From ea08eeccae9297f7aabd2ef7f0c2517ac4549acc Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:18:26 +0000
Subject: [PATCH] write in 30M
---
kernel/drivers/uio/uio_dmem_genirq.c | 59 ++++++++++++++++++++++++++++++++++-------------------------
1 files changed, 34 insertions(+), 25 deletions(-)
diff --git a/kernel/drivers/uio/uio_dmem_genirq.c b/kernel/drivers/uio/uio_dmem_genirq.c
index a00b4ae..9275173 100644
--- a/kernel/drivers/uio/uio_dmem_genirq.c
+++ b/kernel/drivers/uio/uio_dmem_genirq.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* drivers/uio/uio_dmem_genirq.c
*
@@ -6,10 +7,6 @@
* Copyright (C) 2012 Damian Hobson-Garcia
*
* Based on uio_pdrv_genirq.c by Magnus Damm
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published by
- * the Free Software Foundation.
*/
#include <linux/platform_device.h>
@@ -23,6 +20,7 @@
#include <linux/pm_runtime.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
+#include <linux/irq.h>
#include <linux/of.h>
#include <linux/of_platform.h>
@@ -47,7 +45,6 @@
{
struct uio_dmem_genirq_platdata *priv = info->priv;
struct uio_mem *uiomem;
- int ret = 0;
int dmem_region = priv->dmem_region_start;
uiomem = &priv->uioinfo->mem[priv->dmem_region_start];
@@ -71,7 +68,7 @@
mutex_unlock(&priv->alloc_lock);
/* Wait until the Runtime PM code has woken up the device */
pm_runtime_get_sync(&priv->pdev->dev);
- return ret;
+ return 0;
}
static int uio_dmem_genirq_release(struct uio_info *info, struct inode *inode)
@@ -113,8 +110,10 @@
* remember the state so we can allow user space to enable it later.
*/
+ spin_lock(&priv->lock);
if (!test_and_set_bit(0, &priv->flags))
disable_irq_nosync(irq);
+ spin_unlock(&priv->lock);
return IRQ_HANDLED;
}
@@ -128,20 +127,19 @@
* in the interrupt controller, but keep track of the
* state to prevent per-irq depth damage.
*
- * Serialize this operation to support multiple tasks.
+ * Serialize this operation to support multiple tasks and concurrency
+ * with irq handler on SMP systems.
*/
spin_lock_irqsave(&priv->lock, flags);
if (irq_on) {
if (test_and_clear_bit(0, &priv->flags))
enable_irq(dev_info->irq);
- spin_unlock_irqrestore(&priv->lock, flags);
} else {
- if (!test_and_set_bit(0, &priv->flags)) {
- spin_unlock_irqrestore(&priv->lock, flags);
- disable_irq(dev_info->irq);
- }
+ if (!test_and_set_bit(0, &priv->flags))
+ disable_irq_nosync(dev_info->irq);
}
+ spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
@@ -156,8 +154,6 @@
int i;
if (pdev->dev.of_node) {
- int irq;
-
/* alloc uioinfo for one device */
uioinfo = kzalloc(sizeof(*uioinfo), GFP_KERNEL);
if (!uioinfo) {
@@ -165,15 +161,9 @@
dev_err(&pdev->dev, "unable to kmalloc\n");
goto bad2;
}
- uioinfo->name = pdev->dev.of_node->name;
+ uioinfo->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn",
+ pdev->dev.of_node);
uioinfo->version = "devicetree";
-
- /* Multiple IRQs are not supported */
- irq = platform_get_irq(pdev, 0);
- if (irq == -ENXIO)
- uioinfo->irq = UIO_IRQ_NONE;
- else
- uioinfo->irq = irq;
}
if (!uioinfo || !uioinfo->name || !uioinfo->version) {
@@ -203,13 +193,32 @@
mutex_init(&priv->alloc_lock);
if (!uioinfo->irq) {
+ /* Multiple IRQs are not supported */
ret = platform_get_irq(pdev, 0);
- if (ret < 0) {
- dev_err(&pdev->dev, "failed to get IRQ\n");
+ if (ret == -ENXIO && pdev->dev.of_node)
+ ret = UIO_IRQ_NONE;
+ else if (ret < 0)
goto bad1;
- }
uioinfo->irq = ret;
}
+
+ if (uioinfo->irq) {
+ struct irq_data *irq_data = irq_get_irq_data(uioinfo->irq);
+
+ /*
+ * If a level interrupt, dont do lazy disable. Otherwise the
+ * irq will fire again since clearing of the actual cause, on
+ * device level, is done in userspace
+ * irqd_is_level_type() isn't used since isn't valid until
+ * irq is configured.
+ */
+ if (irq_data &&
+ irqd_get_trigger_type(irq_data) & IRQ_TYPE_LEVEL_MASK) {
+ dev_dbg(&pdev->dev, "disable lazy unmask\n");
+ irq_set_status_flags(uioinfo->irq, IRQ_DISABLE_UNLAZY);
+ }
+ }
+
uiomem = &uioinfo->mem[0];
for (i = 0; i < pdev->num_resources; ++i) {
--
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