[patch 06/38] calibrate: Rework delay timer calibration
Thomas Gleixner <[email protected]>
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The header define in asm/timex,h and the naming of the function to read the delay timer are confusing at best. Convert it to a config switch selected by the archictures, which provide the functionality, and rename the function to delay_read_timer(), which makes the purpose clear. Move the declaration to linux/delay.h where it belongs. Remove the resulting empty asm/timex.h files as well. No functional change. Signed-off-by: Thomas Gleixner <[email protected]> Cc: Arnd Bergmann <[email protected]> --- arch/Kconfig | 3 +++ arch/arm/Kconfig | 1 + arch/arm/include/asm/delay.h | 1 - arch/arm/include/asm/timex.h | 5 ++++- arch/arm/lib/delay.c | 10 ++++------ arch/hexagon/Kconfig | 1 + arch/hexagon/include/asm/timex.h | 20 -------------------- arch/hexagon/kernel/time.c | 8 +++++++- arch/openrisc/Kconfig | 1 + arch/openrisc/include/asm/timex.h | 2 -- arch/openrisc/lib/delay.c | 9 ++++----- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/timex.h | 8 -------- arch/riscv/lib/delay.c | 7 ++++++- arch/sparc/Kconfig | 1 + arch/sparc/include/asm/timex_64.h | 2 -- arch/sparc/kernel/time_64.c | 4 ++-- arch/x86/Kconfig | 1 + arch/x86/include/asm/timex.h | 2 -- arch/x86/lib/delay.c | 8 +++----- include/asm-generic/timex.h | 7 ------- include/linux/delay.h | 2 ++ include/linux/timex.h | 2 -- init/calibrate.c | 19 +++++++++---------- 24 files changed, 50 insertions(+), 75 deletions(-) --- a/arch/Kconfig +++ b/arch/Kconfig @@ -363,6 +363,9 @@ config ARCH_HAS_DMA_CLEAR_UNCACHED config ARCH_HAS_CPU_FINALIZE_INIT bool +config ARCH_HAS_DELAY_TIMER + bool + # The architecture has a per-task state that includes the mm's PASID config ARCH_HAS_CPU_PASID bool --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -11,6 +11,7 @@ config ARM select ARCH_HAS_CPU_FINALIZE_INIT if MMU select ARCH_HAS_CURRENT_STACK_POINTER select ARCH_HAS_DEBUG_VIRTUAL if MMU + select ARCH_HAS_DELAY_TIMER select ARCH_HAS_DMA_ALLOC if MMU select ARCH_HAS_DMA_OPS select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE --- a/arch/arm/include/asm/delay.h +++ b/arch/arm/include/asm/delay.h @@ -91,7 +91,6 @@ extern void __loop_udelay(unsigned long extern void __loop_const_udelay(unsigned long); /* Delay-loop timer registration. */ -#define ARCH_HAS_READ_CURRENT_TIMER extern void register_current_timer_delay(const struct delay_timer *timer); #endif /* __ASSEMBLY__ */ --- a/arch/arm/include/asm/timex.h +++ b/arch/arm/include/asm/timex.h @@ -10,7 +10,10 @@ #define _ASMARM_TIMEX_H typedef unsigned long cycles_t; -#define get_cycles() ({ cycles_t c; read_current_timer(&c) ? 0 : c; }) +// Temporary workaround +bool delay_read_timer(unsigned long *t); + +#define get_cycles() ({ cycles_t c; delay_read_timer(&c) ? 0 : c; }) #define random_get_entropy() (((unsigned long)get_cycles()) ?: random_get_entropy_fallback()) #endif --- a/arch/arm/lib/delay.c +++ b/arch/arm/lib/delay.c @@ -12,7 +12,6 @@ #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> -#include <linux/timex.h> /* * Default to the loop-based delay implementation. @@ -27,15 +26,14 @@ static const struct delay_timer *delay_t static bool delay_calibrated; static u64 delay_res; -int read_current_timer(unsigned long *timer_val) +bool delay_read_timer(unsigned long *timer_val) { if (!delay_timer) - return -ENXIO; - + return false; *timer_val = delay_timer->read_current_timer(); - return 0; + return true; } -EXPORT_SYMBOL_GPL(read_current_timer); +EXPORT_SYMBOL_GPL(delay_read_timer); static inline u64 cyc_to_ns(u64 cyc, u32 mult, u32 shift) { --- a/arch/hexagon/Kconfig +++ b/arch/hexagon/Kconfig @@ -5,6 +5,7 @@ comment "Linux Kernel Configuration for config HEXAGON def_bool y select ARCH_32BIT_OFF_T + select ARCH_HAS_DELAY_TIMER select ARCH_HAS_SYNC_DMA_FOR_DEVICE select ARCH_NO_PREEMPT select ARCH_WANT_FRAME_POINTERS --- a/arch/hexagon/include/asm/timex.h +++ /dev/null @@ -1,20 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. - */ - -#ifndef _ASM_TIMEX_H -#define _ASM_TIMEX_H - -#include <asm-generic/timex.h> -#include <asm/hexagon_vm.h> - -#define ARCH_HAS_READ_CURRENT_TIMER - -static inline int read_current_timer(unsigned long *timer_val) -{ - *timer_val = __vmgettime(); - return 0; -} - -#endif --- a/arch/hexagon/kernel/time.c +++ b/arch/hexagon/kernel/time.c @@ -6,6 +6,7 @@ */ #include <linux/init.h> +#include <linux/delay.h> #include <linux/clockchips.h> #include <linux/clocksource.h> #include <linux/interrupt.h> @@ -17,7 +18,6 @@ #include <linux/of_irq.h> #include <linux/module.h> -#include <asm/delay.h> #include <asm/hexagon_vm.h> #include <asm/time.h> @@ -231,3 +231,9 @@ void __udelay(unsigned long usecs) cpu_relax(); /* not sure how this improves readability */ } EXPORT_SYMBOL(__udelay); + +bool delay_read_timer(unsigned long *timer_val) +{ + *timer_val = __vmgettime(); + return true; +} --- a/arch/openrisc/Kconfig +++ b/arch/openrisc/Kconfig @@ -7,6 +7,7 @@ config OPENRISC def_bool y select ARCH_32BIT_OFF_T + select ARCH_HAS_DELAY_TIMER select ARCH_HAS_DMA_SET_UNCACHED select ARCH_HAS_DMA_CLEAR_UNCACHED select ARCH_HAS_SYNC_DMA_FOR_DEVICE --- a/arch/openrisc/include/asm/timex.h +++ b/arch/openrisc/include/asm/timex.h @@ -25,6 +25,4 @@ static inline cycles_t get_cycles(void) } #define get_cycles get_cycles -#define ARCH_HAS_READ_CURRENT_TIMER - #endif --- a/arch/openrisc/lib/delay.c +++ b/arch/openrisc/lib/delay.c @@ -13,18 +13,17 @@ */ #include <linux/kernel.h> +#include <linux/delay.h> #include <linux/export.h> #include <linux/init.h> -#include <linux/timex.h> + #include <asm/param.h> -#include <asm/delay.h> -#include <asm/timex.h> #include <asm/processor.h> -int read_current_timer(unsigned long *timer_value) +bool delay_read_timer(unsigned long *timer_value) { *timer_value = get_cycles(); - return 0; + return true; } void __delay(unsigned long cycles) --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -29,6 +29,7 @@ config RISCV select ARCH_HAS_DEBUG_VIRTUAL if MMU select ARCH_HAS_DEBUG_VM_PGTABLE select ARCH_HAS_DEBUG_WX + select ARCH_HAS_DELAY_TIMER select ARCH_HAS_ELF_CORE_EFLAGS if BINFMT_ELF && ELF_CORE select ARCH_HAS_FAST_MULTIPLIER select ARCH_HAS_FORTIFY_SOURCE --- a/arch/riscv/include/asm/timex.h +++ b/arch/riscv/include/asm/timex.h @@ -80,12 +80,4 @@ static inline u64 get_cycles64(void) return ((u64)hi << 32) | lo; } #endif /* CONFIG_64BIT */ - -#define ARCH_HAS_READ_CURRENT_TIMER -static inline int read_current_timer(unsigned long *timer_val) -{ - *timer_val = get_cycles(); - return 0; -} - #endif /* _ASM_RISCV_TIMEX_H */ --- a/arch/riscv/lib/delay.c +++ b/arch/riscv/lib/delay.c @@ -6,7 +6,6 @@ #include <linux/delay.h> #include <linux/math.h> #include <linux/param.h> -#include <linux/timex.h> #include <linux/types.h> #include <linux/export.h> @@ -109,3 +108,9 @@ void ndelay(unsigned long nsecs) __delay(ncycles >> NDELAY_SHIFT); } EXPORT_SYMBOL(ndelay); + +bool delay_read_timer(unsigned long *timer_val) +{ + *timer_val = get_cycles(); + return true; +} --- a/arch/sparc/Kconfig +++ b/arch/sparc/Kconfig @@ -70,6 +70,7 @@ config SPARC32 config SPARC64 def_bool 64BIT select ALTERNATE_USER_ADDRESS_SPACE + select ARCH_HAS_DELAY_TIMER select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_GRAPH_TRACER select HAVE_KRETPROBES --- a/arch/sparc/include/asm/timex_64.h +++ b/arch/sparc/include/asm/timex_64.h @@ -13,6 +13,4 @@ typedef unsigned long cycles_t; #define get_cycles() tick_ops->get_tick() -#define ARCH_HAS_READ_CURRENT_TIMER - #endif --- a/arch/sparc/kernel/time_64.c +++ b/arch/sparc/kernel/time_64.c @@ -894,8 +894,8 @@ unsigned long long sched_clock(void) return ((get_tick() * quotient) >> SPARC64_NSEC_PER_CYC_SHIFT) - offset; } -int read_current_timer(unsigned long *timer_val) +bool delay_read_timer(unsigned long *timer_val) { *timer_val = get_tick(); - return 0; + return true; } --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -81,6 +81,7 @@ config X86 select ARCH_HAS_CURRENT_STACK_POINTER select ARCH_HAS_DEBUG_VIRTUAL select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE + select ARCH_HAS_DELAY_TIMER select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_DMA_OPS if GART_IOMMU || XEN select ARCH_HAS_EARLY_DEBUG if KGDB --- a/arch/x86/include/asm/timex.h +++ b/arch/x86/include/asm/timex.h @@ -14,6 +14,4 @@ static inline unsigned long random_get_e } #define random_get_entropy random_get_entropy -#define ARCH_HAS_READ_CURRENT_TIMER - #endif /* _ASM_X86_TIMEX_H */ --- a/arch/x86/lib/delay.c +++ b/arch/x86/lib/delay.c @@ -14,12 +14,10 @@ #include <linux/export.h> #include <linux/sched.h> -#include <linux/timex.h> #include <linux/preempt.h> #include <linux/delay.h> #include <asm/processor.h> -#include <asm/delay.h> #include <asm/timer.h> #include <asm/mwait.h> @@ -189,13 +187,13 @@ void use_mwaitx_delay(void) delay_fn = delay_halt; } -int read_current_timer(unsigned long *timer_val) +bool delay_read_timer(unsigned long *timer_val) { if (delay_fn == delay_tsc) { *timer_val = rdtsc(); - return 0; + return true; } - return -1; + return false; } void __delay(unsigned long loops) --- a/include/asm-generic/timex.h +++ b/include/asm-generic/timex.h @@ -13,11 +13,4 @@ static inline cycles_t get_cycles(void) } #endif -/* - * Architectures are encouraged to implement read_current_timer - * and define this in order to avoid the expensive delay loop - * calibration during boot. - */ -#undef ARCH_HAS_READ_CURRENT_TIMER - #endif /* __ASM_GENERIC_TIMEX_H */ --- a/include/linux/delay.h +++ b/include/linux/delay.h @@ -17,6 +17,8 @@ extern unsigned long loops_per_jiffy; #include <asm/delay.h> +bool delay_read_timer(unsigned long *t); + /* * Using udelay() for intervals greater than a few milliseconds can * risk overflow for high loops_per_jiffy (high bogomips) machines. The --- a/include/linux/timex.h +++ b/include/linux/timex.h @@ -156,8 +156,6 @@ extern int do_clock_adjtime(const clocki extern void hardpps(const struct timespec64 *, const struct timespec64 *); -int read_current_timer(unsigned long *timer_val); - /* The clock frequency of the i8253/i8254 PIT */ #define PIT_TICK_RATE 1193182ul --- a/init/calibrate.c +++ b/init/calibrate.c @@ -13,7 +13,6 @@ #include <linux/printk.h> #include <linux/smp.h> #include <linux/stddef.h> -#include <linux/timex.h> unsigned long lpj_fine; unsigned long preset_lpj; @@ -25,9 +24,9 @@ static int __init lpj_setup(char *str) __setup("lpj=", lpj_setup); -#ifdef ARCH_HAS_READ_CURRENT_TIMER +#ifdef CONFIG_ARCH_HAS_DELAY_TIMER -/* This routine uses the read_current_timer() routine and gets the +/* This routine uses the delay_read_timer() routine and gets the * loops per jiffy directly, instead of guessing it using delay(). * Also, this code tries to handle non-maskable asynchronous events * (like SMIs) @@ -48,13 +47,13 @@ static unsigned long calibrate_delay_dir int min = -1; int i; - if (read_current_timer(&pre_start) < 0 ) + if (!delay_read_timer(&pre_start)) return 0; /* * A simple loop like * while ( jiffies < start_jiffies+1) - * start = read_current_timer(); + * start = delay_read_timer(); * will not do. As we don't really know whether jiffy switch * happened first or timer_value was read first. And some asynchronous * event can happen between these two events introducing errors in lpj. @@ -72,22 +71,22 @@ static unsigned long calibrate_delay_dir for (i = 0; i < MAX_DIRECT_CALIBRATION_RETRIES; i++) { pre_start = 0; - read_current_timer(&start); + delay_read_timer(&start); start_jiffies = jiffies; while (time_before_eq(jiffies, start_jiffies + 1)) { pre_start = start; - read_current_timer(&start); + delay_read_timer(&start); } - read_current_timer(&post_start); + delay_read_timer(&post_start); pre_end = 0; end = post_start; while (time_before_eq(jiffies, start_jiffies + 1 + DELAY_CALIBRATION_TICKS)) { pre_end = end; - read_current_timer(&end); + delay_read_timer(&end); } - read_current_timer(&post_end); + delay_read_timer(&post_end); timer_rate_max = (post_end - pre_start) / DELAY_CALIBRATION_TICKS;