pci_iommu.c

linux-2.6.15.6

		       vaddr, ctx, npages);
}

/* Unmap a single streaming mode DMA translation. */
void pci_unmap_single(struct pci_dev *pdev, dma_addr_t bus_addr, size_t sz, int direction)
{
	struct pcidev_cookie *pcp;
	struct pci_iommu *iommu;
	struct pci_strbuf *strbuf;
	iopte_t *base;
	unsigned long flags, npages, ctx, i;

	if (unlikely(direction == PCI_DMA_NONE)) {
		if (printk_ratelimit())
			WARN_ON(1);
		return;
	}

	pcp = pdev->sysdata;
	iommu = pcp->pbm->iommu;
	strbuf = &pcp->pbm->stc;

	npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
	npages >>= IO_PAGE_SHIFT;
	base = iommu->page_table +
		((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
#ifdef DEBUG_PCI_IOMMU
	if (IOPTE_IS_DUMMY(iommu, base))
		printk("pci_unmap_single called on non-mapped region %08x,%08x from %016lx\n",
		       bus_addr, sz, __builtin_return_address(0));
#endif
	bus_addr &= IO_PAGE_MASK;

	spin_lock_irqsave(&iommu->lock, flags);

	/* Record the context, if any. */
	ctx = 0;
	if (iommu->iommu_ctxflush)
		ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;

	/* Step 1: Kick data out of streaming buffers if necessary. */
	if (strbuf->strbuf_enabled)
		pci_strbuf_flush(strbuf, iommu, bus_addr, ctx,
				 npages, direction);

	/* Step 2: Clear out TSB entries. */
	for (i = 0; i < npages; i++)
		iopte_make_dummy(iommu, base + i);

	free_npages(iommu, bus_addr - iommu->page_table_map_base, npages);

	iommu_free_ctx(iommu, ctx);

	spin_unlock_irqrestore(&iommu->lock, flags);
}

#define SG_ENT_PHYS_ADDRESS(SG)	\
	(__pa(page_address((SG)->page)) + (SG)->offset)

static inline void fill_sg(iopte_t *iopte, struct scatterlist *sg,
			   int nused, int nelems, unsigned long iopte_protection)
{
	struct scatterlist *dma_sg = sg;
	struct scatterlist *sg_end = sg + nelems;
	int i;

	for (i = 0; i < nused; i++) {
		unsigned long pteval = ~0UL;
		u32 dma_npages;

		dma_npages = ((dma_sg->dma_address & (IO_PAGE_SIZE - 1UL)) +
			      dma_sg->dma_length +
			      ((IO_PAGE_SIZE - 1UL))) >> IO_PAGE_SHIFT;
		do {
			unsigned long offset;
			signed int len;

			/* If we are here, we know we have at least one
			 * more page to map.  So walk forward until we
			 * hit a page crossing, and begin creating new
			 * mappings from that spot.
			 */
			for (;;) {
				unsigned long tmp;

				tmp = SG_ENT_PHYS_ADDRESS(sg);
				len = sg->length;
				if (((tmp ^ pteval) >> IO_PAGE_SHIFT) != 0UL) {
					pteval = tmp & IO_PAGE_MASK;
					offset = tmp & (IO_PAGE_SIZE - 1UL);
					break;
				}
				if (((tmp ^ (tmp + len - 1UL)) >> IO_PAGE_SHIFT) != 0UL) {
					pteval = (tmp + IO_PAGE_SIZE) & IO_PAGE_MASK;
					offset = 0UL;
					len -= (IO_PAGE_SIZE - (tmp & (IO_PAGE_SIZE - 1UL)));
					break;
				}
				sg++;
			}

			pteval = iopte_protection | (pteval & IOPTE_PAGE);
			while (len > 0) {
				*iopte++ = __iopte(pteval);
				pteval += IO_PAGE_SIZE;
				len -= (IO_PAGE_SIZE - offset);
				offset = 0;
				dma_npages--;
			}

			pteval = (pteval & IOPTE_PAGE) + len;
			sg++;

			/* Skip over any tail mappings we've fully mapped,
			 * adjusting pteval along the way.  Stop when we
			 * detect a page crossing event.
			 */
			while (sg < sg_end &&
			       (pteval << (64 - IO_PAGE_SHIFT)) != 0UL &&
			       (pteval == SG_ENT_PHYS_ADDRESS(sg)) &&
			       ((pteval ^
				 (SG_ENT_PHYS_ADDRESS(sg) + sg->length - 1UL)) >> IO_PAGE_SHIFT) == 0UL) {
				pteval += sg->length;
				sg++;
			}
			if ((pteval << (64 - IO_PAGE_SHIFT)) == 0UL)
				pteval = ~0UL;
		} while (dma_npages != 0);
		dma_sg++;
	}
}

/* Map a set of buffers described by SGLIST with NELEMS array
 * elements in streaming mode for PCI DMA.
 * When making changes here, inspect the assembly output. I was having
 * hard time to kepp this routine out of using stack slots for holding variables.
 */
int pci_map_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, int direction)
{
	struct pcidev_cookie *pcp;
	struct pci_iommu *iommu;
	struct pci_strbuf *strbuf;
	unsigned long flags, ctx, npages, iopte_protection;
	iopte_t *base;
	u32 dma_base;
	struct scatterlist *sgtmp;
	int used;

	/* Fast path single entry scatterlists. */
	if (nelems == 1) {
		sglist->dma_address =
			pci_map_single(pdev,
				       (page_address(sglist->page) + sglist->offset),
				       sglist->length, direction);
		if (unlikely(sglist->dma_address == PCI_DMA_ERROR_CODE))
			return 0;
		sglist->dma_length = sglist->length;
		return 1;
	}

	pcp = pdev->sysdata;
	iommu = pcp->pbm->iommu;
	strbuf = &pcp->pbm->stc;
	
	if (unlikely(direction == PCI_DMA_NONE))
		goto bad_no_ctx;

	/* Step 1: Prepare scatter list. */

	npages = prepare_sg(sglist, nelems);

	/* Step 2: Allocate a cluster and context, if necessary. */

	spin_lock_irqsave(&iommu->lock, flags);

	base = alloc_npages(iommu, npages);
	ctx = 0;
	if (iommu->iommu_ctxflush)
		ctx = iommu_alloc_ctx(iommu);

	spin_unlock_irqrestore(&iommu->lock, flags);

	if (base == NULL)
		goto bad;

	dma_base = iommu->page_table_map_base +
		((base - iommu->page_table) << IO_PAGE_SHIFT);

	/* Step 3: Normalize DMA addresses. */
	used = nelems;

	sgtmp = sglist;
	while (used && sgtmp->dma_length) {
		sgtmp->dma_address += dma_base;
		sgtmp++;
		used--;
	}
	used = nelems - used;

	/* Step 4: Create the mappings. */
	if (strbuf->strbuf_enabled)
		iopte_protection = IOPTE_STREAMING(ctx);
	else
		iopte_protection = IOPTE_CONSISTENT(ctx);
	if (direction != PCI_DMA_TODEVICE)
		iopte_protection |= IOPTE_WRITE;

	fill_sg(base, sglist, used, nelems, iopte_protection);

#ifdef VERIFY_SG
	verify_sglist(sglist, nelems, base, npages);
#endif

	return used;

bad:
	iommu_free_ctx(iommu, ctx);
bad_no_ctx:
	if (printk_ratelimit())
		WARN_ON(1);
	return 0;
}

/* Unmap a set of streaming mode DMA translations. */
void pci_unmap_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, int direction)
{
	struct pcidev_cookie *pcp;
	struct pci_iommu *iommu;
	struct pci_strbuf *strbuf;
	iopte_t *base;
	unsigned long flags, ctx, i, npages;
	u32 bus_addr;

	if (unlikely(direction == PCI_DMA_NONE)) {
		if (printk_ratelimit())
			WARN_ON(1);
	}

	pcp = pdev->sysdata;
	iommu = pcp->pbm->iommu;
	strbuf = &pcp->pbm->stc;
	
	bus_addr = sglist->dma_address & IO_PAGE_MASK;

	for (i = 1; i < nelems; i++)
		if (sglist[i].dma_length == 0)
			break;
	i--;
	npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length) -
		  bus_addr) >> IO_PAGE_SHIFT;

	base = iommu->page_table +
		((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);

#ifdef DEBUG_PCI_IOMMU
	if (IOPTE_IS_DUMMY(iommu, base))
		printk("pci_unmap_sg called on non-mapped region %016lx,%d from %016lx\n", sglist->dma_address, nelems, __builtin_return_address(0));
#endif

	spin_lock_irqsave(&iommu->lock, flags);

	/* Record the context, if any. */
	ctx = 0;
	if (iommu->iommu_ctxflush)
		ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;

	/* Step 1: Kick data out of streaming buffers if necessary. */
	if (strbuf->strbuf_enabled)
		pci_strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);

	/* Step 2: Clear out the TSB entries. */
	for (i = 0; i < npages; i++)
		iopte_make_dummy(iommu, base + i);

	free_npages(iommu, bus_addr - iommu->page_table_map_base, npages);

	iommu_free_ctx(iommu, ctx);

	spin_unlock_irqrestore(&iommu->lock, flags);
}

/* Make physical memory consistent for a single
 * streaming mode DMA translation after a transfer.
 */
void pci_dma_sync_single_for_cpu(struct pci_dev *pdev, dma_addr_t bus_addr, size_t sz, int direction)
{
	struct pcidev_cookie *pcp;
	struct pci_iommu *iommu;
	struct pci_strbuf *strbuf;
	unsigned long flags, ctx, npages;

	pcp = pdev->sysdata;
	iommu = pcp->pbm->iommu;
	strbuf = &pcp->pbm->stc;

	if (!strbuf->strbuf_enabled)
		return;

	spin_lock_irqsave(&iommu->lock, flags);

	npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
	npages >>= IO_PAGE_SHIFT;
	bus_addr &= IO_PAGE_MASK;

	/* Step 1: Record the context, if any. */
	ctx = 0;
	if (iommu->iommu_ctxflush &&
	    strbuf->strbuf_ctxflush) {
		iopte_t *iopte;

		iopte = iommu->page_table +
			((bus_addr - iommu->page_table_map_base)>>IO_PAGE_SHIFT);
		ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
	}

	/* Step 2: Kick data out of streaming buffers. */
	pci_strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);

	spin_unlock_irqrestore(&iommu->lock, flags);
}

/* Make physical memory consistent for a set of streaming
 * mode DMA translations after a transfer.
 */
void pci_dma_sync_sg_for_cpu(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, int direction)
{
	struct pcidev_cookie *pcp;
	struct pci_iommu *iommu;
	struct pci_strbuf *strbuf;
	unsigned long flags, ctx, npages, i;
	u32 bus_addr;

	pcp = pdev->sysdata;
	iommu = pcp->pbm->iommu;
	strbuf = &pcp->pbm->stc;

	if (!strbuf->strbuf_enabled)
		return;

	spin_lock_irqsave(&iommu->lock, flags);

	/* Step 1: Record the context, if any. */
	ctx = 0;
	if (iommu->iommu_ctxflush &&
	    strbuf->strbuf_ctxflush) {
		iopte_t *iopte;

		iopte = iommu->page_table +
			((sglist[0].dma_address - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
		ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
	}

	/* Step 2: Kick data out of streaming buffers. */
	bus_addr = sglist[0].dma_address & IO_PAGE_MASK;
	for(i = 1; i < nelems; i++)
		if (!sglist[i].dma_length)
			break;
	i--;
	npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length)
		  - bus_addr) >> IO_PAGE_SHIFT;
	pci_strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);

	spin_unlock_irqrestore(&iommu->lock, flags);
}

static void ali_sound_dma_hack(struct pci_dev *pdev, int set_bit)
{
	struct pci_dev *ali_isa_bridge;
	u8 val;

	/* ALI sound chips generate 31-bits of DMA, a special register
	 * determines what bit 31 is emitted as.
	 */
	ali_isa_bridge = pci_get_device(PCI_VENDOR_ID_AL,
					 PCI_DEVICE_ID_AL_M1533,
					 NULL);

	pci_read_config_byte(ali_isa_bridge, 0x7e, &val);
	if (set_bit)
		val |= 0x01;
	else
		val &= ~0x01;
	pci_write_config_byte(ali_isa_bridge, 0x7e, val);
	pci_dev_put(ali_isa_bridge);
}

int pci_dma_supported(struct pci_dev *pdev, u64 device_mask)
{
	struct pcidev_cookie *pcp = pdev->sysdata;
	u64 dma_addr_mask;

	if (pdev == NULL) {
		dma_addr_mask = 0xffffffff;
	} else {
		struct pci_iommu *iommu = pcp->pbm->iommu;

		dma_addr_mask = iommu->dma_addr_mask;

		if (pdev->vendor == PCI_VENDOR_ID_AL &&
		    pdev->device == PCI_DEVICE_ID_AL_M5451 &&
		    device_mask == 0x7fffffff) {
			ali_sound_dma_hack(pdev,
					   (dma_addr_mask & 0x80000000) != 0);
			return 1;
		}
	}

	if (device_mask >= (1UL << 32UL))
		return 0;

	return (device_mask & dma_addr_mask) == dma_addr_mask;
}