[PATCH 3/3] powerpc: dma code cleanup

Remi Machet rmachet at slac.stanford.edu
Wed Oct 8 08:06:38 EST 2008


Remove old dma-noncoherent code and hooks. Also remove the config parameters
CONSISTENT_SIZE and CONSISTENT_START which are not used anymore.

Signed-off-by: Remi Machet <rmachet at slac.stanford.edu>
---
 arch/powerpc/lib/dma-noncoherent.c |  427 -------------------------------------
 b/arch/powerpc/Kconfig             |   25 --
 b/arch/powerpc/kernel/dma.c        |    9
 b/arch/powerpc/lib/Makefile        |    1
 4 files changed, 462 deletions(-)

diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index 41fdd48..327a3e3 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -30,9 +30,6 @@ static unsigned long get_dma_direct_offset(struct device *dev)
 void *dma_direct_alloc_coherent(struct device *dev, size_t size,
 				dma_addr_t *dma_handle, gfp_t flag)
 {
-#ifdef CONFIG_NOT_COHERENT_CACHE
-	return __dma_alloc_coherent(size, dma_handle, flag);
-#else
 	struct page *page;
 	void *ret;
 	int node = dev_to_node(dev);
@@ -48,17 +45,12 @@ void *dma_direct_alloc_coherent(struct device *dev, size_t size,
 	*dma_handle = virt_to_abs(ret) + get_dma_direct_offset(dev);
 
 	return ret;
-#endif
 }
 
 void dma_direct_free_coherent(struct device *dev, size_t size,
 			      void *vaddr, dma_addr_t dma_handle)
 {
-#ifdef CONFIG_NOT_COHERENT_CACHE
-	__dma_free_coherent(size, vaddr);
-#else
 	free_pages((unsigned long)vaddr, get_order(size));
-#endif
 }
 
 static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
@@ -103,7 +95,6 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
 					     struct dma_attrs *attrs)
 {
 	BUG_ON(dir == DMA_NONE);
-	__dma_sync_page(page, offset, size, dir);
 	return page_to_phys(page) + offset + get_dma_direct_offset(dev);
 }
 
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index d69912c..0707d7a 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -15,7 +15,6 @@ obj-$(CONFIG_PPC64)	+= copypage_64.o copyuser_64.o \
 			   memcpy_64.o usercopy_64.o mem_64.o string.o
 obj-$(CONFIG_XMON)	+= sstep.o
 obj-$(CONFIG_KPROBES)	+= sstep.o
-obj-$(CONFIG_NOT_COHERENT_CACHE)	+= dma-noncoherent.o
 
 ifeq ($(CONFIG_PPC64),y)
 obj-$(CONFIG_SMP)	+= locks.o
diff --git a/arch/powerpc/lib/dma-noncoherent.c b/arch/powerpc/lib/dma-noncoherent.c
deleted file mode 100644
index 5d83907..0000000
--- a/arch/powerpc/lib/dma-noncoherent.c
+++ /dev/null
@@ -1,427 +0,0 @@
-/*
- *  PowerPC version derived from arch/arm/mm/consistent.c
- *    Copyright (C) 2001 Dan Malek (dmalek at jlc.net)
- *
- *  Copyright (C) 2000 Russell King
- *
- * Consistent memory allocators.  Used for DMA devices that want to
- * share uncached memory with the processor core.  The function return
- * is the virtual address and 'dma_handle' is the physical address.
- * Mostly stolen from the ARM port, with some changes for PowerPC.
- *						-- Dan
- *
- * Reorganized to get rid of the arch-specific consistent_* functions
- * and provide non-coherent implementations for the DMA API. -Matt
- *
- * Added in_interrupt() safe dma_alloc_coherent()/dma_free_coherent()
- * implementation. This is pulled straight from ARM and barely
- * modified. -Matt
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/types.h>
-#include <linux/highmem.h>
-#include <linux/dma-mapping.h>
-
-#include <asm/tlbflush.h>
-
-/*
- * This address range defaults to a value that is safe for all
- * platforms which currently set CONFIG_NOT_COHERENT_CACHE. It
- * can be further configured for specific applications under
- * the "Advanced Setup" menu. -Matt
- */
-#define CONSISTENT_BASE	(CONFIG_CONSISTENT_START)
-#define CONSISTENT_END	(CONFIG_CONSISTENT_START + CONFIG_CONSISTENT_SIZE)
-#define CONSISTENT_OFFSET(x)	(((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT)
-
-/*
- * This is the page table (2MB) covering uncached, DMA consistent allocations
- */
-static pte_t *consistent_pte;
-static DEFINE_SPINLOCK(consistent_lock);
-
-/*
- * VM region handling support.
- *
- * This should become something generic, handling VM region allocations for
- * vmalloc and similar (ioremap, module space, etc).
- *
- * I envisage vmalloc()'s supporting vm_struct becoming:
- *
- *  struct vm_struct {
- *    struct vm_region	region;
- *    unsigned long	flags;
- *    struct page	**pages;
- *    unsigned int	nr_pages;
- *    unsigned long	phys_addr;
- *  };
- *
- * get_vm_area() would then call vm_region_alloc with an appropriate
- * struct vm_region head (eg):
- *
- *  struct vm_region vmalloc_head = {
- *	.vm_list	= LIST_HEAD_INIT(vmalloc_head.vm_list),
- *	.vm_start	= VMALLOC_START,
- *	.vm_end		= VMALLOC_END,
- *  };
- *
- * However, vmalloc_head.vm_start is variable (typically, it is dependent on
- * the amount of RAM found at boot time.)  I would imagine that get_vm_area()
- * would have to initialise this each time prior to calling vm_region_alloc().
- */
-struct vm_region {
-	struct list_head	vm_list;
-	unsigned long		vm_start;
-	unsigned long		vm_end;
-};
-
-static struct vm_region consistent_head = {
-	.vm_list	= LIST_HEAD_INIT(consistent_head.vm_list),
-	.vm_start	= CONSISTENT_BASE,
-	.vm_end		= CONSISTENT_END,
-};
-
-static struct vm_region *
-vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp)
-{
-	unsigned long addr = head->vm_start, end = head->vm_end - size;
-	unsigned long flags;
-	struct vm_region *c, *new;
-
-	new = kmalloc(sizeof(struct vm_region), gfp);
-	if (!new)
-		goto out;
-
-	spin_lock_irqsave(&consistent_lock, flags);
-
-	list_for_each_entry(c, &head->vm_list, vm_list) {
-		if ((addr + size) < addr)
-			goto nospc;
-		if ((addr + size) <= c->vm_start)
-			goto found;
-		addr = c->vm_end;
-		if (addr > end)
-			goto nospc;
-	}
-
- found:
-	/*
-	 * Insert this entry _before_ the one we found.
-	 */
-	list_add_tail(&new->vm_list, &c->vm_list);
-	new->vm_start = addr;
-	new->vm_end = addr + size;
-
-	spin_unlock_irqrestore(&consistent_lock, flags);
-	return new;
-
- nospc:
-	spin_unlock_irqrestore(&consistent_lock, flags);
-	kfree(new);
- out:
-	return NULL;
-}
-
-static struct vm_region *vm_region_find(struct vm_region *head, unsigned long addr)
-{
-	struct vm_region *c;
-
-	list_for_each_entry(c, &head->vm_list, vm_list) {
-		if (c->vm_start == addr)
-			goto out;
-	}
-	c = NULL;
- out:
-	return c;
-}
-
-/*
- * Allocate DMA-coherent memory space and return both the kernel remapped
- * virtual and bus address for that space.
- */
-void *
-__dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
-{
-	struct page *page;
-	struct vm_region *c;
-	unsigned long order;
-	u64 mask = 0x00ffffff, limit; /* ISA default */
-
-	if (!consistent_pte) {
-		printk(KERN_ERR "%s: not initialised\n", __func__);
-		dump_stack();
-		return NULL;
-	}
-
-	size = PAGE_ALIGN(size);
-	limit = (mask + 1) & ~mask;
-	if ((limit && size >= limit) || size >= (CONSISTENT_END - CONSISTENT_BASE)) {
-		printk(KERN_WARNING "coherent allocation too big (requested %#x mask %#Lx)\n",
-		       size, mask);
-		return NULL;
-	}
-
-	order = get_order(size);
-
-	if (mask != 0xffffffff)
-		gfp |= GFP_DMA;
-
-	page = alloc_pages(gfp, order);
-	if (!page)
-		goto no_page;
-
-	/*
-	 * Invalidate any data that might be lurking in the
-	 * kernel direct-mapped region for device DMA.
-	 */
-	{
-		unsigned long kaddr = (unsigned long)page_address(page);
-		memset(page_address(page), 0, size);
-		flush_dcache_range(kaddr, kaddr + size);
-	}
-
-	/*
-	 * Allocate a virtual address in the consistent mapping region.
-	 */
-	c = vm_region_alloc(&consistent_head, size,
-			    gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
-	if (c) {
-		unsigned long vaddr = c->vm_start;
-		pte_t *pte = consistent_pte + CONSISTENT_OFFSET(vaddr);
-		struct page *end = page + (1 << order);
-
-		split_page(page, order);
-
-		/*
-		 * Set the "dma handle"
-		 */
-		*handle = page_to_bus(page);
-
-		do {
-			BUG_ON(!pte_none(*pte));
-
-			SetPageReserved(page);
-			set_pte_at(&init_mm, vaddr,
-				   pte, mk_pte(page, pgprot_noncached(PAGE_KERNEL)));
-			page++;
-			pte++;
-			vaddr += PAGE_SIZE;
-		} while (size -= PAGE_SIZE);
-
-		/*
-		 * Free the otherwise unused pages.
-		 */
-		while (page < end) {
-			__free_page(page);
-			page++;
-		}
-
-		return (void *)c->vm_start;
-	}
-
-	if (page)
-		__free_pages(page, order);
- no_page:
-	return NULL;
-}
-EXPORT_SYMBOL(__dma_alloc_coherent);
-
-/*
- * free a page as defined by the above mapping.
- */
-void __dma_free_coherent(size_t size, void *vaddr)
-{
-	struct vm_region *c;
-	unsigned long flags, addr;
-	pte_t *ptep;
-
-	size = PAGE_ALIGN(size);
-
-	spin_lock_irqsave(&consistent_lock, flags);
-
-	c = vm_region_find(&consistent_head, (unsigned long)vaddr);
-	if (!c)
-		goto no_area;
-
-	if ((c->vm_end - c->vm_start) != size) {
-		printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
-		       __func__, c->vm_end - c->vm_start, size);
-		dump_stack();
-		size = c->vm_end - c->vm_start;
-	}
-
-	ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
-	addr = c->vm_start;
-	do {
-		pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
-		unsigned long pfn;
-
-		ptep++;
-		addr += PAGE_SIZE;
-
-		if (!pte_none(pte) && pte_present(pte)) {
-			pfn = pte_pfn(pte);
-
-			if (pfn_valid(pfn)) {
-				struct page *page = pfn_to_page(pfn);
-				ClearPageReserved(page);
-
-				__free_page(page);
-				continue;
-			}
-		}
-
-		printk(KERN_CRIT "%s: bad page in kernel page table\n",
-		       __func__);
-	} while (size -= PAGE_SIZE);
-
-	flush_tlb_kernel_range(c->vm_start, c->vm_end);
-
-	list_del(&c->vm_list);
-
-	spin_unlock_irqrestore(&consistent_lock, flags);
-
-	kfree(c);
-	return;
-
- no_area:
-	spin_unlock_irqrestore(&consistent_lock, flags);
-	printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
-	       __func__, vaddr);
-	dump_stack();
-}
-EXPORT_SYMBOL(__dma_free_coherent);
-
-/*
- * Initialise the consistent memory allocation.
- */
-static int __init dma_alloc_init(void)
-{
-	pgd_t *pgd;
-	pud_t *pud;
-	pmd_t *pmd;
-	pte_t *pte;
-	int ret = 0;
-
-	do {
-		pgd = pgd_offset(&init_mm, CONSISTENT_BASE);
-		pud = pud_alloc(&init_mm, pgd, CONSISTENT_BASE);
-		pmd = pmd_alloc(&init_mm, pud, CONSISTENT_BASE);
-		if (!pmd) {
-			printk(KERN_ERR "%s: no pmd tables\n", __func__);
-			ret = -ENOMEM;
-			break;
-		}
-		WARN_ON(!pmd_none(*pmd));
-
-		pte = pte_alloc_kernel(pmd, CONSISTENT_BASE);
-		if (!pte) {
-			printk(KERN_ERR "%s: no pte tables\n", __func__);
-			ret = -ENOMEM;
-			break;
-		}
-
-		consistent_pte = pte;
-	} while (0);
-
-	return ret;
-}
-
-core_initcall(dma_alloc_init);
-
-/*
- * make an area consistent.
- */
-void __dma_sync(void *vaddr, size_t size, int direction)
-{
-	unsigned long start = (unsigned long)vaddr;
-	unsigned long end   = start + size;
-
-	switch (direction) {
-	case DMA_NONE:
-		BUG();
-	case DMA_FROM_DEVICE:
-		/*
-		 * invalidate only when cache-line aligned otherwise there is
-		 * the potential for discarding uncommitted data from the cache
-		 */
-		if ((start & (L1_CACHE_BYTES - 1)) || (size & (L1_CACHE_BYTES - 1)))
-			flush_dcache_range(start, end);
-		else
-			invalidate_dcache_range(start, end);
-		break;
-	case DMA_TO_DEVICE:		/* writeback only */
-		clean_dcache_range(start, end);
-		break;
-	case DMA_BIDIRECTIONAL:	/* writeback and invalidate */
-		flush_dcache_range(start, end);
-		break;
-	}
-}
-EXPORT_SYMBOL(__dma_sync);
-
-#ifdef CONFIG_HIGHMEM
-/*
- * __dma_sync_page() implementation for systems using highmem.
- * In this case, each page of a buffer must be kmapped/kunmapped
- * in order to have a virtual address for __dma_sync(). This must
- * not sleep so kmap_atomic()/kunmap_atomic() are used.
- *
- * Note: yes, it is possible and correct to have a buffer extend
- * beyond the first page.
- */
-static inline void __dma_sync_page_highmem(struct page *page,
-		unsigned long offset, size_t size, int direction)
-{
-	size_t seg_size = min((size_t)(PAGE_SIZE - offset), size);
-	size_t cur_size = seg_size;
-	unsigned long flags, start, seg_offset = offset;
-	int nr_segs = 1 + ((size - seg_size) + PAGE_SIZE - 1)/PAGE_SIZE;
-	int seg_nr = 0;
-
-	local_irq_save(flags);
-
-	do {
-		start = (unsigned long)kmap_atomic(page + seg_nr,
-				KM_PPC_SYNC_PAGE) + seg_offset;
-
-		/* Sync this buffer segment */
-		__dma_sync((void *)start, seg_size, direction);
-		kunmap_atomic((void *)start, KM_PPC_SYNC_PAGE);
-		seg_nr++;
-
-		/* Calculate next buffer segment size */
-		seg_size = min((size_t)PAGE_SIZE, size - cur_size);
-
-		/* Add the segment size to our running total */
-		cur_size += seg_size;
-		seg_offset = 0;
-	} while (seg_nr < nr_segs);
-
-	local_irq_restore(flags);
-}
-#endif /* CONFIG_HIGHMEM */
-
-/*
- * __dma_sync_page makes memory consistent. identical to __dma_sync, but
- * takes a struct page instead of a virtual address
- */
-void __dma_sync_page(struct page *page, unsigned long offset,
-	size_t size, int direction)
-{
-#ifdef CONFIG_HIGHMEM
-	__dma_sync_page_highmem(page, offset, size, direction);
-#else
-	unsigned long start = (unsigned long)page_address(page) + offset;
-	__dma_sync((void *)start, size, direction);
-#endif
-}
-EXPORT_SYMBOL(__dma_sync_page);
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 17c988b..d88ea21 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -775,31 +775,6 @@ config TASK_SIZE
 	default "0x80000000" if PPC_PREP || PPC_8xx
 	default "0xc0000000"
 
-config CONSISTENT_START_BOOL
-	bool "Set custom consistent memory pool address"
-	depends on ADVANCED_OPTIONS && NOT_COHERENT_CACHE
-	help
-	  This option allows you to set the base virtual address
-	  of the consistent memory pool.  This pool of virtual
-	  memory is used to make consistent memory allocations.
-
-config CONSISTENT_START
-	hex "Base virtual address of consistent memory pool" if CONSISTENT_START_BOOL
-	default "0xfd000000" if (NOT_COHERENT_CACHE && 8xx)
-	default "0xff100000" if NOT_COHERENT_CACHE
-
-config CONSISTENT_SIZE_BOOL
-	bool "Set custom consistent memory pool size"
-	depends on ADVANCED_OPTIONS && NOT_COHERENT_CACHE
-	help
-	  This option allows you to set the size of the
-	  consistent memory pool.  This pool of virtual memory
-	  is used to make consistent memory allocations.
-
-config CONSISTENT_SIZE
-	hex "Size of consistent memory pool" if CONSISTENT_SIZE_BOOL
-	default "0x00200000" if NOT_COHERENT_CACHE
-
 config PIN_TLB
 	bool "Pinned Kernel TLBs (860 ONLY)"
 	depends on ADVANCED_OPTIONS && 8xx





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