[PATCH net-next 0/2] net: bcmgenet: Interrupt coalescing

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* [PATCH net-next 0/2] net: bcmgenet: Interrupt coalescing
@ 2015-09-16 23:47 Florian Fainelli
  2015-09-16 23:47 ` [PATCH net-next 1/2] net: bcmgenet: Implement TX coalescing control knobs Florian Fainelli
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Florian Fainelli @ 2015-09-16 23:47 UTC (permalink / raw)
  To: netdev; +Cc: Florian Fainelli, davem, jaedon.shin, pgynther

Hi David, Petri, Jaedon,

This patch series adds support for interrupt coalescing for GENET adapters.

Florian Fainelli (2):
  net: bcmgenet: Implement TX coalescing control knobs
  net: bcmgenet: Implement RX coalescing control knobs

 drivers/net/ethernet/broadcom/genet/bcmgenet.c | 150 +++++++++++++++++++++++++
 drivers/net/ethernet/broadcom/genet/bcmgenet.h |   9 +-
 2 files changed, 154 insertions(+), 5 deletions(-)

-- 
2.1.0

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH net-next 1/2] net: bcmgenet: Implement TX coalescing control knobs
  2015-09-16 23:47 [PATCH net-next 0/2] net: bcmgenet: Interrupt coalescing Florian Fainelli
@ 2015-09-16 23:47 ` Florian Fainelli
  2015-09-16 23:47 ` [PATCH net-next 2/2] net: bcmgenet: Implement RX " Florian Fainelli
  2015-09-18  5:19 ` [PATCH net-next 0/2] net: bcmgenet: Interrupt coalescing David Miller
  2 siblings, 0 replies; 6+ messages in thread
From: Florian Fainelli @ 2015-09-16 23:47 UTC (permalink / raw)
  To: netdev; +Cc: Florian Fainelli, davem, jaedon.shin, pgynther

Configuring the ethtool tx-frames property, which translates into N
packets before a TX interrupt is the simplest configuration scheme
because it requires no locking neither at the softare nor hardware
level, and is completely indepedent from the link speed. Since ethtool
does not allow per-tx queue coalescing parameters, we apply the same
setting to any transmit queue.

We can no longer enable the BDONE/PDONE interrupts as those would fire
for each packet/buffer received, which would defeat the MBDONE interrupt
purpose. The MBDONE interrupt is guaranteed to correspond to a
PDONE/BDONE interrupt when the threshold is set to 1, but offers
interrupt coalescing when the value is > 1.

Since the HW is configured to generate an interrupt when the ring
becomes emtpy, we have to deny any timeout/timer settings coming from
user-space to indicate we can only generate an interrupt very <N>
packets.

While we are at it, fix the DMA_INTR_THRESHOLD_MASK value which was off
by one bit (0xff vs. 0x1ff).

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/ethernet/broadcom/genet/bcmgenet.c | 47 ++++++++++++++++++++++++++
 drivers/net/ethernet/broadcom/genet/bcmgenet.h |  6 ++--
 2 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index fadbd0088d3e..5e247c7b379e 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -498,6 +498,51 @@ static void bcmgenet_set_msglevel(struct net_device *dev, u32 level)
 	priv->msg_enable = level;
 }
 
+static int bcmgenet_get_coalesce(struct net_device *dev,
+				 struct ethtool_coalesce *ec)
+{
+	struct bcmgenet_priv *priv = netdev_priv(dev);
+
+	ec->tx_max_coalesced_frames =
+		bcmgenet_tdma_ring_readl(priv, DESC_INDEX,
+					 DMA_MBUF_DONE_THRESH);
+
+	return 0;
+}
+
+static int bcmgenet_set_coalesce(struct net_device *dev,
+				 struct ethtool_coalesce *ec)
+{
+	struct bcmgenet_priv *priv = netdev_priv(dev);
+	unsigned int i;
+
+	if (ec->tx_max_coalesced_frames > DMA_INTR_THRESHOLD_MASK ||
+	    ec->tx_max_coalesced_frames == 0)
+		return -EINVAL;
+
+	/* GENET TDMA hardware does not support a configurable timeout, but will
+	 * always generate an interrupt either after MBDONE packets have been
+	 * transmitted, or when the ring is emtpy.
+	 */
+	if (ec->tx_coalesce_usecs || ec->tx_coalesce_usecs_high ||
+	    ec->tx_coalesce_usecs_irq || ec->tx_coalesce_usecs_high ||
+	    ec->tx_coalesce_usecs_low)
+		return -EOPNOTSUPP;
+
+	/* Program all TX queues with the same values, as there is no
+	 * ethtool knob to do coalescing on a per-queue basis
+	 */
+	for (i = 0; i < priv->hw_params->tx_queues; i++)
+		bcmgenet_tdma_ring_writel(priv, i,
+					  ec->tx_max_coalesced_frames,
+					  DMA_MBUF_DONE_THRESH);
+	bcmgenet_tdma_ring_writel(priv, DESC_INDEX,
+				  ec->tx_max_coalesced_frames,
+				  DMA_MBUF_DONE_THRESH);
+
+	return 0;
+}
+
 /* standard ethtool support functions. */
 enum bcmgenet_stat_type {
 	BCMGENET_STAT_NETDEV = -1,
@@ -844,6 +889,8 @@ static struct ethtool_ops bcmgenet_ethtool_ops = {
 	.get_eee		= bcmgenet_get_eee,
 	.set_eee		= bcmgenet_set_eee,
 	.nway_reset		= bcmgenet_nway_reset,
+	.get_coalesce		= bcmgenet_get_coalesce,
+	.set_coalesce		= bcmgenet_set_coalesce,
 };
 
 /* Power down the unimac, based on mode. */
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
index 7299d1075422..ef7829524d46 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
@@ -309,8 +309,8 @@ struct bcmgenet_mib_counters {
 #define UMAC_IRQ_TXDMA_MBDONE		(1 << 16)
 #define UMAC_IRQ_TXDMA_PDONE		(1 << 17)
 #define UMAC_IRQ_TXDMA_BDONE		(1 << 18)
-#define UMAC_IRQ_TXDMA_DONE		(UMAC_IRQ_TXDMA_PDONE | \
-					 UMAC_IRQ_TXDMA_BDONE)
+#define UMAC_IRQ_TXDMA_DONE		UMAC_IRQ_TXDMA_MBDONE
+
 /* Only valid for GENETv3+ */
 #define UMAC_IRQ_MDIO_DONE		(1 << 23)
 #define UMAC_IRQ_MDIO_ERROR		(1 << 24)
@@ -386,7 +386,7 @@ struct bcmgenet_mib_counters {
 #define DMA_RING_BUFFER_SIZE_MASK	0xFFFF
 
 /* DMA interrupt threshold register */
-#define DMA_INTR_THRESHOLD_MASK		0x00FF
+#define DMA_INTR_THRESHOLD_MASK		0x01FF
 
 /* DMA XON/XOFF register */
 #define DMA_XON_THREHOLD_MASK		0xFFFF
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH net-next 2/2] net: bcmgenet: Implement RX coalescing control knobs
  2015-09-16 23:47 [PATCH net-next 0/2] net: bcmgenet: Interrupt coalescing Florian Fainelli
  2015-09-16 23:47 ` [PATCH net-next 1/2] net: bcmgenet: Implement TX coalescing control knobs Florian Fainelli
@ 2015-09-16 23:47 ` Florian Fainelli
  2015-09-17 17:58   ` Florian Fainelli
  2015-09-18  5:19 ` [PATCH net-next 0/2] net: bcmgenet: Interrupt coalescing David Miller
  2 siblings, 1 reply; 6+ messages in thread
From: Florian Fainelli @ 2015-09-16 23:47 UTC (permalink / raw)
  To: netdev; +Cc: Florian Fainelli, davem, jaedon.shin, pgynther

Add support for the ethtool rx-frames coalescing parameter which allows
defining the number of RX interrupts per frames received. The RDMA
engine supports a configurable timeout with a resolution of
approximately 8.192 us.

We can no longer enable the BDONE/PDONE interrupts as those would
fire for each packet/buffer received, which would defeat the MBDONE
interrupt purpose. The MBDONE interrupt is guaranteed to correspond to a
PDONE/BDONE interrupt when the threshold is set to 1.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/ethernet/broadcom/genet/bcmgenet.c | 105 ++++++++++++++++++++++++-
 drivers/net/ethernet/broadcom/genet/bcmgenet.h |   3 +-
 2 files changed, 105 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 5e247c7b379e..1e72722abbf1 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -205,6 +205,23 @@ enum dma_reg {
 	DMA_INDEX2RING_5,
 	DMA_INDEX2RING_6,
 	DMA_INDEX2RING_7,
+	DMA_RING0_TIMEOUT,
+	DMA_RING1_TIMEOUT,
+	DMA_RING2_TIMEOUT,
+	DMA_RING3_TIMEOUT,
+	DMA_RING4_TIMEOUT,
+	DMA_RING5_TIMEOUT,
+	DMA_RING6_TIMEOUT,
+	DMA_RING7_TIMEOUT,
+	DMA_RING8_TIMEOUT,
+	DMA_RING9_TIMEOUT,
+	DMA_RING10_TIMEOUT,
+	DMA_RING11_TIMEOUT,
+	DMA_RING12_TIMEOUT,
+	DMA_RING13_TIMEOUT,
+	DMA_RING14_TIMEOUT,
+	DMA_RING15_TIMEOUT,
+	DMA_RING16_TIMEOUT,
 };
 
 static const u8 bcmgenet_dma_regs_v3plus[] = {
@@ -216,6 +233,23 @@ static const u8 bcmgenet_dma_regs_v3plus[] = {
 	[DMA_PRIORITY_0]	= 0x30,
 	[DMA_PRIORITY_1]	= 0x34,
 	[DMA_PRIORITY_2]	= 0x38,
+	[DMA_RING0_TIMEOUT]	= 0x2C,
+	[DMA_RING1_TIMEOUT]	= 0x30,
+	[DMA_RING2_TIMEOUT]	= 0x34,
+	[DMA_RING3_TIMEOUT]	= 0x38,
+	[DMA_RING4_TIMEOUT]	= 0x3c,
+	[DMA_RING5_TIMEOUT]	= 0x40,
+	[DMA_RING6_TIMEOUT]	= 0x44,
+	[DMA_RING7_TIMEOUT]	= 0x48,
+	[DMA_RING8_TIMEOUT]	= 0x4c,
+	[DMA_RING9_TIMEOUT]	= 0x50,
+	[DMA_RING10_TIMEOUT]	= 0x54,
+	[DMA_RING11_TIMEOUT]	= 0x58,
+	[DMA_RING12_TIMEOUT]	= 0x5c,
+	[DMA_RING13_TIMEOUT]	= 0x60,
+	[DMA_RING14_TIMEOUT]	= 0x64,
+	[DMA_RING15_TIMEOUT]	= 0x68,
+	[DMA_RING16_TIMEOUT]	= 0x6C,
 	[DMA_INDEX2RING_0]	= 0x70,
 	[DMA_INDEX2RING_1]	= 0x74,
 	[DMA_INDEX2RING_2]	= 0x78,
@@ -235,6 +269,23 @@ static const u8 bcmgenet_dma_regs_v2[] = {
 	[DMA_PRIORITY_0]	= 0x34,
 	[DMA_PRIORITY_1]	= 0x38,
 	[DMA_PRIORITY_2]	= 0x3C,
+	[DMA_RING0_TIMEOUT]	= 0x2C,
+	[DMA_RING1_TIMEOUT]	= 0x30,
+	[DMA_RING2_TIMEOUT]	= 0x34,
+	[DMA_RING3_TIMEOUT]	= 0x38,
+	[DMA_RING4_TIMEOUT]	= 0x3c,
+	[DMA_RING5_TIMEOUT]	= 0x40,
+	[DMA_RING6_TIMEOUT]	= 0x44,
+	[DMA_RING7_TIMEOUT]	= 0x48,
+	[DMA_RING8_TIMEOUT]	= 0x4c,
+	[DMA_RING9_TIMEOUT]	= 0x50,
+	[DMA_RING10_TIMEOUT]	= 0x54,
+	[DMA_RING11_TIMEOUT]	= 0x58,
+	[DMA_RING12_TIMEOUT]	= 0x5c,
+	[DMA_RING13_TIMEOUT]	= 0x60,
+	[DMA_RING14_TIMEOUT]	= 0x64,
+	[DMA_RING15_TIMEOUT]	= 0x68,
+	[DMA_RING16_TIMEOUT]	= 0x6C,
 };
 
 static const u8 bcmgenet_dma_regs_v1[] = {
@@ -245,6 +296,23 @@ static const u8 bcmgenet_dma_regs_v1[] = {
 	[DMA_PRIORITY_0]	= 0x34,
 	[DMA_PRIORITY_1]	= 0x38,
 	[DMA_PRIORITY_2]	= 0x3C,
+	[DMA_RING0_TIMEOUT]	= 0x2C,
+	[DMA_RING1_TIMEOUT]	= 0x30,
+	[DMA_RING2_TIMEOUT]	= 0x34,
+	[DMA_RING3_TIMEOUT]	= 0x38,
+	[DMA_RING4_TIMEOUT]	= 0x3c,
+	[DMA_RING5_TIMEOUT]	= 0x40,
+	[DMA_RING6_TIMEOUT]	= 0x44,
+	[DMA_RING7_TIMEOUT]	= 0x48,
+	[DMA_RING8_TIMEOUT]	= 0x4c,
+	[DMA_RING9_TIMEOUT]	= 0x50,
+	[DMA_RING10_TIMEOUT]	= 0x54,
+	[DMA_RING11_TIMEOUT]	= 0x58,
+	[DMA_RING12_TIMEOUT]	= 0x5c,
+	[DMA_RING13_TIMEOUT]	= 0x60,
+	[DMA_RING14_TIMEOUT]	= 0x64,
+	[DMA_RING15_TIMEOUT]	= 0x68,
+	[DMA_RING16_TIMEOUT]	= 0x6C,
 };
 
 /* Set at runtime once bcmgenet version is known */
@@ -506,6 +574,11 @@ static int bcmgenet_get_coalesce(struct net_device *dev,
 	ec->tx_max_coalesced_frames =
 		bcmgenet_tdma_ring_readl(priv, DESC_INDEX,
 					 DMA_MBUF_DONE_THRESH);
+	ec->rx_max_coalesced_frames =
+		bcmgenet_rdma_ring_readl(priv, DESC_INDEX,
+					 DMA_MBUF_DONE_THRESH);
+	ec->rx_coalesce_usecs =
+		bcmgenet_rdma_readl(priv, DMA_RING16_TIMEOUT) * 8192 / 1000;
 
 	return 0;
 }
@@ -515,9 +588,19 @@ static int bcmgenet_set_coalesce(struct net_device *dev,
 {
 	struct bcmgenet_priv *priv = netdev_priv(dev);
 	unsigned int i;
+	u32 reg;
 
+	/* Base system clock is 125Mhz, DMA timeout is this reference clock
+	 * divided by 1024, which yields roughly 8.192us, our maximum value
+	 * has to fit in the DMA_TIMEOUT_MASK (16 bits)
+	 */
 	if (ec->tx_max_coalesced_frames > DMA_INTR_THRESHOLD_MASK ||
-	    ec->tx_max_coalesced_frames == 0)
+	    ec->tx_max_coalesced_frames == 0 ||
+	    ec->rx_max_coalesced_frames > DMA_INTR_THRESHOLD_MASK ||
+	    ec->rx_coalesce_usecs > (DMA_TIMEOUT_MASK * 8) + 1)
+		return -EINVAL;
+
+	if (ec->rx_coalesce_usecs == 0 && ec->rx_max_coalesced_frames == 0)
 		return -EINVAL;
 
 	/* GENET TDMA hardware does not support a configurable timeout, but will
@@ -540,6 +623,26 @@ static int bcmgenet_set_coalesce(struct net_device *dev,
 				  ec->tx_max_coalesced_frames,
 				  DMA_MBUF_DONE_THRESH);
 
+	for (i = 0; i < priv->hw_params->rx_queues; i++) {
+		bcmgenet_rdma_ring_writel(priv, i,
+					  ec->rx_max_coalesced_frames,
+					  DMA_MBUF_DONE_THRESH);
+
+		reg = bcmgenet_rdma_readl(priv, DMA_RING0_TIMEOUT + i);
+		reg &= ~DMA_TIMEOUT_MASK;
+		reg |= DIV_ROUND_UP(ec->rx_coalesce_usecs * 1000, 8192);
+		bcmgenet_rdma_writel(priv, reg, DMA_RING0_TIMEOUT + i);
+	}
+
+	bcmgenet_rdma_ring_writel(priv, DESC_INDEX,
+				  ec->rx_max_coalesced_frames,
+				  DMA_MBUF_DONE_THRESH);
+
+	reg = bcmgenet_rdma_readl(priv, DMA_RING16_TIMEOUT);
+	reg &= ~DMA_TIMEOUT_MASK;
+	reg |= DIV_ROUND_UP(ec->rx_coalesce_usecs * 1000, 8192);
+	bcmgenet_rdma_writel(priv, reg, DMA_RING16_TIMEOUT);
+
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
index ef7829524d46..29dc2f1bbb19 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
@@ -304,8 +304,7 @@ struct bcmgenet_mib_counters {
 #define UMAC_IRQ_RXDMA_MBDONE		(1 << 13)
 #define UMAC_IRQ_RXDMA_PDONE		(1 << 14)
 #define UMAC_IRQ_RXDMA_BDONE		(1 << 15)
-#define UMAC_IRQ_RXDMA_DONE		(UMAC_IRQ_RXDMA_PDONE | \
-					 UMAC_IRQ_RXDMA_BDONE)
+#define UMAC_IRQ_RXDMA_DONE		UMAC_IRQ_RXDMA_MBDONE
 #define UMAC_IRQ_TXDMA_MBDONE		(1 << 16)
 #define UMAC_IRQ_TXDMA_PDONE		(1 << 17)
 #define UMAC_IRQ_TXDMA_BDONE		(1 << 18)
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH net-next 2/2] net: bcmgenet: Implement RX coalescing control knobs
  2015-09-16 23:47 ` [PATCH net-next 2/2] net: bcmgenet: Implement RX " Florian Fainelli
@ 2015-09-17 17:58   ` Florian Fainelli
  2015-09-17 18:18     ` Florian Fainelli
  0 siblings, 1 reply; 6+ messages in thread
From: Florian Fainelli @ 2015-09-17 17:58 UTC (permalink / raw)
  To: netdev; +Cc: davem, jaedon.shin, pgynther

On 16/09/15 16:47, Florian Fainelli wrote:
> Add support for the ethtool rx-frames coalescing parameter which allows
> defining the number of RX interrupts per frames received. The RDMA
> engine supports a configurable timeout with a resolution of
> approximately 8.192 us.
> 
> We can no longer enable the BDONE/PDONE interrupts as those would
> fire for each packet/buffer received, which would defeat the MBDONE
> interrupt purpose. The MBDONE interrupt is guaranteed to correspond to a
> PDONE/BDONE interrupt when the threshold is set to 1.

*sigh*, I missed the initialization of the INTR_THRESHOLD register, so
right now, we just have no interrupts configured properly for RX, will
re-submit shortly.

Meanwhile, please send feedback if you have any, thanks!
-- 
Florian

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH net-next 2/2] net: bcmgenet: Implement RX coalescing control knobs
  2015-09-17 17:58   ` Florian Fainelli
@ 2015-09-17 18:18     ` Florian Fainelli
  0 siblings, 0 replies; 6+ messages in thread
From: Florian Fainelli @ 2015-09-17 18:18 UTC (permalink / raw)
  To: netdev; +Cc: davem, jaedon.shin, pgynther

On 17/09/15 10:58, Florian Fainelli wrote:
> On 16/09/15 16:47, Florian Fainelli wrote:
>> Add support for the ethtool rx-frames coalescing parameter which allows
>> defining the number of RX interrupts per frames received. The RDMA
>> engine supports a configurable timeout with a resolution of
>> approximately 8.192 us.
>>
>> We can no longer enable the BDONE/PDONE interrupts as those would
>> fire for each packet/buffer received, which would defeat the MBDONE
>> interrupt purpose. The MBDONE interrupt is guaranteed to correspond to a
>> PDONE/BDONE interrupt when the threshold is set to 1.
> 
> *sigh*, I missed the initialization of the INTR_THRESHOLD register, so
> right now, we just have no interrupts configured properly for RX, will
> re-submit shortly.
> 
> Meanwhile, please send feedback if you have any, thanks!
> 

Actually, no that version of the patch is just fine, since we already
programmed the DMA_MBUF_DONE_THRESH since commit
6f5a272c99108d9f8450c454a4baede9e7cc643f (" net: bcmgenet: rework Rx
queue init")

Sorry about the noise, -ENOCOFFEE.
-- 
Florian

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH net-next 0/2] net: bcmgenet: Interrupt coalescing
  2015-09-16 23:47 [PATCH net-next 0/2] net: bcmgenet: Interrupt coalescing Florian Fainelli
  2015-09-16 23:47 ` [PATCH net-next 1/2] net: bcmgenet: Implement TX coalescing control knobs Florian Fainelli
  2015-09-16 23:47 ` [PATCH net-next 2/2] net: bcmgenet: Implement RX " Florian Fainelli
@ 2015-09-18  5:19 ` David Miller
  2 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2015-09-18  5:19 UTC (permalink / raw)
  To: f.fainelli; +Cc: netdev, jaedon.shin, pgynther

From: Florian Fainelli <f.fainelli@gmail.com>
Date: Wed, 16 Sep 2015 16:47:38 -0700

> This patch series adds support for interrupt coalescing for GENET
> adapters.

Series applied, thanks.

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2015-09-18  5:19 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2015-09-16 23:47 [PATCH net-next 0/2] net: bcmgenet: Interrupt coalescing Florian Fainelli
2015-09-16 23:47 ` [PATCH net-next 1/2] net: bcmgenet: Implement TX coalescing control knobs Florian Fainelli
2015-09-16 23:47 ` [PATCH net-next 2/2] net: bcmgenet: Implement RX " Florian Fainelli
2015-09-17 17:58   ` Florian Fainelli
2015-09-17 18:18     ` Florian Fainelli
2015-09-18  5:19 ` [PATCH net-next 0/2] net: bcmgenet: Interrupt coalescing David Miller

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