[PW_SID:1079742] treewide: Cleanup LATCH, CLOCK_TICK_RATE and get_cycles() [ab]use

Documentation/fb/udlfb.rst

@@ -156,8 +156,8 @@ metrics_bytes_sent	 32-bit count of how many bytes were transferred over
 			 USB to communicate the resulting changed pixels to the
 			 hardware. Includes compression and protocol overhead
 
-metrics_cpu_kcycles_used 32-bit count of CPU cycles used in processing the
-			 above pixels (in thousands of cycles).
+metrics_cpu_kcycles_used 32-bit count of microseconds used in processing the
+			 above pixels
 
 metrics_reset		 Write-only. Any write to this file resets all metrics
 			 above to zero.  Note that the 32-bit counters above

arch/Kconfig

@@ -360,9 +360,19 @@ config ARCH_HAS_DMA_SET_UNCACHED
 config ARCH_HAS_DMA_CLEAR_UNCACHED
 	bool
 
+# cycles_t is always 64bit wide
+config ARCH_HAS_CYCLES_T_64
+	bool
+
 config ARCH_HAS_CPU_FINALIZE_INIT
 	bool
 
+config ARCH_HAS_DELAY_TIMER
+	bool
+
+config ARCH_HAS_RANDOM_ENTROPY
+	bool
+
 # The architecture has a per-task state that includes the mm's PASID
 config ARCH_HAS_CPU_PASID
 	bool

arch/alpha/Kconfig

@@ -5,6 +5,7 @@ config ALPHA
 	select ARCH_32BIT_USTAT_F_TINODE
 	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DMA_OPS if PCI
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
 	select ARCH_MODULE_NEEDS_WEAK_PER_CPU if SMP

arch/alpha/include/asm/random.h

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASMALPHA_RANDOM_H
+#define _ASMALPHA_RANDOM_H
+
+/* Use the cycle counter for entropy. */
+static inline unsigned long random_get_entropy(void)
+{
+	unsigned long ret;
+
+	__asm__ __volatile__ ("rpcc %0" : "=r"(ret));
+	return ret;
+}
+
+#endif

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
@@ -21,6 +22,7 @@ config ARM
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_STACKWALK

arch/arm/include/asm/delay.h

@@ -91,7 +91,6 @@ extern void __loop_udelay(unsigned long usecs);
 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__ */

arch/arm/include/asm/random.h

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASMARM_RANDOM_H
+#define _ASMARM_RANDOM_H
+
+bool delay_read_timer(unsigned long *t);
+
+static inline unsigned long random_get_entropy(void)
+{
+	unsigned long t;
+
+	return delay_read_timer(&t) ? t : random_get_entropy_fallback();
+}
+
+#endif

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_timer;
 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)
 {
@@ -44,9 +42,9 @@ static inline u64 cyc_to_ns(u64 cyc, u32 mult, u32 shift)
 
 static void __timer_delay(unsigned long cycles)
 {
-	cycles_t start = get_cycles();
+	cycles_t start = delay_timer->read_current_timer();
 
-	while ((get_cycles() - start) < cycles)
+	while ((delay_timer->read_current_timer() - start) < cycles)
 		cpu_relax();
 }
 

arch/arm/mach-omap1/Kconfig

@@ -74,7 +74,7 @@ config OMAP_32K_TIMER
 	  currently only available for OMAP16XX, 24XX, 34XX, OMAP4/5 and DRA7XX.
 
 	  On OMAP2PLUS this value is only used for CONFIG_HZ and
-	  CLOCK_TICK_RATE compile time calculation.
+	  timer frequency compile time calculation.
 	  The actual timer selection is done in the board file
 	  through the (DT_)MACHINE_START structure.
 

arch/arm64/Kconfig

@@ -45,6 +45,7 @@ config ARM64
 	select ARCH_HAS_PREEMPT_LAZY
 	select ARCH_HAS_PTDUMP
 	select ARCH_HAS_PTE_SPECIAL
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_HAS_HW_PTE_YOUNG
 	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_SET_DIRECT_MAP
@@ -112,6 +113,7 @@ config ARM64
 	select ARCH_SUPPORTS_SCHED_SMT
 	select ARCH_SUPPORTS_SCHED_CLUSTER
 	select ARCH_SUPPORTS_SCHED_MC
+	select ARCH_SUPPORTS_PTP_VMCLOCK if ARCH_SUPPORTS_INT128
 	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
 	select ARCH_WANT_DEFAULT_BPF_JIT

arch/arm64/include/asm/io.h

@@ -100,12 +100,13 @@ static __always_inline u64 __raw_readq(const volatile void __iomem *addr)
 ({									\
 	unsigned long tmp;						\
 									\
-	dma_rmb();								\
+	dma_rmb();							\
 									\
 	/*								\
 	 * Create a dummy control dependency from the IO read to any	\
 	 * later instructions. This ensures that a subsequent call to	\
-	 * udelay() will be ordered due to the ISB in get_cycles().	\
+	 * udelay() will be ordered due to the ISB in			\
+	 * arm_timer_read_counter().					\
 	 */								\
 	asm volatile("eor	%0, %1, %1\n"				\
 		     "cbnz	%0, ."					\

arch/arm64/include/asm/ptp_vmclock.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_PTP_VMCLOCK_H
+#define __ASM_PTP_VMCLOCK_H
+
+#include <asm/arch_timer.h>
+
+static inline u64 ptp_vmclock_read_cpu_counter(void)
+{
+	return arch_timer_read_counter();
+}
+
+#endif

arch/arm64/include/asm/random.h

@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ */
+#ifndef __ASM_RANDOM_H
+#define __ASM_RANDOM_H
+
+/* Out of line to avoid recursive include hell */
+unsigned long random_get_entropy(void);
+
+#endif

arch/arm64/include/asm/rqspinlock.h

@@ -2,6 +2,7 @@
 #ifndef _ASM_RQSPINLOCK_H
 #define _ASM_RQSPINLOCK_H
 
+#include <asm/arch_timer.h>
 #include <asm/barrier.h>
 
 /*

arch/arm64/kernel/time.c

@@ -29,6 +29,7 @@
 
 #include <clocksource/arm_arch_timer.h>
 
+#include <asm/arch_timer.h>
 #include <asm/thread_info.h>
 #include <asm/paravirt.h>
 
@@ -52,6 +53,11 @@ unsigned long profile_pc(struct pt_regs *regs)
 }
 EXPORT_SYMBOL(profile_pc);
 
+static unsigned long random_get_entropy(void)
+{
+	return arch_timer_read_counter();
+}
+
 void __init time_init(void)
 {
 	u32 arch_timer_rate;

arch/arm64/kernel/topology.c

@@ -21,6 +21,7 @@
 #include <linux/sched/isolation.h>
 #include <linux/xarray.h>
 
+#include <asm/arch_timer.h>
 #include <asm/cpu.h>
 #include <asm/cputype.h>
 #include <asm/topology.h>

arch/arm64/kernel/traps.c

@@ -30,6 +30,7 @@
 #include <linux/ubsan.h>
 #include <linux/cfi.h>
 
+#include <asm/arch_timer.h>
 #include <asm/atomic.h>
 #include <asm/bug.h>
 #include <asm/cpufeature.h>

arch/arm64/kvm/emulate-nested.c

@@ -7,6 +7,7 @@
 #include <linux/kvm.h>
 #include <linux/kvm_host.h>
 
+#include <asm/arch_timer.h>
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_nested.h>
 

arch/arm64/kvm/hyp/include/hyp/switch.h

@@ -18,6 +18,7 @@
 
 #include <kvm/arm_psci.h>
 
+#include <asm/arch_timer.h>
 #include <asm/barrier.h>
 #include <asm/cpufeature.h>
 #include <asm/extable.h>

arch/arm64/lib/delay.c

@@ -14,6 +14,7 @@
 #include <linux/timex.h>
 
 #include <clocksource/arm_arch_timer.h>
+#include <asm/arch_timer.h>
 
 #define USECS_TO_CYCLES(time_usecs)			\
 	xloops_to_cycles((time_usecs) * 0x10C7UL)

arch/hexagon/Kconfig

@@ -5,6 +5,7 @@ comment "Linux Kernel Configuration for Hexagon"
 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