> > If that freaks out the CPM, put one
> > byte of zero into the buffer and give it a count of 1. Then you just have
> > to hold the lock across the update of the BD ptr, just like everywhere else.
>
> That will work, but wont the zero show up on the console? hmm, since
> the zero count will be very unlikely case anyhow, I can live with that.
OK, this patch does the above. I left my test function(err_copy_from_user)
to simulate bad copy_from_user() copies every now and then. Just remove
it and change the call in rs_8xx_write when you have tested it.
Works great for me, not even jove(emacs like editor) will break it.
Jocke
Index: arch/ppc/8xx_io/uart.c
===================================================================
RCS file: /home/cvsadmin/cvsroot/kernel/linuxppc/arch/ppc/8xx_io/uart.c,v
retrieving revision 1.7
diff -u -r1.7 uart.c
--- arch/ppc/8xx_io/uart.c 13 Jun 2003 09:04:43 -0000 1.7
+++ arch/ppc/8xx_io/uart.c 27 Sep 2003 13:29:53 -0000
@@ -81,7 +81,11 @@
#define TX_WAKEUP ASYNC_SHARE_IRQ
static char *serial_name = "CPM UART driver";
-static char *serial_version = "0.03";
+static char *serial_version = "0.04";
+
+/* TX buffer length used by my_console_write.
+ Assume minumun length until it gets set by this driver */
+static int console_tx_buf_len = 1;
static DECLARE_TASK_QUEUE(tq_serial);
@@ -196,6 +200,7 @@
/* The number of buffer descriptors and their sizes.
*/
+#define EARLY_BUF_SIZE 4
#define RX_NUM_FIFO 4
#define RX_BUF_SIZE 32
#define TX_NUM_FIFO 4
@@ -1068,6 +1073,7 @@
ser_info_t *info = (ser_info_t *)tty->driver_data;
volatile cbd_t *bdp;
unsigned char *cp;
+ unsigned long flags;
if (serial_paranoia_check(info, tty->device, "rs_put_char"))
return;
@@ -1075,7 +1081,16 @@
if (!tty)
return;
+ local_irq_save(flags);
bdp = info->tx_cur;
+ /* Get next BD.
+ */
+ if (bdp->cbd_sc & BD_SC_WRAP)
+ info->tx_cur = info->tx_bd_base;
+ else
+ info->tx_cur = (cbd_t *)bdp + 1;
+ local_irq_restore(flags);
+
while (bdp->cbd_sc & BD_SC_READY);
cp = info->tx_va_base + ((bdp - info->tx_bd_base) * TX_BUF_SIZE);
@@ -1083,14 +1098,20 @@
bdp->cbd_datlen = 1;
bdp->cbd_sc |= BD_SC_READY;
- /* Get next BD.
- */
- if (bdp->cbd_sc & BD_SC_WRAP)
- bdp = info->tx_bd_base;
- else
- bdp++;
+}
+int err_copy_from_user(void * to, void* from, int len)
+{
+ static int err;
+ int res;
+
+ err = (err+1)%13;
- info->tx_cur = (cbd_t *)bdp;
+ res = copy_from_user(to, from, len);
+ if(!err && len > 1)
+ return len-1; /* partial copy */
+ if(!err)
+ return len; /* nothing copied */
+ return res;
}
static int rs_8xx_write(struct tty_struct * tty, int from_user,
@@ -1100,6 +1121,7 @@
ser_info_t *info = (ser_info_t *)tty->driver_data;
volatile cbd_t *bdp;
unsigned char *cp;
+ unsigned long flags;
#ifdef CONFIG_KGDB_CONSOLE
/* Try to let stub handle output. Returns true if it did. */
@@ -1113,44 +1135,47 @@
if (!tty)
return 0;
- bdp = info->tx_cur;
-
while (1) {
c = MIN(count, TX_BUF_SIZE);
if (c <= 0)
break;
+ local_irq_save(flags);
+ bdp = info->tx_cur;
if (bdp->cbd_sc & BD_SC_READY) {
info->flags |= TX_WAKEUP;
+ local_irq_restore(flags);
break;
}
+ /* Get next BD.
+ */
+ if (bdp->cbd_sc & BD_SC_WRAP)
+ info->tx_cur = info->tx_bd_base;
+ else
+ info->tx_cur = (cbd_t *)bdp + 1;
+ local_irq_restore(flags);
cp = info->tx_va_base + ((bdp - info->tx_bd_base) *
TX_BUF_SIZE);
- if (from_user) {
- if (copy_from_user((void *)cp, buf, c)) {
- if (!ret)
- ret = -EFAULT;
- break;
- }
- } else {
+ if (from_user)
+ c -= err_copy_from_user((void *)cp, buf, c);
+ else
memcpy((void *)cp, buf, c);
+
+ if (c) {
+ bdp->cbd_datlen = c;
+ bdp->cbd_sc |= BD_SC_READY;
+ } else {
+ bdp->cbd_datlen = 1;/* Need to TX at least 1 char to
keep CPM sane */
+ *cp = 0;
+ bdp->cbd_sc |= BD_SC_READY;
+ if (!ret)
+ ret = -EFAULT;
+ break;
}
-
- bdp->cbd_datlen = c;
- bdp->cbd_sc |= BD_SC_READY;
-
buf += c;
count -= c;
ret += c;
-
- /* Get next BD.
- */
- if (bdp->cbd_sc & BD_SC_WRAP)
- bdp = info->tx_bd_base;
- else
- bdp++;
- info->tx_cur = (cbd_t *)bdp;
}
return ret;
}
@@ -1210,28 +1235,28 @@
{
volatile cbd_t *bdp;
unsigned char *cp;
+ unsigned long flags;
ser_info_t *info = (ser_info_t *)tty->driver_data;
if (serial_paranoia_check(info, tty->device, "rs_send_char"))
return;
+ local_irq_save(flags);
bdp = info->tx_cur;
+ /* Get next BD.
+ */
+ if (bdp->cbd_sc & BD_SC_WRAP)
+ info->tx_cur = info->tx_bd_base;
+ else
+ info->tx_cur = (cbd_t *)bdp + 1;
+ local_irq_restore(flags);
while (bdp->cbd_sc & BD_SC_READY);
cp = info->tx_va_base + ((bdp - info->tx_bd_base) * TX_BUF_SIZE);
*cp = ch;
bdp->cbd_datlen = 1;
bdp->cbd_sc |= BD_SC_READY;
-
- /* Get next BD.
- */
- if (bdp->cbd_sc & BD_SC_WRAP)
- bdp = info->tx_bd_base;
- else
- bdp++;
-
- info->tx_cur = (cbd_t *)bdp;
}
/*
@@ -1802,7 +1827,7 @@
static void rs_8xx_wait_until_sent(struct tty_struct *tty, int timeout)
{
ser_info_t *info = (ser_info_t *)tty->driver_data;
- unsigned long orig_jiffies, char_time;
+ unsigned long orig_jiffies, char_time, tst_res;
/*int lsr;*/
volatile cbd_t *bdp;
@@ -1837,6 +1862,7 @@
* are empty.
*/
do {
+ unsigned long flags;
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("lsr = %d (jiff=%lu)...", lsr, jiffies);
#endif
@@ -1854,12 +1880,15 @@
* is the buffer is available. There are still characters
* in the CPM FIFO.
*/
+ local_irq_save(flags);
bdp = info->tx_cur;
if (bdp == info->tx_bd_base)
bdp += (TX_NUM_FIFO-1);
else
bdp--;
- } while (bdp->cbd_sc & BD_SC_READY);
+ tst_res = !!(bdp->cbd_sc & BD_SC_READY);
+ local_irq_restore(flags);
+ } while (tst_res);
current->state = TASK_RUNNING;
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
@@ -2261,10 +2290,11 @@
{
struct serial_state *ser;
ser_info_t *info;
- unsigned i;
+ unsigned i, c, cr_missing, max_tx_size;
volatile cbd_t *bdp, *bdbase;
volatile smc_uart_t *up;
volatile u_char *cp;
+ unsigned long flags;
ser = rs_table + idx;
@@ -2273,40 +2303,39 @@
* we simply use the single buffer allocated.
*/
if ((info = (ser_info_t *)ser->info) != NULL) {
- bdp = info->tx_cur;
bdbase = info->tx_bd_base;
- }
- else {
- /* Pointer to UART in parameter ram.
- */
+ } else {
+ /* Pointer to UART in parameter ram. */
up = (smc_uart_t *)&cpmp->cp_dparam[ser->port];
-
- /* Get the address of the host memory buffer.
- */
- bdp = bdbase = (cbd_t *)&cpmp->cp_dpmem[up->smc_tbase];
+ /* Get the address of the host memory buffer.*/
info = &consinfo;
+ info->tx_bd_base = (cbd_t *)bdbase = (cbd_t
*)&cpmp->cp_dpmem[up->smc_tbase];
+ info->tx_cur = (cbd_t *)bdbase;
}
+ max_tx_size = console_tx_buf_len;
+ cr_missing = 0;
+ while (1){
+ c = MIN(max_tx_size, count);
+ if (c <= 0)
+ break;
- /*
- * We need to gracefully shut down the transmitter, disable
- * interrupts, then send our bytes out.
- */
-
- /*
- * Now, do each character. This is not as bad as it looks
- * since this is a holding FIFO and not a transmitting FIFO.
- * We could add the complexity of filling the entire transmit
- * buffer, but we would just wait longer between accesses......
- */
- for (i = 0; i < count; i++, s++) {
+ local_irq_save(flags);
+ bdp = info->tx_cur;
+ bdbase = info->tx_bd_base;
+ if (bdp->cbd_sc & BD_SC_WRAP)
+ info->tx_cur = (cbd_t *)bdbase;
+ else
+ info->tx_cur = (cbd_t *)(bdp+1);
+ local_irq_restore(flags);
+
/* Wait for transmitter fifo to empty.
* Ready indicates output is ready, and xmt is doing
* that, not that it is ready for us to send.
*/
while (bdp->cbd_sc & BD_SC_READY);
- /* Send the character out.
+ /* Send the characters out.
* If the buffer address is in the CPM DPRAM, don't
* convert it.
*/
@@ -2314,55 +2343,32 @@
cp = (u_char *)(bdp->cbd_bufaddr);
else
cp = info->tx_va_base + ((bdp - info->tx_bd_base) *
TX_BUF_SIZE);
- *cp = *s;
-
- bdp->cbd_datlen = 1;
- bdp->cbd_sc |= BD_SC_READY;
-
- if (bdp->cbd_sc & BD_SC_WRAP)
- bdp = bdbase;
- else
- bdp++;
-
- /* if a LF, also do CR... */
- if (*s == 10) {
- while (bdp->cbd_sc & BD_SC_READY);
-
- /* This 'if' below will never be true, but a few
- * people argued with me that it was a "bug by
- * inspection" that is was easier to add the code
- * than continue the discussion. The only time
- * the buffer address is in DPRAM is during early
- * use by kgdb/xmon, which format their own packets
- * and we never get here. -- Dan
- */
- if ((uint)(bdp->cbd_bufaddr) > (uint)IMAP_ADDR)
- cp = (u_char *)(bdp->cbd_bufaddr);
- else
- cp = info->tx_va_base + ((bdp -
info->tx_bd_base) * TX_BUF_SIZE);
- *cp = 13;
- bdp->cbd_datlen = 1;
- bdp->cbd_sc |= BD_SC_READY;
- if (bdp->cbd_sc & BD_SC_WRAP) {
- bdp = bdbase;
- }
- else {
- bdp++;
- }
+ i=1; /* Keeps track of consumed TX buffer space */
+ if (cr_missing) {
+ /* Previus loop didn't have room for the CR, insert it
first in this */
+ *cp++ = '\r';
+ i++;
+ }
+ cr_missing = 0;
+ for (; i <= c; i++) {
+ if ((*cp++ = *s++) != '\n')
+ continue; /* Copy bytes until a NewLine is
found */
+ /* NewLine found, see if there is space in the TX
buffer to add a CR */
+ if (i < max_tx_size) {
+ *cp++ = '\r'; /* yes, there is space to add a
CR */
+ i++;
+ } else
+ cr_missing = 1; /* No space in the TX buffer,
+ rember it so it can be
inserted in the next loop */
}
- }
-
- /*
- * Finally, Wait for transmitter & holding register to empty
- * and restore the IER
- */
- while (bdp->cbd_sc & BD_SC_READY);
+ count -= (c-cr_missing);
+ bdp->cbd_datlen = i-1;
+ bdp->cbd_sc |= BD_SC_READY;
- if (info)
- info->tx_cur = (cbd_t *)bdp;
+ }
+ /* while (bdp->cbd_sc & BD_SC_READY); is this really needed? */
}
-
static void serial_console_write(struct console *c, const char *s,
unsigned count)
{
@@ -3003,7 +3009,7 @@
}
}
-
+ console_tx_buf_len = TX_BUF_SIZE;
return 0;
}
@@ -3059,7 +3065,7 @@
* memory yet because vm allocator isn't initialized
* during this early console init.
*/
- dp_addr = m8xx_cpm_dpalloc(8);
+ dp_addr = m8xx_cpm_dpalloc(2*EARLY_BUF_SIZE);
mem_addr = (uint)(&cpmp->cp_dpmem[dp_addr]);
/* Allocate space for two buffer descriptors in the DP ram.
@@ -3073,10 +3079,10 @@
bdp->cbd_bufaddr = iopa(mem_addr);
(bdp+1)->cbd_bufaddr = iopa(mem_addr+4);
- consinfo.rx_va_base = mem_addr;
- consinfo.rx_bd_base = bdp;
- consinfo.tx_va_base = mem_addr + 4;
- consinfo.tx_bd_base = bdp+1;
+ consinfo.rx_va_base = (unsigned char *) mem_addr;
+ consinfo.rx_bd_base = (cbd_t *) bdp;
+ consinfo.tx_va_base = (unsigned char *) (mem_addr + EARLY_BUF_SIZE);
+ consinfo.tx_bd_base = (cbd_t *) (bdp+1);
/* For the receive, set empty and wrap.
* For transmit, set wrap.
@@ -3177,7 +3183,7 @@
/* Set up the baud rate generator.
*/
m8xx_cpm_setbrg((ser - rs_table), bd->bi_baudrate);
-
+ console_tx_buf_len = EARLY_BUF_SIZE;
return 0;
}
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