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// SPDX-License-Identifier: GPL-2.0-only
/*
* sgiseeq.c: Seeq8003 ethernet driver for SGI machines.
*
* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
*/
#undef DEBUG
#include <linux/dma-mapping.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/platform_device.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <asm/sgi/hpc3.h>
#include <asm/sgi/ip22.h>
#include <asm/sgi/seeq.h>
#include "sgiseeq.h"
static char *sgiseeqstr = "SGI Seeq8003";
/*
* If you want speed, you do something silly, it always has worked for me. So,
* with that in mind, I've decided to make this driver look completely like a
* stupid Lance from a driver architecture perspective. Only difference is that
* here our "ring buffer" looks and acts like a real Lance one does but is
* laid out like how the HPC DMA and the Seeq want it to. You'd be surprised
* how a stupid idea like this can pay off in performance, not to mention
* making this driver 2,000 times easier to write. ;-)
*/
/* Tune these if we tend to run out often etc. */
#define SEEQ_RX_BUFFERS 16
#define SEEQ_TX_BUFFERS 16
#define PKT_BUF_SZ 1584
#define NEXT_RX(i) (((i) + 1) & (SEEQ_RX_BUFFERS - 1))
#define NEXT_TX(i) (((i) + 1) & (SEEQ_TX_BUFFERS - 1))
#define PREV_RX(i) (((i) - 1) & (SEEQ_RX_BUFFERS - 1))
#define PREV_TX(i) (((i) - 1) & (SEEQ_TX_BUFFERS - 1))
#define TX_BUFFS_AVAIL(sp) ((sp->tx_old <= sp->tx_new) ? \
sp->tx_old + (SEEQ_TX_BUFFERS - 1) - sp->tx_new : \
sp->tx_old - sp->tx_new - 1)
#define VIRT_TO_DMA(sp, v) ((sp)->srings_dma + \
(dma_addr_t)((unsigned long)(v) - \
(unsigned long)((sp)->rx_desc)))
/* Copy frames shorter than rx_copybreak, otherwise pass on up in
* a full sized sk_buff. Value of 100 stolen from tulip.c (!alpha).
*/
static int rx_copybreak = 100;
#define PAD_SIZE (128 - sizeof(struct hpc_dma_desc) - sizeof(void *))
struct sgiseeq_rx_desc {
volatile struct hpc_dma_desc rdma;
u8 padding[PAD_SIZE];
struct sk_buff *skb;
};
struct sgiseeq_tx_desc {
volatile struct hpc_dma_desc tdma;
u8 padding[PAD_SIZE];
struct sk_buff *skb;
};
/*
* Warning: This structure is laid out in a certain way because HPC dma
* descriptors must be 8-byte aligned. So don't touch this without
* some care.
*/
struct sgiseeq_init_block { /* Note the name ;-) */
struct sgiseeq_rx_desc rxvector[SEEQ_RX_BUFFERS];
struct sgiseeq_tx_desc txvector[SEEQ_TX_BUFFERS];
};
struct sgiseeq_private {
struct sgiseeq_init_block *srings;
dma_addr_t srings_dma;
/* Ptrs to the descriptors in uncached space. */
struct sgiseeq_rx_desc *rx_desc;
struct sgiseeq_tx_desc *tx_desc;
char *name;
struct hpc3_ethregs *hregs;
struct sgiseeq_regs *sregs;
/* Ring entry counters. */
unsigned int rx_new, tx_new;
unsigned int rx_old, tx_old;
int is_edlc;
unsigned char control;
unsigned char mode;
spinlock_t tx_lock;
};
static inline void dma_sync_desc_cpu(struct net_device *dev, void *addr)
{
dma_cache_sync(dev->dev.parent, addr, sizeof(struct sgiseeq_rx_desc),
DMA_FROM_DEVICE);
}
static inline void dma_sync_desc_dev(struct net_device *dev, void *addr)
{
dma_cache_sync(dev->dev.parent, addr, sizeof(struct sgiseeq_rx_desc),
DMA_TO_DEVICE);
}
static inline void hpc3_eth_reset(struct hpc3_ethregs *hregs)
{
hregs->reset = HPC3_ERST_CRESET | HPC3_ERST_CLRIRQ;
udelay(20);
hregs->reset = 0;
}
static inline void reset_hpc3_and_seeq(struct hpc3_ethregs *hregs,
struct sgiseeq_regs *sregs)
{
hregs->rx_ctrl = hregs->tx_ctrl = 0;
hpc3_eth_reset(hregs);
}
#define RSTAT_GO_BITS (SEEQ_RCMD_IGOOD | SEEQ_RCMD_IEOF | SEEQ_RCMD_ISHORT | \
SEEQ_RCMD_IDRIB | SEEQ_RCMD_ICRC)
static inline void seeq_go(struct sgiseeq_private *sp,
struct hpc3_ethregs *hregs,
struct sgiseeq_regs *sregs)
{
sregs->rstat = sp->mode | RSTAT_GO_BITS;
hregs->rx_ctrl = HPC3_ERXCTRL_ACTIVE;
}
static inline void __sgiseeq_set_mac_address(struct net_device *dev)
{
struct sgiseeq_private *sp = netdev_priv(dev);
struct sgiseeq_regs *sregs = sp->sregs;
int i;
sregs->tstat = SEEQ_TCMD_RB0;
for (i = 0; i < 6; i++)
sregs->rw.eth_addr[i] = dev->dev_addr[i];
}
static int sgiseeq_set_mac_address(struct net_device *dev, void *addr)
{
struct sgiseeq_private *sp = netdev_priv(dev);
struct sockaddr *sa = addr;
memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
spin_lock_irq(&sp->tx_lock);
__sgiseeq_set_mac_address(dev);
spin_unlock_irq(&sp->tx_lock);
return 0;
}
#define TCNTINFO_INIT (HPCDMA_EOX | HPCDMA_ETXD)
#define RCNTCFG_INIT (HPCDMA_OWN | HPCDMA_EORP | HPCDMA_XIE)
#define RCNTINFO_INIT (RCNTCFG_INIT | (PKT_BUF_SZ & HPCDMA_BCNT))
static int seeq_init_ring(struct net_device *dev)
{
struct sgiseeq_private *sp = netdev_priv(dev);
int i;
netif_stop_queue(dev);
sp->rx_new = sp->tx_new = 0;
sp->rx_old = sp->tx_old = 0;
__sgiseeq_set_mac_address(dev);
/* Setup tx ring. */
for(i = 0; i < SEEQ_TX_BUFFERS; i++) {
sp->tx_desc[i].tdma.cntinfo = TCNTINFO_INIT;
dma_sync_desc_dev(dev, &sp->tx_desc[i]);
}
/* And now the rx ring. */
for (i = 0; i < SEEQ_RX_BUFFERS; i++) {
if (!sp->rx_desc[i].skb) {
dma_addr_t dma_addr;
struct sk_buff *skb = netdev_alloc_skb(dev, PKT_BUF_SZ);
if (skb == NULL)
return -ENOMEM;
skb_reserve(skb, 2);
dma_addr = dma_map_single(dev->dev.parent,
skb->
|