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dmaengine: shdma: synchronize RCU before freeing, simplify spinlock

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List elements, deleted using list_del_rcu(), cannot be freed without
synchronising RCU. Further, the spinlock, used to protect the RCU
writer, is called in process context, so, we don't have to save flags.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Guennadi Liakhovetski 2011-05-02 07:59:02 +00:00 • committed by Paul Mundt
parent 467017b83b
commit 31705e21f9
1 changed files with 8 additions and 8 deletions
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16
drivers/dma/shdma.c
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@ -1077,7 +1077,6 @@ static int __init sh_dmae_probe(struct platform_device *pdev)
struct sh_dmae_pdata *pdata = pdev->dev.platform_data; struct sh_dmae_pdata *pdata = pdev->dev.platform_data;
unsigned long irqflags = IRQF_DISABLED, unsigned long irqflags = IRQF_DISABLED,
chan_flag[SH_DMAC_MAX_CHANNELS] = {}; chan_flag[SH_DMAC_MAX_CHANNELS] = {};
unsigned long flags;
int errirq, chan_irq[SH_DMAC_MAX_CHANNELS]; int errirq, chan_irq[SH_DMAC_MAX_CHANNELS];
int err, i, irq_cnt = 0, irqres = 0; int err, i, irq_cnt = 0, irqres = 0;
struct sh_dmae_device *shdev; struct sh_dmae_device *shdev;
@ -1143,9 +1142,9 @@ static int __init sh_dmae_probe(struct platform_device *pdev)
pm_runtime_enable(&pdev->dev); pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev); pm_runtime_get_sync(&pdev->dev);
spin_lock_irqsave(&sh_dmae_lock, flags); spin_lock_irq(&sh_dmae_lock);
list_add_tail_rcu(&shdev->node, &sh_dmae_devices); list_add_tail_rcu(&shdev->node, &sh_dmae_devices);
spin_unlock_irqrestore(&sh_dmae_lock, flags); spin_unlock_irq(&sh_dmae_lock);
/* reset dma controller - only needed as a test */ /* reset dma controller - only needed as a test */
err = sh_dmae_rst(shdev); err = sh_dmae_rst(shdev);
@ -1250,9 +1249,9 @@ eirqres:
eirq_err: eirq_err:
#endif #endif
rst_err: rst_err:
spin_lock_irqsave(&sh_dmae_lock, flags); spin_lock_irq(&sh_dmae_lock);
list_del_rcu(&shdev->node); list_del_rcu(&shdev->node);
spin_unlock_irqrestore(&sh_dmae_lock, flags); spin_unlock_irq(&sh_dmae_lock);
pm_runtime_put(&pdev->dev); pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev); pm_runtime_disable(&pdev->dev);
@ -1261,6 +1260,7 @@ rst_err:
iounmap(shdev->dmars); iounmap(shdev->dmars);
emapdmars: emapdmars:
iounmap(shdev->chan_reg); iounmap(shdev->chan_reg);
synchronize_rcu();
emapchan: emapchan:
kfree(shdev); kfree(shdev);
ealloc: ealloc:
@ -1276,7 +1276,6 @@ static int __exit sh_dmae_remove(struct platform_device *pdev)
{ {
struct sh_dmae_device *shdev = platform_get_drvdata(pdev); struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
struct resource *res; struct resource *res;
unsigned long flags;
int errirq = platform_get_irq(pdev, 0); int errirq = platform_get_irq(pdev, 0);
dma_async_device_unregister(&shdev->common); dma_async_device_unregister(&shdev->common);
@ -1284,9 +1283,9 @@ static int __exit sh_dmae_remove(struct platform_device *pdev)
if (errirq > 0) if (errirq > 0)
free_irq(errirq, shdev); free_irq(errirq, shdev);
spin_lock_irqsave(&sh_dmae_lock, flags); spin_lock_irq(&sh_dmae_lock);
list_del_rcu(&shdev->node); list_del_rcu(&shdev->node);
spin_unlock_irqrestore(&sh_dmae_lock, flags); spin_unlock_irq(&sh_dmae_lock);
/* channel data remove */ /* channel data remove */
sh_dmae_chan_remove(shdev); sh_dmae_chan_remove(shdev);
@ -1297,6 +1296,7 @@ static int __exit sh_dmae_remove(struct platform_device *pdev)
iounmap(shdev->dmars); iounmap(shdev->dmars);
iounmap(shdev->chan_reg); iounmap(shdev->chan_reg);
synchronize_rcu();
kfree(shdev); kfree(shdev);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0); res = platform_get_resource(pdev, IORESOURCE_MEM, 0);