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: Shannon Nelson <shannon.nelson@intel.com>
Cc: "Williams, Dan J" <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/dma/ioat_dca.c b/drivers/dma/ioat_dca.c
index ba98571..0fa8a98 100644
--- a/drivers/dma/ioat_dca.c
+++ b/drivers/dma/ioat_dca.c
@@ -261,3 +261,167 @@
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;
+}