[PATCH 0/7] ppc: remove cli()/sti() from arch/ppc/*

[PATCH 0/7] ppc: remove cli()/sti() from arch/ppc/*

[James Nelson]

This series of patches is to remove the last cli()/sti() function calls in arch/ppc.

These are the only instances in active code that grep could find.

[PATCH 1/7] ppc: remove cli()/sti() in arch/ppc/4xx_io/serial_sicc.c

[James Nelson]

Signed-off-by: James Nelson <james4765@gmail.com>

diff -urN --exclude='*~' linux-2.6.10-mm1-original/arch/ppc/4xx_io/serial_sicc.c linux-2.6.10-mm1/arch/ppc/4xx_io/serial_sicc.c
--- linux-2.6.10-mm1-original/arch/ppc/4xx_io/serial_sicc.c	2004-12-24 16:33:49.000000000 -0500
+++ linux-2.6.10-mm1/arch/ppc/4xx_io/serial_sicc.c	2005-01-03 19:55:54.048289892 -0500
@@ -385,9 +385,9 @@
     struct SICC_info *info = tty->driver_data;
     unsigned long flags;
 
-    save_flags(flags); cli();
+    local_irq_save(flags);
     siccuart_disable_tx_interrupt(info);
-    restore_flags(flags);
+    local_irq_restore(flags);
 }
 
 static void siccuart_start(struct tty_struct *tty)
@@ -395,11 +395,11 @@
     struct SICC_info *info = tty->driver_data;
     unsigned long flags;
 
-    save_flags(flags); cli();
+    local_irq_save(flags);
     if (info->xmit.head != info->xmit.tail
         && info->xmit.buf)
         siccuart_enable_tx_interrupt(info);
-    restore_flags(flags);
+    local_irq_restore(flags);
 }
 
 
@@ -604,7 +604,7 @@
 	return -ENOMEM;
     }
 
-    save_flags(flags); cli();
+    local_irq_save(flags);
 
     if (info->xmit.buf)
         free_page(page);
@@ -688,12 +688,12 @@
     siccuart_enable_rx_interrupt(info);
 
     info->flags |= ASYNC_INITIALIZED;
-    restore_flags(flags);
+    local_irq_restore(flags);
     return 0;
 
 
 errout:
-    restore_flags(flags);
+    local_irq_restore(flags);
     return retval;
 }
 
@@ -708,7 +708,7 @@
     if (!(info->flags & ASYNC_INITIALIZED))
         return;
 
-    save_flags(flags); cli(); /* Disable interrupts */
+    local_irq_save(flags); /* Disable interrupts */
 
     /*
      * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
@@ -746,7 +746,7 @@
 
     info->flags &= ~ASYNC_INITIALIZED;
 
-    restore_flags(flags);
+    local_irq_restore(flags);
 }
 
 
@@ -869,7 +869,7 @@
     }
 
     /* first, disable everything */
-    save_flags(flags); cli();
+    local_irq_save(flags);
 
     old_rcr = readb(info->port->uart_base + BL_SICC_RCR);
     old_tcr = readb(info->port->uart_base + BL_SICC_TxCR);
@@ -881,7 +881,7 @@
     /*RLBtrace (&ppc403Chan0, 0x2000000c, 0, 0);*/
 
 
-    restore_flags(flags);
+    local_irq_restore(flags);
 
 
     /* Set baud rate */
@@ -909,12 +909,12 @@
     if (!tty || !info->xmit.buf)
         return;
 
-    save_flags(flags); cli();
+    local_irq_save(flags);
     if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SICC_XMIT_SIZE) != 0) {
         info->xmit.buf[info->xmit.head] = ch;
         info->xmit.head = (info->xmit.head + 1) & (SICC_XMIT_SIZE - 1);
     }
-    restore_flags(flags);
+    local_irq_restore(flags);
 }
 
 static void siccuart_flush_chars(struct tty_struct *tty)
@@ -928,9 +928,9 @@
         || !info->xmit.buf)
         return;
 
-    save_flags(flags); cli();
+    local_irq_save(flags);
     siccuart_enable_tx_interrupt(info);
-    restore_flags(flags);
+    local_irq_restore(flags);
 }
 
 static int siccuart_write(struct tty_struct *tty,
@@ -943,8 +943,7 @@
     if (!tty || !info->xmit.buf || !tmp_buf)
         return 0;
 
-    save_flags(flags);
-    cli();
+    local_irq_save(flags);
     while (1) {
         c = CIRC_SPACE_TO_END(info->xmit.head,
                       info->xmit.tail,
@@ -960,7 +959,7 @@
         count -= c;
         ret += c;
     }
-    restore_flags(flags);
+    local_irq_restore(flags);
     if (info->xmit.head != info->xmit.tail
         && !tty->stopped
         && !tty->hw_stopped)
@@ -988,9 +987,9 @@
     unsigned long flags;
 
     pr_debug("siccuart_flush_buffer(%d) called\n", tty->index);
-    save_flags(flags); cli();
+    local_irq_save(flags);
     info->xmit.head = info->xmit.tail = 0;
-    restore_flags(flags);
+    local_irq_restore(flags);
     wake_up_interruptible(&tty->write_wait);
     if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
         tty->ldisc.write_wakeup)
@@ -1019,10 +1018,10 @@
         siccuart_send_xchar(tty, STOP_CHAR(tty));
 
     if (tty->termios->c_cflag & CRTSCTS) {
-        save_flags(flags); cli();
+        local_irq_save(flags);
         info->mctrl &= ~TIOCM_RTS;
         info->port->set_mctrl(info->port, info->mctrl);
-        restore_flags(flags);
+        local_irq_restore(flags);
     }
 }
 
@@ -1039,10 +1038,10 @@
     }
 
     if (tty->termios->c_cflag & CRTSCTS) {
-        save_flags(flags); cli();
+        local_irq_save(flags);
         info->mctrl |= TIOCM_RTS;
         info->port->set_mctrl(info->port, info->mctrl);
-        restore_flags(flags);
+        local_irq_restore(flags);
     }
 }
 
@@ -1181,9 +1180,9 @@
     unsigned int result, status;
     unsigned long flags;
 
-    save_flags(flags); cli();
+    local_irq_save(flags);
     status = readb(info->port->uart_base +  BL_SICC_LSR);
-    restore_flags(flags);
+    local_irq_restore(flags);
     result = status & _LSR_TSR_EMPTY ? TIOCSER_TEMT : 0;
 
     /*
@@ -1234,10 +1233,10 @@
     default:
         return -EINVAL;
     }
-    save_flags(flags); cli();
+    local_irq_save(flags);
     if (old != info->mctrl)
         info->port->set_mctrl(info->port, info->mctrl);
-    restore_flags(flags);
+    local_irq_restore(flags);
     return 0;
 }
 
@@ -1248,14 +1247,14 @@
     unsigned int lcr_h;
 
 
-    save_flags(flags); cli();
+    local_irq_save(flags);
     lcr_h = readb(info->port + BL_SICC_LSR);
     if (break_state == -1)
         lcr_h |=  _LSR_LB_MASK;
     else
         lcr_h &= ~_LSR_LB_MASK;
     writeb(lcr_h, info->port + BL_SICC_LSRS);
-    restore_flags(flags);
+    local_irq_restore(flags);
 }
 
 static int siccuart_ioctl(struct tty_struct *tty, struct file *file,
@@ -1303,9 +1302,9 @@
          *     RI where only 0->1 is counted.
          */
         case TIOCGICOUNT:
-            save_flags(flags); cli();
+            local_irq_save(flags);
             cnow = info->state->icount;
-            restore_flags(flags);
+            local_irq_restore(flags);
             icount.cts = cnow.cts;
             icount.dsr = cnow.dsr;
             icount.rng = cnow.rng;
@@ -1342,22 +1341,22 @@
     /* Handle transition to B0 status */
     if ((old_termios->c_cflag & CBAUD) &&
         !(cflag & CBAUD)) {
-        save_flags(flags); cli();
+        local_irq_save(flags);
         info->mctrl &= ~(TIOCM_RTS | TIOCM_DTR);
         info->port->set_mctrl(info->port, info->mctrl);
-        restore_flags(flags);
+        local_irq_restore(flags);
     }
 
     /* Handle transition away from B0 status */
     if (!(old_termios->c_cflag & CBAUD) &&
         (cflag & CBAUD)) {
-        save_flags(flags); cli();
+        local_irq_save(flags);
         info->mctrl |= TIOCM_DTR;
         if (!(cflag & CRTSCTS) ||
             !test_bit(TTY_THROTTLED, &tty->flags))
             info->mctrl |= TIOCM_RTS;
         info->port->set_mctrl(info->port, info->mctrl);
-        restore_flags(flags);
+        local_irq_restore(flags);
     }
 
     /* Handle turning off CRTSCTS */
@@ -1393,10 +1392,10 @@
 
     //pr_debug("siccuart_close() called\n");
 
-    save_flags(flags); cli();
+    local_irq_save(flags);
 
     if (tty_hung_up_p(filp)) {
-        restore_flags(flags);
+        local_irq_restore(flags);
         return;
     }
 
@@ -1416,11 +1415,11 @@
         state->count = 0;
     }
     if (state->count) {
-        restore_flags(flags);
+        local_irq_restore(flags);
         return;
     }
     info->flags |= ASYNC_CLOSING;
-    restore_flags(flags);
+    local_irq_restore(flags);
     /*
      * Now we wait for the transmit buffer to clear; and we notify
      * the line discipline to only process XON/XOFF characters.
@@ -1569,20 +1568,20 @@
      */
     retval = 0;
     add_wait_queue(&info->open_wait, &wait);
-    save_flags(flags); cli();
+    local_irq_save(flags);
     if (!tty_hung_up_p(filp)) {
         extra_count = 1;
         state->count--;
     }
-    restore_flags(flags);
+    local_irq_restore(flags);
     info->blocked_open++;
     while (1) {
-        save_flags(flags); cli();
+        local_irq_save(flags);
         if (tty->termios->c_cflag & CBAUD) {
             info->mctrl = TIOCM_DTR | TIOCM_RTS;
             info->port->set_mctrl(info->port, info->mctrl);
         }
-        restore_flags(flags);
+        local_irq_restore(flags);
         set_current_state(TASK_INTERRUPTIBLE);
         if (tty_hung_up_p(filp) ||
             !(info->flags & ASYNC_INITIALIZED)) {

[PATCH 2/7] ppc: remove cli()/sti() in arch/ppc/8xx_io/cs4218_tdm.c

[James Nelson]

Signed-off-by: James Nelson <james4765@gmail.com>

diff -urN --exclude='*~' linux-2.6.10-mm1-original/arch/ppc/8xx_io/cs4218_tdm.c linux-2.6.10-mm1/arch/ppc/8xx_io/cs4218_tdm.c
--- linux-2.6.10-mm1-original/arch/ppc/8xx_io/cs4218_tdm.c	2004-12-24 16:33:51.000000000 -0500
+++ linux-2.6.10-mm1/arch/ppc/8xx_io/cs4218_tdm.c	2005-01-03 19:58:01.881032015 -0500
@@ -1206,7 +1206,7 @@
 	volatile cbd_t	*bdp;
 	volatile cpm8xx_t *cp;
 
-	save_flags(flags); cli();
+	local_irq_save(flags);
 #if 0
 	if (awacs_beep_state) {
 		/* sound takes precedence over beeps */
@@ -1263,7 +1263,7 @@
 
 		++sq.active;
 	}
-	restore_flags(flags);
+	local_irq_restore(flags);
 }
 
 
@@ -1275,7 +1275,7 @@
 	if (read_sq.active)
 		return;
 
-	save_flags(flags); cli();
+	local_irq_save(flags);
 
 	/* This is all we have to do......Just start it up.
 	*/
@@ -1284,7 +1284,7 @@
 
 	read_sq.active = 1;
 
-        restore_flags(flags);
+        local_irq_restore(flags);
 }
 
 
@@ -1365,14 +1365,14 @@
 {
 	unsigned long flags;
 
-	save_flags(flags); cli();
+	local_irq_save(flags);
 	if (beep_playing) {
 #if 0
 		st_le16(&beep_dbdma_cmd->command, DBDMA_STOP);
 #endif
 		beep_playing = 0;
 	}
-	restore_flags(flags);
+	local_irq_restore(flags);
 }
 
 static struct timer_list beep_timer = TIMER_INITIALIZER(cs_nosound, 0, 0);
@@ -1401,21 +1401,21 @@
 		return;
 #endif
 	}
-	save_flags(flags); cli();
+	local_irq_save(flags);
 	del_timer(&beep_timer);
 	if (ticks) {
 		beep_timer.expires = jiffies + ticks;
 		add_timer(&beep_timer);
 	}
 	if (beep_playing || sq.active || beep_buf == NULL) {
-		restore_flags(flags);
+		local_irq_restore(flags);
 		return;		/* too hard, sorry :-( */
 	}
 	beep_playing = 1;
 #if 0
 	st_le16(&beep_dbdma_cmd->command, OUTPUT_MORE + BR_ALWAYS);
 #endif
-	restore_flags(flags);
+	local_irq_restore(flags);
 
 	if (hz == beep_hz_cache && beep_volume == beep_volume_cache) {
 		nsamples = beep_nsamples_cache;
@@ -1442,7 +1442,7 @@
 	st_le32(&beep_dbdma_cmd->phy_addr, virt_to_bus(beep_buf));
 	awacs_beep_state = 1;
 
-	save_flags(flags); cli();
+	local_irq_save(flags);
 	if (beep_playing) {	/* i.e. haven't been terminated already */
 		out_le32(&awacs_txdma->control, (RUN|WAKE|FLUSH|PAUSE) << 16);
 		out_le32(&awacs->control,
@@ -1453,7 +1453,7 @@
 		out_le32(&awacs_txdma->control, RUN | (RUN << 16));
 	}
 #endif
-	restore_flags(flags);
+	local_irq_restore(flags);
 }
 
 static MACHINE mach_cs4218 = {

[PATCH 3/7] ppc: remove cli()/sti() in arch/ppc/8xx_io/fec.c

[James Nelson]

Signed-off-by: James Nelson <james4765@gmail.com>

diff -urN --exclude='*~' linux-2.6.10-mm1-original/arch/ppc/8xx_io/fec.c linux-2.6.10-mm1/arch/ppc/8xx_io/fec.c
--- linux-2.6.10-mm1-original/arch/ppc/8xx_io/fec.c	2004-12-24 16:35:28.000000000 -0500
+++ linux-2.6.10-mm1/arch/ppc/8xx_io/fec.c	2005-01-03 19:59:15.827049038 -0500
@@ -817,8 +817,7 @@
 
 	retval = 0;
 
-	save_flags(flags);
-	cli();
+	local_irq_save(flags);
 
 	if ((mip = mii_free) != NULL) {
 		mii_free = mip->mii_next;
@@ -836,7 +835,7 @@
 		retval = 1;
 	}
 
-	restore_flags(flags);
+	local_irq_restore(flags);
 
 	return(retval);
 }

[PATCH 4/7] ppc: remove cli()/sti() in arch/ppc/platforms/apus_setup.c

[James Nelson]

Signed-off-by: James Nelson <james4765@gmail.com>

diff -urN --exclude='*~' linux-2.6.10-mm1-original/arch/ppc/platforms/apus_setup.c linux-2.6.10-mm1/arch/ppc/platforms/apus_setup.c
--- linux-2.6.10-mm1-original/arch/ppc/platforms/apus_setup.c	2004-12-24 16:34:58.000000000 -0500
+++ linux-2.6.10-mm1/arch/ppc/platforms/apus_setup.c	2005-01-03 19:29:40.720694742 -0500
@@ -480,7 +480,7 @@
 void
 apus_restart(char *cmd)
 {
-	cli();
+	local_irq_disable();
 
 	APUS_WRITE(APUS_REG_LOCK,
 		   REGLOCK_BLACKMAGICK1|REGLOCK_BLACKMAGICK2);

[PATCH 5/7] ppc: remove cli()/sti() in arch/ppc/platforms/pal4_setup.c

[James Nelson]

Signed-off-by: James Nelson <james4765@gmail.com>

diff -urN --exclude='*~' linux-2.6.10-mm1-original/arch/ppc/platforms/pal4_setup.c linux-2.6.10-mm1/arch/ppc/platforms/pal4_setup.c
--- linux-2.6.10-mm1-original/arch/ppc/platforms/pal4_setup.c	2004-12-24 16:35:28.000000000 -0500
+++ linux-2.6.10-mm1/arch/ppc/platforms/pal4_setup.c	2005-01-03 19:49:42.123501068 -0500
@@ -81,7 +81,7 @@
 static void
 pal4_restart(char *cmd)
 {
-        __cli();
+        local_irq_disable();
         __asm__ __volatile__("lis  3,0xfff0\n \
                               ori  3,3,0x100\n \
                               mtspr 26,3\n \
@@ -95,7 +95,7 @@
 static void
 pal4_power_off(void)
 {
-	__cli();
+	local_irq_disable();
 	for(;;);
 }
 

[PATCH 6/7] ppc: remove cli()/sti() in arch/ppc/syslib/m8xx_setup.c

[James Nelson]

Signed-off-by: James Nelson <james4765@gmail.com>

diff -urN --exclude='*~' linux-2.6.10-mm1-original/arch/ppc/syslib/m8xx_setup.c linux-2.6.10-mm1/arch/ppc/syslib/m8xx_setup.c
--- linux-2.6.10-mm1-original/arch/ppc/syslib/m8xx_setup.c	2004-12-24 16:34:32.000000000 -0500
+++ linux-2.6.10-mm1/arch/ppc/syslib/m8xx_setup.c	2005-01-03 19:26:53.224307353 -0500
@@ -238,7 +238,7 @@
 {
 	__volatile__ unsigned char dummy;
 
-	cli();
+	local_irq_disable();
 	((immap_t *)IMAP_ADDR)->im_clkrst.car_plprcr |= 0x00000080;
 
 	/* Clear the ME bit in MSR to cause checkstop on machine check

[PATCH 7/7] ppc: remove cli()/sti() in arch/ppc/syslib/qspan_pci.c

[James Nelson]

Signed-off-by: James Nelson <james4765@gmail.com>

diff -urN --exclude='*~' linux-2.6.10-mm1-original/arch/ppc/syslib/qspan_pci.c linux-2.6.10-mm1/arch/ppc/syslib/qspan_pci.c
--- linux-2.6.10-mm1-original/arch/ppc/syslib/qspan_pci.c	2004-12-24 16:34:26.000000000 -0500
+++ linux-2.6.10-mm1/arch/ppc/syslib/qspan_pci.c	2005-01-03 19:13:30.256710849 -0500
@@ -109,8 +109,7 @@
 	}
 
 #ifdef CONFIG_RPXCLASSIC
-	save_flags(flags);
-	cli();
+	local_irq_save(flags);
 	*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
 	eieio();
 #endif
@@ -124,7 +123,7 @@
 #ifdef CONFIG_RPXCLASSIC
 	*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
 	eieio();
-	restore_flags(flags);
+	local_irq_restore(flags);
 #endif
 
 	offset ^= 0x03;
@@ -148,8 +147,7 @@
 	}
 
 #ifdef CONFIG_RPXCLASSIC
-	save_flags(flags);
-	cli();
+	local_irq_save(flags);
 	*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
 	eieio();
 #endif
@@ -164,7 +162,7 @@
 #ifdef CONFIG_RPXCLASSIC
 	*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
 	eieio();
-	restore_flags(flags);
+	local_irq_restore(flags);
 #endif
 
 	sp = ((ushort *)&temp) + ((offset >> 1) & 1);
@@ -185,8 +183,7 @@
 	}
 
 #ifdef CONFIG_RPXCLASSIC
-	save_flags(flags);
-	cli();
+	local_irq_save(flags);
 	*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
 	eieio();
 #endif
@@ -200,7 +197,7 @@
 #ifdef CONFIG_RPXCLASSIC
 	*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
 	eieio();
-	restore_flags(flags);
+	local_irq_restore(flags);
 #endif
 
 	return PCIBIOS_SUCCESSFUL;
@@ -225,8 +222,7 @@
 	*cp = val;
 
 #ifdef CONFIG_RPXCLASSIC
-	save_flags(flags);
-	cli();
+	local_irq_save(flags);
 	*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
 	eieio();
 #endif
@@ -240,7 +236,7 @@
 #ifdef CONFIG_RPXCLASSIC
 	*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
 	eieio();
-	restore_flags(flags);
+	local_irq_restore(flags);
 #endif
 
 	return PCIBIOS_SUCCESSFUL;
@@ -265,8 +261,7 @@
 	*sp = val;
 
 #ifdef CONFIG_RPXCLASSIC
-	save_flags(flags);
-	cli();
+	local_irq_save(flags);
 	*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
 	eieio();
 #endif
@@ -280,7 +275,7 @@
 #ifdef CONFIG_RPXCLASSIC
 	*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
 	eieio();
-	restore_flags(flags);
+	local_irq_restore(flags);
 #endif
 
 	return PCIBIOS_SUCCESSFUL;
@@ -297,8 +292,7 @@
 		return PCIBIOS_DEVICE_NOT_FOUND;
 
 #ifdef CONFIG_RPXCLASSIC
-	save_flags(flags);
-	cli();
+	local_irq_save(flags);
 	*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
 	eieio();
 #endif
@@ -312,7 +306,7 @@
 #ifdef CONFIG_RPXCLASSIC
 	*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
 	eieio();
-	restore_flags(flags);
+	local_irq_restore(flags);
 #endif
 
 	return PCIBIOS_SUCCESSFUL;

Re: [PATCH 0/7] ppc: remove cli()/sti() from arch/ppc/*

[Brian Gerst]

James Nelson wrote:
> This series of patches is to remove the last cli()/sti() function calls in arch/ppc.
> 
> These are the only instances in active code that grep could find.

Are you sure none of these need real spinlocks instead of just disabling 
interrupts?

--
				Brian Gerst

Re: [PATCH 0/7] ppc: remove cli()/sti() from arch/ppc/*

[Jim Nelson]

Brian Gerst wrote:

> James Nelson wrote:
>
>> This series of patches is to remove the last cli()/sti() function 
>> calls in arch/ppc.
>>
>> These are the only instances in active code that grep could find.
>
>
> Are you sure none of these need real spinlocks instead of just 
> disabling interrupts?
>
> -- 
>                 Brian Gerst
>
These are for single-processor systems, mostly evaluation boards and 
embedded processors.  I coudn't find any reference to multiprocessor 
setups for the processors in question after a peruse of the code or a 
quick google on the boards in question.

Jim

Re: [PATCH 0/7] ppc: remove cli()/sti() from arch/ppc/*

[Christoph Hellwig]

On Tue, Jan 04, 2005 at 09:44:06PM -0500, Jim Nelson wrote:
> Brian Gerst wrote:
> 
> >James Nelson wrote:
> >
> >>This series of patches is to remove the last cli()/sti() function 
> >>calls in arch/ppc.
> >>
> >>These are the only instances in active code that grep could find.
> >
> >
> >Are you sure none of these need real spinlocks instead of just 
> >disabling interrupts?
> >
> >-- 
> >                Brian Gerst
> >
> These are for single-processor systems, mostly evaluation boards and 
> embedded processors.  I coudn't find any reference to multiprocessor 
> setups for the processors in question after a peruse of the code or a 
> quick google on the boards in question.

think CONFIG_PREEMPT.  In either case a spinlock becomes
lock_irq_disable in the !SMP, !PREEMPT case but it documents the
intention a whole lot better.

Also you're locking only in a single plpace which is a ***BIG*** warning
sign.  At least look at the other users of the data structure, it's
extremly likely they'll need locking aswell.

Re: [PATCH 0/7] ppc: remove cli()/sti() from arch/ppc/*

[Jim Nelson]

Christoph Hellwig wrote:
> On Tue, Jan 04, 2005 at 09:44:06PM -0500, Jim Nelson wrote:
> 
>>Brian Gerst wrote:
>>
>>
>>>James Nelson wrote:
>>>
>>>
>>>>This series of patches is to remove the last cli()/sti() function 
>>>>calls in arch/ppc.
>>>>
>>>>These are the only instances in active code that grep could find.
>>>
>>>
>>>Are you sure none of these need real spinlocks instead of just 
>>>disabling interrupts?
>>>
>>>-- 
>>>               Brian Gerst
>>>
>>
>>These are for single-processor systems, mostly evaluation boards and 
>>embedded processors.  I coudn't find any reference to multiprocessor 
>>setups for the processors in question after a peruse of the code or a 
>>quick google on the boards in question.
> 
> 
> think CONFIG_PREEMPT.  In either case a spinlock becomes
> lock_irq_disable in the !SMP, !PREEMPT case but it documents the
> intention a whole lot better.
> 
> Also you're locking only in a single plpace which is a ***BIG*** warning
> sign.  At least look at the other users of the data structure, it's
> extremly likely they'll need locking aswell.
> 

Some of the cli() uses were in shutdown and IRQ setup code, where you'd just need 
to disable interrupts.  There are a few files that will need a more thourough 
going-through, however.

I'll start checking those later.

Jim