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authorLinus Torvalds <torvalds@linux-foundation.org>2012-03-21 18:55:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-21 18:55:10 -0700
commit5375871d432ae9fc581014ac117b96aaee3cd0c7 (patch)
treebe98e8255b0f927fb920fb532a598b93fa140dbe /drivers/misc
parentb57cb7231b2ce52d3dda14a7b417ae125fb2eb97 (diff)
parentdfbc2d75c1bd47c3186fa91f1655ea2f3825b0ec (diff)
downloadop-kernel-dev-5375871d432ae9fc581014ac117b96aaee3cd0c7.zip
op-kernel-dev-5375871d432ae9fc581014ac117b96aaee3cd0c7.tar.gz
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc merge from Benjamin Herrenschmidt: "Here's the powerpc batch for this merge window. It is going to be a bit more nasty than usual as in touching things outside of arch/powerpc mostly due to the big iSeriesectomy :-) We finally got rid of the bugger (legacy iSeries support) which was a PITA to maintain and that nobody really used anymore. Here are some of the highlights: - Legacy iSeries is gone. Thanks Stephen ! There's still some bits and pieces remaining if you do a grep -ir series arch/powerpc but they are harmless and will be removed in the next few weeks hopefully. - The 'fadump' functionality (Firmware Assisted Dump) replaces the previous (equivalent) "pHyp assisted dump"... it's a rewrite of a mechanism to get the hypervisor to do crash dumps on pSeries, the new implementation hopefully being much more reliable. Thanks Mahesh Salgaonkar. - The "EEH" code (pSeries PCI error handling & recovery) got a big spring cleaning, motivated by the need to be able to implement a new backend for it on top of some new different type of firwmare. The work isn't complete yet, but a good chunk of the cleanups is there. Note that this adds a field to struct device_node which is not very nice and which Grant objects to. I will have a patch soon that moves that to a powerpc private data structure (hopefully before rc1) and we'll improve things further later on (hopefully getting rid of the need for that pointer completely). Thanks Gavin Shan. - I dug into our exception & interrupt handling code to improve the way we do lazy interrupt handling (and make it work properly with "edge" triggered interrupt sources), and while at it found & fixed a wagon of issues in those areas, including adding support for page fault retry & fatal signals on page faults. - Your usual random batch of small fixes & updates, including a bunch of new embedded boards, both Freescale and APM based ones, etc..." I fixed up some conflicts with the generalized irq-domain changes from Grant Likely, hopefully correctly. * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (141 commits) powerpc/ps3: Do not adjust the wrapper load address powerpc: Remove the rest of the legacy iSeries include files powerpc: Remove the remaining CONFIG_PPC_ISERIES pieces init: Remove CONFIG_PPC_ISERIES powerpc: Remove FW_FEATURE ISERIES from arch code tty/hvc_vio: FW_FEATURE_ISERIES is no longer selectable powerpc/spufs: Fix double unlocks powerpc/5200: convert mpc5200 to use of_platform_populate() powerpc/mpc5200: add options to mpc5200_defconfig powerpc/mpc52xx: add a4m072 board support powerpc/mpc5200: update mpc5200_defconfig to fit for charon board Documentation/powerpc/mpc52xx.txt: Checkpatch cleanup powerpc/44x: Add additional device support for APM821xx SoC and Bluestone board powerpc/44x: Add support PCI-E for APM821xx SoC and Bluestone board MAINTAINERS: Update PowerPC 4xx tree powerpc/44x: The bug fixed support for APM821xx SoC and Bluestone board powerpc: document the FSL MPIC message register binding powerpc: add support for MPIC message register API powerpc/fsl: Added aliased MSIIR register address to MSI node in dts powerpc/85xx: mpc8548cds - add 36-bit dts ...
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/carma/carma-fpga.c114
1 files changed, 72 insertions, 42 deletions
diff --git a/drivers/misc/carma/carma-fpga.c b/drivers/misc/carma/carma-fpga.c
index 366bc15..8c279da 100644
--- a/drivers/misc/carma/carma-fpga.c
+++ b/drivers/misc/carma/carma-fpga.c
@@ -560,6 +560,9 @@ static void data_enable_interrupts(struct fpga_device *priv)
/* flush the writes */
fpga_read_reg(priv, 0, MMAP_REG_STATUS);
+ fpga_read_reg(priv, 1, MMAP_REG_STATUS);
+ fpga_read_reg(priv, 2, MMAP_REG_STATUS);
+ fpga_read_reg(priv, 3, MMAP_REG_STATUS);
/* switch back to the external interrupt source */
iowrite32be(0x3F, priv->regs + SYS_IRQ_SOURCE_CTL);
@@ -591,8 +594,12 @@ static void data_dma_cb(void *data)
list_move_tail(&priv->inflight->entry, &priv->used);
priv->inflight = NULL;
- /* clear the FPGA status and re-enable interrupts */
- data_enable_interrupts(priv);
+ /*
+ * If data dumping is still enabled, then clear the FPGA
+ * status registers and re-enable FPGA interrupts
+ */
+ if (priv->enabled)
+ data_enable_interrupts(priv);
spin_unlock_irqrestore(&priv->lock, flags);
@@ -708,6 +715,15 @@ static irqreturn_t data_irq(int irq, void *dev_id)
spin_lock(&priv->lock);
+ /*
+ * This is an error case that should never happen.
+ *
+ * If this driver has a bug and manages to re-enable interrupts while
+ * a DMA is in progress, then we will hit this statement and should
+ * start paying attention immediately.
+ */
+ BUG_ON(priv->inflight != NULL);
+
/* hide the interrupt by switching the IRQ driver to GPIO */
data_disable_interrupts(priv);
@@ -762,11 +778,15 @@ out:
*/
static int data_device_enable(struct fpga_device *priv)
{
+ bool enabled;
u32 val;
int ret;
/* multiple enables are safe: they do nothing */
- if (priv->enabled)
+ spin_lock_irq(&priv->lock);
+ enabled = priv->enabled;
+ spin_unlock_irq(&priv->lock);
+ if (enabled)
return 0;
/* check that the FPGAs are programmed */
@@ -797,6 +817,9 @@ static int data_device_enable(struct fpga_device *priv)
goto out_error;
}
+ /* prevent the FPGAs from generating interrupts */
+ data_disable_interrupts(priv);
+
/* hookup the irq handler */
ret = request_irq(priv->irq, data_irq, IRQF_SHARED, drv_name, priv);
if (ret) {
@@ -804,11 +827,13 @@ static int data_device_enable(struct fpga_device *priv)
goto out_error;
}
- /* switch to the external FPGA IRQ line */
- data_enable_interrupts(priv);
-
- /* success, we're enabled */
+ /* allow the DMA callback to re-enable FPGA interrupts */
+ spin_lock_irq(&priv->lock);
priv->enabled = true;
+ spin_unlock_irq(&priv->lock);
+
+ /* allow the FPGAs to generate interrupts */
+ data_enable_interrupts(priv);
return 0;
out_error:
@@ -834,41 +859,40 @@ out_error:
*/
static int data_device_disable(struct fpga_device *priv)
{
- int ret;
+ spin_lock_irq(&priv->lock);
/* allow multiple disable */
- if (!priv->enabled)
+ if (!priv->enabled) {
+ spin_unlock_irq(&priv->lock);
return 0;
+ }
+
+ /*
+ * Mark the device disabled
+ *
+ * This stops DMA callbacks from re-enabling interrupts
+ */
+ priv->enabled = false;
- /* switch to the internal GPIO IRQ line */
+ /* prevent the FPGAs from generating interrupts */
data_disable_interrupts(priv);
+ /* wait until all ongoing DMA has finished */
+ while (priv->inflight != NULL) {
+ spin_unlock_irq(&priv->lock);
+ wait_event(priv->wait, priv->inflight == NULL);
+ spin_lock_irq(&priv->lock);
+ }
+
+ spin_unlock_irq(&priv->lock);
+
/* unhook the irq handler */
free_irq(priv->irq, priv);
- /*
- * wait for all outstanding DMA to complete
- *
- * Device interrupts are disabled, therefore another buffer cannot
- * be marked inflight.
- */
- ret = wait_event_interruptible(priv->wait, priv->inflight == NULL);
- if (ret)
- return ret;
-
/* free the correlation table */
sg_free_table(&priv->corl_table);
priv->corl_nents = 0;
- /*
- * We are taking the spinlock not to protect priv->enabled, but instead
- * to make sure that there are no readers in the process of altering
- * the free or used lists while we are setting this flag.
- */
- spin_lock_irq(&priv->lock);
- priv->enabled = false;
- spin_unlock_irq(&priv->lock);
-
/* free all buffers: the free and used lists are not being changed */
data_free_buffers(priv);
return 0;
@@ -896,15 +920,6 @@ static unsigned int list_num_entries(struct list_head *list)
static int data_debug_show(struct seq_file *f, void *offset)
{
struct fpga_device *priv = f->private;
- int ret;
-
- /*
- * Lock the mutex first, so that we get an accurate value for enable
- * Lock the spinlock next, to get accurate list counts
- */
- ret = mutex_lock_interruptible(&priv->mutex);
- if (ret)
- return ret;
spin_lock_irq(&priv->lock);
@@ -917,7 +932,6 @@ static int data_debug_show(struct seq_file *f, void *offset)
seq_printf(f, "num_dropped: %d\n", priv->num_dropped);
spin_unlock_irq(&priv->lock);
- mutex_unlock(&priv->mutex);
return 0;
}
@@ -970,7 +984,13 @@ static ssize_t data_en_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct fpga_device *priv = dev_get_drvdata(dev);
- return snprintf(buf, PAGE_SIZE, "%u\n", priv->enabled);
+ int ret;
+
+ spin_lock_irq(&priv->lock);
+ ret = snprintf(buf, PAGE_SIZE, "%u\n", priv->enabled);
+ spin_unlock_irq(&priv->lock);
+
+ return ret;
}
static ssize_t data_en_set(struct device *dev, struct device_attribute *attr,
@@ -986,6 +1006,7 @@ static ssize_t data_en_set(struct device *dev, struct device_attribute *attr,
return -EINVAL;
}
+ /* protect against concurrent enable/disable */
ret = mutex_lock_interruptible(&priv->mutex);
if (ret)
return ret;
@@ -1079,6 +1100,7 @@ static ssize_t data_read(struct file *filp, char __user *ubuf, size_t count,
struct fpga_reader *reader = filp->private_data;
struct fpga_device *priv = reader->priv;
struct list_head *used = &priv->used;
+ bool drop_buffer = false;
struct data_buf *dbuf;
size_t avail;
void *data;
@@ -1166,10 +1188,12 @@ have_buffer:
* One of two things has happened, the device is disabled, or the
* device has been reconfigured underneath us. In either case, we
* should just throw away the buffer.
+ *
+ * Lockdep complains if this is done under the spinlock, so we
+ * handle it during the unlock path.
*/
if (!priv->enabled || dbuf->size != priv->bufsize) {
- videobuf_dma_unmap(priv->dev, &dbuf->vb);
- data_free_buffer(dbuf);
+ drop_buffer = true;
goto out_unlock;
}
@@ -1178,6 +1202,12 @@ have_buffer:
out_unlock:
spin_unlock_irq(&priv->lock);
+
+ if (drop_buffer) {
+ videobuf_dma_unmap(priv->dev, &dbuf->vb);
+ data_free_buffer(dbuf);
+ }
+
return count;
}
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