qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH 2/2] hw/timer/slavio_timer.c: Switch to transaction-based pti


From: Philippe Mathieu-Daudé
Subject: Re: [PATCH 2/2] hw/timer/slavio_timer.c: Switch to transaction-based ptimer API
Date: Thu, 17 Oct 2019 16:54:08 +0200
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1

Hi Peter,

On 10/17/19 3:23 PM, Peter Maydell wrote:
Switch the slavio_timer code away from bottom-half based ptimers to
the new transaction-based ptimer API.  This just requires adding
begin/commit calls around the various places that modify the ptimer
state, and using the new ptimer_init() function to create the timer.

Signed-off-by: Peter Maydell <address@hidden>
---
  hw/timer/slavio_timer.c | 20 ++++++++++++++++----
  1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/hw/timer/slavio_timer.c b/hw/timer/slavio_timer.c
index 692d213897d..0e2efe6fe89 100644
--- a/hw/timer/slavio_timer.c
+++ b/hw/timer/slavio_timer.c
@@ -30,7 +30,6 @@
  #include "hw/sysbus.h"
  #include "migration/vmstate.h"
  #include "trace.h"
-#include "qemu/main-loop.h"
  #include "qemu/module.h"
/*
@@ -213,6 +212,7 @@ static void slavio_timer_mem_writel(void *opaque, hwaddr 
addr,
      saddr = addr >> 2;
      switch (saddr) {
      case TIMER_LIMIT:
+        ptimer_transaction_begin(t->timer);
          if (slavio_timer_is_user(tc)) {
              uint64_t count;


This part is odd since there is a check on t->timer != NULL later, and ptimer_transaction_commit() can't take NULL.

This won't happen if you restrict to ptimer_* calls:

-- >8 --
@@ -222,18 +222,22 @@ static void slavio_timer_mem_writel(void *opaque, hwaddr addr,
             t->reached = 0;
             count = ((uint64_t)t->counthigh << 32) | t->count;
             trace_slavio_timer_mem_writel_limit(timer_index, count);
+            ptimer_transaction_begin(t->timer);
ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
+            ptimer_transaction_commit(t->timer);
         } else {
             // set limit, reset counter
             qemu_irq_lower(t->irq);
             t->limit = val & TIMER_MAX_COUNT32;
             if (t->timer) {
+                ptimer_transaction_begin(t->timer);
                 if (t->limit == 0) { /* free-run */
                     ptimer_set_limit(t->timer,

LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
                 } else {
ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 1);
                 }
+                ptimer_transaction_commit(t->timer);
             }
         }
         break;
---

@@ -236,6 +236,7 @@ static void slavio_timer_mem_writel(void *opaque, hwaddr addr,
                  }
              }
          }
+        ptimer_transaction_commit(t->timer);
          break;
      case TIMER_COUNTER:
          if (slavio_timer_is_user(tc)) {
@@ -247,7 +248,9 @@ static void slavio_timer_mem_writel(void *opaque, hwaddr 
addr,
              t->reached = 0;
              count = ((uint64_t)t->counthigh) << 32 | t->count;
              trace_slavio_timer_mem_writel_limit(timer_index, count);
+            ptimer_transaction_begin(t->timer);
              ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
+            ptimer_transaction_commit(t->timer);
          } else {
              trace_slavio_timer_mem_writel_counter_invalid();
          }
@@ -255,13 +258,16 @@ static void slavio_timer_mem_writel(void *opaque, hwaddr 
addr,
      case TIMER_COUNTER_NORST:
          // set limit without resetting counter
          t->limit = val & TIMER_MAX_COUNT32;
+        ptimer_transaction_begin(t->timer);
          if (t->limit == 0) { /* free-run */
              ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 
0);
          } else {
              ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 0);
          }
+        ptimer_transaction_commit(t->timer);
          break;
      case TIMER_STATUS:
+        ptimer_transaction_begin(t->timer);
          if (slavio_timer_is_user(tc)) {

I'd move the begin() here.

              // start/stop user counter
              if (val & 1) {
@@ -273,6 +279,7 @@ static void slavio_timer_mem_writel(void *opaque, hwaddr 
addr,
              }
          }
          t->run = val & 1;
+        ptimer_transaction_commit(t->timer);
          break;
      case TIMER_MODE:
          if (timer_index == 0) {
@@ -282,6 +289,7 @@ static void slavio_timer_mem_writel(void *opaque, hwaddr 
addr,
                  unsigned int processor = 1 << i;
                  CPUTimerState *curr_timer = &s->cputimer[i + 1];
+ ptimer_transaction_begin(curr_timer->timer);
                  // check for a change in timer mode for this processor
                  if ((val & processor) != (s->cputimer_mode & processor)) {

Ditto, begin() here.

                      if (val & processor) { // counter -> user timer
@@ -308,6 +316,7 @@ static void slavio_timer_mem_writel(void *opaque, hwaddr 
addr,
                          
trace_slavio_timer_mem_writel_mode_counter(timer_index);
                      }
                  }
+                ptimer_transaction_commit(curr_timer->timer);
              }
          } else {
              trace_slavio_timer_mem_writel_mode_invalid();
@@ -367,10 +376,12 @@ static void slavio_timer_reset(DeviceState *d)
          curr_timer->count = 0;
          curr_timer->reached = 0;
          if (i <= s->num_cpus) {
+            ptimer_transaction_begin(curr_timer->timer);
              ptimer_set_limit(curr_timer->timer,
                               LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
              ptimer_run(curr_timer->timer, 0);
              curr_timer->run = 1;
+            ptimer_transaction_commit(curr_timer->timer);
          }
      }
      s->cputimer_mode = 0;
@@ -380,7 +391,6 @@ static void slavio_timer_init(Object *obj)
  {
      SLAVIO_TIMERState *s = SLAVIO_TIMER(obj);
      SysBusDevice *dev = SYS_BUS_DEVICE(obj);
-    QEMUBH *bh;
      unsigned int i;
      TimerContext *tc;
@@ -392,9 +402,11 @@ static void slavio_timer_init(Object *obj)
          tc->s = s;
          tc->timer_index = i;
- bh = qemu_bh_new(slavio_timer_irq, tc);
-        s->cputimer[i].timer = ptimer_init_with_bh(bh, PTIMER_POLICY_DEFAULT);
+        s->cputimer[i].timer = ptimer_init(slavio_timer_irq, tc,
+                                           PTIMER_POLICY_DEFAULT);
+        ptimer_transaction_begin(s->cputimer[i].timer);
          ptimer_set_period(s->cputimer[i].timer, TIMER_PERIOD);
+        ptimer_transaction_commit(s->cputimer[i].timer);
size = i == 0 ? SYS_TIMER_SIZE : CPU_TIMER_SIZE;
          snprintf(timer_name, sizeof(timer_name), "timer-%i", i);





reply via email to

[Prev in Thread] Current Thread [Next in Thread]