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Commit 05fccb0e authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86: code cleanups in arch/x86/kernel/pci-gart_64.c 



code cleanups:

                                       errors   lines of code   errors/KLOC
 arch/x86/kernel/pci-gart_64.c            183             748         244.6
 arch/x86/kernel/pci-gart_64.c              0             790             0

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent e8d591dc

arch/x86/kernel/pci-gart_64.c

+276 −232
Original line number Diff line number Diff line
@@ -42,16 +42,19 @@ static unsigned long iommu_pages; /* .. and in pages */ 


static u32 *iommu_gatt_base;		/* Remapping table */



/* If this is disabled the IOMMU will use an optimized flushing strategy

   of only flushing when an mapping is reused. With it true the GART is flushed 

   for every mapping. Problem is that doing the lazy flush seems to trigger

   bugs with some popular PCI cards, in particular 3ware (but has been also

   also seen with Qlogic at least). */

/*

 * If this is disabled the IOMMU will use an optimized flushing strategy

 * of only flushing when an mapping is reused. With it true the GART is

 * flushed for every mapping. Problem is that doing the lazy flush seems

 * to trigger bugs with some popular PCI cards, in particular 3ware (but

 * has been also also seen with Qlogic at least).

 */

int iommu_fullflush = 1;



/* Allocation bitmap for the remapping area */ 

/* Allocation bitmap for the remapping area: */

static DEFINE_SPINLOCK(iommu_bitmap_lock);

static unsigned long *iommu_gart_bitmap; /* guarded by iommu_bitmap_lock */

/* Guarded by iommu_bitmap_lock: */

static unsigned long *iommu_gart_bitmap;



static u32 gart_unmapped_entry;
@@ -84,10 +87,12 @@ static unsigned long alloc_iommu(int size) 
	unsigned long offset, flags;



	spin_lock_irqsave(&iommu_bitmap_lock, flags);

	offset = find_next_zero_string(iommu_gart_bitmap,next_bit,iommu_pages,size);

	offset = find_next_zero_string(iommu_gart_bitmap, next_bit,

					iommu_pages, size);

	if (offset == -1) {

		need_flush = 1;

		offset = find_next_zero_string(iommu_gart_bitmap,0,iommu_pages,size);

		offset = find_next_zero_string(iommu_gart_bitmap, 0,

						iommu_pages, size);

	}

	if (offset != -1) {

		set_bit_string(iommu_gart_bitmap, offset, size);
@@ -100,12 +105,14 @@ static unsigned long alloc_iommu(int size) 
	if (iommu_fullflush)

		need_flush = 1;

	spin_unlock_irqrestore(&iommu_bitmap_lock, flags);



	return offset;

}



static void free_iommu(unsigned long offset, int size)

{

	unsigned long flags;



	spin_lock_irqsave(&iommu_bitmap_lock, flags);

	__clear_bit_string(iommu_gart_bitmap, offset, size);

	spin_unlock_irqrestore(&iommu_bitmap_lock, flags);
@@ -117,6 +124,7 @@ static void free_iommu(unsigned long offset, int size) 
static void flush_gart(void)

{

	unsigned long flags;



	spin_lock_irqsave(&iommu_bitmap_lock, flags);

	if (need_flush) {

		k8_flush_garts();
@@ -127,30 +135,42 @@ static void flush_gart(void) 


#ifdef CONFIG_IOMMU_LEAK



#define SET_LEAK(x) if (iommu_leak_tab) \

			iommu_leak_tab[x] = __builtin_return_address(0);

#define CLEAR_LEAK(x) if (iommu_leak_tab) \

			iommu_leak_tab[x] = NULL;

#define SET_LEAK(x)							\

	do {								\

		if (iommu_leak_tab)					\

			iommu_leak_tab[x] = __builtin_return_address(0);\

	} while (0)



#define CLEAR_LEAK(x)							\

	do {								\

		if (iommu_leak_tab)					\

			iommu_leak_tab[x] = NULL;			\

	} while (0)



/* Debugging aid for drivers that don't free their IOMMU tables */

static void **iommu_leak_tab;

static int leak_trace;

static int iommu_leak_pages = 20;



static void dump_leak(void)

{

	int i;

	static int dump;

	if (dump || !iommu_leak_tab) return;



	if (dump || !iommu_leak_tab)

		return;

	dump = 1;

	show_stack(NULL, NULL);



	/* Very crude. dump some from the end of the table too */

	printk("Dumping %d pages from end of IOMMU:\n", iommu_leak_pages); 

	printk(KERN_DEBUG "Dumping %d pages from end of IOMMU:\n",

	       iommu_leak_pages);

	for (i = 0; i < iommu_leak_pages; i += 2) {

		printk("%lu: ", iommu_pages-i);

		printk(KERN_DEBUG "%lu: ", iommu_pages-i);

		printk_address((unsigned long) iommu_leak_tab[iommu_pages-i]);

		printk("%c", (i+1)%2 == 0 ? '\n' : ' '); 

		printk(KERN_CONT "%c", (i+1)%2 == 0 ? '\n' : ' ');

	}

	printk("\n");

	printk(KERN_DEBUG "\n");

}

#else

# define SET_LEAK(x)
@@ -177,29 +197,34 @@ static void iommu_full(struct device *dev, size_t size, int dir) 
		if (dir == PCI_DMA_FROMDEVICE || dir == PCI_DMA_BIDIRECTIONAL)

			panic("PCI-DMA: Memory would be corrupted\n");

		if (dir == PCI_DMA_TODEVICE || dir == PCI_DMA_BIDIRECTIONAL)

			panic(KERN_ERR "PCI-DMA: Random memory would be DMAed\n");

			panic(KERN_ERR

				"PCI-DMA: Random memory would be DMAed\n");

	}



#ifdef CONFIG_IOMMU_LEAK

	dump_leak();

#endif

}



static inline int need_iommu(struct device *dev, unsigned long addr, size_t size)

static inline int

need_iommu(struct device *dev, unsigned long addr, size_t size)

{

	u64 mask = *dev->dma_mask;

	int high = addr + size > mask;

	int mmu = high;



	if (force_iommu)

		mmu = 1;



	return mmu;

}



static inline int nonforced_iommu(struct device *dev, unsigned long addr, size_t size)

static inline int

nonforced_iommu(struct device *dev, unsigned long addr, size_t size)

{

	u64 mask = *dev->dma_mask;

	int high = addr + size > mask;

	int mmu = high;



	return mmu;

}
@@ -212,6 +237,7 @@ static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem, 
	unsigned long npages = to_pages(phys_mem, size);

	unsigned long iommu_page = alloc_iommu(npages);

	int i;



	if (iommu_page == -1) {

		if (!nonforced_iommu(dev, phys_mem, size))

			return phys_mem;
@@ -229,16 +255,19 @@ static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem, 
	return iommu_bus_base + iommu_page*PAGE_SIZE + (phys_mem & ~PAGE_MASK);

}



static dma_addr_t gart_map_simple(struct device *dev, char *buf,

				 size_t size, int dir)

static dma_addr_t

gart_map_simple(struct device *dev, char *buf, size_t size, int dir)

{

	dma_addr_t map = dma_map_area(dev, virt_to_bus(buf), size, dir);



	flush_gart();



	return map;

}



/* Map a single area into the IOMMU */

static dma_addr_t gart_map_single(struct device *dev, void *addr, size_t size, int dir)

static dma_addr_t

gart_map_single(struct device *dev, void *addr, size_t size, int dir)

{

	unsigned long phys_mem, bus;
@@ -250,6 +279,7 @@ static dma_addr_t gart_map_single(struct device *dev, void *addr, size_t size, i 
		return phys_mem;



	bus = gart_map_simple(dev, addr, size, dir);



	return bus;

}
@@ -266,6 +296,7 @@ static void gart_unmap_single(struct device *dev, dma_addr_t dma_addr, 
	if (dma_addr < iommu_bus_base + EMERGENCY_PAGES*PAGE_SIZE ||

	    dma_addr >= iommu_bus_base + iommu_size)

		return;



	iommu_page = (dma_addr - iommu_bus_base)>>PAGE_SHIFT;

	npages = to_pages(dma_addr, size);

	for (i = 0; i < npages; i++) {
@@ -278,7 +309,8 @@ static void gart_unmap_single(struct device *dev, dma_addr_t dma_addr, 
/*

 * Wrapper for pci_unmap_single working with scatterlists.

 */

static void gart_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, int dir)

static void

gart_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, int dir)

{

	struct scatterlist *s;

	int i;
@@ -303,6 +335,7 @@ static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg, 


	for_each_sg(sg, s, nents, i) {

		unsigned long addr = sg_phys(s);



		if (nonforced_iommu(dev, addr, s->length)) {

			addr = dma_map_area(dev, addr, s->length, dir);

			if (addr == bad_dma_address) {
@@ -317,6 +350,7 @@ static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg, 
		s->dma_length = s->length;

	}

	flush_gart();



	return nents;

}
@@ -355,11 +389,12 @@ static int __dma_map_cont(struct scatterlist *start, int nelems, 
		}

	}

	BUG_ON(iommu_page - iommu_start != pages);



	return 0;

}



static inline int dma_map_cont(struct scatterlist *start, int nelems,

		      struct scatterlist *sout,

static inline int

dma_map_cont(struct scatterlist *start, int nelems, struct scatterlist *sout,

	     unsigned long pages, int need)

{

	if (!need) {
@@ -375,15 +410,12 @@ static inline int dma_map_cont(struct scatterlist *start, int nelems, 
 * DMA map all entries in a scatterlist.

 * Merge chunks that have page aligned sizes into a continuous mapping.

 */

static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents,

			int dir)

static int

gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, int dir)

{

	int i;

	int out;

	int start;

	unsigned long pages = 0;

	int need = 0, nextneed;

	struct scatterlist *s, *ps, *start_sg, *sgmap;

	int need = 0, nextneed, i, out, start;

	unsigned long pages = 0;



	if (nents == 0)

		return 0;
@@ -397,6 +429,7 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, 
	ps = NULL; /* shut up gcc */

	for_each_sg(sg, s, nents, i) {

		dma_addr_t addr = sg_phys(s);



		s->dma_address = addr;

		BUG_ON(s->length == 0);
@@ -404,8 +437,11 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, 


		/* Handle the previous not yet processed entries */

		if (i > start) {

			/* Can only merge when the last chunk ends on a page 

			   boundary and the new one doesn't have an offset. */

			/*

			 * Can only merge when the last chunk ends on a

			 * page boundary and the new one doesn't have an

			 * offset.

			 */

			if (!iommu_merge || !nextneed || !need || s->offset ||

			    (ps->offset + ps->length) % PAGE_SIZE) {

				if (dma_map_cont(start_sg, i - start, sgmap,
@@ -436,6 +472,7 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, 
error:

	flush_gart();

	gart_unmap_sg(dev, sg, out, dir);



	/* When it was forced or merged try again in a dumb way */

	if (force_iommu || iommu_merge) {

		out = dma_map_sg_nonforce(dev, sg, nents, dir);
@@ -444,6 +481,7 @@ error: 
	}

	if (panic_on_overflow)

		panic("dma_map_sg: overflow on %lu pages\n", pages);



	iommu_full(dev, pages << PAGE_SHIFT, dir);

	for_each_sg(sg, s, nents, i)

		s->dma_address = bad_dma_address;
@@ -455,6 +493,7 @@ static int no_agp; 
static __init unsigned long check_iommu_size(unsigned long aper, u64 aper_size)

{

	unsigned long a;



	if (!iommu_size) {

		iommu_size = aper_size;

		if (!no_agp)
@@ -464,18 +503,20 @@ static __init unsigned long check_iommu_size(unsigned long aper, u64 aper_size) 
	a = aper + iommu_size;

	iommu_size -= round_up(a, LARGE_PAGE_SIZE) - a;



	if (iommu_size < 64*1024*1024) 

	if (iommu_size < 64*1024*1024) {

		printk(KERN_WARNING

  "PCI-DMA: Warning: Small IOMMU %luMB. Consider increasing the AGP aperture in BIOS\n",iommu_size>>20); 

			"PCI-DMA: Warning: Small IOMMU %luMB."

			" Consider increasing the AGP aperture in BIOS\n",

				iommu_size >> 20);

	}



	return iommu_size;

}



static __init unsigned read_aperture(struct pci_dev *dev, u32 *size)

{

	unsigned aper_size = 0, aper_base_32;

	unsigned aper_size = 0, aper_base_32, aper_order;

	u64 aper_base;

	unsigned aper_order;



	pci_read_config_dword(dev, 0x94, &aper_base_32);

	pci_read_config_dword(dev, 0x90, &aper_order);
@@ -498,10 +539,10 @@ static __init unsigned read_aperture(struct pci_dev *dev, u32 *size) 
 */

static __init int init_k8_gatt(struct agp_kern_info *info)

{

	unsigned aper_size, gatt_size, new_aper_size;

	unsigned aper_base, new_aper_base;

	struct pci_dev *dev;

	void *gatt;

	unsigned aper_base, new_aper_base;

	unsigned aper_size, gatt_size, new_aper_size;

	int i;



	printk(KERN_INFO "PCI-DMA: Disabling AGP.\n");
@@ -529,7 +570,8 @@ static __init int init_k8_gatt(struct agp_kern_info *info) 
	gatt = (void *)__get_free_pages(GFP_KERNEL, get_order(gatt_size));

	if (!gatt)

		panic("Cannot allocate GATT table");

	if (change_page_attr_addr((unsigned long)gatt, gatt_size >> PAGE_SHIFT, PAGE_KERNEL_NOCACHE))

	if (change_page_attr_addr((unsigned long)gatt, gatt_size >> PAGE_SHIFT,

				  PAGE_KERNEL_NOCACHE))

		panic("Could not set GART PTEs to uncacheable pages");

	global_flush_tlb();
@@ -537,8 +579,8 @@ static __init int init_k8_gatt(struct agp_kern_info *info) 
	agp_gatt_table = gatt;



	for (i = 0; i < num_k8_northbridges; i++) {

		u32 ctl; 

		u32 gatt_reg;

		u32 ctl;



		dev = k8_northbridges[i];

		gatt_reg = __pa(gatt) >> 12;
@@ -553,7 +595,8 @@ static __init int init_k8_gatt(struct agp_kern_info *info) 
	}

	flush_gart();



	printk("PCI-DMA: aperture base @ %x size %u KB\n",aper_base, aper_size>>10); 

	printk(KERN_INFO "PCI-DMA: aperture base @ %x size %u KB\n",

	       aper_base, aper_size>>10);

	return 0;



 nommu:
@@ -603,8 +646,8 @@ void gart_iommu_shutdown(void) 
void __init gart_iommu_init(void)

{

	struct agp_kern_info info;

	unsigned long aper_size;

	unsigned long iommu_start;

	unsigned long aper_size;

	unsigned long scratch;

	long i;
@@ -660,7 +703,8 @@ void __init gart_iommu_init(void) 
		if (iommu_leak_tab)

			memset(iommu_leak_tab, 0, iommu_pages * 8);

		else

			printk("PCI-DMA: Cannot allocate leak trace area\n"); 

			printk(KERN_DEBUG

			       "PCI-DMA: Cannot allocate leak trace area\n");

	}

#endif