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Commit 1c98025c authored by Scott Wood's avatar Scott Wood
Browse files

powerpc: Dynamic DMA zone limits 



Platform code can call limit_zone_pfn() to set appropriate limits
for ZONE_DMA and ZONE_DMA32, and dma_direct_alloc_coherent() will
select a suitable zone based on a device's mask and the pfn limits that
platform code has configured.

Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
Cc: Shaohui Xie <Shaohui.Xie@freescale.com>
parent 78eb9094

arch/powerpc/Kconfig

+4 −0
Original line number Original line Diff line number Diff line
@@ -285,6 +285,10 @@ config PPC_EMULATE_SSTEP 
	bool

	bool

	default y if KPROBES || UPROBES || XMON || HAVE_HW_BREAKPOINT

	default y if KPROBES || UPROBES || XMON || HAVE_HW_BREAKPOINT





config ZONE_DMA32

	bool

	default y if PPC64



source "init/Kconfig"

source "init/Kconfig"





source "kernel/Kconfig.freezer"

source "kernel/Kconfig.freezer"

arch/powerpc/include/asm/pgtable.h

+3 −0
Original line number Original line Diff line number Diff line
@@ -4,6 +4,7 @@ 




#ifndef __ASSEMBLY__

#ifndef __ASSEMBLY__

#include <linux/mmdebug.h>

#include <linux/mmdebug.h>

#include <linux/mmzone.h>

#include <asm/processor.h>		/* For TASK_SIZE */

#include <asm/processor.h>		/* For TASK_SIZE */

#include <asm/mmu.h>

#include <asm/mmu.h>

#include <asm/page.h>

#include <asm/page.h>
@@ -281,6 +282,8 @@ extern unsigned long empty_zero_page[]; 




extern pgd_t swapper_pg_dir[];

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);

extern void paging_init(void);





/*

/*

arch/powerpc/kernel/dma.c

+20 −0
Original line number Original line Diff line number Diff line
@@ -40,6 +40,26 @@ void *dma_direct_alloc_coherent(struct device *dev, size_t size, 
#else

#else

	struct page *page;

	struct page *page;

	int node = dev_to_node(dev);

	int node = dev_to_node(dev);

	u64 pfn = (dev->coherent_dma_mask >> PAGE_SHIFT) + 1;

	int zone;



	zone = dma_pfn_limit_to_zone(pfn);

	if (zone < 0) {

		dev_err(dev, "%s: No suitable zone for pfn %#llx\n",

			__func__, pfn);

		return NULL;

	}



	switch (zone) {

	case ZONE_DMA:

		flag |= GFP_DMA;

		break;

#ifdef CONFIG_ZONE_DMA32

	case ZONE_DMA32:

		flag |= GFP_DMA32;

		break;

#endif

	};





	/* ignore region specifiers */

	/* ignore region specifiers */

	flag  &= ~(__GFP_HIGHMEM);

	flag  &= ~(__GFP_HIGHMEM);

arch/powerpc/mm/mem.c

+56 −5
Original line number Original line Diff line number Diff line
@@ -260,6 +260,54 @@ static int __init mark_nonram_nosave(void) 
	return 0;

	return 0;

}

}





static bool zone_limits_final;



static unsigned long max_zone_pfns[MAX_NR_ZONES] = {

	[0 ... MAX_NR_ZONES - 1] = ~0UL

};



/*

 * Restrict the specified zone and all more restrictive zones

 * to be below the specified pfn.  May not be called after

 * paging_init().

 */

void __init limit_zone_pfn(enum zone_type zone, unsigned long pfn_limit)

{

	int i;



	if (WARN_ON(zone_limits_final))

		return;



	for (i = zone; i >= 0; i--) {

		if (max_zone_pfns[i] > pfn_limit)

			max_zone_pfns[i] = pfn_limit;

	}

}



/*

 * Find the least restrictive zone that is entirely below the

 * specified pfn limit.  Returns < 0 if no suitable zone is found.

 *

 * pfn_limit must be u64 because it can exceed 32 bits even on 32-bit

 * systems -- the DMA limit can be higher than any possible real pfn.

 */

int dma_pfn_limit_to_zone(u64 pfn_limit)

{

	enum zone_type top_zone = ZONE_NORMAL;

	int i;



#ifdef CONFIG_HIGHMEM

	top_zone = ZONE_HIGHMEM;

#endif



	for (i = top_zone; i >= 0; i--) {

		if (max_zone_pfns[i] <= pfn_limit)

			return i;

	}



	return -EPERM;

}



/*

/*

 * paging_init() sets up the page tables - in fact we've already done this.

 * paging_init() sets up the page tables - in fact we've already done this.

 */

 */
@@ -267,7 +315,7 @@ void __init paging_init(void) 
{

{

	unsigned long long total_ram = memblock_phys_mem_size();

	unsigned long long total_ram = memblock_phys_mem_size();

	phys_addr_t top_of_ram = memblock_end_of_DRAM();

	phys_addr_t top_of_ram = memblock_end_of_DRAM();

	unsigned long max_zone_pfns[MAX_NR_ZONES];

	enum zone_type top_zone;





#ifdef CONFIG_PPC32

#ifdef CONFIG_PPC32

	unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);

	unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
@@ -289,13 +337,16 @@ void __init paging_init(void) 
	       (unsigned long long)top_of_ram, total_ram);

	       (unsigned long long)top_of_ram, total_ram);

	printk(KERN_DEBUG "Memory hole size: %ldMB\n",

	printk(KERN_DEBUG "Memory hole size: %ldMB\n",

	       (long int)((top_of_ram - total_ram) >> 20));

	       (long int)((top_of_ram - total_ram) >> 20));

	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));



#ifdef CONFIG_HIGHMEM

#ifdef CONFIG_HIGHMEM

	max_zone_pfns[ZONE_DMA] = lowmem_end_addr >> PAGE_SHIFT;

	top_zone = ZONE_HIGHMEM;

	max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;

	limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);

#else

#else

	max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;

	top_zone = ZONE_NORMAL;

#endif

#endif



	limit_zone_pfn(top_zone, top_of_ram >> PAGE_SHIFT);

	zone_limits_final = true;

	free_area_init_nodes(max_zone_pfns);

	free_area_init_nodes(max_zone_pfns);





	mark_nonram_nosave();

	mark_nonram_nosave();