diff options
Diffstat (limited to 'cpukit/score/cpu/sparc/sparc-context-volatile-clobber.S')
| -rw-r--r-- | cpukit/score/cpu/sparc/sparc-context-volatile-clobber.S | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/cpukit/score/cpu/sparc/sparc-context-volatile-clobber.S b/cpukit/score/cpu/sparc/sparc-context-volatile-clobber.S new file mode 100644 index 0000000000..6e364cd3f6 --- /dev/null +++ b/cpukit/score/cpu/sparc/sparc-context-volatile-clobber.S @@ -0,0 +1,156 @@ +/* + * Copyright (c) 2015 embedded brains GmbH. All rights reserved. + * + * embedded brains GmbH + * Dornierstr. 4 + * 82178 Puchheim + * Germany + * <rtems@embedded-brains.de> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + +#ifdef HAVE_CONFIG_H + #include "config.h" +#endif + +#include <rtems/asm.h> +#include <rtems/score/cpu.h> + +#define SCRATCH_0 (CPU_MINIMUM_STACK_FRAME_SIZE) +#define SCRATCH_1 (SCRATCH_0 + 0x04) +#define FRAME_END (SCRATCH_1 + 0x04) +#define FRAME_SIZE \ + ((FRAME_END + CPU_STACK_ALIGNMENT - 1) & ~(CPU_STACK_ALIGNMENT - 1)) + +.macro clobber_register reg + sub %g2, 1, %g2 + mov %g2, \reg +.endm + +.macro clobber_fp_register reg + sub %g2, 1, %g2 + st %g2, [%sp + SCRATCH_0] + ld [%sp + SCRATCH_0], \reg +.endm + + .section ".bss" + .align 4 + + /* + * Use a global variable to vary the clobbered windows in each + * invocation to test the window overflow and underflow conditions. + */ +window_clobber_count: + .skip 4 + + .section ".text" + .align 4 + + PUBLIC(_CPU_Context_volatile_clobber) +SYM(_CPU_Context_volatile_clobber): + + /* Increment number of flushed windows by one */ + sethi %hi(window_clobber_count), %o1 + ld [%o1 + %lo(window_clobber_count)], %o2 + add %o2, 1, %o2 + st %o2, [%o1 + %lo(window_clobber_count)] + + /* Clear window counter number */ + clr %g1 + + /* Save pattern to global register */ + mov %o0, %g2 + +window_clobber: + + /* Switch window */ + + save %sp, -FRAME_SIZE, %sp + + /* Check how many windows shall be flushed */ + sethi %hi(window_clobber_count), %o1 + ld [%o1 + %lo(window_clobber_count)], %o2 + st %o2, [%o1 + %lo(window_clobber_count)] + and %o2, (SPARC_NUMBER_OF_REGISTER_WINDOWS - 1), %o1 + cmp %o1, 0 + bne no_manual_update + nop + add %o1, SPARC_NUMBER_OF_REGISTER_WINDOWS, %o1 + +no_manual_update: + /* Register to determine whether FPU is switched on */ + mov %psr, %o2 + sethi %hi(SPARC_PSR_EF_MASK), %o3 + and %o3, %o2, %o2 + + clobber_register %o3 + clobber_register %o4 + clobber_register %o5 + /* Don't overwrite return address $o7 */ + clobber_register %g3 + clobber_register %g4 + clobber_register %y + + cmp %o2, 0 + be window_update_check + nop + + clobber_fp_register %f0 + clobber_fp_register %f1 + clobber_fp_register %f2 + clobber_fp_register %f3 + clobber_fp_register %f4 + clobber_fp_register %f5 + clobber_fp_register %f6 + clobber_fp_register %f7 + clobber_fp_register %f8 + clobber_fp_register %f9 + clobber_fp_register %f10 + clobber_fp_register %f11 + clobber_fp_register %f12 + clobber_fp_register %f13 + clobber_fp_register %f14 + clobber_fp_register %f15 + clobber_fp_register %f16 + clobber_fp_register %f17 + clobber_fp_register %f18 + clobber_fp_register %f19 + clobber_fp_register %f20 + clobber_fp_register %f21 + clobber_fp_register %f22 + clobber_fp_register %f23 + clobber_fp_register %f24 + clobber_fp_register %f25 + clobber_fp_register %f26 + clobber_fp_register %f27 + clobber_fp_register %f28 + clobber_fp_register %f29 + clobber_fp_register %f30 + clobber_fp_register %f31 + +window_update_check: + + /* Counter to how many windows were switched */ + add %g1, 1, %g1 + cmp %g1, %o1 + bl window_clobber + nop + +restore_check: + + cmp %g1, 0 + be clobber_return + nop + + restore + sub %g1, 1, %g1 + ba restore_check + nop + +clobber_return: + + jmp %o7 + 8 + add %sp, FRAME_SIZE, %sp |