#define __ASM_ARCH_TIMER_H
#include <asm/barrier.h>
+#include <asm/sysreg.h>
#include <linux/bug.h>
#include <linux/init.h>
+#include <linux/jump_label.h>
#include <linux/types.h>
#include <clocksource/arm_arch_timer.h>
+#if IS_ENABLED(CONFIG_FSL_ERRATUM_A008585)
+extern struct static_key_false arch_timer_read_ool_enabled;
+#define needs_fsl_a008585_workaround() \
+ static_branch_unlikely(&arch_timer_read_ool_enabled)
+#else
+#define needs_fsl_a008585_workaround() false
+#endif
+
+u32 __fsl_a008585_read_cntp_tval_el0(void);
+u32 __fsl_a008585_read_cntv_tval_el0(void);
+u64 __fsl_a008585_read_cntvct_el0(void);
+
+/*
+ * The number of retries is an arbitrary value well beyond the highest number
+ * of iterations the loop has been observed to take.
+ */
+#define __fsl_a008585_read_reg(reg) ({ \
+ u64 _old, _new; \
+ int _retries = 200; \
+ \
+ do { \
+ _old = read_sysreg(reg); \
+ _new = read_sysreg(reg); \
+ _retries--; \
+ } while (unlikely(_old != _new) && _retries); \
+ \
+ WARN_ON_ONCE(!_retries); \
+ _new; \
+})
+
+#define arch_timer_reg_read_stable(reg) \
+({ \
+ u64 _val; \
+ if (needs_fsl_a008585_workaround()) \
+ _val = __fsl_a008585_read_##reg(); \
+ else \
+ _val = read_sysreg(reg); \
+ _val; \
+})
+
/*
* These register accessors are marked inline so the compiler can
* nicely work out which register we want, and chuck away the rest of
if (access == ARCH_TIMER_PHYS_ACCESS) {
switch (reg) {
case ARCH_TIMER_REG_CTRL:
- asm volatile("msr cntp_ctl_el0, %0" : : "r" (val));
+ write_sysreg(val, cntp_ctl_el0);
break;
case ARCH_TIMER_REG_TVAL:
- asm volatile("msr cntp_tval_el0, %0" : : "r" (val));
+ write_sysreg(val, cntp_tval_el0);
break;
}
} else if (access == ARCH_TIMER_VIRT_ACCESS) {
switch (reg) {
case ARCH_TIMER_REG_CTRL:
- asm volatile("msr cntv_ctl_el0, %0" : : "r" (val));
+ write_sysreg(val, cntv_ctl_el0);
break;
case ARCH_TIMER_REG_TVAL:
- asm volatile("msr cntv_tval_el0, %0" : : "r" (val));
+ write_sysreg(val, cntv_tval_el0);
break;
}
}
static __always_inline
u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg)
{
- u32 val;
-
if (access == ARCH_TIMER_PHYS_ACCESS) {
switch (reg) {
case ARCH_TIMER_REG_CTRL:
- asm volatile("mrs %0, cntp_ctl_el0" : "=r" (val));
- break;
+ return read_sysreg(cntp_ctl_el0);
case ARCH_TIMER_REG_TVAL:
- asm volatile("mrs %0, cntp_tval_el0" : "=r" (val));
- break;
+ return arch_timer_reg_read_stable(cntp_tval_el0);
}
} else if (access == ARCH_TIMER_VIRT_ACCESS) {
switch (reg) {
case ARCH_TIMER_REG_CTRL:
- asm volatile("mrs %0, cntv_ctl_el0" : "=r" (val));
- break;
+ return read_sysreg(cntv_ctl_el0);
case ARCH_TIMER_REG_TVAL:
- asm volatile("mrs %0, cntv_tval_el0" : "=r" (val));
- break;
+ return arch_timer_reg_read_stable(cntv_tval_el0);
}
}
- return val;
+ BUG();
}
static inline u32 arch_timer_get_cntfrq(void)
{
- u32 val;
- asm volatile("mrs %0, cntfrq_el0" : "=r" (val));
- return val;
+ return read_sysreg(cntfrq_el0);
}
static inline u32 arch_timer_get_cntkctl(void)
{
- u32 cntkctl;
- asm volatile("mrs %0, cntkctl_el1" : "=r" (cntkctl));
- return cntkctl;
+ return read_sysreg(cntkctl_el1);
}
static inline void arch_timer_set_cntkctl(u32 cntkctl)
{
- asm volatile("msr cntkctl_el1, %0" : : "r" (cntkctl));
+ write_sysreg(cntkctl, cntkctl_el1);
}
static inline u64 arch_counter_get_cntpct(void)
static inline u64 arch_counter_get_cntvct(void)
{
- u64 cval;
-
isb();
- asm volatile("mrs %0, cntvct_el0" : "=r" (cval));
-
- return cval;
+ return arch_timer_reg_read_stable(cntvct_el0);
}
static inline int arch_timer_arch_init(void)