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[kernel] Remove most irq blocking, add early EOI in ne2k driver #237

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[kernel] Remove most irq blocking, add early EOI in ne2k driver #237

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57 changes: 35 additions & 22 deletions tlvc/arch/i86/drivers/net/ne2k-asm.S
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Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,7 @@
//
//-----------------------------------------------------------------------------

#include <linuxmt/config.h>
#include <arch/asm-offsets.h>
#include <linuxmt/netstat.h>
#include "netbuf.h"
Expand Down Expand Up @@ -91,6 +92,7 @@ USE_AUI = ETHF_USE_AUI
.data
.extern current
.extern net_port // io-port base
.extern running_qemu

.global ne2k_next_pk
ne2k_next_pk:
Expand All @@ -107,6 +109,10 @@ ne2k_flags:
ne2k_rx_last: // PSTOP - buffer upper bound
.byte rx_last_16 // default to 16K

.global ne2k_imask
ne2k_imask: // current interrupt mask
.byte

.text

//-----------------------------------------------------------------------------
Expand All @@ -130,7 +136,7 @@ ne2k_addr_set:

// load MAC address

mov net_port,%dx
//mov net_port,%dx // Already set
add $io_ne2k_unicast,%dx
mov $6,%cx
cld
Expand Down Expand Up @@ -199,7 +205,7 @@ dma_write:

inc %cx // make byte count even
and $0xfffe,%cx
cli // Mandatory
//cli // Mandatory
call dma_init

// start DMA write
Expand Down Expand Up @@ -253,7 +259,7 @@ check_dma_w:
//mov $0x40,%al // clear DMA intr bit in ISR
out %al,%dx

sti // Mandatory
//sti // Mandatory
pop %cx
ret

Expand All @@ -276,7 +282,7 @@ dma_read:
inc %cx // make byte count even
and $0xfffe,%cx

cli // Experimental - disable INTR
//cli // Experimental - disable INTR
call dma_init

mov %ds,%bx
Expand Down Expand Up @@ -312,17 +318,18 @@ word_loop:
stosw
loop word_loop
3:
mov net_port,%dx
add $io_ne2k_int_stat,%dx
// PROABLY NOT NEEDED
//mov net_port,%dx
//add $io_ne2k_int_stat,%dx
check_dma_r:
in %dx,%al
test $0x40,%al // dma done?
jz check_dma_r
//in %dx,%al
//test $0x40,%al // dma done?
//jz check_dma_r


mov $0x40,%al // clear ISR (RDC bit only)
out %al,%dx
sti //Experimental - Enable INTR
//sti //Experimental - Enable INTR

pop %bx
pop %es
Expand Down Expand Up @@ -439,13 +446,13 @@ ne2k_pack_get:
//mov %sp,%di

// get the 4 byte header first -> arg3
mov 8(%bp),%di
mov 8(%bp),%di // arg3
mov ne2k_next_pk,%bh
xor %bl,%bl // Next pkt to read in BX

mov $4,%cx // Bytes to read
//mov %ds,%ax
//mov %ax,%es // local address space
//mov %ax,%es // local address space
xor %al,%al // indicate kernel DS
call dma_read

Expand Down Expand Up @@ -484,13 +491,16 @@ ne2k_pack_get:
// Removed when read was changed to put data directly into process address space,
// there is no longer anywhere to put the first 4 bytes.

//sub $252,%cx // Got entire packet?
//jle npg_cont
#if 0
sub $252,%cx // Got entire packet?
jle npg_cont
// If not, get rest.
//inc %bh // Point to next page
//cmp $rx_last,%bh // check wraparound
//jnz npg_cont0
//mov $rx_head,%bh
inc %bh // Point to next page
cmp $rx_last,%bh // check wraparound
jnz npg_cont0
mov $rx_head,%bh
#endif

npg_cont0:
//add $256,%di // Update destination memory address
// (keep the 4 byte NIC header)
Expand All @@ -504,7 +514,6 @@ npg_cont0:
pop %ax

// update RX_get pointer (BOUNDARY, end of ring)

npg_cont:
xchg %al,%ah // get pointer to %al
mov %al,ne2k_next_pk // save 'real' next ptr
Expand Down Expand Up @@ -532,7 +541,7 @@ npg_exit:
movw $0,ne2k_has_data

npg_exit_ok:
sti // Enable interrupts
sti
pop %ax // return byte count (from %cx)
//pop %es
pop %di
Expand Down Expand Up @@ -786,6 +795,7 @@ ne2k_init:
// clear if 16bit.
// That way we get around the QEMU RXE bug too.
1: out %al,%dx
mov %al,ne2k_imask

// NOTE: The transmitter is not yet enabled, done in the _start routine.
// FIXME: Should move the int mask and status reg clearing to
Expand Down Expand Up @@ -1007,6 +1017,9 @@ ne2k_get_hw_addr:
// 001f1102602d49534138455448204242, the last 10 bytes being 'ISA8ETH BB'.
// The BB means it's an 8bit card, WW would indicate 16bit bus support.

// NOTE: This routine is called during PROBE only. Otherwise the call to dma_read
// would need irq protection.

w_reset:
call ne2k_base_init // basic initialization

Expand Down Expand Up @@ -1240,8 +1253,8 @@ ne2k_rdc:

ne2k_get_errstat:

// Currently useful only 4 debugging: Needs a regime to regularly collect
// and accumulate the numbers in order to be of statistical value.
// Currently useful only for debugging: Needs a regime to regularly collect
// and accumulate the numbers in order to be of practical value.
#if LATER
push %bp
mov %si,%bp
Expand Down
52 changes: 28 additions & 24 deletions tlvc/arch/i86/drivers/net/ne2k.c
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Original file line number Diff line number Diff line change
Expand Up @@ -51,9 +51,10 @@ static byte_t dev_name[] = "ne0";
static size_t ne2k_getpkg(char *, size_t, word_t);
struct netbuf *netbuf_init(struct netbuf *, int);

extern int ne2k_next_pk;
extern int ne2k_next_pk;
extern word_t ne2k_flags;
extern word_t ne2k_has_data;
extern byte_t ne2k_imask;
extern struct eth eths[];
extern unsigned char macaddr[];

Expand All @@ -68,7 +69,7 @@ extern unsigned char macaddr[];
#endif

/*
* Read a complete packet from the NIC buffer
* Return a complete packet from buffer or directly from the NIC
*/

static size_t ne2k_read(struct inode *inode, struct file *filp, char *data, size_t len)
Expand Down Expand Up @@ -119,7 +120,7 @@ static size_t ne2k_read(struct inode *inode, struct file *filp, char *data, size

/*
* Get a packet from the NIC.
* May be called from the INTR routine and from read(),
* Called from the INTR routine and from read(),
* thus the semaphore.
*/

Expand Down Expand Up @@ -184,21 +185,21 @@ static size_t ne2k_write(struct inode *inode, struct file *file, char *data, siz
while (1) {
prepare_to_wait_interruptible(&txwait);
/* NOTE: tx_stat() checks the command reg, not the tx_status_reg! */
if (ne2k_tx_stat() != NE2K_STAT_TX) {
if (ne2k_tx_stat() != NE2K_ISR_TX) {
#if NET_BUF_STRAT != NO_BUFS
if (tnext) {
/* transmiter is busy, put the data in a buffer if available */
struct netbuf *nxt = tnext;
while (nxt->len) { /* search for available buffer */
if (nxt == tnext) break;
nxt = nxt->next;
if (nxt == tnext) break;
nxt = nxt->next;
}
if (nxt->len == 0) {
kputchar('t');
nxt->len = len;
verified_memcpy_fromfs(nxt->data, data, len);
res = len;
break;
kputchar('t');
nxt->len = len;
verified_memcpy_fromfs(nxt->data, data, len);
res = len;
break;
}
}
#endif
Expand All @@ -216,8 +217,10 @@ static size_t ne2k_write(struct inode *inode, struct file *file, char *data, siz
/* NIC is ready, send the data, no buffering */
if (len > MAX_PACKET_ETH) len = MAX_PACKET_ETH;

if (len < 64) len = 64; /* issue #133 */
if (len < 64) len = 64; /* issue #133 */
outb(0, net_port + EN0_IMR); /* block interrupts from the NIC while moving data to it */
ne2k_pack_put(data, len, BUF_IS_FAR);
outb(ne2k_imask, net_port + EN0_IMR); /* reenable int's */

res = len;
break;
Expand All @@ -237,7 +240,7 @@ int ne2k_select(struct inode *inode, struct file *filp, int sel_type)

switch (sel_type) {
case SEL_OUT:
if ((ne2k_tx_stat() == NE2K_STAT_TX)
if ((ne2k_tx_stat() == NE2K_ISR_TX)
#if NET_BUF_STRAT != NO_BUFS
|| (tnext && !tnext->len)
#endif
Expand Down Expand Up @@ -280,14 +283,15 @@ static void ne2k_int(int irq, struct pt_regs *regs)
word_t stat, page;

kputchar('I');
outb(0x20,0x20); /* EOI to primary controller */
while (1) {
stat = ne2k_int_stat();
if (!stat) break; /* If zero, we're done! */
#if 0 /* debug */
page = ne2k_getpage();
printk("$%04x.%02x$", page,ne2k_next_pk&0xff);
#endif
if (stat & NE2K_STAT_OF) {
if (stat & NE2K_ISR_OF) {
netif_stat.oflow_errors++;
if (verbose) printk(EMSG_OFLOW, dev_name, stat, netif_stat.oflow_keep);
page = ne2k_clr_oflow(netif_stat.oflow_keep);
Expand All @@ -300,7 +304,7 @@ static void ne2k_int(int irq, struct pt_regs *regs)
break;
}

if (stat & NE2K_STAT_RX) {
if (stat & NE2K_ISR_RX) {
kputchar('i');
ne2k_has_data = 1;
}
Expand All @@ -323,10 +327,10 @@ static void ne2k_int(int irq, struct pt_regs *regs)
}
#endif
wake_up(&rxwait);
outb(NE2K_STAT_RX, net_port + EN0_ISR);
outb(NE2K_ISR_RX, net_port + EN0_ISR);
}

if (stat & NE2K_STAT_TX) {
if (stat & NE2K_ISR_TX) {
kputchar('x');
#if NET_BUF_STRAT != NO_BUFS
if (tnext && tnext->len) {
Expand All @@ -335,16 +339,16 @@ static void ne2k_int(int irq, struct pt_regs *regs)
tnext = tnext->next;
}
#endif
outb(NE2K_STAT_TX, net_port + EN0_ISR); // Clear intr bit
outb(NE2K_ISR_TX, net_port + EN0_ISR); // Clear intr bit
inb(net_port + EN0_TSR); /* really needed? */
wake_up(&txwait);
}
//printk("%02X/%d/", stat, ne2k_has_data);
/* shortcut for speed */
if (!(stat&~(NE2K_STAT_TX|NE2K_STAT_RX|NE2K_STAT_OF))) continue;
if (!(stat&~(NE2K_ISR_TX|NE2K_ISR_RX|NE2K_ISR_OF))) continue;

/* These don't happen very often */
if (stat & NE2K_STAT_RDC) {
if (stat & NE2K_ISR_RDC) {
//printk("ne0: Warning - RDC intr. (0x%02x)\n", stat);
/* RDC interrupts should be masked in the low level driver.
* The dma_read, dma_write routines will fail if the RDC intr
Expand All @@ -356,7 +360,7 @@ static void ne2k_int(int irq, struct pt_regs *regs)
ne2k_rdc();
}

if (stat & NE2K_STAT_TXE) {
if (stat & NE2K_ISR_TXE) {
int k;
/* transmit error detected, this should not happen. */
/* ne2k_get_tx_stat resets this bit in the ISR */
Expand All @@ -369,15 +373,15 @@ static void ne2k_int(int irq, struct pt_regs *regs)
* A bug in QEMU will cause continuous interrupts if RXE intr is unmasked.
* Therefore the asm level code will unmask RXE intr only if the NIC is
* running in 8 bit mode */
if (stat & NE2K_STAT_RXE) {
if (stat & NE2K_ISR_RXE) {
/* Receive error detected, may happen when traffic is heavy */
/* The 8 bit interface gets lots of these, all CRC, packet dropped */
/* Don't do anything, just count, report & clr */
netif_stat.rx_errors++;
if (verbose) printk(EMSG_RXERR, dev_name, inb(net_port + EN0_RSR));
outb(NE2K_STAT_RXE, net_port + EN0_ISR); // Clear intr bit
outb(NE2K_ISR_RXE, net_port + EN0_ISR); // Clear intr bit
}
if (stat & NE2K_STAT_CNT) {
if (stat & NE2K_ISR_CNT) {
/* The tally counters will overflow on 8 bit interfaces with
* lots of overruns. Just clear the condition */
ne2k_clr_err_cnt();
Expand Down
27 changes: 20 additions & 7 deletions tlvc/arch/i86/drivers/net/ne2k.h
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Original file line number Diff line number Diff line change
Expand Up @@ -5,15 +5,26 @@

/* NE2K interrupt status bits */

#define NE2K_STAT_RX 0x0001 /* packet received */
#define NE2K_STAT_TX 0x0002 /* packet sent */
#define NE2K_STAT_RXE 0x0004 /* RX error */
#define NE2K_STAT_TXE 0x0008 /* TX error */
#define NE2K_STAT_OF 0x0010 /* RX ring overflow */
#define NE2K_STAT_CNT 0x0020 /* Tally counter overflow */
#define NE2K_STAT_RDC 0x0040 /* Remote DMA complete */
#define NE2K_ISR_RX 0x0001 /* packet received */
#define NE2K_ISR_TX 0x0002 /* packet sent */
#define NE2K_ISR_RXE 0x0004 /* RX error */
#define NE2K_ISR_TXE 0x0008 /* TX error */
#define NE2K_ISR_OF 0x0010 /* RX ring overflow */
#define NE2K_ISR_CNT 0x0020 /* Tally counter overflow */
#define NE2K_ISR_RDC 0x0040 /* Remote DMA complete */

/* NE2K interrupt mask bits */

#define NE2K_IMR_PRXE 0x0001 /* Packet Received Interrupt Enable */
#define NE2K_IMR_PTXE 0x0002 /* Packet Transmitted Interrupt Enable */
#define NE2K_IMR_RXEE 0x0004 /* Receive Error Interrupt Enable */
#define NE2K_IMR_TXEE 0x0008 /* Transmit Error Interrupt Enable */
#define NE2K_IMR_OVWE 0x0010 /* Overwrite Warning Interrupt Enable */
#define NE2K_IMR_CNTE 0x0020 /* Counter Overflow Interrupt Enable */
#define NE2K_IMR_RDCE 0x0040 /* RDMA Complete Interrupt Enable */

/* 8390 Page 0 register offsets (from net_port) */

#define EN0_STARTPG 0x01U /* Starting page of ring bfr WR */
#define EN0_STOPPG 0x02U /* Ending page +1 of ring bfr WR */
#define EN0_BOUNDARY 0x03U /* Boundary page of ring bfr RD WR */
Expand All @@ -27,6 +38,7 @@
#define EN0_IMR 0x0fU /* Interrupt mask reg WR */

/* From low level NE2K MAC */
#ifndef __ASSEMBLER__

extern word_t ne2k_int_stat();

Expand Down Expand Up @@ -59,5 +71,6 @@ extern void ne2k_rdc(void);
extern void ne2k_get_errstat(byte_t *);
extern void ne2k_clr_err_cnt(void);
extern void ne2k_rx_init(void);
#endif

#endif /* !NE2K_H */