From 9f0346dcbea363787186c94ef94dd01aaa215afa Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 5 Sep 2026 11:59:05 -0700 Subject: Merge tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core Pull driver core fixes from Danilo Krummrich: - Fix kernfs listxattr() not returning security xattr names (e.g. SELinux labels) when the kernfs node has no allocated kernfs_iattrs - Fix silent truncation of IRQ vector indices in the Rust PCI abstractions - Don't select OF from DRIVER_PE_KUNIT_TEST; skip the test when OF is disabled instead of silently enabling extra kernel functionality - Russ Weight is retiring from kernel development; update the Firmware Loader sysfs contact to the driver-core mailing list, add a CREDITS entry for Firmware Upload, and update MAINTAINERS accordingly * tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: MAINTAINERS: Remove Russ Weight from Firmware Loader CREDITS: Add CREDITS entry for Firmware Upload firmware_loader: Change contact for sysfs nodes rust: pci: reject IRQ vector indices that do not fit in u32 kernfs: preserve security xattrs without allocating iattrs drivers: base: test: DRIVER_PE_KUNIT_TEST should not select OF --- drivers/dma/virt-dma.c | 143 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 143 insertions(+) create mode 100644 drivers/dma/virt-dma.c (limited to 'drivers/dma/virt-dma.c') diff --git a/drivers/dma/virt-dma.c b/drivers/dma/virt-dma.c new file mode 100644 index 000000000..7961172a7 --- /dev/null +++ b/drivers/dma/virt-dma.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Virtual DMA channel support for DMAengine + * + * Copyright (C) 2012 Russell King + */ +#include +#include +#include +#include + +#include "virt-dma.h" + +static struct virt_dma_desc *to_virt_desc(struct dma_async_tx_descriptor *tx) +{ + return container_of(tx, struct virt_dma_desc, tx); +} + +dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *tx) +{ + struct virt_dma_chan *vc = to_virt_chan(tx->chan); + struct virt_dma_desc *vd = to_virt_desc(tx); + unsigned long flags; + dma_cookie_t cookie; + + spin_lock_irqsave(&vc->lock, flags); + cookie = dma_cookie_assign(tx); + + list_move_tail(&vd->node, &vc->desc_submitted); + spin_unlock_irqrestore(&vc->lock, flags); + + dev_dbg(vc->chan.device->dev, "vchan %p: txd %p[%x]: submitted\n", + vc, vd, cookie); + + return cookie; +} +EXPORT_SYMBOL_GPL(vchan_tx_submit); + +/** + * vchan_tx_desc_free - free a reusable descriptor + * @tx: the transfer + * + * This function frees a previously allocated reusable descriptor. The only + * other way is to clear the DMA_CTRL_REUSE flag and submit one last time the + * transfer. + * + * Returns 0 upon success + */ +int vchan_tx_desc_free(struct dma_async_tx_descriptor *tx) +{ + struct virt_dma_chan *vc = to_virt_chan(tx->chan); + struct virt_dma_desc *vd = to_virt_desc(tx); + unsigned long flags; + + spin_lock_irqsave(&vc->lock, flags); + list_del(&vd->node); + spin_unlock_irqrestore(&vc->lock, flags); + + dev_dbg(vc->chan.device->dev, "vchan %p: txd %p[%x]: freeing\n", + vc, vd, vd->tx.cookie); + vc->desc_free(vd); + return 0; +} +EXPORT_SYMBOL_GPL(vchan_tx_desc_free); + +struct virt_dma_desc *vchan_find_desc(struct virt_dma_chan *vc, + dma_cookie_t cookie) +{ + struct virt_dma_desc *vd; + + list_for_each_entry(vd, &vc->desc_issued, node) + if (vd->tx.cookie == cookie) + return vd; + + return NULL; +} +EXPORT_SYMBOL_GPL(vchan_find_desc); + +/* + * This tasklet handles the completion of a DMA descriptor by + * calling its callback and freeing it. + */ +static void vchan_complete(struct tasklet_struct *t) +{ + struct virt_dma_chan *vc = from_tasklet(vc, t, task); + struct virt_dma_desc *vd, *_vd; + struct dmaengine_desc_callback cb; + LIST_HEAD(head); + + spin_lock_irq(&vc->lock); + list_splice_tail_init(&vc->desc_completed, &head); + vd = vc->cyclic; + if (vd) { + vc->cyclic = NULL; + dmaengine_desc_get_callback(&vd->tx, &cb); + } else { + memset(&cb, 0, sizeof(cb)); + } + spin_unlock_irq(&vc->lock); + + dmaengine_desc_callback_invoke(&cb, &vd->tx_result); + + list_for_each_entry_safe(vd, _vd, &head, node) { + dmaengine_desc_get_callback(&vd->tx, &cb); + + list_del(&vd->node); + dmaengine_desc_callback_invoke(&cb, &vd->tx_result); + vchan_vdesc_fini(vd); + } +} + +void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head) +{ + struct virt_dma_desc *vd, *_vd; + + list_for_each_entry_safe(vd, _vd, head, node) { + list_del(&vd->node); + vchan_vdesc_fini(vd); + } +} +EXPORT_SYMBOL_GPL(vchan_dma_desc_free_list); + +void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev) +{ + dma_cookie_init(&vc->chan); + + spin_lock_init(&vc->lock); + INIT_LIST_HEAD(&vc->desc_allocated); + INIT_LIST_HEAD(&vc->desc_submitted); + INIT_LIST_HEAD(&vc->desc_issued); + INIT_LIST_HEAD(&vc->desc_completed); + INIT_LIST_HEAD(&vc->desc_terminated); + + tasklet_setup(&vc->task, vchan_complete); + + vc->chan.device = dmadev; + list_add_tail(&vc->chan.device_node, &dmadev->channels); +} +EXPORT_SYMBOL_GPL(vchan_init); + +MODULE_AUTHOR("Russell King"); +MODULE_DESCRIPTION("Virtual DMA channel support for DMAengine"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1