[PATCH 1/4] net: macb: Add support for PTP timestamps in DMA descriptors

From: Rafal Ozieblo
Date: Thu Apr 13 2017 - 10:11:31 EST

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This patch adds support for PTP timestamps in
DMA buffer descriptors. It checks capability at runtime
and uses appropriate buffer descriptor.

Signed-off-by: Rafal Ozieblo <rafalo@xxxxxxxxxxx>
---
drivers/net/ethernet/cadence/Kconfig | 10 ++-
drivers/net/ethernet/cadence/macb.c | 133 +++++++++++++++++++++++++++--------
drivers/net/ethernet/cadence/macb.h | 36 ++++++++--
3 files changed, 141 insertions(+), 38 deletions(-)

diff --git a/drivers/net/ethernet/cadence/Kconfig b/drivers/net/ethernet/cadence/Kconfig
index 608bea1..427d65a 100644
--- a/drivers/net/ethernet/cadence/Kconfig
+++ b/drivers/net/ethernet/cadence/Kconfig
@@ -29,7 +29,15 @@ config MACB
support for the MACB/GEM chip.

To compile this driver as a module, choose M here: the module
- will be called macb.
+ will be macb.
+
+config MACB_USE_HWSTAMP
+ bool "Use IEEE 1588 hwstamp"
+ depends on MACB
+ default y
+ imply PTP_1588_CLOCK
+ ---help---
+ Enable IEEE 1588 Precision Time Protocol (PTP) support for MACB.

config MACB_PCI
tristate "Cadence PCI MACB/GEM support"
diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index 5cbd1e7..59d459b 100644
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -79,33 +79,84 @@
#define MACB_HALT_TIMEOUT 1230

/* DMA buffer descriptor might be different size
- * depends on hardware configuration.
+ * depends on hardware configuration:
+ *
+ * 1. dma address width 32 bits:
+ * word 1: 32 bit address of Data Buffer
+ * word 2: control
+ *
+ * 2. dma address width 64 bits:
+ * word 1: 32 bit address of Data Buffer
+ * word 2: control
+ * word 3: upper 32 bit address of Data Buffer
+ * word 4: unused
+ *
+ * 3. dma address width 32 bits with hardware timestamping:
+ * word 1: 32 bit address of Data Buffer
+ * word 2: control
+ * word 3: timestamp word 1
+ * word 4: timestamp word 2
+ *
+ * 4. dma address width 64 bits with hardware timestamping:
+ * word 1: 32 bit address of Data Buffer
+ * word 2: control
+ * word 3: upper 32 bit address of Data Buffer
+ * word 4: unused
+ * word 5: timestamp word 1
+ * word 6: timestamp word 2
*/
static unsigned int macb_dma_desc_get_size(struct macb *bp)
{
-#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
- if (bp->hw_dma_cap == HW_DMA_CAP_64B)
- return sizeof(struct macb_dma_desc) + sizeof(struct macb_dma_desc_64);
+#ifdef MACB_EXT_DESC
+ unsigned int desc_size;
+
+ switch (bp->hw_dma_cap) {
+ case HW_DMA_CAP_64B:
+ desc_size = sizeof(struct macb_dma_desc)
+ + sizeof(struct macb_dma_desc_64);
+ break;
+ case HW_DMA_CAP_PTP:
+ desc_size = sizeof(struct macb_dma_desc)
+ + sizeof(struct macb_dma_desc_ptp);
+ break;
+ case HW_DMA_CAP_64B_PTP:
+ desc_size = sizeof(struct macb_dma_desc)
+ + sizeof(struct macb_dma_desc_64)
+ + sizeof(struct macb_dma_desc_ptp);
+ break;
+ default:
+ desc_size = sizeof(struct macb_dma_desc);
+ }
+ return desc_size;
#endif
return sizeof(struct macb_dma_desc);
}

-static unsigned int macb_adj_dma_desc_idx(struct macb *bp, unsigned int idx)
+static unsigned int macb_adj_dma_desc_idx(struct macb *bp, unsigned int desc_idx)
{
-#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
- /* Dma buffer descriptor is 4 words length (instead of 2 words)
- * for 64b GEM.
- */
- if (bp->hw_dma_cap == HW_DMA_CAP_64B)
- idx <<= 1;
+#ifdef MACB_EXT_DESC
+ switch (bp->hw_dma_cap) {
+ case HW_DMA_CAP_64B:
+ case HW_DMA_CAP_PTP:
+ desc_idx <<= 1;
+ break;
+ case HW_DMA_CAP_64B_PTP:
+ desc_idx *= 3;
+ break;
+ default:
+ break;
+ }
+ return desc_idx;
#endif
- return idx;
+ return desc_idx;
}

#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
static struct macb_dma_desc_64 *macb_64b_desc(struct macb *bp, struct macb_dma_desc *desc)
{
- return (struct macb_dma_desc_64 *)((void *)desc + sizeof(struct macb_dma_desc));
+ if (bp->hw_dma_cap & HW_DMA_CAP_64B)
+ return (struct macb_dma_desc_64 *)((void *)desc + sizeof(struct macb_dma_desc));
+ return NULL;
}
#endif

@@ -600,7 +651,7 @@ static void macb_set_addr(struct macb *bp, struct macb_dma_desc *desc, dma_addr_
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
struct macb_dma_desc_64 *desc_64;

- if (bp->hw_dma_cap == HW_DMA_CAP_64B) {
+ if (bp->hw_dma_cap & HW_DMA_CAP_64B) {
desc_64 = macb_64b_desc(bp, desc);
desc_64->addrh = upper_32_bits(addr);
}
@@ -614,7 +665,7 @@ static dma_addr_t macb_get_addr(struct macb *bp, struct macb_dma_desc *desc)
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
struct macb_dma_desc_64 *desc_64;

- if (bp->hw_dma_cap == HW_DMA_CAP_64B) {
+ if (bp->hw_dma_cap & HW_DMA_CAP_64B) {
desc_64 = macb_64b_desc(bp, desc);
addr = ((u64)(desc_64->addrh) << 32);
}
@@ -713,7 +764,7 @@ static void macb_tx_error_task(struct work_struct *work)
/* Reinitialize the TX desc queue */
queue_writel(queue, TBQP, lower_32_bits(queue->tx_ring_dma));
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
- if (bp->hw_dma_cap == HW_DMA_CAP_64B)
+ if (bp->hw_dma_cap & HW_DMA_CAP_64B)
queue_writel(queue, TBQPH, upper_32_bits(queue->tx_ring_dma));
#endif
/* Make TX ring reflect state of hardware */
@@ -1921,9 +1972,13 @@ static void macb_configure_dma(struct macb *bp)
dmacfg &= ~GEM_BIT(TXCOEN);

#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
- if (bp->hw_dma_cap == HW_DMA_CAP_64B)
+ if (bp->hw_dma_cap & HW_DMA_CAP_64B)
dmacfg |= GEM_BIT(ADDR64);
#endif
+#ifdef CONFIG_MACB_USE_HWSTAMP
+ if (bp->hw_dma_cap & HW_DMA_CAP_PTP)
+ dmacfg |= GEM_BIT(RXEXT) | GEM_BIT(TXEXT);
+#endif
netdev_dbg(bp->dev, "Cadence configure DMA with 0x%08x\n",
dmacfg);
gem_writel(bp, DMACFG, dmacfg);
@@ -1971,14 +2026,15 @@ static void macb_init_hw(struct macb *bp)
/* Initialize TX and RX buffers */
macb_writel(bp, RBQP, lower_32_bits(bp->rx_ring_dma));
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
- if (bp->hw_dma_cap == HW_DMA_CAP_64B)
+ if (bp->hw_dma_cap & HW_DMA_CAP_64B)
macb_writel(bp, RBQPH, upper_32_bits(bp->rx_ring_dma));
#endif
for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
queue_writel(queue, TBQP, lower_32_bits(queue->tx_ring_dma));
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
- if (bp->hw_dma_cap == HW_DMA_CAP_64B)
- queue_writel(queue, TBQPH, upper_32_bits(queue->tx_ring_dma));
+ if (bp->hw_dma_cap & HW_DMA_CAP_64B)
+ queue_writel(queue, TBQPH,
+ upper_32_bits(queue->tx_ring_dma));
#endif

/* Enable interrupts */
@@ -2579,6 +2635,18 @@ static void macb_configure_caps(struct macb *bp,
dcfg = gem_readl(bp, DCFG2);
if ((dcfg & (GEM_BIT(RX_PKT_BUFF) | GEM_BIT(TX_PKT_BUFF))) == 0)
bp->caps |= MACB_CAPS_FIFO_MODE;
+ /* if HWSTAMP is configure and gem has the capability */
+#ifdef CONFIG_MACB_USE_HWSTAMP
+ bp->ptp_hw_support = false;
+ if (gem_has_ptp(bp)) {
+ if (!GEM_BFEXT(TSU, gem_readl(bp, DCFG5)))
+ pr_err("GEM doesn't support hardware ptp.\n");
+ else {
+ pr_emerg("rozieblo: ptp_hw_support = true");
+ bp->ptp_hw_support = true;
+ }
+ }
+#endif
}

dev_dbg(&bp->pdev->dev, "Cadence caps 0x%08x\n", bp->caps);
@@ -2716,7 +2784,7 @@ static int macb_init(struct platform_device *pdev)
queue->IMR = GEM_IMR(hw_q - 1);
queue->TBQP = GEM_TBQP(hw_q - 1);
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
- if (bp->hw_dma_cap == HW_DMA_CAP_64B)
+ if (bp->hw_dma_cap & HW_DMA_CAP_64B)
queue->TBQPH = GEM_TBQPH(hw_q - 1);
#endif
} else {
@@ -2727,7 +2795,7 @@ static int macb_init(struct platform_device *pdev)
queue->IMR = MACB_IMR;
queue->TBQP = MACB_TBQP;
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
- if (bp->hw_dma_cap == HW_DMA_CAP_64B)
+ if (bp->hw_dma_cap & HW_DMA_CAP_64B)
queue->TBQPH = MACB_TBQPH;
#endif
}
@@ -3307,19 +3375,24 @@ static int macb_probe(struct platform_device *pdev)
bp->wol |= MACB_WOL_HAS_MAGIC_PACKET;
device_init_wakeup(&pdev->dev, bp->wol & MACB_WOL_HAS_MAGIC_PACKET);

-#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
- if (GEM_BFEXT(DAW64, gem_readl(bp, DCFG6))) {
- dma_set_mask(&pdev->dev, DMA_BIT_MASK(44));
- bp->hw_dma_cap = HW_DMA_CAP_64B;
- } else
- bp->hw_dma_cap = HW_DMA_CAP_32B;
-#endif
-
spin_lock_init(&bp->lock);

/* setup capabilities */
macb_configure_caps(bp, macb_config);

+#ifdef MACB_EXT_DESC
+ bp->hw_dma_cap = HW_DMA_CAP_32B;
+#endif
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ if (GEM_BFEXT(DAW64, gem_readl(bp, DCFG6))) {
+ dma_set_mask(&pdev->dev, DMA_BIT_MASK(44));
+ bp->hw_dma_cap |= HW_DMA_CAP_64B;
+ }
+#endif
+#ifdef CONFIG_MACB_USE_HWSTAMP
+ if (bp->ptp_hw_support)
+ bp->hw_dma_cap |= HW_DMA_CAP_PTP;
+#endif
platform_set_drvdata(pdev, dev);

dev->irq = platform_get_irq(pdev, 0);
diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index ec037b0..2606970 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -12,6 +12,10 @@

#include <linux/phy.h>

+#if defined(CONFIG_ARCH_DMA_ADDR_T_64BIT) || defined(CONFIG_MACB_USE_HWSTAMP)
+#define MACB_EXT_DESC
+#endif
+
#define MACB_GREGS_NBR 16
#define MACB_GREGS_VERSION 2
#define MACB_MAX_QUEUES 8
@@ -269,6 +273,10 @@
#define GEM_RXBS_SIZE 8
#define GEM_DDRP_OFFSET 24 /* disc_when_no_ahb */
#define GEM_DDRP_SIZE 1
+#define GEM_RXEXT_OFFSET 28 /* RX extended Buffer Descriptor mode */
+#define GEM_RXEXT_SIZE 1
+#define GEM_TXEXT_OFFSET 29 /* TX extended Buffer Descriptor mode */
+#define GEM_TXEXT_SIZE 1
#define GEM_ADDR64_OFFSET 30 /* Address bus width - 64b or 32b */
#define GEM_ADDR64_SIZE 1

@@ -425,6 +433,11 @@
#define GEM_TX_PKT_BUFF_OFFSET 21
#define GEM_TX_PKT_BUFF_SIZE 1

+
+/* Bitfields in DCFG5. */
+#define GEM_TSU_OFFSET 8
+#define GEM_TSU_SIZE 1
+
/* Bitfields in DCFG6. */
#define GEM_PBUF_LSO_OFFSET 27
#define GEM_PBUF_LSO_SIZE 1
@@ -546,16 +559,21 @@ struct macb_dma_desc {
u32 ctrl;
};

-#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
-enum macb_hw_dma_cap {
- HW_DMA_CAP_32B,
- HW_DMA_CAP_64B,
-};
+#ifdef MACB_EXT_DESC
+#define HW_DMA_CAP_32B 0
+#define HW_DMA_CAP_64B (1 << 0)
+#define HW_DMA_CAP_PTP (1 << 1)
+#define HW_DMA_CAP_64B_PTP (HW_DMA_CAP_64B | HW_DMA_CAP_PTP)

struct macb_dma_desc_64 {
u32 addrh;
u32 resvd;
};
+
+struct macb_dma_desc_ptp {
+ u32 ts_1;
+ u32 ts_2;
+};
#endif

/* DMA descriptor bitfields */
@@ -954,8 +972,12 @@ struct macb {
u32 wol;

struct macb_ptp_info *ptp_info; /* macb-ptp interface */
-#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
- enum macb_hw_dma_cap hw_dma_cap;
+#ifdef MACB_EXT_DESC
+ uint8_t hw_dma_cap;
+#endif
+
+#ifdef CONFIG_MACB_USE_HWSTAMP
+ bool ptp_hw_support;
#endif
};

--
2.4.5

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