[U-Boot] [PATCH 1/1] arm: ls102xa: timer: Fix undefined behavior
PL1 Physical Comp Value is set in inline assembly by using mcrr. The %Q0 and %R0 modifier required a 64-bit argument but only a 32-bit is passed. This results in the following code: [...] 82000ccc: e3e03000 mvn r3, #0 82000cd0: ec443f2e mcrr 15, 2, r3, r4, cr14 [...] While r4 is uninitialized it depends on the value in initcall_run_list how the timer is programmed. It has been observed that this code works by coincidence with one toolchain while it breaks with another one which uses different registers in initcall_run_list. Fix this by actually using a 64-bit variable.
Signed-off-by: Alexander Stein alexander.stein@systec-electronic.com --- arch/arm/cpu/armv7/ls102xa/timer.c | 3 ++- arch/arm/include/asm/arch-ls102xa/immap_ls102xa.h | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/arm/cpu/armv7/ls102xa/timer.c b/arch/arm/cpu/armv7/ls102xa/timer.c index 11b17b2..f964288 100644 --- a/arch/arm/cpu/armv7/ls102xa/timer.c +++ b/arch/arm/cpu/armv7/ls102xa/timer.c @@ -56,7 +56,8 @@ static inline unsigned long long us_to_tick(unsigned long long usec) int timer_init(void) { struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR; - unsigned long ctrl, val, freq; + unsigned long ctrl, freq; + u64 val;
/* Enable System Counter */ writel(SYS_COUNTER_CTRL_ENABLE, &sctr->cntcr); diff --git a/arch/arm/include/asm/arch-ls102xa/immap_ls102xa.h b/arch/arm/include/asm/arch-ls102xa/immap_ls102xa.h index d34044a..e45c20e 100644 --- a/arch/arm/include/asm/arch-ls102xa/immap_ls102xa.h +++ b/arch/arm/include/asm/arch-ls102xa/immap_ls102xa.h @@ -31,7 +31,7 @@ #define RCWSR4_SRDS1_PRTCL_SHIFT 24 #define RCWSR4_SRDS1_PRTCL_MASK 0xff000000
-#define TIMER_COMP_VAL 0xffffffff +#define TIMER_COMP_VAL ~0ULL #define ARCH_TIMER_CTRL_ENABLE (1 << 0) #define SYS_COUNTER_CTRL_ENABLE (1 << 24)
-----Original Message----- From: Alexander Stein [mailto:alexander.stein@systec-electronic.com] Sent: Wednesday, August 12, 2015 9:56 PM To: u-boot@lists.denx.de; Albert Aribaud; Jingchang Lu; Kushwaha Prabhakar-B32579; Wang Huan-B18965; Jin Zhengxiong-R64188; Wang Huan- B18965; Sun York-R58495; Lian Minghuan-B31939; Tang Yuantian-B29983; Badola Nikhil-B46172 Cc: Alexander Stein Subject: [PATCH 1/1] arm: ls102xa: timer: Fix undefined behavior
PL1 Physical Comp Value is set in inline assembly by using mcrr. The %Q0 and %R0 modifier required a 64-bit argument but only a 32-bit is passed. This results in the following code: [...] 82000ccc: e3e03000 mvn r3, #0 82000cd0: ec443f2e mcrr 15, 2, r3, r4, cr14 [...] While r4 is uninitialized it depends on the value in initcall_run_list how the timer is programmed. It has been observed that this code works by coincidence with one toolchain while it breaks with another one which uses different registers in initcall_run_list. Fix this by actually using a 64-bit variable.
Signed-off-by: Alexander Stein alexander.stein@systec-electronic.com
arch/arm/cpu/armv7/ls102xa/timer.c | 3 ++- arch/arm/include/asm/arch-ls102xa/immap_ls102xa.h | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/arm/cpu/armv7/ls102xa/timer.c b/arch/arm/cpu/armv7/ls102xa/timer.c index 11b17b2..f964288 100644 --- a/arch/arm/cpu/armv7/ls102xa/timer.c +++ b/arch/arm/cpu/armv7/ls102xa/timer.c @@ -56,7 +56,8 @@ static inline unsigned long long us_to_tick(unsigned long long usec) int timer_init(void) { struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR;
- unsigned long ctrl, val, freq;
unsigned long ctrl, freq;
u64 val;
/* Enable System Counter */ writel(SYS_COUNTER_CTRL_ENABLE, &sctr->cntcr); diff --git
a/arch/arm/include/asm/arch-ls102xa/immap_ls102xa.h b/arch/arm/include/asm/arch-ls102xa/immap_ls102xa.h index d34044a..e45c20e 100644 --- a/arch/arm/include/asm/arch-ls102xa/immap_ls102xa.h +++ b/arch/arm/include/asm/arch-ls102xa/immap_ls102xa.h @@ -31,7 +31,7 @@ #define RCWSR4_SRDS1_PRTCL_SHIFT 24 #define RCWSR4_SRDS1_PRTCL_MASK 0xff000000
-#define TIMER_COMP_VAL 0xffffffff +#define TIMER_COMP_VAL ~0ULL #define ARCH_TIMER_CTRL_ENABLE (1 << 0) #define SYS_COUNTER_CTRL_ENABLE (1 << 24)
[Alison Wang] Please refer to the comments in this link http://patchwork.ozlabs.org/patch/495476/ .
Best Regards, Alison Wang
participants (2)
-
Alexander Stein -
Huan Wang