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xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git
commit 0628019c2cb08dce06a128eef162bbe3e9ba0c8b
Author: David Sidrane <david.sidr...@nscdg.com>
AuthorDate: Wed Jul 13 11:01:49 2022 -0700
imxrt:Enet ensure proper dcache for Writeback mode
Use aligned_data
added proper handeling for Writeback
---
arch/arm/src/imxrt/imxrt_enet.c | 112 +++++++++++++++++++++-------------------
1 file changed, 58 insertions(+), 54 deletions(-)
diff --git a/arch/arm/src/imxrt/imxrt_enet.c b/arch/arm/src/imxrt/imxrt_enet.c
index f9d3838939..07f52752a2 100644
--- a/arch/arm/src/imxrt/imxrt_enet.c
+++ b/arch/arm/src/imxrt/imxrt_enet.c
@@ -154,28 +154,6 @@
# error "Need at least one RX buffer"
#endif
-#define NENET_NBUFFERS \
- (CONFIG_IMXRT_ENET_NTXBUFFERS + CONFIG_IMXRT_ENET_NRXBUFFERS)
-
-/* Normally you would clean the cache after writing new values to the DMA
- * memory so assure that the dirty cache lines are flushed to memory
- * before the DMA occurs. And you would invalid the cache after a data is
- * received via DMA so that you fetch the actual content of the data from
- * the cache.
- *
- * These conditions are not fully supported here. If the write-throuch
- * D-Cache is enabled, however, then many of these issues go away: The
- * cache clean operation does nothing (because there are not dirty cache
- * lines) and the cache invalid operation is innocuous (because there are
- * never dirty cache lines to be lost; valid data will always be reloaded).
- *
- * At present, we simply insist that write through cache be enabled.
- */
-
-#if defined(CONFIG_ARMV7M_DCACHE) &&
!defined(CONFIG_ARMV7M_DCACHE_WRITETHROUGH)
-# error Write back D-Cache not yet supported
-#endif
-
/* Align assuming that the D-Cache is enabled (probably 32-bytes).
*
* REVISIT: The size of descriptors and buffers must also be in even units
@@ -190,6 +168,14 @@
#define ENET_ALIGN_MASK (ENET_ALIGN - 1)
#define ENET_ALIGN_UP(n) (((n) + ENET_ALIGN_MASK) & ~ENET_ALIGN_MASK)
+#define DESC_SIZE sizeof(struct enet_desc_s)
+#define DESC_PADSIZE ENET_ALIGN_UP(DESC_SIZE)
+
+#define ALIGNED_BUFSIZE ENET_ALIGN_UP(CONFIG_NET_ETH_PKTSIZE + \
+ CONFIG_NET_GUARDSIZE)
+#define NENET_NBUFFERS \
+ (CONFIG_IMXRT_ENET_NTXBUFFERS + CONFIG_IMXRT_ENET_NRXBUFFERS)
+
/* TX timeout = 1 minute */
#define IMXRT_TXTIMEOUT (60 * CLK_TCK)
@@ -300,9 +286,6 @@
#define BUF ((struct eth_hdr_s *)priv->dev.d_buf)
-#define IMXRT_BUF_SIZE ENET_ALIGN_UP(CONFIG_NET_ETH_PKTSIZE + \
- CONFIG_NET_GUARDSIZE)
-
/****************************************************************************
* Private Types
****************************************************************************/
@@ -331,27 +314,31 @@ struct imxrt_driver_s
struct net_driver_s dev; /* Interface understood by the network */
};
+/* This union type forces the allocated size of TX&RX descriptors to be
+ * padded to a exact multiple of the Cortex-M7 D-Cache line size.
+ */
+
+union enet_desc_u
+{
+ uint8_t pad[DESC_PADSIZE];
+ struct enet_desc_s desc;
+};
+
/****************************************************************************
* Private Data
****************************************************************************/
static struct imxrt_driver_s g_enet[CONFIG_IMXRT_ENET_NETHIFS];
-/* The DMA descriptors. A unaligned uint8_t is used to allocate the
- * memory; 16 is added to assure that we can meet the descriptor alignment
- * requirements.
- */
+/* The DMA descriptors */
-static uint8_t g_desc_pool[NENET_NBUFFERS * sizeof(struct enet_desc_s)]
- aligned_data(ENET_ALIGN);
+static union enet_desc_u g_desc_pool[NENET_NBUFFERS]
+ aligned_data(ENET_ALIGN);
-/* The DMA buffers. Again, A unaligned uint8_t is used to allocate the
- * memory; 16 is added to assure that we can meet the descriptor alignment
- * requirements.
- */
+/* The DMA buffers */
-static uint8_t g_buffer_pool[NENET_NBUFFERS * IMXRT_BUF_SIZE]
- aligned_data(ENET_ALIGN);
+static uint8_t g_buffer_pool[NENET_NBUFFERS][ALIGNED_BUFSIZE]
+ aligned_data(ENET_ALIGN);
/****************************************************************************
* Private Function Prototypes
@@ -359,12 +346,12 @@ static uint8_t g_buffer_pool[NENET_NBUFFERS *
IMXRT_BUF_SIZE]
/* Utility functions */
-static inline uint32_t imxrt_enet_getreg32(FAR struct imxrt_driver_s *priv,
+static inline uint32_t imxrt_enet_getreg32(struct imxrt_driver_s *priv,
uint32_t offset);
-static inline void imxrt_enet_putreg32(FAR struct imxrt_driver_s *priv,
+static inline void imxrt_enet_putreg32(struct imxrt_driver_s *priv,
uint32_t value, uint32_t offset);
-static inline void imxrt_enet_modifyreg32(FAR struct imxrt_driver_s *priv,
+static inline void imxrt_enet_modifyreg32(struct imxrt_driver_s *priv,
unsigned int offset,
uint32_t clearbits,
uint32_t setbits);
@@ -461,8 +448,8 @@ static void imxrt_reset(struct imxrt_driver_s *priv);
*
****************************************************************************/
-static inline uint32_t
-imxrt_enet_getreg32(FAR struct imxrt_driver_s *priv, uint32_t offset)
+static inline uint32_t imxrt_enet_getreg32(struct imxrt_driver_s *priv,
+ uint32_t offset)
{
return getreg32(priv->base + offset);
}
@@ -484,7 +471,7 @@ imxrt_enet_getreg32(FAR struct imxrt_driver_s *priv,
uint32_t offset)
*
****************************************************************************/
-static inline void imxrt_enet_modifyreg32(FAR struct imxrt_driver_s *priv,
+static inline void imxrt_enet_modifyreg32(struct imxrt_driver_s *priv,
unsigned int offset,
uint32_t clearbits,
uint32_t setbits)
@@ -508,7 +495,7 @@ static inline void imxrt_enet_modifyreg32(FAR struct
imxrt_driver_s *priv,
*
****************************************************************************/
-static inline void imxrt_enet_putreg32(FAR struct imxrt_driver_s *priv,
+static inline void imxrt_enet_putreg32(struct imxrt_driver_s *priv,
uint32_t value, uint32_t offset)
{
putreg32(value, priv->base + offset);
@@ -666,18 +653,31 @@ static int imxrt_transmit(struct imxrt_driver_s *priv)
buf = (uint8_t *)imxrt_swap32((uint32_t)priv->dev.d_buf);
+ struct enet_desc_s *rxdesc = &priv->rxdesc[priv->rxtail];
+
+ up_invalidate_dcache((uintptr_t)rxdesc,
+ (uintptr_t)rxdesc + sizeof(struct enet_desc_s));
+
+ if (rxdesc->data == buf)
+ {
/* Data was written into the RX buffer, so swap the TX and RX buffers */
DEBUGASSERT((rxdesc->status1 & RXDESC_E) == 0);
rxdesc->data = txdesc->data;
txdesc->data = buf;
+ up_clean_dcache((uintptr_t)rxdesc,
+ (uintptr_t)rxdesc + sizeof(struct enet_desc_s));
}
else
{
DEBUGASSERT(txdesc->data == buf);
}
- /* Make the following operations atomic */
+ up_clean_dcache((uintptr_t)txdesc,
+ (uintptr_t)txdesc + sizeof(struct enet_desc_s));
+
+ up_clean_dcache((uintptr_t)priv->dev.d_buf,
+ (uintptr_t)priv->dev.d_buf + priv->dev.d_len);
/* Start the TX transfer (if it was not already waiting for buffers) */
@@ -989,6 +989,9 @@ static void imxrt_receive(struct imxrt_driver_s *priv)
imxrt_swap32((uint32_t)priv->txdesc[priv->txhead].data);
rxdesc->status1 |= RXDESC_E;
+ up_clean_dcache((uintptr_t)rxdesc,
+ (uintptr_t)rxdesc + sizeof(struct enet_desc_s));
+
/* Update the index to the next descriptor */
priv->rxtail++;
@@ -1223,8 +1226,8 @@ static void imxrt_enet_interrupt_work(void *arg)
static int imxrt_enet_interrupt(int irq, void *context, void *arg)
{
- register FAR struct imxrt_driver_s *priv =
- (FAR struct imxrt_driver_s *) arg;
+ register struct imxrt_driver_s *priv =
+ (struct imxrt_driver_s *)arg;
/* Disable further Ethernet interrupts. Because Ethernet interrupts are
* also disabled if the TX timeout event occurs, there can be no race
@@ -1393,7 +1396,7 @@ static int imxrt_ifup_action(struct net_driver_s *dev,
bool resetphy)
/* Set the RX buffer size */
- imxrt_enet_putreg32(priv, IMXRT_BUF_SIZE, IMXRT_ENET_MRBR_OFFSET);
+ imxrt_enet_putreg32(priv, ALIGNED_BUFSIZE, IMXRT_ENET_MRBR_OFFSET);
/* Point to the start of the circular RX buffer descriptor queue */
@@ -2419,13 +2422,11 @@ static void imxrt_initbuffers(struct imxrt_driver_s
*priv)
/* Get an aligned TX descriptor (array) address */
- addr = (uintptr_t)g_desc_pool;
- priv->txdesc = (struct enet_desc_s *)addr;
+ priv->txdesc = &g_desc_pool[0].desc;
/* Get an aligned RX descriptor (array) address */
- addr += CONFIG_IMXRT_ENET_NTXBUFFERS * sizeof(struct enet_desc_s);
- priv->rxdesc = (struct enet_desc_s *)addr;
+ priv->rxdesc = &g_desc_pool[CONFIG_IMXRT_ENET_NTXBUFFERS].desc;
/* Get the beginning of the first aligned buffer */
@@ -2441,7 +2442,7 @@ static void imxrt_initbuffers(struct imxrt_driver_s *priv)
#ifdef CONFIG_IMXRT_ENETENHANCEDBD
priv->txdesc[i].status2 = TXDESC_IINS | TXDESC_PINS;
#endif
- addr += IMXRT_BUF_SIZE;
+ addr += ALIGNED_BUFSIZE;
}
/* Then fill in the RX descriptors */
@@ -2455,7 +2456,7 @@ static void imxrt_initbuffers(struct imxrt_driver_s *priv)
priv->rxdesc[i].bdu = 0;
priv->rxdesc[i].status2 = RXDESC_INT;
#endif
- addr += IMXRT_BUF_SIZE;
+ addr += ALIGNED_BUFSIZE;
}
/* Set the wrap bit in the last descriptors to form a ring */
@@ -2463,6 +2464,9 @@ static void imxrt_initbuffers(struct imxrt_driver_s *priv)
priv->txdesc[CONFIG_IMXRT_ENET_NTXBUFFERS - 1].status1 |= TXDESC_W;
priv->rxdesc[CONFIG_IMXRT_ENET_NRXBUFFERS - 1].status1 |= RXDESC_W;
+ up_clean_dcache((uintptr_t)g_desc_pool,
+ (uintptr_t)g_desc_pool + sizeof(g_desc_pool));
+
/* We start with RX descriptor 0 and with no TX descriptors in use */
priv->txtail = 0;
