On Fri, 2013-06-28 at 13:08 +0530, Varun Sethi wrote:
> Following is a brief description of the PAMU hardware:
> PAMU determines what action to take and whether to authorize the action on
> the basis of the memory address, a Logical IO Device Number (LIODN), and
> PAACT table (logically) indexed by LIODN and address. Hardware devices which
> need to access memory must provide an LIODN in addition to the memory address.
>
> Peripheral Access Authorization and Control Tables (PAACTs) are the primary
> data structures used by PAMU. A PAACT is a table of peripheral access
> authorization and control entries (PAACE).Each PAACE defines the range of
> I/O bus address space that is accessible by the LIOD and the associated access
> capabilities.
>
> There are two types of PAACTs: primary PAACT (PPAACT) and secondary PAACT
> (SPAACT).A given physical I/O device may be able to act as one or more
> independent logical I/O devices (LIODs). Each such logical I/O device is
> assigned an identifier called logical I/O device number (LIODN). A LIODN is
> allocated a contiguous portion of the I/O bus address space called the DSA
> window
> for performing DSA operations. The DSA window may optionally be divided into
> multiple sub-windows, each of which may be used to map to a region in system
> storage space. The first sub-window is referred to as the primary sub-window
> and the remaining are called secondary sub-windows.
>
> This patch provides the PAMU driver (fsl_pamu.c) and the corresponding IOMMU
> API implementation (fsl_pamu_domain.c). The PAMU hardware driver (fsl_pamu.c)
> has been derived from the work done by Ashish Kalra and Timur Tabi.
[snip]
> +#define REQ_ACS_FLAGS (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR |
> PCI_ACS_UF)
> +
> +static struct iommu_group *get_device_iommu_group(struct device *dev)
> +{
> + struct iommu_group *group;
> +
> + group = iommu_group_get(dev);
> + if (!group)
> + group = iommu_group_alloc();
> +
> + return group;
> +}
> +
> +static bool check_pci_ctl_endpt_part(struct pci_controller *pci_ctl)
> +{
> + u32 version;
> +
> + /* Check the PCI controller version number by readding BRR1 register */
> + version = in_be32(pci_ctl->cfg_addr + (PCI_FSL_BRR1 >> 2));
> + version &= PCI_FSL_BRR1_VER;
> + /* If PCI controller version is >= 0x204 we can partition endpoints*/
> + if (version >= 0x204)
> + return 1;
> +
> + return 0;
> +}
> +
> +/* Get iommu group information from peer devices or devices on the parent
> bus */
> +static struct iommu_group *get_peer_pci_device_group(struct pci_dev *pdev)
> +{
> + struct pci_dev *tmp;
> + struct iommu_group *group = NULL;
> +
> + /* check if this is the first device on the bus*/
> + if (list_is_singular(&pdev->bus_list)) {
> + struct pci_bus *bus = pdev->bus->parent;
> + /* Traverese the parent bus list to get
> + * the iommu group for devices on the
> + * parent bus.
> + */
> + while (bus && !group) {
> + list_for_each_entry(tmp, &bus->devices, bus_list) {
> + group = iommu_group_get(&tmp->dev);
> + if (group)
> + break;
> + }
> +
> + bus = bus->parent;
> + }
> + } else {
> + /*
> + * Get the iommu group for the sibling device
> + */
> + list_for_each_entry(tmp, &pdev->bus_list, bus_list) {
> + if (tmp == pdev)
> + continue;
> + group = iommu_group_get(&tmp->dev);
> + if (group)
> + break;
> + }
> + }
> +
> + return group;
Can't we handle both of these with one loop?
struct pci_bus *bus = pdev->bus;
while (bus) {
list_for_each_entry(tmp, &bus->devices, bus_list) {
if (tmp == pdev)
continue;
group = iommu_group_get(&tmp->dev);
if (group)
return group;
}
bus = bus->parent;
}
return NULL;
get_shared_pci_device_group() might be another naming option.
> +}
> +
> +static struct iommu_group *get_pci_device_group(struct pci_dev *pdev)
> +{
> + struct pci_controller *pci_ctl;
> + bool pci_endpt_partioning;
> + struct iommu_group *group = NULL;
> + struct pci_dev *bridge, *dma_pdev = NULL;
> +
> + pci_ctl = pci_bus_to_host(pdev->bus);
> + pci_endpt_partioning = check_pci_ctl_endpt_part(pci_ctl);
> + /* We can partition PCIe devices so assign device group to the device */
> + if (pci_endpt_partioning) {
> + bridge = pci_find_upstream_pcie_bridge(pdev);
> + if (bridge) {
> + if (pci_is_pcie(bridge))
> + dma_pdev = pci_get_domain_bus_and_slot(
> + pci_domain_nr(pdev->bus),
> + bridge->subordinate->number, 0);
> + if (!dma_pdev)
> + dma_pdev = pci_dev_get(bridge);
> + } else
> + dma_pdev = pci_dev_get(pdev);
> +
> + /* Account for quirked devices */
> + swap_pci_ref(&dma_pdev, pci_get_dma_source(dma_pdev));
> +
> + /*
> + * If it's a multifunction device that does not support our
> + * required ACS flags, add to the same group as lowest numbered
> + * function that also does not suport the required ACS flags.
> + */
> + if (dma_pdev->multifunction &&
> + !pci_acs_enabled(dma_pdev, REQ_ACS_FLAGS)) {
> + u8 i, slot = PCI_SLOT(dma_pdev->devfn);
> +
> + for (i = 0; i < 8; i++) {
> + struct pci_dev *tmp;
> +
> + tmp = pci_get_slot(dma_pdev->bus,
> PCI_DEVFN(slot, i));
> + if (!tmp)
> + continue;
> +
> + if (!pci_acs_enabled(tmp, REQ_ACS_FLAGS)) {
> + swap_pci_ref(&dma_pdev, tmp);
> + break;
> + }
> + pci_dev_put(tmp);
> + }
> + }
> +
> + /*
> + * Devices on the root bus go through the iommu. If that's not
> us,
> + * find the next upstream device and test ACS up to the root
> bus.
> + * Finding the next device may require skipping virtual buses.
> + */
> + while (!pci_is_root_bus(dma_pdev->bus)) {
> + struct pci_bus *bus = dma_pdev->bus;
> +
> + while (!bus->self) {
> + if (!pci_is_root_bus(bus))
> + bus = bus->parent;
> + else
> + goto root_bus;
> + }
> +
> + if (pci_acs_path_enabled(bus->self, NULL,
> REQ_ACS_FLAGS))
> + break;
> +
> + swap_pci_ref(&dma_pdev, pci_dev_get(bus->self));
> + }
> +
> +root_bus:
> + group = get_device_iommu_group(&dma_pdev->dev);
> + pci_dev_put(dma_pdev);
> + /*
> + * PCIe controller is not a paritionable entity
> + * free the controller device iommu_group.
> + */
> + if (pci_ctl->parent->iommu_group)
> + iommu_group_remove_device(pci_ctl->parent);
> + } else {
> + /*
> + * All devices connected to the controller will share the
> + * PCI controllers device group. If this is the first
> + * device to be probed for the pci controller, copy the
> + * device group information from the PCI controller device
> + * node and remove the PCI controller iommu group.
> + * For subsequent devices, the iommu group information can
> + * be obtained from sibling devices (i.e. from the bus_devices
> + * link list).
> + */
> + if (pci_ctl->parent->iommu_group) {
> + group = get_device_iommu_group(pci_ctl->parent);
> + iommu_group_remove_device(pci_ctl->parent);
> + } else
> + group = get_peer_pci_device_group(pdev);
> + }
> +
> + return group;
> +}
> +
> +static int fsl_pamu_add_device(struct device *dev)
> +{
> + struct iommu_group *group = NULL;
> + struct pci_dev *pdev;
> + const u32 *prop;
> + int ret, len;
> +
> + /*
> + * For platform devices we allocate a separate group for
> + * each of the devices.
> + */
> + if (dev->bus == &pci_bus_type) {
> + pdev = to_pci_dev(dev);
> + /* Don't create device groups for virtual PCI bridges */
> + if (pdev->subordinate)
> + return 0;
> +
> + group = get_pci_device_group(pdev);
> +
> + } else {
> + prop = of_get_property(dev->of_node, "fsl,liodn", &len);
> + if (prop)
> + group = get_device_iommu_group(dev);
> + }
> +
> + if (!group || IS_ERR(group))
> + return PTR_ERR(group);
> +
> + ret = iommu_group_add_device(group, dev);
> +
> + iommu_group_put(group);
> + return ret;
> +}
> +
> +static void fsl_pamu_remove_device(struct device *dev)
> +{
> + iommu_group_remove_device(dev);
> +}
Seems ok otherwise. Thanks,
Alex
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
