powerpc: Dynamic DMA zone limits (1c98025c) · Commits · 戴 / test

arch/powerpc/Kconfig

+4 −0

Original line number	Diff line number	Diff line
		@@ -285,6 +285,10 @@ config PPC_EMULATE_SSTEP
		bool
		default y if KPROBES \|\| UPROBES \|\| XMON \|\| HAVE_HW_BREAKPOINT

		config ZONE_DMA32
		bool
		default y if PPC64

		source "init/Kconfig"

		source "kernel/Kconfig.freezer"

arch/powerpc/include/asm/pgtable.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -4,6 +4,7 @@

		#ifndef __ASSEMBLY__
		#include <linux/mmdebug.h>
		#include <linux/mmzone.h>
		#include <asm/processor.h> /* For TASK_SIZE */
		#include <asm/mmu.h>
		#include <asm/page.h>
		@@ -281,6 +282,8 @@ 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.c

+20 −0

Original line number	Diff line number	Diff line
		@@ -40,6 +40,26 @@ void dma_direct_alloc_coherent(struct device dev, size_t size,
		#else
		struct page *page;
		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 */
		flag &= ~(__GFP_HIGHMEM);

arch/powerpc/mm/mem.c

+56 −5

Original line number	Diff line number	Diff line
		@@ -260,6 +260,54 @@ static int __init mark_nonram_nosave(void)
		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.
		*/
		@@ -267,7 +315,7 @@ void __init paging_init(void)
		{
		unsigned long long total_ram = memblock_phys_mem_size();
		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
		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);
		printk(KERN_DEBUG "Memory hole size: %ldMB\n",
		(long int)((top_of_ram - total_ram) >> 20));
		memset(max_zone_pfns, 0, sizeof(max_zone_pfns));

		#ifdef CONFIG_HIGHMEM
		max_zone_pfns[ZONE_DMA] = lowmem_end_addr >> PAGE_SHIFT;
		max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
		top_zone = ZONE_HIGHMEM;
		limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);
		#else
		max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
		top_zone = ZONE_NORMAL;
		#endif

		limit_zone_pfn(top_zone, top_of_ram >> PAGE_SHIFT);
		zone_limits_final = true;
		free_area_init_nodes(max_zone_pfns);

		mark_nonram_nosave();

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