Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 77 insertions, 51 deletions

diff --git a/arch/arm/mach-tegra/dma.c b/arch/arm/mach-tegra/dma.c
index c0cf967e47d3..abea4f6e2dd5 100644
--- a/arch/arm/mach-tegra/dma.c
+++ b/arch/arm/mach-tegra/dma.c
@@ -33,6 +33,8 @@
 #include <mach/iomap.h>
 #include <mach/suspend.h>
 
+#include "apbio.h"
+
 #define APB_DMA_GEN				0x000
 #define GEN_ENABLE				(1<<31)
 
@@ -50,8 +52,6 @@
 #define CSR_ONCE				(1<<27)
 #define CSR_FLOW				(1<<21)
 #define CSR_REQ_SEL_SHIFT			16
-#define CSR_REQ_SEL_MASK			(0x1F<<CSR_REQ_SEL_SHIFT)
-#define CSR_REQ_SEL_INVALID			(31<<CSR_REQ_SEL_SHIFT)
 #define CSR_WCOUNT_SHIFT			2
 #define CSR_WCOUNT_MASK				0xFFFC
 
@@ -133,6 +133,7 @@ struct tegra_dma_channel {
 
 static bool tegra_dma_initialized;
 static DEFINE_MUTEX(tegra_dma_lock);
+static DEFINE_SPINLOCK(enable_lock);
 
 static DECLARE_BITMAP(channel_usage, NV_DMA_MAX_CHANNELS);
 static struct tegra_dma_channel dma_channels[NV_DMA_MAX_CHANNELS];
@@ -180,36 +181,94 @@ static void tegra_dma_stop(struct tegra_dma_channel *ch)
 
 static int tegra_dma_cancel(struct tegra_dma_channel *ch)
 {
-	u32 csr;
 	unsigned long irq_flags;
 
 	spin_lock_irqsave(&ch->lock, irq_flags);
 	while (!list_empty(&ch->list))
 		list_del(ch->list.next);
 
-	csr = readl(ch->addr + APB_DMA_CHAN_CSR);
-	csr &= ~CSR_REQ_SEL_MASK;
-	csr |= CSR_REQ_SEL_INVALID;
-	writel(csr, ch->addr + APB_DMA_CHAN_CSR);
-
 	tegra_dma_stop(ch);
 
 	spin_unlock_irqrestore(&ch->lock, irq_flags);
 	return 0;
 }
 
+static unsigned int get_channel_status(struct tegra_dma_channel *ch,
+			struct tegra_dma_req *req, bool is_stop_dma)
+{
+	void __iomem *addr = IO_ADDRESS(TEGRA_APB_DMA_BASE);
+	unsigned int status;
+
+	if (is_stop_dma) {
+		/*
+		 * STOP the DMA and get the transfer count.
+		 * Getting the transfer count is tricky.
+		 *  - Globally disable DMA on all channels
+		 *  - Read the channel's status register to know the number
+		 *    of pending bytes to be transfered.
+		 *  - Stop the dma channel
+		 *  - Globally re-enable DMA to resume other transfers
+		 */
+		spin_lock(&enable_lock);
+		writel(0, addr + APB_DMA_GEN);
+		udelay(20);
+		status = readl(ch->addr + APB_DMA_CHAN_STA);
+		tegra_dma_stop(ch);
+		writel(GEN_ENABLE, addr + APB_DMA_GEN);
+		spin_unlock(&enable_lock);
+		if (status & STA_ISE_EOC) {
+			pr_err("Got Dma Int here clearing");
+			writel(status, ch->addr + APB_DMA_CHAN_STA);
+		}
+		req->status = TEGRA_DMA_REQ_ERROR_ABORTED;
+	} else {
+		status = readl(ch->addr + APB_DMA_CHAN_STA);
+	}
+	return status;
+}
+
+/* should be called with the channel lock held */
+static unsigned int dma_active_count(struct tegra_dma_channel *ch,
+	struct tegra_dma_req *req, unsigned int status)
+{
+	unsigned int to_transfer;
+	unsigned int req_transfer_count;
+	unsigned int bytes_transferred;
+
+	to_transfer = ((status & STA_COUNT_MASK) >> STA_COUNT_SHIFT) + 1;
+	req_transfer_count = ch->req_transfer_count + 1;
+	bytes_transferred = req_transfer_count;
+	if (status & STA_BUSY)
+		bytes_transferred -= to_transfer;
+	/*
+	 * In continuous transfer mode, DMA only tracks the count of the
+	 * half DMA buffer. So, if the DMA already finished half the DMA
+	 * then add the half buffer to the completed count.
+	 */
+	if (ch->mode & TEGRA_DMA_MODE_CONTINOUS) {
+		if (req->buffer_status == TEGRA_DMA_REQ_BUF_STATUS_HALF_FULL)
+			bytes_transferred += req_transfer_count;
+		if (status & STA_ISE_EOC)
+			bytes_transferred += req_transfer_count;
+	}
+	bytes_transferred *= 4;
+	return bytes_transferred;
+}
+
 int tegra_dma_dequeue_req(struct tegra_dma_channel *ch,
 	struct tegra_dma_req *_req)
 {
-	unsigned int csr;
 	unsigned int status;
 	struct tegra_dma_req *req = NULL;
 	int found = 0;
 	unsigned long irq_flags;
-	int to_transfer;
-	int req_transfer_count;
+	int stop = 0;
 
 	spin_lock_irqsave(&ch->lock, irq_flags);
+
+	if (list_entry(ch->list.next, struct tegra_dma_req, node) == _req)
+		stop = 1;
+
 	list_for_each_entry(req, &ch->list, node) {
 		if (req == _req) {
 			list_del(&req->node);
@@ -222,47 +281,12 @@ int tegra_dma_dequeue_req(struct tegra_dma_channel *ch,
 		return 0;
 	}
 
-	/* STOP the DMA and get the transfer count.
-	 * Getting the transfer count is tricky.
-	 *  - Change the source selector to invalid to stop the DMA from
-	 *    FIFO to memory.
-	 *  - Read the status register to know the number of pending
-	 *    bytes to be transferred.
-	 *  - Finally stop or program the DMA to the next buffer in the
-	 *    list.
-	 */
-	csr = readl(ch->addr + APB_DMA_CHAN_CSR);
-	csr &= ~CSR_REQ_SEL_MASK;
-	csr |= CSR_REQ_SEL_INVALID;
-	writel(csr, ch->addr + APB_DMA_CHAN_CSR);
-
-	/* Get the transfer count */
-	status = readl(ch->addr + APB_DMA_CHAN_STA);
-	to_transfer = (status & STA_COUNT_MASK) >> STA_COUNT_SHIFT;
-	req_transfer_count = ch->req_transfer_count;
-	req_transfer_count += 1;
-	to_transfer += 1;
-
-	req->bytes_transferred = req_transfer_count;
-
-	if (status & STA_BUSY)
-		req->bytes_transferred -= to_transfer;
-
-	/* In continuous transfer mode, DMA only tracks the count of the
-	 * half DMA buffer. So, if the DMA already finished half the DMA
-	 * then add the half buffer to the completed count.
-	 *
-	 *	FIXME: There can be a race here. What if the req to
-	 *	dequue happens at the same time as the DMA just moved to
-	 *	the new buffer and SW didn't yet received the interrupt?
-	 */
-	if (ch->mode & TEGRA_DMA_MODE_CONTINOUS)
-		if (req->buffer_status == TEGRA_DMA_REQ_BUF_STATUS_HALF_FULL)
-			req->bytes_transferred += req_transfer_count;
+	if (!stop)
+		goto skip_stop_dma;
 
-	req->bytes_transferred *= 4;
+	status = get_channel_status(ch, req, true);
+	req->bytes_transferred = dma_active_count(ch, req, status);
 
-	tegra_dma_stop(ch);
 	if (!list_empty(&ch->list)) {
 		/* if the list is not empty, queue the next request */
 		struct tegra_dma_req *next_req;
@@ -270,6 +294,8 @@ int tegra_dma_dequeue_req(struct tegra_dma_channel *ch,
 			typeof(*next_req), node);
 		tegra_dma_update_hw(ch, next_req);
 	}
+
+skip_stop_dma:
 	req->status = -TEGRA_DMA_REQ_ERROR_ABORTED;
 
 	spin_unlock_irqrestore(&ch->lock, irq_flags);
@@ -357,7 +383,7 @@ struct tegra_dma_channel *tegra_dma_allocate_channel(int mode)
 	int channel;
 	struct tegra_dma_channel *ch = NULL;
 
-	if (WARN_ON(!tegra_dma_initialized))
+	if (!tegra_dma_initialized)
 		return NULL;
 
 	mutex_lock(&tegra_dma_lock);