PCI: Move ATS implementation into own file

[karo-tx-linux.git] / drivers / pci / ats.c

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
new file mode 100644 (file)
index 0000000..ae4bf87
--- /dev/null
+++ b/drivers/pci/ats.c
@@ -0,0 +1,155 @@
+/*
+ * drivers/pci/ats.c
+ *
+ * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
+ *
+ * PCI Express I/O Virtualization (IOV) support.
+ *   Address Translation Service 1.0
+ */
+
+#include <linux/pci-ats.h>
+#include <linux/pci.h>
+
+#include "pci.h"
+
+static int ats_alloc_one(struct pci_dev *dev, int ps)
+{
+       int pos;
+       u16 cap;
+       struct pci_ats *ats;
+
+       pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
+       if (!pos)
+               return -ENODEV;
+
+       ats = kzalloc(sizeof(*ats), GFP_KERNEL);
+       if (!ats)
+               return -ENOMEM;
+
+       ats->pos = pos;
+       ats->stu = ps;
+       pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
+       ats->qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
+                                           PCI_ATS_MAX_QDEP;
+       dev->ats = ats;
+
+       return 0;
+}
+
+static void ats_free_one(struct pci_dev *dev)
+{
+       kfree(dev->ats);
+       dev->ats = NULL;
+}
+
+/**
+ * pci_enable_ats - enable the ATS capability
+ * @dev: the PCI device
+ * @ps: the IOMMU page shift
+ *
+ * Returns 0 on success, or negative on failure.
+ */
+int pci_enable_ats(struct pci_dev *dev, int ps)
+{
+       int rc;
+       u16 ctrl;
+
+       BUG_ON(dev->ats && dev->ats->is_enabled);
+
+       if (ps < PCI_ATS_MIN_STU)
+               return -EINVAL;
+
+       if (dev->is_physfn || dev->is_virtfn) {
+               struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;
+
+               mutex_lock(&pdev->sriov->lock);
+               if (pdev->ats)
+                       rc = pdev->ats->stu == ps ? 0 : -EINVAL;
+               else
+                       rc = ats_alloc_one(pdev, ps);
+
+               if (!rc)
+                       pdev->ats->ref_cnt++;
+               mutex_unlock(&pdev->sriov->lock);
+               if (rc)
+                       return rc;
+       }
+
+       if (!dev->is_physfn) {
+               rc = ats_alloc_one(dev, ps);
+               if (rc)
+                       return rc;
+       }
+
+       ctrl = PCI_ATS_CTRL_ENABLE;
+       if (!dev->is_virtfn)
+               ctrl |= PCI_ATS_CTRL_STU(ps - PCI_ATS_MIN_STU);
+       pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
+
+       dev->ats->is_enabled = 1;
+
+       return 0;
+}
+
+/**
+ * pci_disable_ats - disable the ATS capability
+ * @dev: the PCI device
+ */
+void pci_disable_ats(struct pci_dev *dev)
+{
+       u16 ctrl;
+
+       BUG_ON(!dev->ats || !dev->ats->is_enabled);
+
+       pci_read_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, &ctrl);
+       ctrl &= ~PCI_ATS_CTRL_ENABLE;
+       pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
+
+       dev->ats->is_enabled = 0;
+
+       if (dev->is_physfn || dev->is_virtfn) {
+               struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;
+
+               mutex_lock(&pdev->sriov->lock);
+               pdev->ats->ref_cnt--;
+               if (!pdev->ats->ref_cnt)
+                       ats_free_one(pdev);
+               mutex_unlock(&pdev->sriov->lock);
+       }
+
+       if (!dev->is_physfn)
+               ats_free_one(dev);
+}
+
+/**
+ * pci_ats_queue_depth - query the ATS Invalidate Queue Depth
+ * @dev: the PCI device
+ *
+ * Returns the queue depth on success, or negative on failure.
+ *
+ * The ATS spec uses 0 in the Invalidate Queue Depth field to
+ * indicate that the function can accept 32 Invalidate Request.
+ * But here we use the `real' values (i.e. 1~32) for the Queue
+ * Depth; and 0 indicates the function shares the Queue with
+ * other functions (doesn't exclusively own a Queue).
+ */
+int pci_ats_queue_depth(struct pci_dev *dev)
+{
+       int pos;
+       u16 cap;
+
+       if (dev->is_virtfn)
+               return 0;
+
+       if (dev->ats)
+               return dev->ats->qdep;
+
+       pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
+       if (!pos)
+               return -ENODEV;
+
+       pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
+
+       return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
+                                      PCI_ATS_MAX_QDEP;
+}