From patchwork series 499449

https://patchwork.ozlabs.org//project/linuxppc-dev/list/?series=499449

Author: Fox Snowpatch

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/alpha/include/asm/timex.h

@@ -7,10 +7,6 @@
 #ifndef _ASMALPHA_TIMEX_H
 #define _ASMALPHA_TIMEX_H
 
-/* With only one or two oddballs, we use the RTC as the ticker, selecting
-   the 32.768kHz reference clock, which nicely divides down to our HZ.  */
-#define CLOCK_TICK_RATE	32768
-
 /*
  * Standard way to access the cycle counter.
  * Currently only used on SMP for scheduling.
@@ -19,9 +15,6 @@
  * But this only means we'll force a reschedule every 8 seconds or so,
  * which isn't an evil thing.
  */
-
-typedef unsigned int cycles_t;
-
 static inline cycles_t get_cycles (void)
 {
 	cycles_t ret;

arch/arc/include/asm/timex.h

@@ -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/Kconfig

@@ -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/delay.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/include/asm/random.h

@@ -9,8 +9,10 @@
 #ifndef _ASMARM_TIMEX_H
 #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