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Commit 286a8372 authored by Giuseppe CAVALLARO's avatar Giuseppe CAVALLARO Committed by David S. Miller
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stmmac: add CHAINED descriptor mode support (V4) 



This patch enhances the STMMAC driver to support CHAINED mode of
descriptor.

STMMAC supports DMA descriptor to operate both in dual buffer(RING)
and linked-list(CHAINED) mode. In RING mode (default) each descriptor
points to two data buffer pointers whereas in CHAINED mode they point
to only one data buffer pointer.

In CHAINED mode each descriptor will have pointer to next descriptor in
the list, hence creating the explicit chaining in the descriptor itself,
whereas such explicit chaining is not possible in RING mode.

First version of this work has been done by Rayagond.
Then the patch has been reworked avoiding ifdef inside the C code.
A new header file has been added to define all the functions needed for
managing enhanced and normal descriptors.
In fact, these have to be specialized according to the ring/chain usage.
Two new C files have been also added to implement the helper routines
needed to manage: jumbo frames, chain and ring setup (i.e. desc3).

Signed-off-by: default avatarRayagond Kokatanur <rayagond@vayavyalabs.com>
Signed-off-by: default avatarGiuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 38fe7a93

drivers/net/ethernet/stmicro/stmmac/Kconfig

+18 −0
Original line number Diff line number Diff line
@@ -63,4 +63,22 @@ config STMMAC_RTC_TIMER 


endchoice



choice

	prompt "Select the DMA TX/RX descriptor operating modes"

	depends on STMMAC_ETH

	---help---

	  This driver supports DMA descriptor to operate both in dual buffer

	  (RING) and linked-list(CHAINED) mode. In RING mode each descriptor

	  points to two data buffer pointers whereas in CHAINED mode they

	  points to only one data buffer pointer.



config STMMAC_RING

	bool "Enable Descriptor Ring Mode"



config STMMAC_CHAINED

	bool "Enable Descriptor Chained Mode"



endchoice





endif

drivers/net/ethernet/stmicro/stmmac/Makefile

+2 −0
Original line number Diff line number Diff line 
obj-$(CONFIG_STMMAC_ETH) += stmmac.o

stmmac-$(CONFIG_STMMAC_TIMER) += stmmac_timer.o

stmmac-$(CONFIG_STMMAC_RING) += ring_mode.o

stmmac-$(CONFIG_STMMAC_CHAINED) += chain_mode.o

stmmac-objs:= stmmac_main.o stmmac_ethtool.o stmmac_mdio.o	\

	      dwmac_lib.o dwmac1000_core.o  dwmac1000_dma.o	\

	      dwmac100_core.o dwmac100_dma.o enh_desc.o  norm_desc.o \

drivers/net/ethernet/stmicro/stmmac/chain_mode.c

0 → 100644
+137 −0
Original line number Diff line number Diff line 
/*******************************************************************************

  Specialised functions for managing Chained mode



  Copyright(C) 2011  STMicroelectronics Ltd



  It defines all the functions used to handle the normal/enhanced

  descriptors in case of the DMA is configured to work in chained or

  in ring mode.



  This program is free software; you can redistribute it and/or modify it

  under the terms and conditions of the GNU General Public License,

  version 2, as published by the Free Software Foundation.



  This program is distributed in the hope it will be useful, but WITHOUT

  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

  more details.



  You should have received a copy of the GNU General Public License along with

  this program; if not, write to the Free Software Foundation, Inc.,

  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.



  The full GNU General Public License is included in this distribution in

  the file called "COPYING".



  Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>

*******************************************************************************/



#include "stmmac.h"



unsigned int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)

{

	struct stmmac_priv *priv = (struct stmmac_priv *) p;

	unsigned int txsize = priv->dma_tx_size;

	unsigned int entry = priv->cur_tx % txsize;

	struct dma_desc *desc = priv->dma_tx + entry;

	unsigned int nopaged_len = skb_headlen(skb);

	unsigned int bmax;

	unsigned int i = 1, len;



	if (priv->plat->enh_desc)

		bmax = BUF_SIZE_8KiB;

	else

		bmax = BUF_SIZE_2KiB;



	len = nopaged_len - bmax;



	desc->des2 = dma_map_single(priv->device, skb->data,

				    bmax, DMA_TO_DEVICE);

	priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum);



	while (len != 0) {

		entry = (++priv->cur_tx) % txsize;

		desc = priv->dma_tx + entry;



		if (len > bmax) {

			desc->des2 = dma_map_single(priv->device,

						    (skb->data + bmax * i),

						    bmax, DMA_TO_DEVICE);

			priv->hw->desc->prepare_tx_desc(desc, 0, bmax,

							csum);

			priv->hw->desc->set_tx_owner(desc);

			priv->tx_skbuff[entry] = NULL;

			len -= bmax;

			i++;

		} else {

			desc->des2 = dma_map_single(priv->device,

						    (skb->data + bmax * i), len,

						    DMA_TO_DEVICE);

			priv->hw->desc->prepare_tx_desc(desc, 0, len,

							csum);

			priv->hw->desc->set_tx_owner(desc);

			priv->tx_skbuff[entry] = NULL;

			len = 0;

		}

	}

	return entry;

}



static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc)

{

	unsigned int ret = 0;



	if ((enh_desc && (len > BUF_SIZE_8KiB)) ||

	    (!enh_desc && (len > BUF_SIZE_2KiB))) {

		ret = 1;

	}



	return ret;

}



static void stmmac_refill_desc3(int bfsize, struct dma_desc *p)

{

}



static void stmmac_init_desc3(int des3_as_data_buf, struct dma_desc *p)

{

}



static void stmmac_clean_desc3(struct dma_desc *p)

{

}



static void stmmac_init_dma_chain(struct dma_desc *des, dma_addr_t phy_addr,

				  unsigned int size)

{

	/*

	 * In chained mode the des3 points to the next element in the ring.

	 * The latest element has to point to the head.

	 */

	int i;

	struct dma_desc *p = des;

	dma_addr_t dma_phy = phy_addr;



	for (i = 0; i < (size - 1); i++) {

		dma_phy += sizeof(struct dma_desc);

		p->des3 = (unsigned int)dma_phy;

		p++;

	}

	p->des3 = (unsigned int)phy_addr;

}



static int stmmac_set_16kib_bfsize(int mtu)

{

	/* Not supported */

	return 0;

}



const struct stmmac_ring_mode_ops ring_mode_ops = {

	.is_jumbo_frm = stmmac_is_jumbo_frm,

	.jumbo_frm = stmmac_jumbo_frm,

	.refill_desc3 = stmmac_refill_desc3,

	.init_desc3 = stmmac_init_desc3,

	.init_dma_chain = stmmac_init_dma_chain,

	.clean_desc3 = stmmac_clean_desc3,

	.set_16kib_bfsize = stmmac_set_16kib_bfsize,

};

drivers/net/ethernet/stmicro/stmmac/common.h

+13 −0
Original line number Diff line number Diff line
@@ -287,10 +287,22 @@ struct mii_regs { 
	unsigned int data;	/* MII Data */

};



struct stmmac_ring_mode_ops {

	unsigned int (*is_jumbo_frm) (int len, int ehn_desc);

	unsigned int (*jumbo_frm) (void *priv, struct sk_buff *skb, int csum);

	void (*refill_desc3) (int bfsize, struct dma_desc *p);

	void (*init_desc3) (int des3_as_data_buf, struct dma_desc *p);

	void (*init_dma_chain) (struct dma_desc *des, dma_addr_t phy_addr,

				unsigned int size);

	void (*clean_desc3) (struct dma_desc *p);

	int (*set_16kib_bfsize) (int mtu);

};



struct mac_device_info {

	const struct stmmac_ops		*mac;

	const struct stmmac_desc_ops	*desc;

	const struct stmmac_dma_ops	*dma;

	const struct stmmac_ring_mode_ops	*ring;

	struct mii_regs mii;	/* MII register Addresses */

	struct mac_link link;

	unsigned int synopsys_uid;
@@ -304,3 +316,4 @@ extern void stmmac_set_mac_addr(void __iomem *ioaddr, u8 addr[6], 
extern void stmmac_get_mac_addr(void __iomem *ioaddr, unsigned char *addr,

				unsigned int high, unsigned int low);

extern void dwmac_dma_flush_tx_fifo(void __iomem *ioaddr);

extern const struct stmmac_ring_mode_ops ring_mode_ops;

drivers/net/ethernet/stmicro/stmmac/descs_com.h

0 → 100644
+126 −0
Original line number Diff line number Diff line 
/*******************************************************************************

  Header File to describe Normal/enhanced descriptor functions used for RING

  and CHAINED modes.



  Copyright(C) 2011  STMicroelectronics Ltd



  It defines all the functions used to handle the normal/enhanced

  descriptors in case of the DMA is configured to work in chained or

  in ring mode.



  This program is free software; you can redistribute it and/or modify it

  under the terms and conditions of the GNU General Public License,

  version 2, as published by the Free Software Foundation.



  This program is distributed in the hope it will be useful, but WITHOUT

  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

  more details.



  You should have received a copy of the GNU General Public License along with

  this program; if not, write to the Free Software Foundation, Inc.,

  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.



  The full GNU General Public License is included in this distribution in

  the file called "COPYING".



  Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>

*******************************************************************************/



#if defined(CONFIG_STMMAC_RING)

static inline void ehn_desc_rx_set_on_ring_chain(struct dma_desc *p, int end)

{

	p->des01.erx.buffer2_size = BUF_SIZE_8KiB - 1;

	if (end)

		p->des01.erx.end_ring = 1;

}



static inline void ehn_desc_tx_set_on_ring_chain(struct dma_desc *p, int end)

{

	if (end)

		p->des01.etx.end_ring = 1;

}



static inline void enh_desc_end_tx_desc(struct dma_desc *p, int ter)

{

	p->des01.etx.end_ring = ter;

}



static inline void enh_set_tx_desc_len(struct dma_desc *p, int len)

{

	if (unlikely(len > BUF_SIZE_4KiB)) {

		p->des01.etx.buffer1_size = BUF_SIZE_4KiB;

		p->des01.etx.buffer2_size = len - BUF_SIZE_4KiB;

	} else

		p->des01.etx.buffer1_size = len;

}



static inline void ndesc_rx_set_on_ring_chain(struct dma_desc *p, int end)

{

	p->des01.rx.buffer2_size = BUF_SIZE_2KiB - 1;

	if (end)

		p->des01.rx.end_ring = 1;

}



static inline void ndesc_tx_set_on_ring_chain(struct dma_desc *p, int end)

{

	if (end)

		p->des01.tx.end_ring = 1;

}



static inline void ndesc_end_tx_desc(struct dma_desc *p, int ter)

{

	p->des01.tx.end_ring = ter;

}



static inline void norm_set_tx_desc_len(struct dma_desc *p, int len)

{

	if (unlikely(len > BUF_SIZE_2KiB)) {

		p->des01.etx.buffer1_size = BUF_SIZE_2KiB - 1;

		p->des01.etx.buffer2_size = len - p->des01.etx.buffer1_size;

	} else

		p->des01.tx.buffer1_size = len;

}



#else



static inline void ehn_desc_rx_set_on_ring_chain(struct dma_desc *p, int end)

{

	p->des01.erx.second_address_chained = 1;

}



static inline void ehn_desc_tx_set_on_ring_chain(struct dma_desc *p, int end)

{

	p->des01.etx.second_address_chained = 1;

}



static inline void enh_desc_end_tx_desc(struct dma_desc *p, int ter)

{

	p->des01.etx.second_address_chained = 1;

}



static inline void enh_set_tx_desc_len(struct dma_desc *p, int len)

{

	p->des01.etx.buffer1_size = len;

}



static inline void ndesc_rx_set_on_ring_chain(struct dma_desc *p, int end)

{

	p->des01.rx.second_address_chained = 1;

}



static inline void ndesc_tx_set_on_ring_chain(struct dma_desc *p, int ring_size)

{

	p->des01.tx.second_address_chained = 1;

}



static inline void ndesc_end_tx_desc(struct dma_desc *p, int ter)

{

	p->des01.tx.second_address_chained = 1;

}



static inline void norm_set_tx_desc_len(struct dma_desc *p, int len)

{

	p->des01.tx.buffer1_size = len;

}

#endif