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Diffstat (limited to 'drivers/dma/shdma.c')
-rw-r--r--drivers/dma/shdma.c131
1 files changed, 113 insertions, 18 deletions
diff --git a/drivers/dma/shdma.c b/drivers/dma/shdma.c
index eb6b54dbb80..28720d3103c 100644
--- a/drivers/dma/shdma.c
+++ b/drivers/dma/shdma.c
@@ -27,7 +27,10 @@
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/sh_dma.h>
-
+#include <linux/notifier.h>
+#include <linux/kdebug.h>
+#include <linux/spinlock.h>
+#include <linux/rculist.h>
#include "shdma.h"
/* DMA descriptor control */
@@ -43,6 +46,13 @@ enum sh_dmae_desc_status {
/* Default MEMCPY transfer size = 2^2 = 4 bytes */
#define LOG2_DEFAULT_XFER_SIZE 2
+/*
+ * Used for write-side mutual exclusion for the global device list,
+ * read-side synchronization by way of RCU.
+ */
+static DEFINE_SPINLOCK(sh_dmae_lock);
+static LIST_HEAD(sh_dmae_devices);
+
/* A bitmask with bits enough for enum sh_dmae_slave_chan_id */
static unsigned long sh_dmae_slave_used[BITS_TO_LONGS(SH_DMA_SLAVE_NUMBER)];
@@ -817,10 +827,9 @@ static irqreturn_t sh_dmae_interrupt(int irq, void *data)
return ret;
}
-#if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARCH_SHMOBILE)
-static irqreturn_t sh_dmae_err(int irq, void *data)
+static unsigned int sh_dmae_reset(struct sh_dmae_device *shdev)
{
- struct sh_dmae_device *shdev = (struct sh_dmae_device *)data;
+ unsigned int handled = 0;
int i;
/* halt the dma controller */
@@ -829,25 +838,35 @@ static irqreturn_t sh_dmae_err(int irq, void *data)
/* We cannot detect, which channel caused the error, have to reset all */
for (i = 0; i < SH_DMAC_MAX_CHANNELS; i++) {
struct sh_dmae_chan *sh_chan = shdev->chan[i];
- if (sh_chan) {
- struct sh_desc *desc;
- /* Stop the channel */
- dmae_halt(sh_chan);
- /* Complete all */
- list_for_each_entry(desc, &sh_chan->ld_queue, node) {
- struct dma_async_tx_descriptor *tx = &desc->async_tx;
- desc->mark = DESC_IDLE;
- if (tx->callback)
- tx->callback(tx->callback_param);
- }
- list_splice_init(&sh_chan->ld_queue, &sh_chan->ld_free);
+ struct sh_desc *desc;
+
+ if (!sh_chan)
+ continue;
+
+ /* Stop the channel */
+ dmae_halt(sh_chan);
+
+ /* Complete all */
+ list_for_each_entry(desc, &sh_chan->ld_queue, node) {
+ struct dma_async_tx_descriptor *tx = &desc->async_tx;
+ desc->mark = DESC_IDLE;
+ if (tx->callback)
+ tx->callback(tx->callback_param);
}
+
+ list_splice_init(&sh_chan->ld_queue, &sh_chan->ld_free);
+ handled++;
}
+
sh_dmae_rst(shdev);
- return IRQ_HANDLED;
+ return !!handled;
+}
+
+static irqreturn_t sh_dmae_err(int irq, void *data)
+{
+ return IRQ_RETVAL(sh_dmae_reset(data));
}
-#endif
static void dmae_do_tasklet(unsigned long data)
{
@@ -876,6 +895,60 @@ static void dmae_do_tasklet(unsigned long data)
sh_dmae_chan_ld_cleanup(sh_chan, false);
}
+static bool sh_dmae_nmi_notify(struct sh_dmae_device *shdev)
+{
+ unsigned int handled;
+
+ /* Fast path out if NMIF is not asserted for this controller */
+ if ((dmaor_read(shdev) & DMAOR_NMIF) == 0)
+ return false;
+
+ handled = sh_dmae_reset(shdev);
+ if (handled)
+ return true;
+
+ return false;
+}
+
+static int sh_dmae_nmi_handler(struct notifier_block *self,
+ unsigned long cmd, void *data)
+{
+ struct sh_dmae_device *shdev;
+ int ret = NOTIFY_DONE;
+ bool triggered;
+
+ /*
+ * Only concern ourselves with NMI events.
+ *
+ * Normally we would check the die chain value, but as this needs
+ * to be architecture independent, check for NMI context instead.
+ */
+ if (!in_nmi())
+ return NOTIFY_DONE;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(shdev, &sh_dmae_devices, node) {
+ /*
+ * Only stop if one of the controllers has NMIF asserted,
+ * we do not want to interfere with regular address error
+ * handling or NMI events that don't concern the DMACs.
+ */
+ triggered = sh_dmae_nmi_notify(shdev);
+ if (triggered == true)
+ ret = NOTIFY_OK;
+ }
+ rcu_read_unlock();
+
+ return ret;
+}
+
+static struct notifier_block sh_dmae_nmi_notifier __read_mostly = {
+ .notifier_call = sh_dmae_nmi_handler,
+
+ /* Run before NMI debug handler and KGDB */
+ .priority = 1,
+};
+
static int __devinit sh_dmae_chan_probe(struct sh_dmae_device *shdev, int id,
int irq, unsigned long flags)
{
@@ -967,6 +1040,7 @@ static int __init sh_dmae_probe(struct platform_device *pdev)
struct sh_dmae_pdata *pdata = pdev->dev.platform_data;
unsigned long irqflags = IRQF_DISABLED,
chan_flag[SH_DMAC_MAX_CHANNELS] = {};
+ unsigned long flags;
int errirq, chan_irq[SH_DMAC_MAX_CHANNELS];
int err, i, irq_cnt = 0, irqres = 0;
struct sh_dmae_device *shdev;
@@ -1032,6 +1106,10 @@ static int __init sh_dmae_probe(struct platform_device *pdev)
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
+ spin_lock_irqsave(&sh_dmae_lock, flags);
+ list_add_tail_rcu(&shdev->node, &sh_dmae_devices);
+ spin_unlock_irqrestore(&sh_dmae_lock, flags);
+
/* reset dma controller */
err = sh_dmae_rst(shdev);
if (err)
@@ -1135,6 +1213,10 @@ eirqres:
eirq_err:
#endif
rst_err:
+ spin_lock_irqsave(&sh_dmae_lock, flags);
+ list_del_rcu(&shdev->node);
+ spin_unlock_irqrestore(&sh_dmae_lock, flags);
+
pm_runtime_put(&pdev->dev);
if (dmars)
iounmap(shdev->dmars);
@@ -1155,6 +1237,7 @@ static int __exit sh_dmae_remove(struct platform_device *pdev)
{
struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
struct resource *res;
+ unsigned long flags;
int errirq = platform_get_irq(pdev, 0);
dma_async_device_unregister(&shdev->common);
@@ -1162,6 +1245,10 @@ static int __exit sh_dmae_remove(struct platform_device *pdev)
if (errirq > 0)
free_irq(errirq, shdev);
+ spin_lock_irqsave(&sh_dmae_lock, flags);
+ list_del_rcu(&shdev->node);
+ spin_unlock_irqrestore(&sh_dmae_lock, flags);
+
/* channel data remove */
sh_dmae_chan_remove(shdev);
@@ -1200,6 +1287,11 @@ static struct platform_driver sh_dmae_driver = {
static int __init sh_dmae_init(void)
{
+ /* Wire up NMI handling */
+ int err = register_die_notifier(&sh_dmae_nmi_notifier);
+ if (err)
+ return err;
+
return platform_driver_probe(&sh_dmae_driver, sh_dmae_probe);
}
module_init(sh_dmae_init);
@@ -1207,9 +1299,12 @@ module_init(sh_dmae_init);
static void __exit sh_dmae_exit(void)
{
platform_driver_unregister(&sh_dmae_driver);
+
+ unregister_die_notifier(&sh_dmae_nmi_notifier);
}
module_exit(sh_dmae_exit);
MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>");
MODULE_DESCRIPTION("Renesas SH DMA Engine driver");
MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:sh-dma-engine");
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-19 05:58:43 +0000