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SAMA4 EMAC buffer allocation logic

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This commit is contained in:
Gregory Nutt 2013-09-15 14:26:25 -06:00
parent 45e4425687
commit ec03861315
1 changed files with 110 additions and 0 deletions
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110
arch/arm/src/sama5/sam_emac.c
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@ -223,6 +223,10 @@ struct sam_emac_s
/* Used to track transmit and receive descriptors */
uint8_t *rxbuffer; /* Allocated RX buffers */
uint8_t *txbuffer; /* Allocated TX buffers */
struct emac_rxdesc_s *rxdesc; /* Allocated RX descriptors */
struct emac_txdesc_s *txdesc; /* Allocated TX descriptors */
struct emac_txdesc_s *txhead; /* Next available TX descriptor */
struct emac_rxdesc_s *rxhead; /* Next available RX descriptor */
@ -256,8 +260,37 @@ struct sam_emac_s
* Private Data
****************************************************************************/
/* The driver state singleton */
static struct sam_emac_s g_emac;
#ifdef CONFIG_SAMA5_EMAC_PREALLOCATE
/* Preallocated data */
/* TX descriptors list */
static struct emac_txdesc_s g_txdesc[TX_BUFFERS] __attribute__((aligned(8)));
/* RX descriptors list */
static struct emac_rxdesc_s g_rxdesc[RX_BUFFERS]__attribute__((aligned(8)));
/* Transmit Buffers
*
* Section 3.6 of AMBA 2.0 spec states that burst should not cross 1K Boundaries.
* Receive buffer manager writes are burst of 2 words => 3 lsb bits of the address
* shall be set to 0
*/
static uint8_t g_txbuffer[CONFIG_SAMA5_EMAC_NTXBUFFERS * EMAC_TX_UNITSIZE];
__attribute__((aligned(8)))
/* Receive Buffers */
static uint8_t g_rxbuffer[CONFIG_SAMA5_EMAC_NRXBUFFERS * EMAC_RX_UNITSIZE]
__attribute__((aligned(8)));
#endif
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
@ -339,6 +372,7 @@ static int sam_macconfig(FAR struct sam_emac_s *priv);
static void sam_macaddress(FAR struct sam_emac_s *priv);
static int sam_macenable(FAR struct sam_emac_s *priv);
static int sam_ethconfig(FAR struct sam_emac_s *priv);
static int sam_buffer_initialize(struct sam_emac_s *priv);
/****************************************************************************
* Private Functions
@ -2591,6 +2625,82 @@ static int sam_ethconfig(FAR struct sam_emac_s *priv)
return sam_macenable(priv);
}
/****************************************************************************
* Function: sam_buffer_initialize
*
* Description:
* Allocate alligned TX and RX descriptors and buffers. For the case of
* pre-allocated structures, the function degenerates to a few assignements.
*
* Input Parameters:
* priv - The EMAC driver state
*
* Returned Value:
* OK on success; Negated errno on failure.
*
* Assumptions:
* Called very early in the initialization sequence.
*
****************************************************************************/
static int sam_buffer_initialize(struct sam_emac_s *priv)
{
#ifdef CONFIG_SAMA5_EMAC_PREALLOCATE
/* Use pre-allocated buffers */
priv->txdesc = g_txdesc;
priv->rxdesc = g_rxdesc;
priv->txbuffer = g_txbuffer;
priv->rxbuffer = g_rxbuffer;
#else
/* Allocate buffers */
priv->txdesc = (struct emac_txdesc_s *)
kmemalign(8, CONFIG_SAMA5_EMAC_NTXBUFFERS * sizeof(struct emac_txdesc_s));
if (!priv->txdesc)
{
nlldbg("ERROR: Failed to allocate TX descriptors\n");
return -ENOMEM;
}
priv->rxdesc = (struct emac_rxdesc_s *)
kmemalign(8, CONFIG_SAMA5_EMAC_NRXBUFFERS * sizeof(struct emac_rxdesc_s));
if (!priv->txdesc)
{
nlldbg("ERROR: Failed to allocate RX descriptors\n");
kfree(priv->txdesc);
return -ENOMEM;
}
priv->txbuffer = (uint8_t *)
kmemalign(8, CONFIG_SAMA5_GMAC_NTXBUFFERS * GMAC_TX_UNITSIZE);
if (!priv->txbuffer)
{
nlldbg("ERROR: Failed to allocate TX buffer\n");
kfree(priv->txdesc);
kfree(priv->rxdesc);
return -ENOMEM;
}
priv->rxbuffer = (uint8_t *)kmemalign(8, CONFIG_SAMA5_GMAC_NRXBUFFERS * GMAC_RX_UNITSIZE);
if (!priv->rxbuffer)
{
nlldbg("ERROR: Failed to allocate RX buffer\n");
kfree(priv->txdesc);
kfree(priv->rxdesc);
kfree(priv->rxbuffer);
return -ENOMEM;
}
#endif
DEBUGASSERT(((uintptr_t)priv->rxdesc & 7) = 0 &&
((uintptr_t)priv->rxbuffer & 7) = 0 &&
((uintptr_t)priv->txdesc & 7) = 0 &&
((uintptr_t)priv->rxbuffer & 7) = 0 &&
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/