Changeset f619ec11 in mainline for kernel/arch

Timestamp:

2007-02-03T21:26:54Z (19 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

cf5ddf6

Parents:

80bcaed

Message:

When clock() is called by an external interrupt dispatched by the IRQ dispatcher,
no spinlock can be held or the kernel will not be preemptive. This fixes Ticket #24.

Formating and indentation fixes.

Location:

kernel/arch

Files:

• ia32/src/drivers/i8254.c (modified) (2 diffs)
• ia32/src/drivers/i8259.c (modified) (2 diffs)
• ia32/src/ia32.c (modified) (1 diff)
• ia32/src/interrupt.c (modified) (1 diff)
• ia32/src/smp/smp.c (modified) (2 diffs)
• ia32xen/src/ia32xen.c (modified) (1 diff)
• ia32xen/src/smp/apic.c (modified) (7 diffs)
• ia64/src/drivers/it.c (modified) (1 diff)
• ia64/src/ia64.c (modified) (1 diff)
• mips32/src/interrupt.c (modified) (1 diff)
• sparc64/src/drivers/tick.c (modified) (1 diff)
• sparc64/src/sparc64.c (modified) (2 diffs)

kernel/arch/ia32/src/drivers/i8254.c

@@ -69 +69 @@
 static void i8254_irq_handler(irq_t *irq, void *arg, ...)
 {
+        /*
+         * This IRQ is responsible for kernel preemption.
+         * Nevertheless, we are now holding a spinlock which prevents
+         * preemption. For this particular IRQ, we don't need the
+         * lock. We just release it, call clock() and then reacquire it again.
+         */
+        spinlock_unlock(&irq->lock);
         clock();
+        spinlock_lock(&irq->lock);
 }
 
@@ -137 +145 @@
         o2 |= inb(CLK_PORT1) << 8;
 
-        CPU->delay_loop_const = ((MAGIC_NUMBER*LOOPS)/1000) / ((t1-t2)-(o1-o2)) + (((MAGIC_NUMBER*LOOPS)/1000) % ((t1-t2)-(o1-o2)) ? 1 : 0);
+        CPU->delay_loop_const =
+            ((MAGIC_NUMBER * LOOPS) / 1000) / ((t1 - t2) - (o1 - o2)) +
+            (((MAGIC_NUMBER * LOOPS) / 1000) % ((t1 - t2) - (o1 - o2)) ? 1 : 0);
 
         clk1 = get_cycle();

kernel/arch/ia32/src/drivers/i8259.c

@@ -87 +87 @@
 
         pic_disable_irqs(0xffff);               /* disable all irq's */
-        pic_enable_irqs(1<<IRQ_PIC1);           /* but enable pic1 */
+        pic_enable_irqs(1 << IRQ_PIC1);         /* but enable pic1 */
 }
 
@@ -120 +120 @@
 void pic_eoi(void)
 {
-        outb(0x20,0x20);
-        outb(0xa0,0x20);
+        outb(0x20, 0x20);
+        outb(0xa0, 0x20);
 }
 

kernel/arch/ia32/src/ia32.c

@@ -119 +119 @@
                 memory_print_map();
                 
-                #ifdef CONFIG_SMP
+#ifdef CONFIG_SMP
                 acpi_init();
-                #endif /* CONFIG_SMP */
+#endif /* CONFIG_SMP */
         }
 }

kernel/arch/ia32/src/interrupt.c

@@ -141 +141 @@
 {
         uint32_t mxcsr;
-        asm
-        (
+        asm (
                 "stmxcsr %0;\n"
                 :"=m"(mxcsr)
         );
         fault_if_from_uspace(istate, "SIMD FP exception(19), MXCSR: %#zx",
-                             (unative_t)mxcsr);
+            (unative_t)mxcsr);
 
         decode_istate(istate);

kernel/arch/ia32/src/smp/smp.c

@@ -113 +113 @@
          * Set the warm-reset vector to the real-mode address of 4K-aligned ap_boot()
          */
-        *((uint16_t *) (PA2KA(0x467+0))) =  ((uintptr_t) ap_boot) >> 4; /* segment */
-        *((uint16_t *) (PA2KA(0x467+2))) =  0;                          /* offset */
+        *((uint16_t *) (PA2KA(0x467 + 0))) =  ((uintptr_t) ap_boot) >> 4;       /* segment */
+        *((uint16_t *) (PA2KA(0x467 + 2))) =  0;                                /* offset */
         
         /*
@@ -120 +120 @@
          * BIOS will not do the POST after the INIT signal.
          */
-        outb(0x70,0xf);
-        outb(0x71,0xa);
+        outb(0x70, 0xf);
+        outb(0x71, 0xa);
 
         pic_disable_irqs(0xffff);

kernel/arch/ia32xen/src/ia32xen.c

@@ -163 +163 @@
                 memory_print_map();
                 
-                #ifdef CONFIG_SMP
+#ifdef CONFIG_SMP
                 acpi_init();
-                #endif /* CONFIG_SMP */
+#endif /* CONFIG_SMP */
         }
 }

kernel/arch/ia32xen/src/smp/apic.c

@@ -152 +152 @@
          */
         idreg.value = io_apic_read(IOAPICID);
-        if ((1<<idreg.apic_id) & apic_id_mask) {        /* see if IO APIC ID is used already */
+        if ((1 << idreg.apic_id) & apic_id_mask) {      /* see if IO APIC ID is used already */
                 for (i = 0; i < APIC_ID_COUNT; i++) {
                         if (!((1<<i) & apic_id_mask)) {
@@ -303 +303 @@
                  * If this is not 82489DX-based l_apic we must send two STARTUP IPI's.
                  */
-                for (i = 0; i<2; i++) {
+                for (i = 0; i < 2; i++) {
                         icr.lo = l_apic[ICRlo];
                         icr.delmod = DELMOD_STARTUP;
@@ -402 +402 @@
         /* Program Logical Destination Register. */
         ldr.value = l_apic[LDR];
-        if (CPU->id < sizeof(CPU->id)*8)        /* size in bits */
-                ldr.id = (1<<CPU->id);
+        if (CPU->id < sizeof(CPU->id) * 8)      /* size in bits */
+                ldr.id = (1 << CPU->id);
         l_apic[LDR] = ldr.value;
         
@@ -508 +508 @@
                 dlvr = DELMOD_LOWPRI;
 
-        reg.lo = io_apic_read(IOREDTBL + pin*2);
-        reg.hi = io_apic_read(IOREDTBL + pin*2 + 1);
+        reg.lo = io_apic_read(IOREDTBL + pin * 2);
+        reg.hi = io_apic_read(IOREDTBL + pin * 2 + 1);
         
         reg.dest = dest;
@@ -518 +518 @@
         reg.intvec = v;
 
-        io_apic_write(IOREDTBL + pin*2, reg.lo);
-        io_apic_write(IOREDTBL + pin*2 + 1, reg.hi);
+        io_apic_write(IOREDTBL + pin * 2, reg.lo);
+        io_apic_write(IOREDTBL + pin * 2 + 1, reg.hi);
 }
 
@@ -540 +540 @@
                         pin = smp_irq_to_pin(i);
                         if (pin != -1) {
-                                reg.lo = io_apic_read(IOREDTBL + pin*2);
+                                reg.lo = io_apic_read(IOREDTBL + pin * 2);
                                 reg.masked = true;
                                 io_apic_write(IOREDTBL + pin*2, reg.lo);
@@ -567 +567 @@
                         pin = smp_irq_to_pin(i);
                         if (pin != -1) {
-                                reg.lo = io_apic_read(IOREDTBL + pin*2);
+                                reg.lo = io_apic_read(IOREDTBL + pin * 2);
                                 reg.masked = false;
                                 io_apic_write(IOREDTBL + pin*2, reg.lo);

kernel/arch/ia64/src/drivers/it.c

@@ -114 +114 @@
         itm_write(m);
         srlz_d();                               /* propagate changes */
-        
+
+        /*
+         * We are holding a lock which prevents preemption.
+         * Release the lock, call clock() and reacquire the lock again.
+         */
+        spinlock_unlock(&irq->lock);    
         clock();
+        spinlock_lock(&irq->lock);
 }
 

kernel/arch/ia64/src/ia64.c

@@ -82 +82 @@
         
 }
-
-
 
 void arch_post_mm_init(void)

kernel/arch/mips32/src/interrupt.c

@@ -114 +114 @@
         nextcount = cp0_count_read() + cp0_compare_value - drift;
         cp0_compare_write(nextcount);
+
+        /*
+         * We are holding a lock which prevents preemption.
+         * Release the lock, call clock() and reacquire the lock again.
+         */
+        spinlock_unlock(&irq->lock);
         clock();
+        spinlock_lock(&irq->lock);
         
         if (virtual_timer_fnc != NULL)

kernel/arch/sparc64/src/drivers/tick.c

@@ -100 +100 @@
                 CPU->missed_clock_ticks++;
         }
-        CPU->arch.next_tick_cmpr = tick_read() + (CPU->arch.clock_frequency /
-                HZ) - drift;
+        CPU->arch.next_tick_cmpr = tick_read() +
+            (CPU->arch.clock_frequency / HZ) - drift;
         tick_compare_write(CPU->arch.next_tick_cmpr);
         clock();

kernel/arch/sparc64/src/sparc64.c

@@ -137 +137 @@
 {
         uint64_t stop = tick_read() + (uint64_t) usec * (uint64_t)
-                CPU->arch.clock_frequency / 1000000;
+            CPU->arch.clock_frequency / 1000000;
 
         while (tick_read() < stop)
@@ -147 +147 @@
 {
         switch_to_userspace((uintptr_t) kernel_uarg->uspace_entry,
-                ((uintptr_t) kernel_uarg->uspace_stack) + STACK_SIZE
-                - (ALIGN_UP(STACK_ITEM_SIZE, STACK_ALIGNMENT) + STACK_BIAS),
-                (uintptr_t) kernel_uarg->uspace_uarg);
+            ((uintptr_t) kernel_uarg->uspace_stack) + STACK_SIZE
+            - (ALIGN_UP(STACK_ITEM_SIZE, STACK_ALIGNMENT) + STACK_BIAS),
+            (uintptr_t) kernel_uarg->uspace_uarg);
 
         for (;;)