Rename iommu_dt_device_is_assigned() to iommu_dt_device_is_assigned_locked(). Remove static type so this can also be used by SMMU drivers to check if the device is being used before removing.
Moving spin_lock to caller was done to prevent the concurrent access to iommu_dt_device_is_assigned while doing add/remove/assign/deassign. Signed-off-by: Vikram Garhwal <vikram.garh...@amd.com> --- Changes from v6: Created a private header and moved iommu_dt_device_is_assigned() to header. --- xen/drivers/passthrough/device_tree.c | 20 ++++++++++++++++---- xen/include/xen/iommu-private.h | 27 +++++++++++++++++++++++++++ 2 files changed, 43 insertions(+), 4 deletions(-) create mode 100644 xen/include/xen/iommu-private.h diff --git a/xen/drivers/passthrough/device_tree.c b/xen/drivers/passthrough/device_tree.c index 1c32d7b50c..52e370db01 100644 --- a/xen/drivers/passthrough/device_tree.c +++ b/xen/drivers/passthrough/device_tree.c @@ -18,6 +18,7 @@ #include <xen/device_tree.h> #include <xen/guest_access.h> #include <xen/iommu.h> +#include <xen/iommu-private.h> #include <xen/lib.h> #include <xen/sched.h> #include <xsm/xsm.h> @@ -83,16 +84,14 @@ fail: return rc; } -static bool_t iommu_dt_device_is_assigned(const struct dt_device_node *dev) +bool_t iommu_dt_device_is_assigned_locked(const struct dt_device_node *dev) { bool_t assigned = 0; if ( !dt_device_is_protected(dev) ) return 0; - spin_lock(&dtdevs_lock); assigned = !list_empty(&dev->domain_list); - spin_unlock(&dtdevs_lock); return assigned; } @@ -213,27 +212,40 @@ int iommu_do_dt_domctl(struct xen_domctl *domctl, struct domain *d, if ( (d && d->is_dying) || domctl->u.assign_device.flags ) break; + spin_lock(&dtdevs_lock); + ret = dt_find_node_by_gpath(domctl->u.assign_device.u.dt.path, domctl->u.assign_device.u.dt.size, &dev); if ( ret ) + { + spin_unlock(&dtdevs_lock); break; + } ret = xsm_assign_dtdevice(XSM_HOOK, d, dt_node_full_name(dev)); if ( ret ) + { + spin_unlock(&dtdevs_lock); break; + } if ( domctl->cmd == XEN_DOMCTL_test_assign_device ) { - if ( iommu_dt_device_is_assigned(dev) ) + + if ( iommu_dt_device_is_assigned_locked(dev) ) { printk(XENLOG_G_ERR "%s already assigned.\n", dt_node_full_name(dev)); ret = -EINVAL; } + + spin_unlock(&dtdevs_lock); break; } + spin_unlock(&dtdevs_lock); + if ( d == dom_io ) return -EINVAL; diff --git a/xen/include/xen/iommu-private.h b/xen/include/xen/iommu-private.h new file mode 100644 index 0000000000..5615decaff --- /dev/null +++ b/xen/include/xen/iommu-private.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + /* + * xen/iommu-private.h + * + * + * Copyright (C) 2023, Advanced Micro Devices, Inc. All Rights Reserved. + * Written by Vikram Garhwal <vikram.garh...@amd.com> + * + */ +#ifndef __XEN_IOMMU_PRIVATE_H__ +#define __XEN_IOMMU_PRIVATE_H__ + +#ifdef CONFIG_HAS_DEVICE_TREE +#include <xen/device_tree.h> +bool_t iommu_dt_device_is_assigned_locked(const struct dt_device_node *dev); +#endif + +#endif /* __XEN_IOMMU_PRIVATE_H__ */ +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ -- 2.17.1