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Commit cce335ae authored by Ralf Baechle's avatar Ralf Baechle
Browse files

[MIPS] 64-bit Sibyte kernels need DMA32. 



Sibyte SOCs only have 32-bit PCI.  Due to the sparse use of the address
space only the first 1GB of memory is mapped at physical addresses
below 1GB.  If a system has more than 1GB of memory 32-bit DMA will
not be able to reach all of it.

For now this patch is good enough to keep Sibyte users happy but it seems
eventually something like swiotlb will be needed for Sibyte.

Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 940f6b48

arch/mips/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -515,6 +515,7 @@ config SIBYTE_SWARM 
	select SYS_SUPPORTS_HIGHMEM

	select SYS_SUPPORTS_KGDB

	select SYS_SUPPORTS_LITTLE_ENDIAN

	select ZONE_DMA32 if 64BIT



config SIBYTE_LITTLESUR

	bool "Sibyte BCM91250C2-LittleSur"
@@ -565,6 +566,7 @@ config SIBYTE_BIGSUR 
	select SYS_SUPPORTS_BIG_ENDIAN

	select SYS_SUPPORTS_HIGHMEM

	select SYS_SUPPORTS_LITTLE_ENDIAN

	select ZONE_DMA32 if 64BIT



config SNI_RM

	bool "SNI RM200/300/400"
@@ -1664,6 +1666,9 @@ config ARCH_DISCONTIGMEM_ENABLE 
	  or have huge holes in the physical address space for other reasons.

	  See <file:Documentation/vm/numa> for more.



config ARCH_POPULATES_NODE_MAP

	def_bool y



config ARCH_SPARSEMEM_ENABLE

	bool

	select SPARSEMEM_STATIC
@@ -1969,6 +1974,9 @@ config I8253 
config PCSPEAKER

	bool



config ZONE_DMA32

	bool



source "drivers/pcmcia/Kconfig"



source "drivers/pci/hotplug/Kconfig"

arch/mips/kernel/setup.c

+30 −1
Original line number Diff line number Diff line
@@ -269,7 +269,7 @@ static void __init bootmem_init(void) 


static void __init bootmem_init(void)

{

	unsigned long reserved_end;

	unsigned long init_begin, reserved_end;

	unsigned long mapstart = ~0UL;

	unsigned long bootmap_size;

	int i;
@@ -342,6 +342,35 @@ static void __init bootmem_init(void) 
	 */

	bootmap_size = init_bootmem_node(NODE_DATA(0), mapstart,

					 min_low_pfn, max_low_pfn);





	init_begin = PFN_UP(__pa_symbol(&__init_begin));

	for (i = 0; i < boot_mem_map.nr_map; i++) {

		unsigned long start, end;



		start = PFN_UP(boot_mem_map.map[i].addr);

		end = PFN_DOWN(boot_mem_map.map[i].addr

				+ boot_mem_map.map[i].size);



		if (start <= init_begin)

			start = init_begin;

		if (start >= end)

			continue;



#ifndef CONFIG_HIGHMEM

		if (end > max_low_pfn)

			end = max_low_pfn;



		/*

		 * ... finally, is the area going away?

		 */

		if (end <= start)

			continue;

#endif



		add_active_range(0, start, end);

	}



	/*

	 * Register fully available low RAM pages with the bootmem allocator.

	 */

arch/mips/mm/dma-default.c

+28 −9
Original line number Diff line number Diff line
@@ -40,16 +40,38 @@ static inline int cpu_is_noncoherent_r10000(struct device *dev) 
	       current_cpu_type() == CPU_R12000);

}



static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)

{

	/* ignore region specifiers */

	gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);



#ifdef CONFIG_ZONE_DMA32

	if (dev == NULL)

		gfp |= __GFP_DMA;

	else if (dev->coherent_dma_mask < DMA_BIT_MASK(24))

		gfp |= __GFP_DMA;

	else

#endif

#ifdef CONFIG_ZONE_DMA32

	     if (dev->coherent_dma_mask < DMA_BIT_MASK(32))

		gfp |= __GFP_DMA32;

	else

#endif

		;



	/* Don't invoke OOM killer */

	gfp |= __GFP_NORETRY;



	return gfp;

}



void *dma_alloc_noncoherent(struct device *dev, size_t size,

	dma_addr_t * dma_handle, gfp_t gfp)

{

	void *ret;



	/* ignore region specifiers */

	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);

	gfp = massage_gfp_flags(dev, gfp);



	if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))

		gfp |= GFP_DMA;

	ret = (void *) __get_free_pages(gfp, get_order(size));



	if (ret != NULL) {
@@ -67,11 +89,8 @@ void *dma_alloc_coherent(struct device *dev, size_t size, 
{

	void *ret;



	/* ignore region specifiers */

	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);

	gfp = massage_gfp_flags(dev, gfp);



	if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))

		gfp |= GFP_DMA;

	ret = (void *) __get_free_pages(gfp, get_order(size));



	if (ret) {
@@ -343,7 +362,7 @@ int dma_supported(struct device *dev, u64 mask) 
	 * so we can't guarantee allocations that must be

	 * within a tighter range than GFP_DMA..

	 */

	if (mask < 0x00ffffff)

	if (mask < DMA_BIT_MASK(24))

		return 0;



	return 1;

arch/mips/mm/init.c

+16 −27
Original line number Diff line number Diff line
@@ -347,11 +347,8 @@ static int __init page_is_ram(unsigned long pagenr) 


void __init paging_init(void)

{

	unsigned long zones_size[MAX_NR_ZONES] = { 0, };

#ifndef CONFIG_FLATMEM

	unsigned long zholes_size[MAX_NR_ZONES] = { 0, };

	unsigned long i, j, pfn;

#endif

	unsigned long max_zone_pfns[MAX_NR_ZONES];

	unsigned long lastpfn;



	pagetable_init();
@@ -361,35 +358,27 @@ void __init paging_init(void) 
	kmap_coherent_init();



#ifdef CONFIG_ZONE_DMA

	if (min_low_pfn < MAX_DMA_PFN && MAX_DMA_PFN <= max_low_pfn) {

		zones_size[ZONE_DMA] = MAX_DMA_PFN - min_low_pfn;

		zones_size[ZONE_NORMAL] = max_low_pfn - MAX_DMA_PFN;

	} else if (max_low_pfn < MAX_DMA_PFN)

		zones_size[ZONE_DMA] = max_low_pfn - min_low_pfn;

	else

	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;

#endif

	zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;



#ifdef CONFIG_ZONE_DMA32

	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;

#endif

	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;

	lastpfn = max_low_pfn;

#ifdef CONFIG_HIGHMEM

	zones_size[ZONE_HIGHMEM] = highend_pfn - highstart_pfn;

	max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;

	lastpfn = highend_pfn;



	if (cpu_has_dc_aliases && zones_size[ZONE_HIGHMEM]) {

	if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {

		printk(KERN_WARNING "This processor doesn't support highmem."

		       " %ldk highmem ignored\n", zones_size[ZONE_HIGHMEM]);

		zones_size[ZONE_HIGHMEM] = 0;

		       " %ldk highmem ignored\n",

		       (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));

		max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;

		lastpfn = max_low_pfn;

	}

#endif



#ifdef CONFIG_FLATMEM

	free_area_init(zones_size);

#else

	pfn = min_low_pfn;

	for (i = 0; i < MAX_NR_ZONES; i++)

		for (j = 0; j < zones_size[i]; j++, pfn++)

			if (!page_is_ram(pfn))

				zholes_size[i]++;

	free_area_init_node(0, NODE_DATA(0), zones_size, 0, zholes_size);

#endif

	free_area_init_nodes(max_zone_pfns);

}



static struct kcore_list kcore_mem, kcore_vmalloc;

include/asm-mips/dma.h

+1 −0
Original line number Diff line number Diff line
@@ -92,6 +92,7 @@ 
#define MAX_DMA_ADDRESS		(PAGE_OFFSET + 0x01000000)

#endif

#define MAX_DMA_PFN		PFN_DOWN(virt_to_phys((void *)MAX_DMA_ADDRESS))

#define MAX_DMA32_PFN		(1UL << (32 - PAGE_SHIFT))



/* 8237 DMA controllers */

#define IO_DMA1_BASE	0x00	/* 8 bit slave DMA, channels 0..3 */