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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/dma/virt-dma.h
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/dma/virt-dma.h')
-rw-r--r--drivers/dma/virt-dma.h237
1 files changed, 237 insertions, 0 deletions
diff --git a/drivers/dma/virt-dma.h b/drivers/dma/virt-dma.h
new file mode 100644
index 000000000..59d9eabc8
--- /dev/null
+++ b/drivers/dma/virt-dma.h
@@ -0,0 +1,237 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Virtual DMA channel support for DMAengine
+ *
+ * Copyright (C) 2012 Russell King
+ */
+#ifndef VIRT_DMA_H
+#define VIRT_DMA_H
+
+#include <linux/dmaengine.h>
+#include <linux/interrupt.h>
+
+#include "dmaengine.h"
+
+struct virt_dma_desc {
+ struct dma_async_tx_descriptor tx;
+ struct dmaengine_result tx_result;
+ /* protected by vc.lock */
+ struct list_head node;
+};
+
+struct virt_dma_chan {
+ struct dma_chan chan;
+ struct tasklet_struct task;
+ void (*desc_free)(struct virt_dma_desc *);
+
+ spinlock_t lock;
+
+ /* protected by vc.lock */
+ struct list_head desc_allocated;
+ struct list_head desc_submitted;
+ struct list_head desc_issued;
+ struct list_head desc_completed;
+ struct list_head desc_terminated;
+
+ struct virt_dma_desc *cyclic;
+};
+
+static inline struct virt_dma_chan *to_virt_chan(struct dma_chan *chan)
+{
+ return container_of(chan, struct virt_dma_chan, chan);
+}
+
+void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head);
+void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev);
+struct virt_dma_desc *vchan_find_desc(struct virt_dma_chan *, dma_cookie_t);
+extern dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *);
+extern int vchan_tx_desc_free(struct dma_async_tx_descriptor *);
+
+/**
+ * vchan_tx_prep - prepare a descriptor
+ * @vc: virtual channel allocating this descriptor
+ * @vd: virtual descriptor to prepare
+ * @tx_flags: flags argument passed in to prepare function
+ */
+static inline struct dma_async_tx_descriptor *vchan_tx_prep(struct virt_dma_chan *vc,
+ struct virt_dma_desc *vd, unsigned long tx_flags)
+{
+ unsigned long flags;
+
+ dma_async_tx_descriptor_init(&vd->tx, &vc->chan);
+ vd->tx.flags = tx_flags;
+ vd->tx.tx_submit = vchan_tx_submit;
+ vd->tx.desc_free = vchan_tx_desc_free;
+
+ vd->tx_result.result = DMA_TRANS_NOERROR;
+ vd->tx_result.residue = 0;
+
+ spin_lock_irqsave(&vc->lock, flags);
+ list_add_tail(&vd->node, &vc->desc_allocated);
+ spin_unlock_irqrestore(&vc->lock, flags);
+
+ return &vd->tx;
+}
+
+/**
+ * vchan_issue_pending - move submitted descriptors to issued list
+ * @vc: virtual channel to update
+ *
+ * vc.lock must be held by caller
+ */
+static inline bool vchan_issue_pending(struct virt_dma_chan *vc)
+{
+ lockdep_assert_held(&vc->lock);
+
+ list_splice_tail_init(&vc->desc_submitted, &vc->desc_issued);
+ return !list_empty(&vc->desc_issued);
+}
+
+/**
+ * vchan_cookie_complete - report completion of a descriptor
+ * @vd: virtual descriptor to update
+ *
+ * vc.lock must be held by caller
+ */
+static inline void vchan_cookie_complete(struct virt_dma_desc *vd)
+{
+ struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
+ dma_cookie_t cookie;
+
+ lockdep_assert_held(&vc->lock);
+
+ cookie = vd->tx.cookie;
+ dma_cookie_complete(&vd->tx);
+ dev_vdbg(vc->chan.device->dev, "txd %p[%x]: marked complete\n",
+ vd, cookie);
+ list_add_tail(&vd->node, &vc->desc_completed);
+
+ tasklet_schedule(&vc->task);
+}
+
+/**
+ * vchan_vdesc_fini - Free or reuse a descriptor
+ * @vd: virtual descriptor to free/reuse
+ */
+static inline void vchan_vdesc_fini(struct virt_dma_desc *vd)
+{
+ struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
+
+ if (dmaengine_desc_test_reuse(&vd->tx)) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&vc->lock, flags);
+ list_add(&vd->node, &vc->desc_allocated);
+ spin_unlock_irqrestore(&vc->lock, flags);
+ } else {
+ vc->desc_free(vd);
+ }
+}
+
+/**
+ * vchan_cyclic_callback - report the completion of a period
+ * @vd: virtual descriptor
+ */
+static inline void vchan_cyclic_callback(struct virt_dma_desc *vd)
+{
+ struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
+
+ vc->cyclic = vd;
+ tasklet_schedule(&vc->task);
+}
+
+/**
+ * vchan_terminate_vdesc - Disable pending cyclic callback
+ * @vd: virtual descriptor to be terminated
+ *
+ * vc.lock must be held by caller
+ */
+static inline void vchan_terminate_vdesc(struct virt_dma_desc *vd)
+{
+ struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
+
+ lockdep_assert_held(&vc->lock);
+
+ list_add_tail(&vd->node, &vc->desc_terminated);
+
+ if (vc->cyclic == vd)
+ vc->cyclic = NULL;
+}
+
+/**
+ * vchan_next_desc - peek at the next descriptor to be processed
+ * @vc: virtual channel to obtain descriptor from
+ *
+ * vc.lock must be held by caller
+ */
+static inline struct virt_dma_desc *vchan_next_desc(struct virt_dma_chan *vc)
+{
+ lockdep_assert_held(&vc->lock);
+
+ return list_first_entry_or_null(&vc->desc_issued,
+ struct virt_dma_desc, node);
+}
+
+/**
+ * vchan_get_all_descriptors - obtain all submitted and issued descriptors
+ * @vc: virtual channel to get descriptors from
+ * @head: list of descriptors found
+ *
+ * vc.lock must be held by caller
+ *
+ * Removes all submitted and issued descriptors from internal lists, and
+ * provides a list of all descriptors found
+ */
+static inline void vchan_get_all_descriptors(struct virt_dma_chan *vc,
+ struct list_head *head)
+{
+ lockdep_assert_held(&vc->lock);
+
+ list_splice_tail_init(&vc->desc_allocated, head);
+ list_splice_tail_init(&vc->desc_submitted, head);
+ list_splice_tail_init(&vc->desc_issued, head);
+ list_splice_tail_init(&vc->desc_completed, head);
+ list_splice_tail_init(&vc->desc_terminated, head);
+}
+
+static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
+{
+ struct virt_dma_desc *vd;
+ unsigned long flags;
+ LIST_HEAD(head);
+
+ spin_lock_irqsave(&vc->lock, flags);
+ vchan_get_all_descriptors(vc, &head);
+ list_for_each_entry(vd, &head, node)
+ dmaengine_desc_clear_reuse(&vd->tx);
+ spin_unlock_irqrestore(&vc->lock, flags);
+
+ vchan_dma_desc_free_list(vc, &head);
+}
+
+/**
+ * vchan_synchronize() - synchronize callback execution to the current context
+ * @vc: virtual channel to synchronize
+ *
+ * Makes sure that all scheduled or active callbacks have finished running. For
+ * proper operation the caller has to ensure that no new callbacks are scheduled
+ * after the invocation of this function started.
+ * Free up the terminated cyclic descriptor to prevent memory leakage.
+ */
+static inline void vchan_synchronize(struct virt_dma_chan *vc)
+{
+ LIST_HEAD(head);
+ unsigned long flags;
+
+ tasklet_kill(&vc->task);
+
+ spin_lock_irqsave(&vc->lock, flags);
+
+ list_splice_tail_init(&vc->desc_terminated, &head);
+
+ spin_unlock_irqrestore(&vc->lock, flags);
+
+ vchan_dma_desc_free_list(vc, &head);
+}
+
+#endif