From b554e396e51ce3d378a560666f85c6836a8323fd Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 12 Feb 2024 09:22:26 +0800 Subject: iommu: Make iopf_group_response() return void The iopf_group_response() should return void, as nothing can do anything with the failure. This implies that ops->page_response() must also return void; this is consistent with what the drivers do. The failure paths, which are all integrity validations of the fault, should be WARN_ON'd, not return codes. If the iommu core fails to enqueue the fault, it should respond the fault directly by calling ops->page_response() instead of returning an error number and relying on the iommu drivers to do so. Consolidate the error fault handling code in the core. Co-developed-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20240212012227.119381-16-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 50 ++++------- drivers/iommu/intel/iommu.h | 4 +- drivers/iommu/intel/svm.c | 18 +--- drivers/iommu/io-pgfault.c | 132 +++++++++++++++------------- include/linux/iommu.h | 14 ++- 5 files changed, 98 insertions(+), 120 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 4e93e845458c..42eb59cb99f4 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -920,31 +920,29 @@ static int arm_smmu_cmdq_batch_submit(struct arm_smmu_device *smmu, return arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmds, cmds->num, true); } -static int arm_smmu_page_response(struct device *dev, - struct iopf_fault *unused, - struct iommu_page_response *resp) +static void arm_smmu_page_response(struct device *dev, struct iopf_fault *unused, + struct iommu_page_response *resp) { struct arm_smmu_cmdq_ent cmd = {0}; struct arm_smmu_master *master = dev_iommu_priv_get(dev); int sid = master->streams[0].id; - if (master->stall_enabled) { - cmd.opcode = CMDQ_OP_RESUME; - cmd.resume.sid = sid; - cmd.resume.stag = resp->grpid; - switch (resp->code) { - case IOMMU_PAGE_RESP_INVALID: - case IOMMU_PAGE_RESP_FAILURE: - cmd.resume.resp = CMDQ_RESUME_0_RESP_ABORT; - break; - case IOMMU_PAGE_RESP_SUCCESS: - cmd.resume.resp = CMDQ_RESUME_0_RESP_RETRY; - break; - default: - return -EINVAL; - } - } else { - return -ENODEV; + if (WARN_ON(!master->stall_enabled)) + return; + + cmd.opcode = CMDQ_OP_RESUME; + cmd.resume.sid = sid; + cmd.resume.stag = resp->grpid; + switch (resp->code) { + case IOMMU_PAGE_RESP_INVALID: + case IOMMU_PAGE_RESP_FAILURE: + cmd.resume.resp = CMDQ_RESUME_0_RESP_ABORT; + break; + case IOMMU_PAGE_RESP_SUCCESS: + cmd.resume.resp = CMDQ_RESUME_0_RESP_RETRY; + break; + default: + break; } arm_smmu_cmdq_issue_cmd(master->smmu, &cmd); @@ -954,8 +952,6 @@ static int arm_smmu_page_response(struct device *dev, * terminated... at some point in the future. PRI_RESP is fire and * forget. */ - - return 0; } /* Context descriptor manipulation functions */ @@ -1516,16 +1512,6 @@ static int arm_smmu_handle_evt(struct arm_smmu_device *smmu, u64 *evt) } ret = iommu_report_device_fault(master->dev, &fault_evt); - if (ret && flt->type == IOMMU_FAULT_PAGE_REQ) { - /* Nobody cared, abort the access */ - struct iommu_page_response resp = { - .pasid = flt->prm.pasid, - .grpid = flt->prm.grpid, - .code = IOMMU_PAGE_RESP_FAILURE, - }; - arm_smmu_page_response(master->dev, &fault_evt, &resp); - } - out_unlock: mutex_unlock(&smmu->streams_mutex); return ret; diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index 696d95293a69..cf9a28c7fab8 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -1079,8 +1079,8 @@ struct iommu_domain *intel_nested_domain_alloc(struct iommu_domain *parent, void intel_svm_check(struct intel_iommu *iommu); int intel_svm_enable_prq(struct intel_iommu *iommu); int intel_svm_finish_prq(struct intel_iommu *iommu); -int intel_svm_page_response(struct device *dev, struct iopf_fault *evt, - struct iommu_page_response *msg); +void intel_svm_page_response(struct device *dev, struct iopf_fault *evt, + struct iommu_page_response *msg); struct iommu_domain *intel_svm_domain_alloc(void); void intel_svm_remove_dev_pasid(struct device *dev, ioasid_t pasid); void intel_drain_pasid_prq(struct device *dev, u32 pasid); diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index e1cbcb9515f0..2f8716636dbb 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -740,9 +740,8 @@ prq_advance: return IRQ_RETVAL(handled); } -int intel_svm_page_response(struct device *dev, - struct iopf_fault *evt, - struct iommu_page_response *msg) +void intel_svm_page_response(struct device *dev, struct iopf_fault *evt, + struct iommu_page_response *msg) { struct device_domain_info *info = dev_iommu_priv_get(dev); struct intel_iommu *iommu = info->iommu; @@ -751,7 +750,6 @@ int intel_svm_page_response(struct device *dev, bool private_present; bool pasid_present; bool last_page; - int ret = 0; u16 sid; prm = &evt->fault.prm; @@ -760,16 +758,6 @@ int intel_svm_page_response(struct device *dev, private_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA; last_page = prm->flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE; - if (!pasid_present) { - ret = -EINVAL; - goto out; - } - - if (prm->pasid == 0 || prm->pasid >= PASID_MAX) { - ret = -EINVAL; - goto out; - } - /* * Per VT-d spec. v3.0 ch7.7, system software must respond * with page group response if private data is present (PDP) @@ -798,8 +786,6 @@ int intel_svm_page_response(struct device *dev, qi_submit_sync(iommu, &desc, 1, 0); } -out: - return ret; } static int intel_svm_set_dev_pasid(struct iommu_domain *domain, diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c index 05e49e2e6a52..6a325bff8164 100644 --- a/drivers/iommu/io-pgfault.c +++ b/drivers/iommu/io-pgfault.c @@ -39,7 +39,7 @@ static void iopf_put_dev_fault_param(struct iommu_fault_param *fault_param) kfree_rcu(fault_param, rcu); } -void iopf_free_group(struct iopf_group *group) +static void __iopf_free_group(struct iopf_group *group) { struct iopf_fault *iopf, *next; @@ -50,6 +50,11 @@ void iopf_free_group(struct iopf_group *group) /* Pair with iommu_report_device_fault(). */ iopf_put_dev_fault_param(group->fault_param); +} + +void iopf_free_group(struct iopf_group *group) +{ + __iopf_free_group(group); kfree(group); } EXPORT_SYMBOL_GPL(iopf_free_group); @@ -97,14 +102,49 @@ static int report_partial_fault(struct iommu_fault_param *fault_param, return 0; } +static struct iopf_group *iopf_group_alloc(struct iommu_fault_param *iopf_param, + struct iopf_fault *evt, + struct iopf_group *abort_group) +{ + struct iopf_fault *iopf, *next; + struct iopf_group *group; + + group = kzalloc(sizeof(*group), GFP_KERNEL); + if (!group) { + /* + * We always need to construct the group as we need it to abort + * the request at the driver if it can't be handled. + */ + group = abort_group; + } + + group->fault_param = iopf_param; + group->last_fault.fault = evt->fault; + INIT_LIST_HEAD(&group->faults); + INIT_LIST_HEAD(&group->pending_node); + list_add(&group->last_fault.list, &group->faults); + + /* See if we have partial faults for this group */ + mutex_lock(&iopf_param->lock); + list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) { + if (iopf->fault.prm.grpid == evt->fault.prm.grpid) + /* Insert *before* the last fault */ + list_move(&iopf->list, &group->faults); + } + list_add(&group->pending_node, &iopf_param->faults); + mutex_unlock(&iopf_param->lock); + + return group; +} + /** * iommu_report_device_fault() - Report fault event to device driver * @dev: the device * @evt: fault event data * * Called by IOMMU drivers when a fault is detected, typically in a threaded IRQ - * handler. When this function fails and the fault is recoverable, it is the - * caller's responsibility to complete the fault. + * handler. If this function fails then ops->page_response() was called to + * complete evt if required. * * This module doesn't handle PCI PASID Stop Marker; IOMMU drivers must discard * them before reporting faults. A PASID Stop Marker (LRW = 0b100) doesn't @@ -143,22 +183,18 @@ int iommu_report_device_fault(struct device *dev, struct iopf_fault *evt) { struct iommu_fault *fault = &evt->fault; struct iommu_fault_param *iopf_param; - struct iopf_fault *iopf, *next; - struct iommu_domain *domain; + struct iopf_group abort_group = {}; struct iopf_group *group; int ret; - if (fault->type != IOMMU_FAULT_PAGE_REQ) - return -EOPNOTSUPP; - iopf_param = iopf_get_dev_fault_param(dev); - if (!iopf_param) + if (WARN_ON(!iopf_param)) return -ENODEV; if (!(fault->prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE)) { ret = report_partial_fault(iopf_param, fault); iopf_put_dev_fault_param(iopf_param); - + /* A request that is not the last does not need to be ack'd */ return ret; } @@ -170,56 +206,33 @@ int iommu_report_device_fault(struct device *dev, struct iopf_fault *evt) * will send a response to the hardware. We need to clean up before * leaving, otherwise partial faults will be stuck. */ - domain = get_domain_for_iopf(dev, fault); - if (!domain) { - ret = -EINVAL; - goto cleanup_partial; - } - - group = kzalloc(sizeof(*group), GFP_KERNEL); - if (!group) { + group = iopf_group_alloc(iopf_param, evt, &abort_group); + if (group == &abort_group) { ret = -ENOMEM; - goto cleanup_partial; + goto err_abort; } - group->fault_param = iopf_param; - group->last_fault.fault = *fault; - INIT_LIST_HEAD(&group->faults); - INIT_LIST_HEAD(&group->pending_node); - group->domain = domain; - list_add(&group->last_fault.list, &group->faults); - - /* See if we have partial faults for this group */ - mutex_lock(&iopf_param->lock); - list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) { - if (iopf->fault.prm.grpid == fault->prm.grpid) - /* Insert *before* the last fault */ - list_move(&iopf->list, &group->faults); - } - list_add(&group->pending_node, &iopf_param->faults); - mutex_unlock(&iopf_param->lock); - - ret = domain->iopf_handler(group); - if (ret) { - mutex_lock(&iopf_param->lock); - list_del_init(&group->pending_node); - mutex_unlock(&iopf_param->lock); - iopf_free_group(group); + group->domain = get_domain_for_iopf(dev, fault); + if (!group->domain) { + ret = -EINVAL; + goto err_abort; } - return ret; - -cleanup_partial: - mutex_lock(&iopf_param->lock); - list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) { - if (iopf->fault.prm.grpid == fault->prm.grpid) { - list_del(&iopf->list); - kfree(iopf); - } - } - mutex_unlock(&iopf_param->lock); - iopf_put_dev_fault_param(iopf_param); + /* + * On success iopf_handler must call iopf_group_response() and + * iopf_free_group() + */ + ret = group->domain->iopf_handler(group); + if (ret) + goto err_abort; + return 0; +err_abort: + iopf_group_response(group, IOMMU_PAGE_RESP_FAILURE); + if (group == &abort_group) + __iopf_free_group(group); + else + iopf_free_group(group); return ret; } EXPORT_SYMBOL_GPL(iommu_report_device_fault); @@ -259,11 +272,9 @@ EXPORT_SYMBOL_GPL(iopf_queue_flush_dev); * iopf_group_response - Respond a group of page faults * @group: the group of faults with the same group id * @status: the response code - * - * Return 0 on success and <0 on error. */ -int iopf_group_response(struct iopf_group *group, - enum iommu_page_response_code status) +void iopf_group_response(struct iopf_group *group, + enum iommu_page_response_code status) { struct iommu_fault_param *fault_param = group->fault_param; struct iopf_fault *iopf = &group->last_fault; @@ -274,17 +285,14 @@ int iopf_group_response(struct iopf_group *group, .grpid = iopf->fault.prm.grpid, .code = status, }; - int ret = -EINVAL; /* Only send response if there is a fault report pending */ mutex_lock(&fault_param->lock); if (!list_empty(&group->pending_node)) { - ret = ops->page_response(dev, &group->last_fault, &resp); + ops->page_response(dev, &group->last_fault, &resp); list_del_init(&group->pending_node); } mutex_unlock(&fault_param->lock); - - return ret; } EXPORT_SYMBOL_GPL(iopf_group_response); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index f8ed1cc7212e..f632775414a5 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -574,9 +574,8 @@ struct iommu_ops { int (*dev_enable_feat)(struct device *dev, enum iommu_dev_features f); int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f); - int (*page_response)(struct device *dev, - struct iopf_fault *evt, - struct iommu_page_response *msg); + void (*page_response)(struct device *dev, struct iopf_fault *evt, + struct iommu_page_response *msg); int (*def_domain_type)(struct device *dev); void (*remove_dev_pasid)(struct device *dev, ioasid_t pasid); @@ -1547,8 +1546,8 @@ void iopf_queue_free(struct iopf_queue *queue); int iopf_queue_discard_partial(struct iopf_queue *queue); void iopf_free_group(struct iopf_group *group); int iommu_report_device_fault(struct device *dev, struct iopf_fault *evt); -int iopf_group_response(struct iopf_group *group, - enum iommu_page_response_code status); +void iopf_group_response(struct iopf_group *group, + enum iommu_page_response_code status); #else static inline int iopf_queue_add_device(struct iopf_queue *queue, struct device *dev) @@ -1590,10 +1589,9 @@ iommu_report_device_fault(struct device *dev, struct iopf_fault *evt) return -ENODEV; } -static inline int iopf_group_response(struct iopf_group *group, - enum iommu_page_response_code status) +static inline void iopf_group_response(struct iopf_group *group, + enum iommu_page_response_code status) { - return -ENODEV; } #endif /* CONFIG_IOMMU_IOPF */ #endif /* __LINUX_IOMMU_H */ -- cgit v1.2.3