Changeset 2382d09 in mainline for arch/ia32

Timestamp:

2006-04-29T15:01:41Z (19 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

407862e

Parents:

69a5600

Message:

Improve SYS_IOSPACE_ENABLE support.
The general protection fault handler now contains
code to service early I/O Permission bitmap faults.

Location:

arch/ia32

Files:

• include/cpu.h (modified) (1 diff)
• include/ddi/ddi.h (added)
• include/proc/task.h (modified) (1 diff)
• src/ddi/ddi.c (modified) (4 diffs)
• src/interrupt.c (modified) (2 diffs)
• src/proc/scheduler.c (modified) (2 diffs)

arch/ia32/include/cpu.h

@@ -43 +43 @@
         int stepping;
         struct tss *tss;
+        
+        count_t iomapver_copy;  /** Copy of TASK's I/O Permission bitmap generation count. */
 };
 

arch/ia32/include/proc/task.h

@@ -35 +35 @@
 
 typedef struct {
-        bitmap_t iomap;
+        count_t iomapver;       /**< I/O Permission bitmap Generation counter. */
+        bitmap_t iomap;         /**< I/O Permission bitmap. */
 } task_arch_t;
 

arch/ia32/src/ddi/ddi.c

@@ -28 +28 @@
 
 #include <ddi/ddi.h>
+#include <arch/ddi/ddi.h>
 #include <proc/task.h>
 #include <arch/types.h>
@@ -36 +37 @@
 #include <errno.h>
 #include <arch/cpu.h>
+#include <cpu.h>
+#include <arch.h>
 
 /** Enable I/O space range for task.
@@ -90 +93 @@
         bitmap_clear_range(&task->arch.iomap, (index_t) ioaddr, (count_t) size);
 
+        /*
+         * Increment I/O Permission bitmap generation counter.
+         */
+        task->arch.iomapver++;
+
         return 0;
 }
@@ -106 +114 @@
         return 0;
 }
+
+/** Install I/O Permission bitmap.
+ *
+ * Current task's I/O permission bitmap, if any, is installed
+ * in the current CPU's TSS.
+ *
+ * Interrupts must be disabled prior this call.
+ */
+void io_perm_bitmap_install(void)
+{
+        count_t bits;
+        ptr_16_32_t cpugdtr;
+        descriptor_t *gdt_p;
+        count_t ver;
+
+        /* First, copy the I/O Permission Bitmap. */
+        spinlock_lock(&TASK->lock);
+        ver = TASK->arch.iomapver;
+        if ((bits = TASK->arch.iomap.bits)) {
+                bitmap_t iomap;
+        
+                ASSERT(TASK->arch.iomap.map);
+                bitmap_initialize(&iomap, CPU->arch.tss->iomap, TSS_IOMAP_SIZE * 8);
+                bitmap_copy(&iomap, &TASK->arch.iomap, TASK->arch.iomap.bits);
+                /*
+                 * It is safe to set the trailing eight bits because of the extra
+                 * convenience byte in TSS_IOMAP_SIZE.
+                 */
+                bitmap_set_range(&iomap, TASK->arch.iomap.bits, 8);
+        }
+        spinlock_unlock(&TASK->lock);
+
+        /* Second, adjust TSS segment limit. */
+        gdtr_store(&cpugdtr);
+        gdt_p = (descriptor_t *) cpugdtr.base;
+        gdt_setlimit(&gdt_p[TSS_DES], TSS_BASIC_SIZE + BITS2BYTES(bits) - 1);
+        gdtr_load(&cpugdtr);
+
+        /*
+         * Before we load new TSS limit, the current TSS descriptor
+         * type must be changed to describe inactive TSS.
+         */
+        gdt_p[TSS_DES].access = AR_PRESENT | AR_TSS | DPL_KERNEL;
+        tr_load(selector(TSS_DES));
+        
+        /*
+         * Update the generation count so that faults caused by
+         * early accesses can be serviced.
+         */
+        CPU->arch.iomapver_copy = ver;
+}

arch/ia32/src/interrupt.c

@@ -41 +41 @@
 #include <symtab.h>
 #include <proc/thread.h>
+#include <proc/task.h>
+#include <synch/spinlock.h>
+#include <arch/ddi/ddi.h>
 
 /*
@@ -79 +82 @@
 }
 
+/** General Protection Fault. */
 void gp_fault(int n, istate_t *istate)
 {
+        if (TASK) {
+                count_t ver;
+                
+                spinlock_lock(&TASK->lock);
+                ver = TASK->arch.iomapver;
+                spinlock_unlock(&TASK->lock);
+        
+                if (CPU->arch.iomapver_copy != ver) {
+                        /*
+                         * This fault can be caused by an early access
+                         * to I/O port because of an out-dated
+                         * I/O Permission bitmap installed on CPU.
+                         * Install the fresh copy and restart
+                         * the instruction.
+                         */
+                        io_perm_bitmap_install();
+                        return;
+                }
+        }
+
         PRINT_INFO_ERRCODE(istate);
         panic("general protection fault\n");

arch/ia32/src/proc/scheduler.c

@@ -36 +36 @@
 #include <arch/pm.h>
 #include <arch/asm.h>
-#include <adt/bitmap.h>
-#include <print.h>
+#include <arch/ddi/ddi.h>
 
 /** Perform ia32 specific tasks needed before the new task is run.
@@ -45 +44 @@
 void before_task_runs_arch(void)
 {
-        count_t bits;
-        ptr_16_32_t cpugdtr;
-        descriptor_t *gdt_p;
-
-        /*
-         * Switch the I/O Permission Bitmap, if necessary.
-         */
-
-        /* First, copy the I/O Permission Bitmap. */
-        spinlock_lock(&TASK->lock);
-        if ((bits = TASK->arch.iomap.bits)) {
-                bitmap_t iomap;
-        
-                ASSERT(TASK->arch.iomap.map);
-                bitmap_initialize(&iomap, CPU->arch.tss->iomap, TSS_IOMAP_SIZE * 8);
-                bitmap_copy(&iomap, &TASK->arch.iomap, TASK->arch.iomap.bits);
-                /*
-                 * It is safe to set the trailing eight bits because of the extra
-                 * convenience byte in TSS_IOMAP_SIZE.
-                 */
-                bitmap_set_range(&iomap, TASK->arch.iomap.bits, 8);
-        }
-        spinlock_unlock(&TASK->lock);
-
-        /* Second, adjust TSS segment limit. */
-        gdtr_store(&cpugdtr);
-        gdt_p = (descriptor_t *) cpugdtr.base;
-        gdt_setlimit(&gdt_p[TSS_DES], TSS_BASIC_SIZE + BITS2BYTES(bits) - 1);
-        gdtr_load(&cpugdtr);
-
-        /*
-         * Before we load new TSS limit, the current TSS descriptor
-         * type must be changed to describe inactive TSS.
-         */
-        gdt_p[TSS_DES].access = AR_PRESENT | AR_TSS | DPL_KERNEL;
-        tr_load(selector(TSS_DES));
+        io_perm_bitmap_install();
 }