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u-boot/arch/powerpc/lib/ticks.S

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SPDX: Convert all of our single license tags to Linux Kernel style When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-06 21:58:06 +00:00
/* SPDX-License-Identifier: GPL-2.0+ */
Initial revision
2001-11-26 22:06:16 +00:00
/*
* (C) Copyright 2000, 2001
* Erik Theisen, Wave 7 Optics, etheisen@mindspring.com.
* base on code by
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*/
#include <ppc_asm.tmpl>
#include <ppc_defs.h>
#include <config.h>
#include <watchdog.h>
/*
* unsigned long long get_ticks(void);
*
* read timebase as "long long"
*/
.globl get_ticks
get_ticks:
1: mftbu r3
mftb r4
mftbu r5
cmp 0,r3,r5
bne 1b
blr
/*
* Delay for a number of ticks
*/
.globl wait_ticks
wait_ticks:
ppc: Create a stack frame for wait_ticks() wait_ticks() calls get_ticks() without building a back chain which makes gdb unhappy when doing back trace. This can also cause improper memory accesses. Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
2012-07-16 21:25:40 +00:00
stwu r1, -16(r1)
mflr r0 /* save link register */
stw r0, 20(r1) /* Use r0 or GDB will be unhappy */
powerpc/lib: fix unsafe register handling in wait_ticks If watchdog is enabled, the arch/powerpc/lib/ticks.S::wait_ticks() function calls the function specified by the WATCHDOG_RESET macro. The wait_ticks function depends on the registers r0, r6 and r7 being preserved however that is not guaranteed, e.g. if the reset function is a C function this will probably overwrite r0 and cause an endless loop. The following patch changes to using r14+r15 instead of r6+r7 (to resemble what would have been generated by a C compiler) and saves all necessary registers on the stack. The patch has been tested on a custom MPC5125 based machine using the 512x powerpc architecture. Signed-off-by: Mats Karrman <mats.karrman@tritech.se> Cc: Wolfgang Denk <wd@denx.de> Acked-by: Joakim Tjernlund <joakim.tjernlund@transmode.se> Tested-by: Stefan Roese <sr@denx.de>
2013-04-09 15:10:59 +00:00
stw r14, 12(r1) /* save used registers */
stw r15, 8(r1)
mr r14, r3 /* save tick count */
Initial revision
2001-11-26 22:06:16 +00:00
bl get_ticks /* Get start time */
/* Calculate end time */
powerpc/lib: fix unsafe register handling in wait_ticks If watchdog is enabled, the arch/powerpc/lib/ticks.S::wait_ticks() function calls the function specified by the WATCHDOG_RESET macro. The wait_ticks function depends on the registers r0, r6 and r7 being preserved however that is not guaranteed, e.g. if the reset function is a C function this will probably overwrite r0 and cause an endless loop. The following patch changes to using r14+r15 instead of r6+r7 (to resemble what would have been generated by a C compiler) and saves all necessary registers on the stack. The patch has been tested on a custom MPC5125 based machine using the 512x powerpc architecture. Signed-off-by: Mats Karrman <mats.karrman@tritech.se> Cc: Wolfgang Denk <wd@denx.de> Acked-by: Joakim Tjernlund <joakim.tjernlund@transmode.se> Tested-by: Stefan Roese <sr@denx.de>
2013-04-09 15:10:59 +00:00
addc r14, r4, r14 /* Compute end time lower */
addze r15, r3 /* and end time upper */
Initial revision
2001-11-26 22:06:16 +00:00
WATCHDOG_RESET /* Trigger watchdog, if needed */
1: bl get_ticks /* Get current time */
powerpc/lib: fix unsafe register handling in wait_ticks If watchdog is enabled, the arch/powerpc/lib/ticks.S::wait_ticks() function calls the function specified by the WATCHDOG_RESET macro. The wait_ticks function depends on the registers r0, r6 and r7 being preserved however that is not guaranteed, e.g. if the reset function is a C function this will probably overwrite r0 and cause an endless loop. The following patch changes to using r14+r15 instead of r6+r7 (to resemble what would have been generated by a C compiler) and saves all necessary registers on the stack. The patch has been tested on a custom MPC5125 based machine using the 512x powerpc architecture. Signed-off-by: Mats Karrman <mats.karrman@tritech.se> Cc: Wolfgang Denk <wd@denx.de> Acked-by: Joakim Tjernlund <joakim.tjernlund@transmode.se> Tested-by: Stefan Roese <sr@denx.de>
2013-04-09 15:10:59 +00:00
subfc r4, r4, r14 /* Subtract current time from end time */
subfe. r3, r3, r15
Initial revision
2001-11-26 22:06:16 +00:00
bge 1b /* Loop until time expired */
powerpc/lib: fix unsafe register handling in wait_ticks If watchdog is enabled, the arch/powerpc/lib/ticks.S::wait_ticks() function calls the function specified by the WATCHDOG_RESET macro. The wait_ticks function depends on the registers r0, r6 and r7 being preserved however that is not guaranteed, e.g. if the reset function is a C function this will probably overwrite r0 and cause an endless loop. The following patch changes to using r14+r15 instead of r6+r7 (to resemble what would have been generated by a C compiler) and saves all necessary registers on the stack. The patch has been tested on a custom MPC5125 based machine using the 512x powerpc architecture. Signed-off-by: Mats Karrman <mats.karrman@tritech.se> Cc: Wolfgang Denk <wd@denx.de> Acked-by: Joakim Tjernlund <joakim.tjernlund@transmode.se> Tested-by: Stefan Roese <sr@denx.de>
2013-04-09 15:10:59 +00:00
lwz r15, 8(r1) /* restore saved registers */
lwz r14, 12(r1)
lwz r0, 20(r1)
ppc: Create a stack frame for wait_ticks() wait_ticks() calls get_ticks() without building a back chain which makes gdb unhappy when doing back trace. This can also cause improper memory accesses. Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
2012-07-16 21:25:40 +00:00
addi r1,r1,16
powerpc/lib: fix unsafe register handling in wait_ticks If watchdog is enabled, the arch/powerpc/lib/ticks.S::wait_ticks() function calls the function specified by the WATCHDOG_RESET macro. The wait_ticks function depends on the registers r0, r6 and r7 being preserved however that is not guaranteed, e.g. if the reset function is a C function this will probably overwrite r0 and cause an endless loop. The following patch changes to using r14+r15 instead of r6+r7 (to resemble what would have been generated by a C compiler) and saves all necessary registers on the stack. The patch has been tested on a custom MPC5125 based machine using the 512x powerpc architecture. Signed-off-by: Mats Karrman <mats.karrman@tritech.se> Cc: Wolfgang Denk <wd@denx.de> Acked-by: Joakim Tjernlund <joakim.tjernlund@transmode.se> Tested-by: Stefan Roese <sr@denx.de>
2013-04-09 15:10:59 +00:00
mtlr r0
Initial revision
2001-11-26 22:06:16 +00:00
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