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Commit 7bb67c14 authored by Shannon Nelson's avatar Shannon Nelson Committed by Linus Torvalds
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I/OAT: Add support for version 2 of ioatdma device 



Add support for version 2 of the ioatdma device.  This device handles
the descriptor chain and DCA services slightly differently:
 - Instead of moving the dma descriptors between a busy and an idle chain,
   this new version uses a single circular chain so that we don't have
   rewrite the next_descriptor pointers as we add new requests, and the
   device doesn't need to re-read the last descriptor.
 - The new device has the DCA tags defined internally instead of needing
   them defined statically.

Signed-off-by: default avatarShannon Nelson <shannon.nelson@intel.com>
Cc: "Williams, Dan J" <dan.j.williams@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cc9f2f8f

drivers/dma/ioat.c

+11 −0
Original line number Diff line number Diff line
@@ -39,10 +39,14 @@ MODULE_LICENSE("GPL"); 
MODULE_AUTHOR("Intel Corporation");



static struct pci_device_id ioat_pci_tbl[] = {

	/* I/OAT v1 platforms */

	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT) },

	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_CNB)  },

	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SCNB) },

	{ PCI_DEVICE(PCI_VENDOR_ID_UNISYS, PCI_DEVICE_ID_UNISYS_DMA_DIRECTOR) },



	/* I/OAT v2 platforms */

	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SNB) },

	{ 0, }

};
@@ -74,10 +78,17 @@ static int ioat_setup_functionality(struct pci_dev *pdev, void __iomem *iobase) 
		if (device->dma && ioat_dca_enabled)

			device->dca = ioat_dca_init(pdev, iobase);

		break;

	case IOAT_VER_2_0:

		device->dma = ioat_dma_probe(pdev, iobase);

		if (device->dma && ioat_dca_enabled)

			device->dca = ioat2_dca_init(pdev, iobase);

		break;

	default:

		err = -ENODEV;

		break;

	}

	if (!device->dma)

		err = -ENODEV;

	return err;

}

drivers/dma/ioat_dca.c

+164 −0
Original line number Diff line number Diff line
@@ -261,3 +261,167 @@ struct dca_provider *ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase) 
	return dca;

}





static int ioat2_dca_add_requester(struct dca_provider *dca, struct device *dev)

{

	struct ioat_dca_priv *ioatdca = dca_priv(dca);

	struct pci_dev *pdev;

	int i;

	u16 id;

	u16 global_req_table;



	/* This implementation only supports PCI-Express */

	if (dev->bus != &pci_bus_type)

		return -ENODEV;

	pdev = to_pci_dev(dev);

	id = dcaid_from_pcidev(pdev);



	if (ioatdca->requester_count == ioatdca->max_requesters)

		return -ENODEV;



	for (i = 0; i < ioatdca->max_requesters; i++) {

		if (ioatdca->req_slots[i].pdev == NULL) {

			/* found an empty slot */

			ioatdca->requester_count++;

			ioatdca->req_slots[i].pdev = pdev;

			ioatdca->req_slots[i].rid = id;

			global_req_table =

			      readw(ioatdca->dca_base + IOAT_DCA_GREQID_OFFSET);

			writel(id | IOAT_DCA_GREQID_VALID,

			       ioatdca->iobase + global_req_table + (i * 4));

			return i;

		}

	}

	/* Error, ioatdma->requester_count is out of whack */

	return -EFAULT;

}



static int ioat2_dca_remove_requester(struct dca_provider *dca,

				      struct device *dev)

{

	struct ioat_dca_priv *ioatdca = dca_priv(dca);

	struct pci_dev *pdev;

	int i;

	u16 global_req_table;



	/* This implementation only supports PCI-Express */

	if (dev->bus != &pci_bus_type)

		return -ENODEV;

	pdev = to_pci_dev(dev);



	for (i = 0; i < ioatdca->max_requesters; i++) {

		if (ioatdca->req_slots[i].pdev == pdev) {

			global_req_table =

			      readw(ioatdca->dca_base + IOAT_DCA_GREQID_OFFSET);

			writel(0, ioatdca->iobase + global_req_table + (i * 4));

			ioatdca->req_slots[i].pdev = NULL;

			ioatdca->req_slots[i].rid = 0;

			ioatdca->requester_count--;

			return i;

		}

	}

	return -ENODEV;

}



static u8 ioat2_dca_get_tag(struct dca_provider *dca, int cpu)

{

	u8 tag;



	tag = ioat_dca_get_tag(dca, cpu);

	tag = (~tag) & 0x1F;

	return tag;

}



static struct dca_ops ioat2_dca_ops = {

	.add_requester		= ioat2_dca_add_requester,

	.remove_requester	= ioat2_dca_remove_requester,

	.get_tag		= ioat2_dca_get_tag,

};



static int ioat2_dca_count_dca_slots(void *iobase, u16 dca_offset)

{

	int slots = 0;

	u32 req;

	u16 global_req_table;



	global_req_table = readw(iobase + dca_offset + IOAT_DCA_GREQID_OFFSET);

	if (global_req_table == 0)

		return 0;

	do {

		req = readl(iobase + global_req_table + (slots * sizeof(u32)));

		slots++;

	} while ((req & IOAT_DCA_GREQID_LASTID) == 0);



	return slots;

}



struct dca_provider *ioat2_dca_init(struct pci_dev *pdev, void __iomem *iobase)

{

	struct dca_provider *dca;

	struct ioat_dca_priv *ioatdca;

	int slots;

	int i;

	int err;

	u32 tag_map;

	u16 dca_offset;

	u16 csi_fsb_control;

	u16 pcie_control;

	u8 bit;



	if (!system_has_dca_enabled(pdev))

		return NULL;



	dca_offset = readw(iobase + IOAT_DCAOFFSET_OFFSET);

	if (dca_offset == 0)

		return NULL;



	slots = ioat2_dca_count_dca_slots(iobase, dca_offset);

	if (slots == 0)

		return NULL;



	dca = alloc_dca_provider(&ioat2_dca_ops,

				 sizeof(*ioatdca)

				      + (sizeof(struct ioat_dca_slot) * slots));

	if (!dca)

		return NULL;



	ioatdca = dca_priv(dca);

	ioatdca->iobase = iobase;

	ioatdca->dca_base = iobase + dca_offset;

	ioatdca->max_requesters = slots;



	/* some bios might not know to turn these on */

	csi_fsb_control = readw(ioatdca->dca_base + IOAT_FSB_CAP_ENABLE_OFFSET);

	if ((csi_fsb_control & IOAT_FSB_CAP_ENABLE_PREFETCH) == 0) {

		csi_fsb_control |= IOAT_FSB_CAP_ENABLE_PREFETCH;

		writew(csi_fsb_control,

		       ioatdca->dca_base + IOAT_FSB_CAP_ENABLE_OFFSET);

	}

	pcie_control = readw(ioatdca->dca_base + IOAT_PCI_CAP_ENABLE_OFFSET);

	if ((pcie_control & IOAT_PCI_CAP_ENABLE_MEMWR) == 0) {

		pcie_control |= IOAT_PCI_CAP_ENABLE_MEMWR;

		writew(pcie_control,

		       ioatdca->dca_base + IOAT_PCI_CAP_ENABLE_OFFSET);

	}





	/* TODO version, compatibility and configuration checks */



	/* copy out the APIC to DCA tag map */

	tag_map = readl(ioatdca->dca_base + IOAT_APICID_TAG_MAP_OFFSET);

	for (i = 0; i < 5; i++) {

		bit = (tag_map >> (4 * i)) & 0x0f;

		if (bit < 8)

			ioatdca->tag_map[i] = bit | DCA_TAG_MAP_VALID;

		else

			ioatdca->tag_map[i] = 0;

	}



	err = register_dca_provider(dca, &pdev->dev);

	if (err) {

		free_dca_provider(dca);

		return NULL;

	}



	return dca;

}