SCMI fixes for v5.15
A few fixes addressing: - Kconfig dependency between VIRTIO and ARM_SCMI_PROTOCOL - Link-time error with __exit annotation for virtio_scmi_exit - Unnecessary nested irqsave/irqrestore spinlocks in virtio transport - Missing SMP barriers to protect accesses to SCMI virtio device -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEunHlEgbzHrJD3ZPhAEG6vDF+4pgFAmFdfQ0ACgkQAEG6vDF+ 4piS7g//TS0lhdY7oFWb2XpyQtcY7oudREtfV76pcrtYrdepKrfa3SzfjNVwTmq6 Tp2W+viRD1fLtqx0tPhO6YurgMFPUke+j7njS/yTMTitPhgzqm93l9Re+TxI7XiU qEuSoC+fenQhrhqNTXRaEkGFLWiQrENw5SUjz+ZcE/3QKUv35PU6HG5Od9gywssB wQ69Slr4AAHyPBPD3CVj5QUQhRvfp+YwOqSY/DwngjRCg/zDidWBFZ8XVLYRZ1Dl rAgdPsnnLTZ9sPgscIHciR/lyQdDqkY6A++U85oDLXjs7vZ27mlq+bFq3Rp6um3M WTbw89Fcvu8cQUMjEHFtGblEPgVn/BrK5po6DZA8RbSowcp7AMj87Gi0IhSRakPE ALN8qb9W84CbgzwcmCqCZiVzeEgy+uCVqtPIc4feupu4ukrah/+TPlAeM29JPVOO D5CtWushTxabRDb+/xGIBuww0qXiXm0he7I0QpVfW7JGBr+Bo62G2OWmNvwMlor0 Gc0ecz47P+vywra4Spa9w6VzvfDFOk0xmHp07RyyWXdbLL1IqvWW+DBW2E9fJMrf b4m65V822fTOv19mUIPzcou5erzL8wtfN9kSR+8gJ9iIlJ+0Xs/UoIT7fY3CAgpu xBUhBjcOD/Zjv607tO3XsJyRj5VgU88Dqod3k5oJfqXzg97fAH4= =4s/W -----END PGP SIGNATURE----- gpgsig -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEo6/YBQwIrVS28WGKmmx57+YAGNkFAmFfRvwACgkQmmx57+YA GNlnGA/+N9u/OQlwfB2kMoV/4iGGFUzQ0gCN+F+uKitS3hNnR8ke6npDV/wjytRC EAbUvnecdJvwXCOSRVm+HRZMbHtmeKi+wm9CzOzBlUH6wjDuDQ3aSjMwlDeWNVVS EAhvFojqFZQAk2QbnUfWAvM4gTtdY8UOrSXsrFI2y4J5ukzeCWDJ5OlJ3/qs0k/5 zmAHbgubvQYhg2wFhDx4Z/4YdT2mkZj6gyz7bX2qPJDPQb1mQUYbVYXhbkqXlQ96 9b76F3x+4/KO6OqM7lZFI1yNBBaRR9clqVQWClCEXTbXLyTG/q56KWGQww3sdY94 oi+ZfoiK4y+P/0oareBJq1Epp+c8A4RXy04ovV92OvxnM7qcmkNFZskYXhK1wnnc 2R0UyNWEq9o3V2KT/3q94PSXppFVDe918hMvEq3qPaF/8wTQ/ZrpuLOmCtZi/OmH dl3M36lZNbQyvXg9jX2ZKGJgw7j2Ig6aTnpjsbxW4O5KmTLKskDV7PoFNeVnfokI 7mJ6WWYTFUK0WnyCVI+t1AIKnWBDu80puhna5shWVaIQaxW0AlyA+Rhf5YRHqNga GUHNJatzL5iMyplV2TUbDNmFwHt9wYxGUN4hgfK0z0YsATjf6zbtixLVHb4ZBI/M bsNMiys5ZCQ+u0Btwk3blXSQwK/Gr6m/9HKWPpDnol4b/LBA2dM= =UP9E -----END PGP SIGNATURE----- Merge tag 'scmi-fixes-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into arm/fixes SCMI fixes for v5.15 A few fixes addressing: - Kconfig dependency between VIRTIO and ARM_SCMI_PROTOCOL - Link-time error with __exit annotation for virtio_scmi_exit - Unnecessary nested irqsave/irqrestore spinlocks in virtio transport - Missing SMP barriers to protect accesses to SCMI virtio device * tag 'scmi-fixes-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux: firmware: arm_scmi: Add proper barriers to scmi virtio device firmware: arm_scmi: Simplify spinlocks in virtio transport firmware: arm_scmi: Remove __exit annotation firmware: arm_scmi: Fix virtio transport Kconfig dependency Link: https://lore.kernel.org/r/20211007102822.27886-1-sudeep.holla@arm.com Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Arnd Bergmann
commit
6aaa843438
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@ -68,7 +68,7 @@ config ARM_SCMI_TRANSPORT_SMC
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config ARM_SCMI_TRANSPORT_VIRTIO
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bool "SCMI transport based on VirtIO"
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depends on VIRTIO
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depends on VIRTIO=y || VIRTIO=ARM_SCMI_PROTOCOL
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select ARM_SCMI_HAVE_TRANSPORT
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select ARM_SCMI_HAVE_MSG
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help
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@ -110,18 +110,16 @@ static void scmi_finalize_message(struct scmi_vio_channel *vioch,
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if (vioch->is_rx) {
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scmi_vio_feed_vq_rx(vioch, msg);
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} else {
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unsigned long flags;
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spin_lock_irqsave(&vioch->lock, flags);
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/* Here IRQs are assumed to be already disabled by the caller */
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spin_lock(&vioch->lock);
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list_add(&msg->list, &vioch->free_list);
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spin_unlock_irqrestore(&vioch->lock, flags);
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spin_unlock(&vioch->lock);
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}
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}
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static void scmi_vio_complete_cb(struct virtqueue *vqueue)
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{
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unsigned long ready_flags;
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unsigned long flags;
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unsigned int length;
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struct scmi_vio_channel *vioch;
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struct scmi_vio_msg *msg;
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@ -140,7 +138,8 @@ static void scmi_vio_complete_cb(struct virtqueue *vqueue)
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goto unlock_ready_out;
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}
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spin_lock_irqsave(&vioch->lock, flags);
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/* IRQs already disabled here no need to irqsave */
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spin_lock(&vioch->lock);
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if (cb_enabled) {
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virtqueue_disable_cb(vqueue);
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cb_enabled = false;
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@ -151,7 +150,7 @@ static void scmi_vio_complete_cb(struct virtqueue *vqueue)
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goto unlock_out;
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cb_enabled = true;
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}
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spin_unlock_irqrestore(&vioch->lock, flags);
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spin_unlock(&vioch->lock);
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if (msg) {
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msg->rx_len = length;
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@ -161,11 +160,18 @@ static void scmi_vio_complete_cb(struct virtqueue *vqueue)
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scmi_finalize_message(vioch, msg);
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}
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/*
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* Release ready_lock and re-enable IRQs between loop iterations
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* to allow virtio_chan_free() to possibly kick in and set the
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* flag vioch->ready to false even in between processing of
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* messages, so as to force outstanding messages to be ignored
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* when system is shutting down.
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*/
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spin_unlock_irqrestore(&vioch->ready_lock, ready_flags);
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}
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unlock_out:
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spin_unlock_irqrestore(&vioch->lock, flags);
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spin_unlock(&vioch->lock);
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unlock_ready_out:
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spin_unlock_irqrestore(&vioch->ready_lock, ready_flags);
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}
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@ -384,8 +390,11 @@ static int scmi_vio_probe(struct virtio_device *vdev)
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struct virtqueue *vqs[VIRTIO_SCMI_VQ_MAX_CNT];
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/* Only one SCMI VirtiO device allowed */
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if (scmi_vdev)
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return -EINVAL;
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if (scmi_vdev) {
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dev_err(dev,
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"One SCMI Virtio device was already initialized: only one allowed.\n");
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return -EBUSY;
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}
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have_vq_rx = scmi_vio_have_vq_rx(vdev);
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vq_cnt = have_vq_rx ? VIRTIO_SCMI_VQ_MAX_CNT : 1;
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@ -428,16 +437,25 @@ static int scmi_vio_probe(struct virtio_device *vdev)
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}
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vdev->priv = channels;
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scmi_vdev = vdev;
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/* Ensure initialized scmi_vdev is visible */
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smp_store_mb(scmi_vdev, vdev);
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return 0;
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}
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static void scmi_vio_remove(struct virtio_device *vdev)
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{
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/*
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* Once we get here, virtio_chan_free() will have already been called by
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* the SCMI core for any existing channel and, as a consequence, all the
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* virtio channels will have been already marked NOT ready, causing any
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* outstanding message on any vqueue to be ignored by complete_cb: now
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* we can just stop processing buffers and destroy the vqueues.
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*/
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vdev->config->reset(vdev);
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vdev->config->del_vqs(vdev);
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scmi_vdev = NULL;
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/* Ensure scmi_vdev is visible as NULL */
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smp_store_mb(scmi_vdev, NULL);
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}
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static int scmi_vio_validate(struct virtio_device *vdev)
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@ -476,7 +494,7 @@ static int __init virtio_scmi_init(void)
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return register_virtio_driver(&virtio_scmi_driver);
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}
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static void __exit virtio_scmi_exit(void)
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static void virtio_scmi_exit(void)
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{
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unregister_virtio_driver(&virtio_scmi_driver);
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}
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