[src/trunk]: src/sys/arch/arm/iomd Adjust code and register usage so that r4 ...

[skrll <skrll%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/827615fc4da6
branches:  trunk
changeset: 978442:827615fc4da6
user:      skrll <skrll%NetBSD.org@localhost>
date:      Sat Nov 21 19:52:56 2020 +0000

description:
Adjust code and register usage so that r4 and r5 are preserved as
cur{cpu,lwp} respectively as required by the change to make ASTs
operate per-LWP rather than per-CPU.  These registers are used by
DO_AST_AND_RESTORE_ALIGNMENT_FAULTS expecting this usage.

XXX untested

diffstat:

 sys/arch/arm/iomd/iomd_irq.S |  40 ++++++++++++++++++----------------------
 1 files changed, 18 insertions(+), 22 deletions(-)

diffs (126 lines):

diff -r dfe82fab25ff -r 827615fc4da6 sys/arch/arm/iomd/iomd_irq.S
--- a/sys/arch/arm/iomd/iomd_irq.S      Sat Nov 21 19:46:13 2020 +0000
+++ b/sys/arch/arm/iomd/iomd_irq.S      Sat Nov 21 19:52:56 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: iomd_irq.S,v 1.17 2020/11/21 09:36:26 skrll Exp $      */
+/*     $NetBSD: iomd_irq.S,v 1.18 2020/11/21 19:52:56 skrll Exp $      */
 
 /*
  * Copyright (c) 1994-1998 Mark Brinicombe.
@@ -100,10 +100,11 @@
  * Register usage
  *
  *  r4  - Address of cpu_info
- *  r5  - Address of ffs table
+ *  r5  - Address of curlwp
  *  r6  - Address of current handler
  *  r7  - Pointer to handler pointer list
  *  r8  - Current IRQ requests.
+ *  r9  - scratch
  *  r10 - Base address of IOMD
  *  r11 - IRQ requests still to service.
  */
@@ -118,7 +119,7 @@
        sub     lr, lr, #0x00000004     /* Adjust the lr */
 
        PUSHFRAMEINSVC                  /* Push an interrupt frame */
-       ENABLE_ALIGNMENT_FAULTS
+       ENABLE_ALIGNMENT_FAULTS         /* puts cur{cpu,lwp} in r4/r5 */
 
        str     r7, [sp, #TF_FILL]      /* save r7 */
 
@@ -212,22 +213,20 @@
        bic     r0, r0, #I32_bit
        msr     cpsr_all, r0
 
-       ldr     r7, Lirqhandlers
-
        /*
         * take a copy of the IRQ request so that we can strip bits out of it
         * note that we only use 24 bits with iomd2 chips
         */
-       ldr     r5, Larm7500_ioc_found
-       ldr     r5, [r5]                        /* get the flag      */
-       cmp     r5, #0
+       ldr     r7, Larm7500_ioc_found
+       ldr     r7, [r7]                        /* get the flag      */
+       cmp     r7, #0
        movne   r11, r8                         /* ARM7500  -> copy all bits   */
        biceq   r11, r8, #0xff000000            /* !ARM7500 -> only use 24 bit */
 
        /* ffs routine to find first irq to service */
        /* standard trick to isolate bottom bit in a0 or 0 if a0 = 0 on entry */
-       rsb     r5, r11, #0
-       ands    r10, r11, r5
+       rsb     r7, r11, #0
+       ands    r10, r11, r7
 
        /*
         * now r10 has at most 1 set bit, call this X
@@ -235,22 +234,22 @@
         */
        beq     exitirq
 irqloop:
-       adr     r5, Lirq_ffs_table
+       ldr     r6, Lirqhandlers
+       adr     r7, Lirq_ffs_table
        /*
         * at this point:
-        *      r5 = address of ffs table
-        *      r7 = address of irq handlers table
+        *      r6 = address of irq handlers table
+        *      r7 = address of ffs table
         *      r8 = irq request
         *      r10 = bit of irq to be serviced
         *      r11 = bitmask of IRQ's to service
         */
-
        /* find the set bit */
        orr     r9, r10, r10, lsl #4    /* X * 0x11 */
        orr     r9, r9, r9, lsl #6      /* X * 0x451 */
        rsb     r9, r9, r9, lsl #16     /* X * 0x0450fbaf */
        /* fetch the bit number */
-       ldrb    r9, [r5, r9, lsr #26 ]
+       ldrb    r9, [r7, r9, lsr #26 ]
 
        /*
         * r9 = irq to service
@@ -265,7 +264,7 @@
         *      - unsetting of the irq bit in r11
         *      - irq stats (if enabled) also get put in the mix
         */
-       ldr     r6, [r7, r9, lsl #2]    /* Get address of first handler structure */
+       ldr     r6, [r6, r9, lsl #2]    /* Get address of first handler structure */
 
        teq     r6, #0x00000000         /* Do we have a handler */
        moveq   r0, r8                  /* IRQ requests as arg 0 */
@@ -301,6 +300,7 @@
        ldr     r0, [r6, #(IH_ARG)]     /* Get argument pointer */
        teq     r0, #0x00000000         /* If arg is zero pass stack frame */
        addeq   r0, sp, #8              /* ... stack frame [XXX needs care] */
+
        mov     lr, pc                  /* return address */
        ldr     pc, [r6, #(IH_FUNC)]    /* Call handler */
 
@@ -313,8 +313,8 @@
        bne     irqchainloop
 nextirq:
        /* Check for next irq */
-       rsb     r5, r11, #0
-       ands    r10, r11, r5
+       rsb     r7, r11, #0
+       ands    r10, r11, r7
        /* check if there are anymore irq's to service */
        bne     irqloop
 
@@ -326,10 +326,6 @@
 
        bl      _C_LABEL(irq_setmasks)
 
-#if __HAVE_FAST_SOFTINTS
-       bl      _C_LABEL(dosoftints)    /* Handle the soft interrupts */
-#endif
-
        /* Kill IRQ's in preparation for exit */
         mrs     r0, cpsr
         orr     r0, r0, #(I32_bit)