Changeset 83d2d0e in mainline

Timestamp:

2006-03-05T20:28:31Z (19 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

e1c68e0c

Parents:

bc314be8

Message:

ia64 work.

ivt.S:
Detect userspace stack in heavyweight handler and switch to kernel stack.
Remember the old stack pointer.
As for register stack, kernel stack is assumed still.
Fix alignment issues that showed when STACK_ITEMS was odd.
Fix ld8 instruction that did subtraction of 8 instead of addition of 8.

scheduler.c:
Change before_thread_runs_arch() to calculate address of top of the stack
for the interrupt handler.

Files:

• arch/ia64/include/interrupt.h (modified) (1 diff)
• arch/ia64/include/register.h (modified) (1 diff)
• arch/ia64/src/ivt.S (modified) (6 diffs)
• arch/ia64/src/proc/scheduler.c (modified) (2 diffs)
• doc/arch/ia64 (modified) (1 diff)

arch/ia64/include/interrupt.h

@@ -60 +60 @@
         __address cr_iip;
         __u64 pr;
+        __address sp;
 } __attribute__ ((packed));
 

arch/ia64/include/register.h

@@ -42 +42 @@
 #define PSR_RT_MASK     (1<<27)
 #define PSR_IT_MASK     0x0000001000000000
+
+#define PSR_CPL_SHIFT           32
+#define PSR_CPL_MASK_SHIFTED    3
 
 /** Application registers. */

arch/ia64/src/ivt.S

@@ -30 +30 @@
 #include <arch/stack.h>
 #include <arch/register.h>
-
-#define STACK_ITEMS             12
-#define STACK_FRAME_SIZE        ((STACK_ITEMS*STACK_ITEM_SIZE) + STACK_SCRATCH_AREA_SIZE)
-
-#if (STACK_FRAME_SIZE % STACK_ALIGNMENT != 0)
-#error Memory stack must be 16-byte aligned.
+#include <arch/mm/page.h>
+#include <align.h>
+
+#define STACK_ITEMS             13
+#define STACK_FRAME_SIZE        ALIGN_UP((STACK_ITEMS*STACK_ITEM_SIZE) + STACK_SCRATCH_AREA_SIZE, STACK_ALIGNMENT)
+
+#if (STACK_ITEMS % 2 == 0)
+#       define STACK_FRAME_BIAS 8
+#else
+#       define STACK_FRAME_BIAS 16
 #endif
 
@@ -71 +75 @@
     
         /*
-         * Note that r24-r31 from bank0 can be used only as long as PSR.ic = 0.
+         * Note that r24-r31 from bank 0 can be used only as long as PSR.ic = 0.
          */
         mov r24 = cr.iip
@@ -83 +87 @@
         
     /* 3. switch to kernel memory stack */
-        /* TODO: support interruptions from userspace */
-        /* assume kernel stack */
-        
-        add r31 = -8, r12 ;;
+        mov r30 = cr.ipsr
+        shr.u r31 = r12, VRN_SHIFT ;; 
+
+        /*
+         * Set p6 to true if the stack register references kernel address space.
+         * Set p7 to false if the stack register doesn't reference kernel address space.
+         */
+        cmp.eq p6, p7 = VRN_KERNEL, r31 ;;
+        
+        (p6) shr.u r30 = r30, PSR_CPL_SHIFT ;;
+        (p6) and r30 = PSR_CPL_MASK_SHIFTED, r30 ;;
+
+        /*
+         * Set p6 to true if the interrupted context executed in kernel mode.
+         * Set p7 to false if the interrupted context didn't execute in kernel mode.
+         */
+        (p6) cmp.eq p6, p7 = r30, r0 ;;
+        
+        /*
+         * Now, p7 is true iff the stack needs to be switched to kernel stack.
+         */
+        mov r30 = r12
+        (p7) mov r12 = R_KSTACK ;;
+        
+        add r31 = -STACK_FRAME_BIAS, r12 ;;
         add r12 = -STACK_FRAME_SIZE, r12
 
     /* 4. save registers in bank 0 into memory stack */ 
-        st8 [r31] = r29, -8 ;;  /* save predicate registers */
-
-        st8 [r31] = r24, -8 ;;  /* save cr.iip */
-        st8 [r31] = r25, -8 ;;  /* save cr.ipsr */
-        st8 [r31] = r26, -8 ;;  /* save cr.iipa */
-        st8 [r31] = r27, -8 ;;  /* save cr.isr */
-        st8 [r31] = r28, -8     /* save cr.ifa */               
+        st8 [r31] = r30, -8 ;;          /* save old stack pointer */ 
+        
+        st8 [r31] = r29, -8 ;;          /* save predicate registers */
+
+        st8 [r31] = r24, -8 ;;          /* save cr.iip */
+        st8 [r31] = r25, -8 ;;          /* save cr.ipsr */
+        st8 [r31] = r26, -8 ;;          /* save cr.iipa */
+        st8 [r31] = r27, -8 ;;          /* save cr.isr */
+        st8 [r31] = r28, -8 ;;          /* save cr.ifa */
 
     /* 5. RSE switch from interrupted context */
@@ -104 +131 @@
         mov r26 = cr.ifs
         
-        st8 [r31] = r24, -8;;   /* save ar.rsc */
-        st8 [r31] = r25, -8;;   /* save ar.pfs */
+        st8 [r31] = r24, -8 ;;  /* save ar.rsc */
+        st8 [r31] = r25, -8 ;;  /* save ar.pfs */
         st8 [r31] = r26, -8     /* save ar.ifs */
         
@@ -121 +148 @@
         st8 [r31] = r27, -8 ;;  /* save ar.rnat */
         st8 [r31] = r28, -8 ;;  /* save ar.bspstore */
-        st8 [r31] = r29, -8     /* save ar.bsp */
+        st8 [r31] = r29, -8     /* save ar.bsp */
         
         mov ar.rsc = r24        /* restore RSE's setting */
@@ -175 +202 @@
 
     /* 18. restore predicate registers from memory stack */
-        ld8 r29 = [r31] , -8 ;; /* load predicate registers */
+        ld8 r29 = [r31], +8 ;;  /* load predicate registers */
         mov pr = r29
         
     /* 19. return from interruption */
-        add r12 = STACK_FRAME_SIZE, r12
+        ld8 r12 = [r31]         /* load stack pointer */ 
         rfi ;;
 

arch/ia64/src/proc/scheduler.c

@@ -31 +31 @@
 #include <arch.h>
 #include <arch/register.h>
+#include <arch/context.h>
 #include <arch/mm/tlb.h>
 #include <config.h>
@@ -58 +59 @@
                 "mov r23 = %0\n"
                 "bsw.1\n"
-                 : : "r" (THREAD->kstack));
+                 : : "r" (&THREAD->kstack[THREAD_STACK_SIZE - SP_DELTA]));
 }
 

doc/arch/ia64

@@ -12 +12 @@
 
 TOOLCHAIN REQUIREMENTS
-        o binutils 2.15, 2.16
-        o gcc 4.0.0
+        o binutils 2.15, 2.16, 2.16.1
+        o gcc 4.0.0, 4.0.1
         o older versions may do as well, but are now obsoleted