[linux-2.6-block.git] / arch / s390 / pci / pci_dma.c

/*
 * Copyright IBM Corp. 2012
 *
 * Author(s):
 *   Jan Glauber <jang@linux.vnet.ibm.com>
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/iommu-helper.h>
#include <linux/dma-mapping.h>
#include <linux/vmalloc.h>
#include <linux/pci.h>
#include <asm/pci_dma.h>

static struct kmem_cache *dma_region_table_cache;
static struct kmem_cache *dma_page_table_cache;
static int s390_iommu_strict;

static int zpci_refresh_global(struct zpci_dev *zdev)
{
	return zpci_refresh_trans((u64) zdev->fh << 32, zdev->start_dma,
				  zdev->iommu_pages * PAGE_SIZE);
}

unsigned long *dma_alloc_cpu_table(void)
{
	unsigned long *table, *entry;

	table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
	if (!table)
		return NULL;

	for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
		*entry = ZPCI_TABLE_INVALID | ZPCI_TABLE_PROTECTED;
	return table;
}

static void dma_free_cpu_table(void *table)
{
	kmem_cache_free(dma_region_table_cache, table);
}

static unsigned long *dma_alloc_page_table(void)
{
	unsigned long *table, *entry;

	table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
	if (!table)
		return NULL;

	for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
		*entry = ZPCI_PTE_INVALID | ZPCI_TABLE_PROTECTED;
	return table;
}

static void dma_free_page_table(void *table)
{
	kmem_cache_free(dma_page_table_cache, table);
}

static unsigned long *dma_get_seg_table_origin(unsigned long *entry)
{
	unsigned long *sto;

	if (reg_entry_isvalid(*entry))
		sto = get_rt_sto(*entry);
	else {
		sto = dma_alloc_cpu_table();
		if (!sto)
			return NULL;

		set_rt_sto(entry, sto);
		validate_rt_entry(entry);
		entry_clr_protected(entry);
	}
	return sto;
}

static unsigned long *dma_get_page_table_origin(unsigned long *entry)
{
	unsigned long *pto;

	if (reg_entry_isvalid(*entry))
		pto = get_st_pto(*entry);
	else {
		pto = dma_alloc_page_table();
		if (!pto)
			return NULL;
		set_st_pto(entry, pto);
		validate_st_entry(entry);
		entry_clr_protected(entry);
	}
	return pto;
}

static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
{
	unsigned long *sto, *pto;
	unsigned int rtx, sx, px;

	rtx = calc_rtx(dma_addr);
	sto = dma_get_seg_table_origin(&rto[rtx]);
	if (!sto)
		return NULL;

	sx = calc_sx(dma_addr);
	pto = dma_get_page_table_origin(&sto[sx]);
	if (!pto)
		return NULL;

	px = calc_px(dma_addr);
	return &pto[px];
}

void dma_update_cpu_trans(unsigned long *dma_table, void *page_addr,
			  dma_addr_t dma_addr, int flags)
{
	unsigned long *entry;

	entry = dma_walk_cpu_trans(dma_table, dma_addr);
	if (!entry) {
		WARN_ON_ONCE(1);
		return;
	}

	if (flags & ZPCI_PTE_INVALID) {
		invalidate_pt_entry(entry);
		return;
	} else {
		set_pt_pfaa(entry, page_addr);
		validate_pt_entry(entry);
	}

	if (flags & ZPCI_TABLE_PROTECTED)
		entry_set_protected(entry);
	else
		entry_clr_protected(entry);
}

static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
			    dma_addr_t dma_addr, size_t size, int flags)
{
	unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
	u8 *page_addr = (u8 *) (pa & PAGE_MASK);
	dma_addr_t start_dma_addr = dma_addr;
	unsigned long irq_flags;
	int i, rc = 0;

	if (!nr_pages)
		return -EINVAL;

	spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
	if (!zdev->dma_table)
		goto no_refresh;

	for (i = 0; i < nr_pages; i++) {
		dma_update_cpu_trans(zdev->dma_table, page_addr, dma_addr,
				     flags);
		page_addr += PAGE_SIZE;
		dma_addr += PAGE_SIZE;
	}

	/*
	 * With zdev->tlb_refresh == 0, rpcit is not required to establish new
	 * translations when previously invalid translation-table entries are
	 * validated. With lazy unmap, it also is skipped for previously valid
	 * entries, but a global rpcit is then required before any address can
	 * be re-used, i.e. after each iommu bitmap wrap-around.
	 */
	if (!zdev->tlb_refresh &&
			(!s390_iommu_strict ||
			((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)))
		goto no_refresh;

	rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
				nr_pages * PAGE_SIZE);

no_refresh:
	spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
	return rc;
}

void dma_free_seg_table(unsigned long entry)
{
	unsigned long *sto = get_rt_sto(entry);
	int sx;

	for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
		if (reg_entry_isvalid(sto[sx]))
			dma_free_page_table(get_st_pto(sto[sx]));

	dma_free_cpu_table(sto);
}

void dma_cleanup_tables(unsigned long *table)
{
	int rtx;

	if (!table)
		return;

	for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
		if (reg_entry_isvalid(table[rtx]))
			dma_free_seg_table(table[rtx]);

	dma_free_cpu_table(table);
}

static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev,
				       unsigned long start, int size)
{
	unsigned long boundary_size;

	boundary_size = ALIGN(dma_get_seg_boundary(&zdev->pdev->dev) + 1,
			      PAGE_SIZE) >> PAGE_SHIFT;
	return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
				start, size, 0, boundary_size, 0);
}

static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size)
{
	unsigned long offset, flags;
	int wrap = 0;

	spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
	offset = __dma_alloc_iommu(zdev, zdev->next_bit, size);
	if (offset == -1) {
		/* wrap-around */
		offset = __dma_alloc_iommu(zdev, 0, size);
		wrap = 1;
	}

	if (offset != -1) {
		zdev->next_bit = offset + size;
		if (!zdev->tlb_refresh && !s390_iommu_strict && wrap)
			/* global flush after wrap-around with lazy unmap */
			zpci_refresh_global(zdev);
	}
	spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
	return offset;
}

static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size)
{
	unsigned long flags;

	spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
	if (!zdev->iommu_bitmap)
		goto out;
	bitmap_clear(zdev->iommu_bitmap, offset, size);
	/*
	 * Lazy flush for unmap: need to move next_bit to avoid address re-use
	 * until wrap-around.
	 */
	if (!s390_iommu_strict && offset >= zdev->next_bit)
		zdev->next_bit = offset + size;
out:
	spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
}

static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
				     unsigned long offset, size_t size,
				     enum dma_data_direction direction,
				     struct dma_attrs *attrs)
{
	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
	unsigned long nr_pages, iommu_page_index;
	unsigned long pa = page_to_phys(page) + offset;
	int flags = ZPCI_PTE_VALID;
	dma_addr_t dma_addr;

	/* This rounds up number of pages based on size and offset */
	nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
	iommu_page_index = dma_alloc_iommu(zdev, nr_pages);
	if (iommu_page_index == -1)
		goto out_err;

	/* Use rounded up size */
	size = nr_pages * PAGE_SIZE;

	dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
	if (dma_addr + size > zdev->end_dma)
		goto out_free;

	if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
		flags |= ZPCI_TABLE_PROTECTED;

	if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
		atomic64_add(nr_pages, &zdev->mapped_pages);
		return dma_addr + (offset & ~PAGE_MASK);
	}

out_free:
	dma_free_iommu(zdev, iommu_page_index, nr_pages);
out_err:
	zpci_err("map error:\n");
	zpci_err_hex(&pa, sizeof(pa));
	return DMA_ERROR_CODE;
}

static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
				 size_t size, enum dma_data_direction direction,
				 struct dma_attrs *attrs)
{
	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
	unsigned long iommu_page_index;
	int npages;

	npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
	dma_addr = dma_addr & PAGE_MASK;
	if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
			     ZPCI_TABLE_PROTECTED | ZPCI_PTE_INVALID)) {
		zpci_err("unmap error:\n");
		zpci_err_hex(&dma_addr, sizeof(dma_addr));
	}

	atomic64_add(npages, &zdev->unmapped_pages);
	iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
	dma_free_iommu(zdev, iommu_page_index, npages);
}

static void *s390_dma_alloc(struct device *dev, size_t size,
			    dma_addr_t *dma_handle, gfp_t flag,
			    struct dma_attrs *attrs)
{
	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
	struct page *page;
	unsigned long pa;
	dma_addr_t map;

	size = PAGE_ALIGN(size);
	page = alloc_pages(flag, get_order(size));
	if (!page)
		return NULL;

	pa = page_to_phys(page);
	memset((void *) pa, 0, size);

	map = s390_dma_map_pages(dev, page, pa % PAGE_SIZE,
				 size, DMA_BIDIRECTIONAL, NULL);
	if (dma_mapping_error(dev, map)) {
		free_pages(pa, get_order(size));
		return NULL;
	}

	atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages);
	if (dma_handle)
		*dma_handle = map;
	return (void *) pa;
}

static void s390_dma_free(struct device *dev, size_t size,
			  void *pa, dma_addr_t dma_handle,
			  struct dma_attrs *attrs)
{
	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));

	size = PAGE_ALIGN(size);
	atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages);
	s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, NULL);
	free_pages((unsigned long) pa, get_order(size));
}

static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
			   int nr_elements, enum dma_data_direction dir,
			   struct dma_attrs *attrs)
{
	int mapped_elements = 0;
	struct scatterlist *s;
	int i;

	for_each_sg(sg, s, nr_elements, i) {
		struct page *page = sg_page(s);
		s->dma_address = s390_dma_map_pages(dev, page, s->offset,
						    s->length, dir, NULL);
		if (!dma_mapping_error(dev, s->dma_address)) {
			s->dma_length = s->length;
			mapped_elements++;
		} else
			goto unmap;
	}
out:
	return mapped_elements;

unmap:
	for_each_sg(sg, s, mapped_elements, i) {
		if (s->dma_address)
			s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
					     dir, NULL);
		s->dma_address = 0;
		s->dma_length = 0;
	}
	mapped_elements = 0;
	goto out;
}

static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
			      int nr_elements, enum dma_data_direction dir,
			      struct dma_attrs *attrs)
{
	struct scatterlist *s;
	int i;

	for_each_sg(sg, s, nr_elements, i) {
		s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
		s->dma_address = 0;
		s->dma_length = 0;
	}
}

int zpci_dma_init_device(struct zpci_dev *zdev)
{
	int rc;

	/*
	 * At this point, if the device is part of an IOMMU domain, this would
	 * be a strong hint towards a bug in the IOMMU API (common) code and/or
	 * simultaneous access via IOMMU and DMA API. So let's issue a warning.
	 */
	WARN_ON(zdev->s390_domain);

	spin_lock_init(&zdev->iommu_bitmap_lock);
	spin_lock_init(&zdev->dma_table_lock);

	zdev->dma_table = dma_alloc_cpu_table();
	if (!zdev->dma_table) {
		rc = -ENOMEM;
		goto out_clean;
	}

	zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
	zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
	zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
	if (!zdev->iommu_bitmap) {
		rc = -ENOMEM;
		goto out_reg;
	}

	rc = zpci_register_ioat(zdev,
				0,
				zdev->start_dma + PAGE_OFFSET,
				zdev->start_dma + zdev->iommu_size - 1,
				(u64) zdev->dma_table);
	if (rc)
		goto out_reg;
	return 0;

out_reg:
	dma_free_cpu_table(zdev->dma_table);
out_clean:
	return rc;
}

void zpci_dma_exit_device(struct zpci_dev *zdev)
{
	/*
	 * At this point, if the device is part of an IOMMU domain, this would
	 * be a strong hint towards a bug in the IOMMU API (common) code and/or
	 * simultaneous access via IOMMU and DMA API. So let's issue a warning.
	 */
	WARN_ON(zdev->s390_domain);

	zpci_unregister_ioat(zdev, 0);
	dma_cleanup_tables(zdev->dma_table);
	zdev->dma_table = NULL;
	vfree(zdev->iommu_bitmap);
	zdev->iommu_bitmap = NULL;
	zdev->next_bit = 0;
}

static int __init dma_alloc_cpu_table_caches(void)
{
	dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
					ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
					0, NULL);
	if (!dma_region_table_cache)
		return -ENOMEM;

	dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
					ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
					0, NULL);
	if (!dma_page_table_cache) {
		kmem_cache_destroy(dma_region_table_cache);
		return -ENOMEM;
	}
	return 0;
}

int __init zpci_dma_init(void)
{
	return dma_alloc_cpu_table_caches();
}

void zpci_dma_exit(void)
{
	kmem_cache_destroy(dma_page_table_cache);
	kmem_cache_destroy(dma_region_table_cache);
}

#define PREALLOC_DMA_DEBUG_ENTRIES	(1 << 16)

static int __init dma_debug_do_init(void)
{
	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
	return 0;
}
fs_initcall(dma_debug_do_init);

struct dma_map_ops s390_dma_ops = {
	.alloc		= s390_dma_alloc,
	.free		= s390_dma_free,
	.map_sg		= s390_dma_map_sg,
	.unmap_sg	= s390_dma_unmap_sg,
	.map_page	= s390_dma_map_pages,
	.unmap_page	= s390_dma_unmap_pages,
	/* if we support direct DMA this must be conditional */
	.is_phys	= 0,
	/* dma_supported is unconditionally true without a callback */
};
EXPORT_SYMBOL_GPL(s390_dma_ops);

static int __init s390_iommu_setup(char *str)
{
	if (!strncmp(str, "strict", 6))
		s390_iommu_strict = 1;
	return 0;
}

__setup("s390_iommu=", s390_iommu_setup);
Commit	Line	Data
828b35f6 JG	1	/*
	2	* Copyright IBM Corp. 2012
	3	*
	4	* Author(s):
	5	* Jan Glauber <jang@linux.vnet.ibm.com>
	6	*/
	7
	8	#include <linux/kernel.h>
	9	#include <linux/slab.h>
	10	#include <linux/export.h>
	11	#include <linux/iommu-helper.h>
	12	#include <linux/dma-mapping.h>
22459321	13	#include <linux/vmalloc.h>
828b35f6 JG	14	#include <linux/pci.h>
	15	#include <asm/pci_dma.h>
	16
828b35f6 JG	17	static struct kmem_cache *dma_region_table_cache;
828b35f6 JG	18	static struct kmem_cache *dma_page_table_cache;
c60d1ae4 GS	19	static int s390_iommu_strict;
	20
	21	static int zpci_refresh_global(struct zpci_dev *zdev)
	22	{
	23	return zpci_refresh_trans((u64) zdev->fh << 32, zdev->start_dma,
	24	zdev->iommu_pages * PAGE_SIZE);
	25	}
828b35f6	26
8128f23c	27	unsigned long *dma_alloc_cpu_table(void)
828b35f6 JG	28	{
	29	unsigned long table, entry;
	30
	31	table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
	32	if (!table)
	33	return NULL;
	34
	35	for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
	36	*entry = ZPCI_TABLE_INVALID \| ZPCI_TABLE_PROTECTED;
	37	return table;
	38	}
	39
	40	static void dma_free_cpu_table(void *table)
	41	{
	42	kmem_cache_free(dma_region_table_cache, table);
	43	}
	44
	45	static unsigned long *dma_alloc_page_table(void)
	46	{
	47	unsigned long table, entry;
	48
	49	table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
	50	if (!table)
	51	return NULL;
	52
	53	for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
	54	*entry = ZPCI_PTE_INVALID \| ZPCI_TABLE_PROTECTED;
	55	return table;
	56	}
	57
	58	static void dma_free_page_table(void *table)
	59	{
	60	kmem_cache_free(dma_page_table_cache, table);
	61	}
	62
	63	static unsigned long dma_get_seg_table_origin(unsigned long entry)
	64	{
	65	unsigned long *sto;
	66
	67	if (reg_entry_isvalid(*entry))
	68	sto = get_rt_sto(*entry);
	69	else {
	70	sto = dma_alloc_cpu_table();
	71	if (!sto)
	72	return NULL;
	73
	74	set_rt_sto(entry, sto);
	75	validate_rt_entry(entry);
	76	entry_clr_protected(entry);
	77	}
	78	return sto;
	79	}
	80
	81	static unsigned long dma_get_page_table_origin(unsigned long entry)
	82	{
	83	unsigned long *pto;
	84
	85	if (reg_entry_isvalid(*entry))
	86	pto = get_st_pto(*entry);
	87	else {
	88	pto = dma_alloc_page_table();
	89	if (!pto)
	90	return NULL;
	91	set_st_pto(entry, pto);
92	validate_st_entry(entry);
93	entry_clr_protected(entry);
94	}
95	return pto;
96	}
97
98	static unsigned long dma_walk_cpu_trans(unsigned long rto, dma_addr_t dma_addr)
99	{
100	unsigned long sto, pto;
101	unsigned int rtx, sx, px;
102
103	rtx = calc_rtx(dma_addr);
104	sto = dma_get_seg_table_origin(&rto[rtx]);
105	if (!sto)
106	return NULL;
107
108	sx = calc_sx(dma_addr);
109	pto = dma_get_page_table_origin(&sto[sx]);
110	if (!pto)
111	return NULL;
112
113	px = calc_px(dma_addr);
114	return &pto[px];
115	}
116
8128f23c GS	117	void dma_update_cpu_trans(unsigned long dma_table, void page_addr,
8128f23c GS	118	dma_addr_t dma_addr, int flags)
828b35f6 JG	119	{
	120	unsigned long *entry;
	121
8128f23c	122	entry = dma_walk_cpu_trans(dma_table, dma_addr);
828b35f6 JG	123	if (!entry) {
	124	WARN_ON_ONCE(1);
	125	return;
	126	}
	127
	128	if (flags & ZPCI_PTE_INVALID) {
	129	invalidate_pt_entry(entry);
	130	return;
	131	} else {
	132	set_pt_pfaa(entry, page_addr);
	133	validate_pt_entry(entry);
	134	}
	135
	136	if (flags & ZPCI_TABLE_PROTECTED)
	137	entry_set_protected(entry);
	138	else
	139	entry_clr_protected(entry);
	140	}
	141
	142	static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
	143	dma_addr_t dma_addr, size_t size, int flags)
	144	{
	145	unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
	146	u8 page_addr = (u8 ) (pa & PAGE_MASK);
	147	dma_addr_t start_dma_addr = dma_addr;
	148	unsigned long irq_flags;
	149	int i, rc = 0;
	150
	151	if (!nr_pages)
	152	return -EINVAL;
	153
	154	spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
1f1dcbd4	155	if (!zdev->dma_table)
828b35f6	156	goto no_refresh;
828b35f6 JG	157
828b35f6 JG	158	for (i = 0; i < nr_pages; i++) {
8128f23c GS	159	dma_update_cpu_trans(zdev->dma_table, page_addr, dma_addr,
8128f23c GS	160	flags);
828b35f6 JG	161	page_addr += PAGE_SIZE;
	162	dma_addr += PAGE_SIZE;
	163	}
	164
	165	/*
c60d1ae4 GS	166	* With zdev->tlb_refresh == 0, rpcit is not required to establish new
	167	* translations when previously invalid translation-table entries are
	168	* validated. With lazy unmap, it also is skipped for previously valid
	169	* entries, but a global rpcit is then required before any address can
	170	* be re-used, i.e. after each iommu bitmap wrap-around.
828b35f6 JG	171	*/
828b35f6 JG	172	if (!zdev->tlb_refresh &&
c60d1ae4 GS	173	(!s390_iommu_strict \|\|
c60d1ae4 GS	174	((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)))
828b35f6	175	goto no_refresh;
b2a9e87d	176
9389339f MS	177	rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
9389339f MS	178	nr_pages * PAGE_SIZE);
828b35f6 JG	179
	180	no_refresh:
	181	spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
	182	return rc;
	183	}
	184
8128f23c	185	void dma_free_seg_table(unsigned long entry)
828b35f6 JG	186	{
	187	unsigned long *sto = get_rt_sto(entry);
	188	int sx;
	189
	190	for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
	191	if (reg_entry_isvalid(sto[sx]))
	192	dma_free_page_table(get_st_pto(sto[sx]));
	193
	194	dma_free_cpu_table(sto);
	195	}
	196
8128f23c	197	void dma_cleanup_tables(unsigned long *table)
828b35f6	198	{
828b35f6 JG	199	int rtx;
828b35f6 JG	200
8128f23c	201	if (!table)
828b35f6 JG	202	return;
	203
	204	for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
	205	if (reg_entry_isvalid(table[rtx]))
	206	dma_free_seg_table(table[rtx]);
	207
	208	dma_free_cpu_table(table);
828b35f6 JG	209	}
828b35f6 JG	210
5ec6d491 GS	211	static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev,
5ec6d491 GS	212	unsigned long start, int size)
828b35f6	213	{
5ec6d491	214	unsigned long boundary_size;
828b35f6	215
5ec6d491 GS	216	boundary_size = ALIGN(dma_get_seg_boundary(&zdev->pdev->dev) + 1,
5ec6d491 GS	217	PAGE_SIZE) >> PAGE_SHIFT;
828b35f6 JG	218	return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
	219	start, size, 0, boundary_size, 0);
	220	}
	221
	222	static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size)
	223	{
	224	unsigned long offset, flags;
c60d1ae4	225	int wrap = 0;
828b35f6 JG	226
	227	spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
	228	offset = __dma_alloc_iommu(zdev, zdev->next_bit, size);
c60d1ae4 GS	229	if (offset == -1) {
c60d1ae4 GS	230	/* wrap-around */
828b35f6	231	offset = __dma_alloc_iommu(zdev, 0, size);
c60d1ae4 GS	232	wrap = 1;
c60d1ae4 GS	233	}
828b35f6 JG	234
	235	if (offset != -1) {
	236	zdev->next_bit = offset + size;
c60d1ae4 GS	237	if (!zdev->tlb_refresh && !s390_iommu_strict && wrap)
	238	/* global flush after wrap-around with lazy unmap */
	239	zpci_refresh_global(zdev);
828b35f6 JG	240	}
	241	spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
	242	return offset;
	243	}
	244
	245	static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size)
	246	{
	247	unsigned long flags;
	248
	249	spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
	250	if (!zdev->iommu_bitmap)
	251	goto out;
	252	bitmap_clear(zdev->iommu_bitmap, offset, size);
c60d1ae4 GS	253	/*
	254	* Lazy flush for unmap: need to move next_bit to avoid address re-use
	255	* until wrap-around.
	256	*/
	257	if (!s390_iommu_strict && offset >= zdev->next_bit)
828b35f6 JG	258	zdev->next_bit = offset + size;
	259	out:
	260	spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
	261	}
	262
828b35f6 JG	263	static dma_addr_t s390_dma_map_pages(struct device dev, struct page page,
	264	unsigned long offset, size_t size,
	265	enum dma_data_direction direction,
	266	struct dma_attrs *attrs)
	267	{
198a5278	268	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
828b35f6 JG	269	unsigned long nr_pages, iommu_page_index;
	270	unsigned long pa = page_to_phys(page) + offset;
	271	int flags = ZPCI_PTE_VALID;
	272	dma_addr_t dma_addr;
	273
828b35f6 JG	274	/* This rounds up number of pages based on size and offset */
	275	nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
	276	iommu_page_index = dma_alloc_iommu(zdev, nr_pages);
	277	if (iommu_page_index == -1)
	278	goto out_err;
	279
	280	/* Use rounded up size */
	281	size = nr_pages * PAGE_SIZE;
	282
	283	dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
1f1dcbd4	284	if (dma_addr + size > zdev->end_dma)
828b35f6	285	goto out_free;
828b35f6 JG	286
	287	if (direction == DMA_NONE \|\| direction == DMA_TO_DEVICE)
	288	flags \|= ZPCI_TABLE_PROTECTED;
	289
d0b08853	290	if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
6001018a	291	atomic64_add(nr_pages, &zdev->mapped_pages);
186f50fa	292	return dma_addr + (offset & ~PAGE_MASK);
d0b08853	293	}
828b35f6 JG	294
	295	out_free:
	296	dma_free_iommu(zdev, iommu_page_index, nr_pages);
	297	out_err:
1f1dcbd4 SO	298	zpci_err("map error:\n");
1f1dcbd4 SO	299	zpci_err_hex(&pa, sizeof(pa));
828b35f6 JG	300	return DMA_ERROR_CODE;
	301	}
	302
	303	static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
	304	size_t size, enum dma_data_direction direction,
	305	struct dma_attrs *attrs)
	306	{
198a5278	307	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
828b35f6 JG	308	unsigned long iommu_page_index;
	309	int npages;
	310
	311	npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
	312	dma_addr = dma_addr & PAGE_MASK;
	313	if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
1f1dcbd4 SO	314	ZPCI_TABLE_PROTECTED \| ZPCI_PTE_INVALID)) {
	315	zpci_err("unmap error:\n");
	316	zpci_err_hex(&dma_addr, sizeof(dma_addr));
	317	}
828b35f6	318
6001018a	319	atomic64_add(npages, &zdev->unmapped_pages);
828b35f6 JG	320	iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
	321	dma_free_iommu(zdev, iommu_page_index, npages);
	322	}
	323
	324	static void s390_dma_alloc(struct device dev, size_t size,
	325	dma_addr_t *dma_handle, gfp_t flag,
	326	struct dma_attrs *attrs)
	327	{
198a5278	328	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
828b35f6 JG	329	struct page *page;
	330	unsigned long pa;
	331	dma_addr_t map;
	332
	333	size = PAGE_ALIGN(size);
	334	page = alloc_pages(flag, get_order(size));
	335	if (!page)
	336	return NULL;
d0b08853	337
828b35f6 JG	338	pa = page_to_phys(page);
	339	memset((void *) pa, 0, size);
	340
	341	map = s390_dma_map_pages(dev, page, pa % PAGE_SIZE,
	342	size, DMA_BIDIRECTIONAL, NULL);
	343	if (dma_mapping_error(dev, map)) {
	344	free_pages(pa, get_order(size));
	345	return NULL;
	346	}
	347
6001018a	348	atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages);
828b35f6 JG	349	if (dma_handle)
	350	*dma_handle = map;
	351	return (void *) pa;
	352	}
	353
	354	static void s390_dma_free(struct device *dev, size_t size,
	355	void *pa, dma_addr_t dma_handle,
	356	struct dma_attrs *attrs)
	357	{
198a5278	358	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
f7038b7c SO	359
f7038b7c SO	360	size = PAGE_ALIGN(size);
6001018a	361	atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages);
f7038b7c	362	s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, NULL);
828b35f6 JG	363	free_pages((unsigned long) pa, get_order(size));
	364	}
	365
	366	static int s390_dma_map_sg(struct device dev, struct scatterlist sg,
	367	int nr_elements, enum dma_data_direction dir,
	368	struct dma_attrs *attrs)
	369	{
	370	int mapped_elements = 0;
	371	struct scatterlist *s;
	372	int i;
	373
	374	for_each_sg(sg, s, nr_elements, i) {
	375	struct page *page = sg_page(s);
	376	s->dma_address = s390_dma_map_pages(dev, page, s->offset,
	377	s->length, dir, NULL);
	378	if (!dma_mapping_error(dev, s->dma_address)) {
	379	s->dma_length = s->length;
	380	mapped_elements++;
	381	} else
	382	goto unmap;
	383	}
	384	out:
	385	return mapped_elements;
	386
	387	unmap:
	388	for_each_sg(sg, s, mapped_elements, i) {
	389	if (s->dma_address)
	390	s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
	391	dir, NULL);
	392	s->dma_address = 0;
	393	s->dma_length = 0;
	394	}
	395	mapped_elements = 0;
	396	goto out;
	397	}
	398
	399	static void s390_dma_unmap_sg(struct device dev, struct scatterlist sg,
	400	int nr_elements, enum dma_data_direction dir,
	401	struct dma_attrs *attrs)
	402	{
	403	struct scatterlist *s;
	404	int i;
	405
	406	for_each_sg(sg, s, nr_elements, i) {
	407	s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
	408	s->dma_address = 0;
	409	s->dma_length = 0;
	410	}
	411	}
	412
	413	int zpci_dma_init_device(struct zpci_dev *zdev)
	414	{
828b35f6 JG	415	int rc;
828b35f6 JG	416
8128f23c GS	417	/*
	418	* At this point, if the device is part of an IOMMU domain, this would
	419	* be a strong hint towards a bug in the IOMMU API (common) code and/or
	420	* simultaneous access via IOMMU and DMA API. So let's issue a warning.
	421	*/
	422	WARN_ON(zdev->s390_domain);
	423
828b35f6 JG	424	spin_lock_init(&zdev->iommu_bitmap_lock);
	425	spin_lock_init(&zdev->dma_table_lock);
	426
	427	zdev->dma_table = dma_alloc_cpu_table();
	428	if (!zdev->dma_table) {
	429	rc = -ENOMEM;
	430	goto out_clean;
	431	}
	432
	433	zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
	434	zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
22459321	435	zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
828b35f6 JG	436	if (!zdev->iommu_bitmap) {
	437	rc = -ENOMEM;
	438	goto out_reg;
	439	}
	440
	441	rc = zpci_register_ioat(zdev,
	442	0,
	443	zdev->start_dma + PAGE_OFFSET,
	444	zdev->start_dma + zdev->iommu_size - 1,
	445	(u64) zdev->dma_table);
	446	if (rc)
	447	goto out_reg;
	448	return 0;
	449
	450	out_reg:
	451	dma_free_cpu_table(zdev->dma_table);
	452	out_clean:
	453	return rc;
	454	}
	455
	456	void zpci_dma_exit_device(struct zpci_dev *zdev)
	457	{
8128f23c GS	458	/*
	459	* At this point, if the device is part of an IOMMU domain, this would
	460	* be a strong hint towards a bug in the IOMMU API (common) code and/or
	461	* simultaneous access via IOMMU and DMA API. So let's issue a warning.
	462	*/
	463	WARN_ON(zdev->s390_domain);
	464
828b35f6	465	zpci_unregister_ioat(zdev, 0);
8128f23c GS	466	dma_cleanup_tables(zdev->dma_table);
8128f23c GS	467	zdev->dma_table = NULL;
22459321	468	vfree(zdev->iommu_bitmap);
828b35f6 JG	469	zdev->iommu_bitmap = NULL;
	470	zdev->next_bit = 0;
	471	}
	472
	473	static int __init dma_alloc_cpu_table_caches(void)
	474	{
	475	dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
	476	ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
	477	0, NULL);
	478	if (!dma_region_table_cache)
	479	return -ENOMEM;
	480
	481	dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
	482	ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
	483	0, NULL);
	484	if (!dma_page_table_cache) {
	485	kmem_cache_destroy(dma_region_table_cache);
	486	return -ENOMEM;
	487	}
	488	return 0;
	489	}
	490
	491	int __init zpci_dma_init(void)
	492	{
	493	return dma_alloc_cpu_table_caches();
	494	}
	495
	496	void zpci_dma_exit(void)
	497	{
	498	kmem_cache_destroy(dma_page_table_cache);
	499	kmem_cache_destroy(dma_region_table_cache);
	500	}
	501
	502	#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
	503
	504	static int __init dma_debug_do_init(void)
	505	{
	506	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
	507	return 0;
	508	}
	509	fs_initcall(dma_debug_do_init);
	510
	511	struct dma_map_ops s390_dma_ops = {
	512	.alloc = s390_dma_alloc,
	513	.free = s390_dma_free,
	514	.map_sg = s390_dma_map_sg,
	515	.unmap_sg = s390_dma_unmap_sg,
	516	.map_page = s390_dma_map_pages,
	517	.unmap_page = s390_dma_unmap_pages,
	518	/* if we support direct DMA this must be conditional */
	519	.is_phys = 0,
	520	/* dma_supported is unconditionally true without a callback */
	521	};
	522	EXPORT_SYMBOL_GPL(s390_dma_ops);
c60d1ae4 GS	523
	524	static int __init s390_iommu_setup(char *str)
	525	{
	526	if (!strncmp(str, "strict", 6))
	527	s390_iommu_strict = 1;
	528	return 0;
	529	}
	530
	531	__setup("s390_iommu=", s390_iommu_setup);