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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-buf/dma-fence-array.c
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-buf/dma-fence-array.c')
-rw-r--r--drivers/dma-buf/dma-fence-array.c332
1 files changed, 332 insertions, 0 deletions
diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c
new file mode 100644
index 000000000..5e10e8df3
--- /dev/null
+++ b/drivers/dma-buf/dma-fence-array.c
@@ -0,0 +1,332 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * dma-fence-array: aggregate fences to be waited together
+ *
+ * Copyright (C) 2016 Collabora Ltd
+ * Copyright (C) 2016 Advanced Micro Devices, Inc.
+ * Authors:
+ * Gustavo Padovan <gustavo@padovan.org>
+ * Christian König <christian.koenig@amd.com>
+ */
+
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/dma-fence-array.h>
+
+#define PENDING_ERROR 1
+
+static const char *dma_fence_array_get_driver_name(struct dma_fence *fence)
+{
+ return "dma_fence_array";
+}
+
+static const char *dma_fence_array_get_timeline_name(struct dma_fence *fence)
+{
+ return "unbound";
+}
+
+static void dma_fence_array_set_pending_error(struct dma_fence_array *array,
+ int error)
+{
+ /*
+ * Propagate the first error reported by any of our fences, but only
+ * before we ourselves are signaled.
+ */
+ if (error)
+ cmpxchg(&array->base.error, PENDING_ERROR, error);
+}
+
+static void dma_fence_array_clear_pending_error(struct dma_fence_array *array)
+{
+ /* Clear the error flag if not actually set. */
+ cmpxchg(&array->base.error, PENDING_ERROR, 0);
+}
+
+static void irq_dma_fence_array_work(struct irq_work *wrk)
+{
+ struct dma_fence_array *array = container_of(wrk, typeof(*array), work);
+
+ dma_fence_array_clear_pending_error(array);
+
+ dma_fence_signal(&array->base);
+ dma_fence_put(&array->base);
+}
+
+static void dma_fence_array_cb_func(struct dma_fence *f,
+ struct dma_fence_cb *cb)
+{
+ struct dma_fence_array_cb *array_cb =
+ container_of(cb, struct dma_fence_array_cb, cb);
+ struct dma_fence_array *array = array_cb->array;
+
+ dma_fence_array_set_pending_error(array, f->error);
+
+ if (atomic_dec_and_test(&array->num_pending))
+ irq_work_queue(&array->work);
+ else
+ dma_fence_put(&array->base);
+}
+
+static bool dma_fence_array_enable_signaling(struct dma_fence *fence)
+{
+ struct dma_fence_array *array = to_dma_fence_array(fence);
+ struct dma_fence_array_cb *cb = array->callbacks;
+ unsigned i;
+
+ for (i = 0; i < array->num_fences; ++i) {
+ cb[i].array = array;
+ /*
+ * As we may report that the fence is signaled before all
+ * callbacks are complete, we need to take an additional
+ * reference count on the array so that we do not free it too
+ * early. The core fence handling will only hold the reference
+ * until we signal the array as complete (but that is now
+ * insufficient).
+ */
+ dma_fence_get(&array->base);
+ if (dma_fence_add_callback(array->fences[i], &cb[i].cb,
+ dma_fence_array_cb_func)) {
+ int error = array->fences[i]->error;
+
+ dma_fence_array_set_pending_error(array, error);
+ dma_fence_put(&array->base);
+ if (atomic_dec_and_test(&array->num_pending)) {
+ dma_fence_array_clear_pending_error(array);
+ return false;
+ }
+ }
+ }
+
+ return true;
+}
+
+static bool dma_fence_array_signaled(struct dma_fence *fence)
+{
+ struct dma_fence_array *array = to_dma_fence_array(fence);
+ int num_pending;
+ unsigned int i;
+
+ /*
+ * We need to read num_pending before checking the enable_signal bit
+ * to avoid racing with the enable_signaling() implementation, which
+ * might decrement the counter, and cause a partial check.
+ * atomic_read_acquire() pairs with atomic_dec_and_test() in
+ * dma_fence_array_enable_signaling()
+ *
+ * The !--num_pending check is here to account for the any_signaled case
+ * if we race with enable_signaling(), that means the !num_pending check
+ * in the is_signalling_enabled branch might be outdated (num_pending
+ * might have been decremented), but that's fine. The user will get the
+ * right value when testing again later.
+ */
+ num_pending = atomic_read_acquire(&array->num_pending);
+ if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &array->base.flags)) {
+ if (num_pending <= 0)
+ goto signal;
+ return false;
+ }
+
+ for (i = 0; i < array->num_fences; ++i) {
+ if (dma_fence_is_signaled(array->fences[i]) && !--num_pending)
+ goto signal;
+ }
+ return false;
+
+signal:
+ dma_fence_array_clear_pending_error(array);
+ return true;
+}
+
+static void dma_fence_array_release(struct dma_fence *fence)
+{
+ struct dma_fence_array *array = to_dma_fence_array(fence);
+ unsigned i;
+
+ for (i = 0; i < array->num_fences; ++i)
+ dma_fence_put(array->fences[i]);
+
+ kfree(array->fences);
+ dma_fence_free(fence);
+}
+
+static void dma_fence_array_set_deadline(struct dma_fence *fence,
+ ktime_t deadline)
+{
+ struct dma_fence_array *array = to_dma_fence_array(fence);
+ unsigned i;
+
+ for (i = 0; i < array->num_fences; ++i)
+ dma_fence_set_deadline(array->fences[i], deadline);
+}
+
+const struct dma_fence_ops dma_fence_array_ops = {
+ .get_driver_name = dma_fence_array_get_driver_name,
+ .get_timeline_name = dma_fence_array_get_timeline_name,
+ .enable_signaling = dma_fence_array_enable_signaling,
+ .signaled = dma_fence_array_signaled,
+ .release = dma_fence_array_release,
+ .set_deadline = dma_fence_array_set_deadline,
+};
+EXPORT_SYMBOL(dma_fence_array_ops);
+
+/**
+ * dma_fence_array_alloc - Allocate a custom fence array
+ * @num_fences: [in] number of fences to add in the array
+ *
+ * Return dma fence array on success, NULL on failure
+ */
+struct dma_fence_array *dma_fence_array_alloc(int num_fences)
+{
+ struct dma_fence_array *array;
+
+ return kzalloc_flex(*array, callbacks, num_fences);
+}
+EXPORT_SYMBOL(dma_fence_array_alloc);
+
+/**
+ * dma_fence_array_init - Init a custom fence array
+ * @array: [in] dma fence array to arm
+ * @num_fences: [in] number of fences to add in the array
+ * @fences: [in] array containing the fences
+ * @context: [in] fence context to use
+ * @seqno: [in] sequence number to use
+ *
+ * Implementation of @dma_fence_array_create without allocation. Useful to init
+ * a preallocated dma fence array in the path of reclaim or dma fence signaling.
+ */
+void dma_fence_array_init(struct dma_fence_array *array,
+ int num_fences, struct dma_fence **fences,
+ u64 context, unsigned seqno)
+{
+ static struct lock_class_key dma_fence_array_lock_key;
+
+ WARN_ON(!num_fences || !fences);
+
+ array->num_fences = num_fences;
+
+ dma_fence_init(&array->base, &dma_fence_array_ops, NULL, context,
+ seqno);
+ init_irq_work(&array->work, irq_dma_fence_array_work);
+
+ /*
+ * dma_fence_array_enable_signaling() is invoked while holding
+ * array->base.inline_lock and may call dma_fence_add_callback()
+ * on the underlying fences, which takes their inline_lock.
+ *
+ * Since both locks share the same lockdep class, this legitimate
+ * nesting confuses lockdep and triggers a recursive locking
+ * warning. Assign a separate lockdep class to the array lock
+ * to model this hierarchy correctly.
+ */
+ lockdep_set_class(&array->base.inline_lock, &dma_fence_array_lock_key);
+
+ atomic_set(&array->num_pending, num_fences);
+ array->fences = fences;
+
+ array->base.error = PENDING_ERROR;
+
+ /*
+ * dma_fence_array objects should never contain any other fence
+ * containers or otherwise we run into recursion and potential kernel
+ * stack overflow on operations on the dma_fence_array.
+ *
+ * The correct way of handling this is to flatten out the array by the
+ * caller instead.
+ *
+ * Enforce this here by checking that we don't create a dma_fence_array
+ * with any container inside.
+ */
+ while (num_fences--)
+ WARN_ON(dma_fence_is_container(fences[num_fences]));
+}
+EXPORT_SYMBOL(dma_fence_array_init);
+
+/**
+ * dma_fence_array_create - Create a custom fence array
+ * @num_fences: [in] number of fences to add in the array
+ * @fences: [in] array containing the fences
+ * @context: [in] fence context to use
+ * @seqno: [in] sequence number to use
+ *
+ * Allocate a dma_fence_array object and initialize the base fence with
+ * dma_fence_init().
+ * In case of error it returns NULL.
+ *
+ * The caller should allocate the fences array with num_fences size
+ * and fill it with the fences it wants to add to the object. Ownership of this
+ * array is taken and dma_fence_put() is used on each fence on release.
+ *
+ * If @signal_on_any is true the fence array signals if any fence in the array
+ * signals, otherwise it signals when all fences in the array signal.
+ */
+struct dma_fence_array *dma_fence_array_create(int num_fences,
+ struct dma_fence **fences,
+ u64 context, unsigned seqno)
+{
+ struct dma_fence_array *array;
+
+ array = dma_fence_array_alloc(num_fences);
+ if (!array)
+ return NULL;
+
+ dma_fence_array_init(array, num_fences, fences, context, seqno);
+
+ return array;
+}
+EXPORT_SYMBOL(dma_fence_array_create);
+
+/**
+ * dma_fence_match_context - Check if all fences are from the given context
+ * @fence: [in] fence or fence array
+ * @context: [in] fence context to check all fences against
+ *
+ * Checks the provided fence or, for a fence array, all fences in the array
+ * against the given context. Returns false if any fence is from a different
+ * context.
+ */
+bool dma_fence_match_context(struct dma_fence *fence, u64 context)
+{
+ struct dma_fence_array *array = to_dma_fence_array(fence);
+ unsigned i;
+
+ if (!dma_fence_is_array(fence))
+ return fence->context == context;
+
+ for (i = 0; i < array->num_fences; i++) {
+ if (array->fences[i]->context != context)
+ return false;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL(dma_fence_match_context);
+
+struct dma_fence *dma_fence_array_first(struct dma_fence *head)
+{
+ struct dma_fence_array *array;
+
+ if (!head)
+ return NULL;
+
+ array = to_dma_fence_array(head);
+ if (!array)
+ return head;
+
+ if (!array->num_fences)
+ return NULL;
+
+ return array->fences[0];
+}
+EXPORT_SYMBOL(dma_fence_array_first);
+
+struct dma_fence *dma_fence_array_next(struct dma_fence *head,
+ unsigned int index)
+{
+ struct dma_fence_array *array = to_dma_fence_array(head);
+
+ if (!array || index >= array->num_fences)
+ return NULL;
+
+ return array->fences[index];
+}
+EXPORT_SYMBOL(dma_fence_array_next);