On Thu, 2004-03-25 at 17:47, Benjamin Herrenschmidt wrote:
> Hi !
>
> I've start looking into the various issues of running
> CONFIG_PREEMPT on ppc32. I found some problems, there
> may be more, but here's a first patch that should apply on a
> recent 2.6.x.
>
> I suggest if you want to try this out that you run with the
> various kernel debugging options enabled. Report me remaining
> problems.
And here's an updated version of that patch that doesn't break
sleep on laptops.
Ben.
===== arch/ppc/kernel/entry.S 1.44 vs edited =====
--- 1.44/arch/ppc/kernel/entry.S Mon Feb 16 18:06:27 2004
+++ edited/arch/ppc/kernel/entry.S Thu Mar 25 14:10:41 2004
@@ -171,9 +171,10 @@
bl do_show_syscall
#endif /* SHOW_SYSCALLS */
rlwinm r10,r1,0,0,18 /* current_thread_info() */
+ lwz r11,TI_LOCAL_FLAGS(r10)
+ rlwinm r11,r11,0,~_TIFL_FORCE_NOERROR
+ stw r11,TI_LOCAL_FLAGS(r10)
lwz r11,TI_FLAGS(r10)
- rlwinm r11,r11,0,~_TIF_FORCE_NOERROR
- stw r11,TI_FLAGS(r10)
andi. r11,r11,_TIF_SYSCALL_TRACE
bne- syscall_dotrace
syscall_dotrace_cont:
@@ -196,8 +197,8 @@
cmpl 0,r3,r11
rlwinm r12,r1,0,0,18 /* current_thread_info() */
blt+ 30f
- lwz r11,TI_FLAGS(r12)
- andi. r11,r11,_TIF_FORCE_NOERROR
+ lwz r11,TI_LOCAL_FLAGS(r12)
+ andi. r11,r11,_TIFL_FORCE_NOERROR
bne 30f
neg r3,r3
lwz r10,_CCR(r1) /* Set SO bit in CR */
===== arch/ppc/kernel/pci.c 1.57 vs edited =====
--- 1.57/arch/ppc/kernel/pci.c Tue Mar 23 16:42:53 2004
+++ edited/arch/ppc/kernel/pci.c Thu Mar 25 15:09:51 2004
@@ -1557,6 +1557,7 @@
}
vma->vm_pgoff = offset >> PAGE_SHIFT;
+
return ret;
}
===== arch/ppc/kernel/process.c 1.57 vs edited =====
--- 1.57/arch/ppc/kernel/process.c Mon Nov 17 12:29:47 2003
+++ edited/arch/ppc/kernel/process.c Thu Mar 25 14:35:07 2004
@@ -164,6 +164,7 @@
void
enable_kernel_altivec(void)
{
+ preempt_disable();
#ifdef CONFIG_SMP
if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
giveup_altivec(current);
@@ -172,12 +173,14 @@
#else
giveup_altivec(last_task_used_altivec);
#endif /* __SMP __ */
+ preempt_enable();
}
#endif /* CONFIG_ALTIVEC */
void
enable_kernel_fp(void)
{
+ preempt_disable();
#ifdef CONFIG_SMP
if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
giveup_fpu(current);
@@ -186,13 +189,16 @@
#else
giveup_fpu(last_task_used_math);
#endif /* CONFIG_SMP */
+ preempt_enable();
}
int
dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
{
+ preempt_disable();
if (regs->msr & MSR_FP)
giveup_fpu(current);
+ preempt_enable();
memcpy(fpregs, ¤t->thread.fpr[0], sizeof(*fpregs));
return 1;
}
@@ -330,12 +336,14 @@
if (regs == NULL)
return;
+ preempt_disable();
if (regs->msr & MSR_FP)
giveup_fpu(current);
#ifdef CONFIG_ALTIVEC
if (regs->msr & MSR_VEC)
giveup_altivec(current);
#endif /* CONFIG_ALTIVEC */
+ preempt_enable();
}
/*
@@ -480,12 +488,14 @@
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
+ preempt_disable();
if (regs->msr & MSR_FP)
giveup_fpu(current);
#ifdef CONFIG_ALTIVEC
if (regs->msr & MSR_VEC)
giveup_altivec(current);
#endif /* CONFIG_ALTIVEC */
+ preempt_enable();
error = do_execve(filename, (char __user *__user *) a1,
(char __user *__user *) a2, regs);
if (error == 0)
===== arch/ppc/kernel/traps.c 1.44 vs edited =====
--- 1.44/arch/ppc/kernel/traps.c Tue Mar 23 12:46:58 2004
+++ edited/arch/ppc/kernel/traps.c Thu Mar 25 13:21:47 2004
@@ -438,8 +438,14 @@
int code = 0;
u32 fpscr;
+ /* We must make sure the FP state is consistent with
+ * our MSR_FP in regs
+ */
+ preempt_disable();
if (regs->msr & MSR_FP)
giveup_fpu(current);
+ preempt_enable();
+
fpscr = current->thread.fpscr;
fpscr &= fpscr << 22; /* mask summary bits with enables */
if (fpscr & FPSCR_VX)
@@ -603,8 +609,11 @@
void
AltivecAssistException(struct pt_regs *regs)
{
+ preempt_disable();
if (regs->msr & MSR_VEC)
giveup_altivec(current);
+ preempt_enable();
+
/* XXX quick hack for now: set the non-Java bit in the VSCR */
current->thread.vscr.u[3] |= 0x10000;
}
===== arch/ppc/syslib/prom_init.c 1.26 vs edited =====
--- 1.26/arch/ppc/syslib/prom_init.c Sat Feb 14 19:29:14 2004
+++ edited/arch/ppc/syslib/prom_init.c Wed Mar 24 12:35:20 2004
@@ -44,8 +44,12 @@
* things like "driver,AAPL,MacOS,PowerPC" properties. But this value
* does need to be big enough to ensure that we don't lose things
* like the interrupt-map property on a PCI-PCI bridge.
+ *
+ * 24/03/2004 - BenH: Bump that limitation to 512k and remove the
+ * filter for the MacOS drivers as we may now run
+ * those in a shell
*/
-#define MAX_PROPERTY_LENGTH 4096
+#define MAX_PROPERTY_LENGTH (512 * 1024)
#ifndef FB_MAX /* avoid pulling in all of the fb stuff */
#define FB_MAX 8
===== drivers/macintosh/adbhid.c 1.33 vs edited =====
--- 1.33/drivers/macintosh/adbhid.c Sat Feb 14 19:29:16 2004
+++ edited/drivers/macintosh/adbhid.c Thu Mar 25 16:16:56 2004
@@ -107,7 +107,6 @@
static void adbhid_probe(void);
static void adbhid_input_keycode(int, int, int, struct pt_regs *);
-static void leds_done(struct adb_request *);
static void init_trackpad(int id);
static void init_trackball(int id);
@@ -446,24 +445,54 @@
static struct adb_request led_request;
static int leds_pending[16];
+static int leds_req_pending;
static int pending_devs[16];
static int pending_led_start=0;
static int pending_led_end=0;
+static spinlock_t leds_lock = SPIN_LOCK_UNLOCKED;
+
+static void leds_done(struct adb_request *req)
+{
+ int leds, device;
+ unsigned long flags;
+
+ spin_lock_irqsave(&leds_lock, flags);
+
+ if (pending_led_start != pending_led_end) {
+ device = pending_devs[pending_led_start];
+ leds = leds_pending[device] & 0xff;
+ leds_pending[device] = 0;
+ pending_led_start++;
+ pending_led_start = (pending_led_start < 16) ?
pending_led_start : 0;
+ } else
+ leds_req_pending = 0;
+
+ spin_unlock_irqrestore(&leds_lock, flags);
+ if (leds_req_pending)
+ adb_request(&led_request, leds_done, 0, 3,
+ ADB_WRITEREG(device, KEYB_LEDREG), 0xff, ~leds);
+}
static void real_leds(unsigned char leds, int device)
{
- if (led_request.complete) {
- adb_request(&led_request, leds_done, 0, 3,
- ADB_WRITEREG(device, KEYB_LEDREG), 0xff,
- ~leds);
- } else {
- if (!(leds_pending[device] & 0x100)) {
- pending_devs[pending_led_end] = device;
- pending_led_end++;
- pending_led_end = (pending_led_end < 16) ? pending_led_end : 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&leds_lock, flags);
+ if (!leds_req_pending) {
+ leds_req_pending = 1;
+ spin_unlock_irqrestore(&leds_lock, flags);
+ adb_request(&led_request, leds_done, 0, 3,
+ ADB_WRITEREG(device, KEYB_LEDREG), 0xff, ~leds);
+ return;
+ } else {
+ if (!(leds_pending[device] & 0x100)) {
+ pending_devs[pending_led_end] = device;
+ pending_led_end++;
+ pending_led_end = (pending_led_end < 16) ?
pending_led_end : 0;
+ }
+ leds_pending[device] = leds | 0x100;
}
- leds_pending[device] = leds | 0x100;
- }
+ spin_unlock_irqrestore(&leds_lock, flags);
}
/*
@@ -487,21 +516,6 @@
return -1;
}
-static void leds_done(struct adb_request *req)
-{
- int leds,device;
-
- if (pending_led_start != pending_led_end) {
- device = pending_devs[pending_led_start];
- leds = leds_pending[device] & 0xff;
- leds_pending[device] = 0;
- pending_led_start++;
- pending_led_start = (pending_led_start < 16) ? pending_led_start : 0;
- real_leds(leds,device);
- }
-
-}
-
static int
adb_message_handler(struct notifier_block *this, unsigned long code, void *x)
{
@@ -518,7 +532,7 @@
}
/* Stop pending led requests */
- while(!led_request.complete)
+ while(leds_req_pending)
adb_poll();
break;
===== drivers/macintosh/via-pmu.c 1.61 vs edited =====
--- 1.61/drivers/macintosh/via-pmu.c Thu Mar 4 13:04:36 2004
+++ edited/drivers/macintosh/via-pmu.c Thu Mar 25 18:52:00 2004
@@ -137,7 +137,8 @@
static int data_len;
static volatile int adb_int_pending;
static volatile int disable_poll;
-static struct adb_request bright_req_1, bright_req_2, bright_req_3;
+static struct adb_request bright_req_1, bright_req_2;
+static unsigned long async_req_locks;
static struct device_node *vias;
static int pmu_kind = PMU_UNKNOWN;
static int pmu_fully_inited = 0;
@@ -404,7 +405,6 @@
bright_req_1.complete = 1;
bright_req_2.complete = 1;
- bright_req_3.complete = 1;
#ifdef CONFIG_PMAC_PBOOK
batt_req.complete = 1;
if (pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,0,-1) >= 0)
@@ -710,6 +710,8 @@
pmu_batteries[pmu_cur_battery].amperage = amperage;
pmu_batteries[pmu_cur_battery].voltage = voltage;
pmu_batteries[pmu_cur_battery].time_remaining = time;
+
+ clear_bit(0, &async_req_locks);
}
static void __pmac
@@ -785,12 +787,14 @@
pmu_batteries[pmu_cur_battery].time_remaining = 0;
pmu_cur_battery = (pmu_cur_battery + 1) % pmu_battery_count;
+
+ clear_bit(0, &async_req_locks);
}
static void __pmac
query_battery_state(void)
{
- if (!batt_req.complete)
+ if (test_and_set_bit(0, &async_req_locks))
return;
if (pmu_kind == PMU_OHARE_BASED)
pmu_request(&batt_req, done_battery_state_ohare,
@@ -1690,20 +1694,30 @@
return 0;
}
+static void __openfirmware
+pmu_bright_complete(struct adb_request *req)
+{
+ if (req == &bright_req_1)
+ clear_bit(1, &async_req_locks);
+ if (req == &bright_req_2)
+ clear_bit(2, &async_req_locks);
+}
+
static int __openfirmware
pmu_set_backlight_level(int level, void* data)
{
if (vias == NULL)
return -ENODEV;
- if (!bright_req_1.complete)
+ if (test_and_set_bit(1, &async_req_locks))
return -EAGAIN;
- pmu_request(&bright_req_1, NULL, 2, PMU_BACKLIGHT_BRIGHT,
+ pmu_request(&bright_req_1, pmu_bright_complete, 2, PMU_BACKLIGHT_BRIGHT,
backlight_to_bright[level]);
- if (!bright_req_2.complete)
+ if (test_and_set_bit(2, &async_req_locks))
return -EAGAIN;
- pmu_request(&bright_req_2, NULL, 2, PMU_POWER_CTRL, PMU_POW_BACKLIGHT
- | (level > BACKLIGHT_OFF ? PMU_POW_ON : PMU_POW_OFF));
+ pmu_request(&bright_req_2, pmu_bright_complete, 2, PMU_POWER_CTRL,
+ PMU_POW_BACKLIGHT | (level > BACKLIGHT_OFF ?
+ PMU_POW_ON : PMU_POW_OFF));
return 0;
}
@@ -2330,6 +2344,8 @@
return -EBUSY;
}
+ preempt_disable();
+
/* Make sure the decrementer won't interrupt us */
asm volatile("mtdec %0" : : "r" (0x7fffffff));
/* Make sure any pending DEC interrupt occurring while we did
@@ -2352,6 +2368,7 @@
if (ret) {
wakeup_decrementer();
local_irq_enable();
+ preempt_enable();
device_resume();
broadcast_wake();
printk(KERN_ERR "Driver powerdown failed\n");
@@ -2360,7 +2377,8 @@
/* Wait for completion of async backlight requests */
while (!bright_req_1.complete || !bright_req_2.complete ||
- !bright_req_3.complete || !batt_req.complete)
+
+ !batt_req.complete)
pmu_poll();
/* Giveup the lazy FPU & vec so we don't have to back them
@@ -2398,6 +2416,8 @@
pmu_blink(1);
+ preempt_enable();
+
/* Resume devices */
device_resume();
@@ -2673,9 +2693,9 @@
mb();
pmac_wakeup_devices();
-
pbook_free_pci_save();
iounmap(mem_ctrl);
+
return 0;
}
===== include/asm-ppc/ptrace.h 1.11 vs edited =====
--- 1.11/include/asm-ppc/ptrace.h Tue Jun 24 14:45:56 2003
+++ edited/include/asm-ppc/ptrace.h Thu Mar 25 14:02:44 2004
@@ -49,7 +49,10 @@
#define instruction_pointer(regs) ((regs)->nip)
#define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
-#define force_successful_syscall_return() set_thread_flag(TIF_FORCE_NOERROR)
+#define force_successful_syscall_return() \
+ do { \
+ current_thread_info()->local_flags |= _TIFL_FORCE_NOERROR; \
+ } while(0)
/*
* We use the least-significant bit of the trap field to indicate
===== include/asm-ppc/thread_info.h 1.17 vs edited =====
--- 1.17/include/asm-ppc/thread_info.h Tue Oct 14 17:28:08 2003
+++ edited/include/asm-ppc/thread_info.h Thu Mar 25 14:03:56 2004
@@ -18,6 +18,7 @@
struct task_struct *task; /* main task structure */
struct exec_domain *exec_domain; /* execution domain */
unsigned long flags; /* low level flags */
+ unsigned long local_flags; /* non-racy flags */
int cpu; /* cpu we're on */
int preempt_count;
struct restart_block restart_block;
@@ -28,6 +29,7 @@
.task = &tsk, \
.exec_domain = &default_exec_domain, \
.flags = 0, \
+ .local_flags = 0, \
.cpu = 0, \
.preempt_count = 1, \
.restart_block = { \
@@ -69,8 +71,9 @@
#define TI_TASK 0
#define TI_EXECDOMAIN 4
#define TI_FLAGS 8
-#define TI_CPU 12
-#define TI_PREEMPT 16
+#define TI_LOCAL_FLAGS 12
+#define TI_CPU 16
+#define TI_PREEMPT 20
#define PREEMPT_ACTIVE 0x4000000
@@ -83,16 +86,22 @@
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_POLLING_NRFLAG 4 /* true if poll_idle() is polling
TIF_NEED_RESCHED */
-#define TIF_FORCE_NOERROR 5 /* don't return error from current
- syscall even if result < 0 */
-
/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
-#define _TIF_FORCE_NOERROR (1<<TIF_FORCE_NOERROR)
+
+/*
+ * Non racy (local) flags bit numbers
+ */
+#define TIFL_FORCE_NOERROR 0 /* don't return error from current
+ syscall even if result < 0 */
+
+/* as above, but as bit values */
+#define _TIFL_FORCE_NOERROR (1<<TIFL_FORCE_NOERROR)
+
#endif /* __KERNEL__ */
===== sound/oss/dmasound/dmasound_core.c 1.22 vs edited =====
--- 1.22/sound/oss/dmasound/dmasound_core.c Mon Feb 9 13:18:52 2004
+++ edited/sound/oss/dmasound/dmasound_core.c Thu Mar 25 18:41:02 2004
@@ -1004,6 +1004,7 @@
static int sq_fsync(struct file *filp, struct dentry *dentry)
{
int rc = 0;
+ int timeout = 5;
write_sq.syncing |= 1;
sq_play(); /* there may be an incomplete frame waiting */
@@ -1016,6 +1017,12 @@
* and clear the queue. */
sq_reset_output();
rc = -EINTR;
+ break;
+ }
+ if (!--timeout) {
+ printk(KERN_WARNING "dmasound: Timeout draining
output\n");
+ sq_reset_output();
+ rc = -EIO;
break;
}
}
