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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-24 08:46:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-24 08:46:03 -0700
commitcf9610f9116d55c5a66ef9f1faecacabd93a9322 (patch)
tree757a3d280760c654767631cab5ad8af2d86d1848 /lib/irq_poll.c
downloadlinux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.tar.gz
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Merge tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrlgrafted
Pull pin control updates from Linus Walleij: "Core changes: - Use the non-blocking mux_state_try_select() in the generic MUX pin control back-end - Free pin maps on pinctrl_generic_to_map() failure in the core helpers New hardware pin control: - Qualcomm Maili TLMM SoC, PMG1110 PMIC, and Eliza LPASS LPI TLMM SoC (this is for the low power audio, LPASS = Low Power Audio SubSystem portions) - Upboard support on top of the Intel pin controller - Apple T6030 and T6031 support (just compatible strings) - Samsung Exynos 8855 SoC - Mediatek MT6858 SoC - Rockchip RK3308B and RV1106 SoCs - Airoha EN7523 and AN7563 SoCs Improvements: - Qualcomm TLMM GPIOs are unconditionally marked as wakeup capable - Qualcomm improvements on top of the Qualcomm PDC (power domain controller) irqchip improvements from tglx:s tree - Qualcomm IPQ806x and IPQ9650 non-urgent pin grop fixups - The NPCM8xx driver has been put into shape fixing many pin and group definitions - Some non-urgent Tegra 264 pin assignments are fixed up - Some non-urgent fixups to Airoha AN7581 and AN7583 registers and pin assignments, missing features etc" * tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (130 commits) dt-bindings: pinctrl: Convert TI DA850 pupd to DT schema pinctrl: meson: sync some modify from A4 pinctrl: meson: a4: Add input enable pin configuration pinctrl: realtek: rtd1625: remove unused group name spdif_sel pinctrl: realtek: rtd1625: fix base_bit for VE4 GPIO 13 dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema Revert "Merge branch 'ib-rsk7204' into devel" pinctrl: rockchip: Add RV1106 pinctrl support dt-bindings: pinctrl: rockchip: Add RV1106 compatible pinctrl: rockchip: Decode drive strength in the get function pinctrl: fix PINCTRL_GENERIC_MUX not always being selectable pinctrl: airoha: add support of an7563 SoC dt-bindings: pinctrl: airoha: add support of an7563 pin controller pinctrl: airoha: try to find chip scu node by phandle first pinctrl: airoha: add support of en7523 SoC dt-bindings: pinctrl: airoha: add support of en7523 pin controller pinctrl: airoha: an7583: add support for olt pinmux pinctrl: airoha: an7583: add support for pon_alt pinmux pinctrl: airoha: an7583: add support for npu_uart pinmux dt-bindings: pinctrl: airoha: an7583: add missed features ...
Diffstat (limited to 'lib/irq_poll.c')
-rw-r--r--lib/irq_poll.c219
1 files changed, 219 insertions, 0 deletions
diff --git a/lib/irq_poll.c b/lib/irq_poll.c
new file mode 100644
index 000000000..08b242bbd
--- /dev/null
+++ b/lib/irq_poll.c
@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions related to interrupt-poll handling in the block layer. This
+ * is similar to NAPI for network devices.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bio.h>
+#include <linux/interrupt.h>
+#include <linux/cpu.h>
+#include <linux/irq_poll.h>
+#include <linux/delay.h>
+
+static unsigned int irq_poll_budget __read_mostly = 256;
+
+static DEFINE_PER_CPU(struct list_head, blk_cpu_iopoll);
+
+/**
+ * irq_poll_sched - Schedule a run of the iopoll handler
+ * @iop: The parent iopoll structure
+ *
+ * Description:
+ * Add this irq_poll structure to the pending poll list and trigger the
+ * raise of the blk iopoll softirq.
+ **/
+void irq_poll_sched(struct irq_poll *iop)
+{
+ unsigned long flags;
+
+ if (test_bit(IRQ_POLL_F_DISABLE, &iop->state))
+ return;
+ if (test_and_set_bit(IRQ_POLL_F_SCHED, &iop->state))
+ return;
+
+ local_irq_save(flags);
+ list_add_tail(&iop->list, this_cpu_ptr(&blk_cpu_iopoll));
+ raise_softirq_irqoff(IRQ_POLL_SOFTIRQ);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(irq_poll_sched);
+
+/**
+ * __irq_poll_complete - Mark this @iop as un-polled again
+ * @iop: The parent iopoll structure
+ *
+ * Description:
+ * See irq_poll_complete(). This function must be called with interrupts
+ * disabled.
+ **/
+static void __irq_poll_complete(struct irq_poll *iop)
+{
+ list_del(&iop->list);
+ smp_mb__before_atomic();
+ clear_bit_unlock(IRQ_POLL_F_SCHED, &iop->state);
+}
+
+/**
+ * irq_poll_complete - Mark this @iop as un-polled again
+ * @iop: The parent iopoll structure
+ *
+ * Description:
+ * If a driver consumes less than the assigned budget in its run of the
+ * iopoll handler, it'll end the polled mode by calling this function. The
+ * iopoll handler will not be invoked again before irq_poll_sched()
+ * is called.
+ **/
+void irq_poll_complete(struct irq_poll *iop)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __irq_poll_complete(iop);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(irq_poll_complete);
+
+static void __latent_entropy irq_poll_softirq(void)
+{
+ struct list_head *list = this_cpu_ptr(&blk_cpu_iopoll);
+ int rearm = 0, budget = irq_poll_budget;
+ unsigned long start_time = jiffies;
+
+ local_irq_disable();
+
+ while (!list_empty(list)) {
+ struct irq_poll *iop;
+ int work, weight;
+
+ /*
+ * If softirq window is exhausted then punt.
+ */
+ if (budget <= 0 || time_after(jiffies, start_time)) {
+ rearm = 1;
+ break;
+ }
+
+ local_irq_enable();
+
+ /* Even though interrupts have been re-enabled, this
+ * access is safe because interrupts can only add new
+ * entries to the tail of this list, and only ->poll()
+ * calls can remove this head entry from the list.
+ */
+ iop = list_entry(list->next, struct irq_poll, list);
+
+ weight = iop->weight;
+ work = 0;
+ if (test_bit(IRQ_POLL_F_SCHED, &iop->state))
+ work = iop->poll(iop, weight);
+
+ budget -= work;
+
+ local_irq_disable();
+
+ /*
+ * Drivers must not modify the iopoll state, if they
+ * consume their assigned weight (or more, some drivers can't
+ * easily just stop processing, they have to complete an
+ * entire mask of commands).In such cases this code
+ * still "owns" the iopoll instance and therefore can
+ * move the instance around on the list at-will.
+ */
+ if (work >= weight) {
+ if (test_bit(IRQ_POLL_F_DISABLE, &iop->state))
+ __irq_poll_complete(iop);
+ else
+ list_move_tail(&iop->list, list);
+ }
+ }
+
+ if (rearm)
+ __raise_softirq_irqoff(IRQ_POLL_SOFTIRQ);
+
+ local_irq_enable();
+}
+
+/**
+ * irq_poll_disable - Disable iopoll on this @iop
+ * @iop: The parent iopoll structure
+ *
+ * Description:
+ * Disable io polling and wait for any pending callbacks to have completed.
+ **/
+void irq_poll_disable(struct irq_poll *iop)
+{
+ set_bit(IRQ_POLL_F_DISABLE, &iop->state);
+ while (test_and_set_bit(IRQ_POLL_F_SCHED, &iop->state))
+ msleep(1);
+ clear_bit(IRQ_POLL_F_DISABLE, &iop->state);
+}
+EXPORT_SYMBOL(irq_poll_disable);
+
+/**
+ * irq_poll_enable - Enable iopoll on this @iop
+ * @iop: The parent iopoll structure
+ *
+ * Description:
+ * Enable iopoll on this @iop. Note that the handler run will not be
+ * scheduled, it will only mark it as active.
+ **/
+void irq_poll_enable(struct irq_poll *iop)
+{
+ BUG_ON(!test_bit(IRQ_POLL_F_SCHED, &iop->state));
+ smp_mb__before_atomic();
+ clear_bit_unlock(IRQ_POLL_F_SCHED, &iop->state);
+}
+EXPORT_SYMBOL(irq_poll_enable);
+
+/**
+ * irq_poll_init - Initialize this @iop
+ * @iop: The parent iopoll structure
+ * @weight: The default weight (or command completion budget)
+ * @poll_fn: The handler to invoke
+ *
+ * Description:
+ * Initialize and enable this irq_poll structure.
+ **/
+void irq_poll_init(struct irq_poll *iop, int weight, irq_poll_fn *poll_fn)
+{
+ memset(iop, 0, sizeof(*iop));
+ INIT_LIST_HEAD(&iop->list);
+ iop->weight = weight;
+ iop->poll = poll_fn;
+}
+EXPORT_SYMBOL(irq_poll_init);
+
+static int irq_poll_cpu_dead(unsigned int cpu)
+{
+ /*
+ * If a CPU goes away, splice its entries to the current CPU and
+ * set the POLL softirq bit. The local_bh_disable()/enable() pair
+ * ensures that it is handled. Otherwise the current CPU could
+ * reach idle with the POLL softirq pending.
+ */
+ local_bh_disable();
+ local_irq_disable();
+ list_splice_init(&per_cpu(blk_cpu_iopoll, cpu),
+ this_cpu_ptr(&blk_cpu_iopoll));
+ __raise_softirq_irqoff(IRQ_POLL_SOFTIRQ);
+ local_irq_enable();
+ local_bh_enable();
+
+ return 0;
+}
+
+static __init int irq_poll_setup(void)
+{
+ int i;
+
+ for_each_possible_cpu(i)
+ INIT_LIST_HEAD(&per_cpu(blk_cpu_iopoll, i));
+
+ open_softirq(IRQ_POLL_SOFTIRQ, irq_poll_softirq);
+ cpuhp_setup_state_nocalls(CPUHP_IRQ_POLL_DEAD, "irq_poll:dead", NULL,
+ irq_poll_cpu_dead);
+ return 0;
+}
+subsys_initcall(irq_poll_setup);