linux/arch/powerpc/xmon/spr_access.S
Nicholas Piggin dab3b8f4fd powerpc/64: asm use consistent global variable declaration and access
Use helper macros to access global variables, and place them in .data
sections rather than in .toc. Putting addresses in TOC is not required
because the kernel is linked with a single TOC.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220926034057.2360083-3-npiggin@gmail.com
2022-09-28 19:22:12 +10:00

48 lines
814 B
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
#include <asm/ppc_asm.h>
#include <asm/asm-compat.h>
/* unsigned long xmon_mfspr(sprn, default_value) */
_GLOBAL(xmon_mfspr)
LOAD_REG_ADDR(r5, .Lmfspr_table)
b xmon_mxspr
/* void xmon_mtspr(sprn, new_value) */
_GLOBAL(xmon_mtspr)
LOAD_REG_ADDR(r5, .Lmtspr_table)
b xmon_mxspr
/*
* r3 = sprn
* r4 = default or new value
* r5 = table base
*/
xmon_mxspr:
/*
* To index into the table of mxsprs we need:
* i = (sprn & 0x3ff) * 8
* or using rwlinm:
* i = (sprn << 3) & (0x3ff << 3)
*/
rlwinm r3, r3, 3, 0x3ff << 3
add r5, r5, r3
mtctr r5
mr r3, r4 /* put default_value in r3 for mfspr */
bctr
.Lmfspr_table:
spr = 0
.rept 1024
mfspr r3, spr
blr
spr = spr + 1
.endr
.Lmtspr_table:
spr = 0
.rept 1024
mtspr spr, r4
blr
spr = spr + 1
.endr