Changeset fd67c9f in mainline

Timestamp:

2019-04-06T08:10:27Z (5 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

534bcdf

Parents:

ef56a43

Message:

Handle PIC spurious IRQs with care

Location:

kernel

Files:

• arch/amd64/src/interrupt.c (modified) (3 diffs)
• arch/ia32/src/interrupt.c (modified) (3 diffs)
• arch/mips32/include/arch/mach/malta/malta.h (modified) (1 diff)
• arch/mips32/src/mach/malta/malta.c (modified) (2 diffs)
• genarch/include/genarch/drivers/i8259/i8259.h (modified) (3 diffs)
• genarch/src/drivers/i8259/i8259.c (modified) (3 diffs)

kernel/arch/amd64/src/interrupt.c

@@ -172 +172 @@
         bool ack = false;
         assert(inum < IRQ_COUNT);
-        assert(inum != IRQ_PIC0_SPUR);
-        assert(inum != IRQ_PIC1_SPUR);
         assert(inum != IRQ_PIC1);
 
@@ -190 +188 @@
                 irq_spinlock_unlock(&irq->lock, false);
         } else {
-                /*
-                 * Spurious interrupt.
-                 */
 #ifdef CONFIG_DEBUG
-                log(LF_ARCH, LVL_DEBUG, "cpu%u: spurious interrupt (inum=%u)",
-                    CPU->id, inum);
+                log(LF_ARCH, LVL_DEBUG, "cpu%u: unhandled IRQ %u", CPU->id,
+                    inum);
 #endif
         }
@@ -205 +200 @@
 static void pic_spurious(unsigned int n, istate_t *istate)
 {
-        /*
-         * XXX: Examine ISR to figure out whether this is indeed a spurious
-         *      or actual IRQ.
-         */
+        unsigned int inum = n - IVT_IRQBASE;
+        if (!pic_is_spurious(inum)) {
+                /* This is actually not a spurious IRQ, so proceed as usual. */
+                irq_interrupt(n, istate);
+                return;
+        }
+        pic_handle_spurious(n);
 #ifdef CONFIG_DEBUG
-        log(LF_ARCH, LVL_DEBUG, "cpu%u: PIC spurious interrupt", CPU->id);
+        log(LF_ARCH, LVL_DEBUG, "cpu%u: PIC spurious interrupt %u", CPU->id,
+            inum);
 #endif
 }

kernel/arch/ia32/src/interrupt.c

@@ -192 +192 @@
         bool ack = false;
         assert(inum < IRQ_COUNT);
-        assert(inum != IRQ_PIC0_SPUR);
-        assert(inum != IRQ_PIC1_SPUR);
         assert(inum != IRQ_PIC1);
 
@@ -210 +208 @@
                 irq_spinlock_unlock(&irq->lock, false);
         } else {
-                /*
-                 * Spurious interrupt.
-                 */
 #ifdef CONFIG_DEBUG
-                printf("cpu%u: spurious interrupt (inum=%u)\n", CPU->id, inum);
+                log(LF_ARCH, LVL_DEBUG, "cpu%u: unhandled IRQ %u", CPU->id,
+                    inum);
 #endif
         }
@@ -224 +220 @@
 static void pic_spurious(unsigned int n, istate_t *istate)
 {
-        /*
-         * XXX: Examine ISR to figure out whether this is indeed a spurious
-         *      or actual IRQ.
-         */
+        unsigned int inum = n - IVT_IRQBASE;
+        if (!pic_is_spurious(inum)) {
+                /* This is actually not a spurious IRQ, so proceed as usual. */
+                irq_interrupt(n, istate);
+                return;
+        }
+        pic_handle_spurious(n);
 #ifdef CONFIG_DEBUG
-        log(LF_ARCH, LVL_DEBUG, "cpu%u: PIC spurious interrupt", CPU->id);
+        log(LF_ARCH, LVL_DEBUG, "cpu%u: PIC spurious interrupt %u", CPU->id,
+            inum);
 #endif
 }

kernel/arch/mips32/include/arch/mach/malta/malta.h

@@ -45 +45 @@
 
 #define PIC0_BASE               (MALTA_PCI_BASE + 0x20)
-#define PIC0_SPURIOUS_IRQ       7
 #define PIC1_BASE               (MALTA_PCI_BASE + 0xa0)
-#define PIC1_SPURIOUS_IRQ       15
 
 #define ISA_IRQ_COUNT           16

kernel/arch/mips32/src/mach/malta/malta.c

@@ -74 +74 @@
 {
         uint8_t isa_irq = host2uint32_t_le(pio_read_32(GT64120_PCI0_INTACK));
-        if (isa_irq == PIC0_SPURIOUS_IRQ || isa_irq == PIC1_SPURIOUS_IRQ) {
-                /*
-                 * XXX: Examine ISR to figure out whether this is indeed a
-                 *      spurious or actual IRQ.
-                 */
+        if (pic_is_spurious(isa_irq)) {
+                pic_handle_spurious(isa_irq);
 #ifdef CONFIG_DEBUG
-                log(LF_ARCH, LVL_DEBUG, "cpu%u: PIC spurious interrupt",
-                    CPU->id);
+                log(LF_ARCH, LVL_DEBUG, "cpu%u: PIC spurious interrupt %u",
+                    CPU->id, isa_irq);
                 return;
 #endif
@@ -91 +88 @@
         } else {
 #ifdef CONFIG_DEBUG
-                log(LF_ARCH, LVL_DEBUG, "cpu%u: spurious IRQ (irq=%u)",
+                log(LF_ARCH, LVL_DEBUG, "cpu%u: unhandled IRQ (irq=%u)",
                     CPU->id, isa_irq);
 #endif

kernel/genarch/include/genarch/drivers/i8259/i8259.h

@@ -38 +38 @@
 #include <typedefs.h>
 #include <arch/interrupt.h>
+#include <stdbool.h>
 
 /* ICW1 bits */
@@ -43 +44 @@
 #define PIC_ICW1_NEEDICW4  (1 << 0)
 
+/* OCW3 bits */
+#define PIC_OCW3           (1 << 3)
+#define PIC_OCW3_READ_ISR  (3 << 0)
+
 /* OCW4 bits */
 #define PIC_OCW4           (0 << 3)
 #define PIC_OCW4_NSEOI     (1 << 5)
+
+#define PIC_IRQ_COUNT      8
+#define PIC_SPURIOUS_IRQ   7
 
 typedef struct {
@@ -56 +64 @@
 extern void pic_disable_irqs(uint16_t);
 extern void pic_eoi(unsigned int);
+extern bool pic_is_spurious(unsigned int);
+extern void pic_handle_spurious(unsigned int);
 
 #endif

kernel/genarch/src/drivers/i8259/i8259.c

@@ -90 +90 @@
                     (uint8_t) (x & (~(irqmask & 0xff))));
         }
-        if (irqmask >> 8) {
+        if (irqmask >> PIC_IRQ_COUNT) {
                 x = pio_read_8(&saved_pic1->port2);
                 pio_write_8(&saved_pic1->port2,
-                    (uint8_t) (x & (~(irqmask >> 8))));
+                    (uint8_t) (x & (~(irqmask >> PIC_IRQ_COUNT))));
         }
 }
@@ -106 +106 @@
                     (uint8_t) (x | (irqmask & 0xff)));
         }
-        if (irqmask >> 8) {
+        if (irqmask >> PIC_IRQ_COUNT) {
                 x = pio_read_8(&saved_pic1->port2);
-                pio_write_8(&saved_pic1->port2, (uint8_t) (x | (irqmask >> 8)));
+                pio_write_8(&saved_pic1->port2,
+                    (uint8_t) (x | (irqmask >> PIC_IRQ_COUNT)));
         }
 }
@@ -114 +115 @@
 void pic_eoi(unsigned int irq)
 {
-        if (irq >= 8)
+        if (irq >= PIC_IRQ_COUNT)
                 pio_write_8(&saved_pic1->port1, PIC_OCW4 | PIC_OCW4_NSEOI);
         pio_write_8(&saved_pic0->port1, PIC_OCW4 | PIC_OCW4_NSEOI);
 }
 
+bool pic_is_spurious(unsigned int irq)
+{
+        pio_write_8(&saved_pic0->port1, PIC_OCW3 | PIC_OCW3_READ_ISR);
+        pio_write_8(&saved_pic1->port1, PIC_OCW3 | PIC_OCW3_READ_ISR);
+        uint8_t isr_lo = pio_read_8(&saved_pic0->port1);
+        uint8_t isr_hi = pio_read_8(&saved_pic1->port1);
+        return !(((isr_hi << PIC_IRQ_COUNT) | isr_lo) & (1 << irq));
+}
+
+void pic_handle_spurious(unsigned int irq)
+{
+        /* For spurious IRQs from pic1, we need to isssue an EOI to pic0 */
+        if (irq >= PIC_IRQ_COUNT)
+                pio_write_8(&saved_pic0->port1, PIC_OCW4 | PIC_OCW4_NSEOI);
+}
+
 /** @}
  */