /* _ASM_POWERPC_PAGE_H */

arch/powerpc/include/asm/pgtable.h

+0 −1
Original line number Diff line number Diff line
@@ -66,7 +66,6 @@ extern unsigned long empty_zero_page[]; 


extern pgd_t swapper_pg_dir[];



void limit_zone_pfn(enum zone_type zone, unsigned long max_pfn);

int dma_pfn_limit_to_zone(u64 pfn_limit);

extern void paging_init(void);

arch/powerpc/kernel/dma-swiotlb.c

+1 −5
Original line number Diff line number Diff line
@@ -108,12 +108,8 @@ int __init swiotlb_setup_bus_notifier(void) 


void __init swiotlb_detect_4g(void)

{

	if ((memblock_end_of_DRAM() - 1) > 0xffffffff) {

	if ((memblock_end_of_DRAM() - 1) > 0xffffffff)

		ppc_swiotlb_enable = 1;

#ifdef CONFIG_ZONE_DMA32

		limit_zone_pfn(ZONE_DMA32, (1ULL << 32) >> PAGE_SHIFT);

#endif

	}

}



static int __init check_swiotlb_enabled(void)

arch/powerpc/kernel/dma.c

+3 −5
Original line number Diff line number Diff line
@@ -50,7 +50,8 @@ static int dma_nommu_dma_supported(struct device *dev, u64 mask) 
		return 1;



#ifdef CONFIG_FSL_SOC

	/* Freescale gets another chance via ZONE_DMA/ZONE_DMA32, however

	/*

	 * Freescale gets another chance via ZONE_DMA, however

	 * that will have to be refined if/when they support iommus

	 */

	return 1;
@@ -88,13 +89,10 @@ void *__dma_nommu_alloc_coherent(struct device *dev, size_t size, 
	}



	switch (zone) {

#ifdef CONFIG_ZONE_DMA

	case ZONE_DMA:

		flag |= GFP_DMA;

		break;

#ifdef CONFIG_ZONE_DMA32

	case ZONE_DMA32:

		flag |= GFP_DMA32;

		break;

#endif

	};

#endif /* CONFIG_FSL_SOC */