pc: consolidate __const_udelay for linux drivers

Use common implementation used by wifi and (not merged) audio driver.
Avoid usage of lib/delay.c since lpj and loop_for_jiffies are not calibrated
for the ported drivers as done on native Linux during boot and leads to wrong
delays for usb and intel_fb.

Issue #4540

repos/dde_linux/src/lib/lx_emul/spec/x86/start.c

@@ -26,7 +26,6 @@ unsigned long long sched_clock(void)
 void time_init(void)
 {
 	lx_emul_time_init(); /* replaces timer_probe() */
-	lpj_fine = 1000000 / HZ;
 }
 
 

repos/pc/lib/import/import-pc_lx_emul.mk

@@ -47,6 +47,7 @@ SRC_C   += lx_emul/sched_core.c
 SRC_C   += lx_emul/slab_common.c
 SRC_C   += lx_emul/softirq.c
 SRC_C   += lx_emul/vmalloc.c
+SRC_C   += lx_emul/delay.c
 
 SRC_C   += lx_emul/shadow/fs/libfs.c
 SRC_C   += lx_emul/shadow/kernel/rcu/tiny.c

repos/pc/src/drivers/framebuffer/intel/pc/spec/x86_32/source.list

@@ -1,4 +1,3 @@
-arch/x86/lib/delay.c
 arch/x86/lib/hweight.S
 arch/x86/pci/legacy.c
 arch/x86/platform/intel/iosf_mbi.c

repos/pc/src/drivers/framebuffer/intel/pc/spec/x86_64/source.list

@@ -1,4 +1,3 @@
-arch/x86/lib/delay.c
 arch/x86/lib/hweight.S
 arch/x86/lib/memcpy_64.S
 arch/x86/lib/memmove_64.S

repos/pc/src/drivers/framebuffer/intel/pc/target.inc

@@ -11,6 +11,7 @@ INC_DIR += $(REL_PRG_DIR)/shadow
 SRC_CC  += main.cc
 SRC_CC  += misc.cc
 SRC_CC  += emul.cc
+SRC_CC  += time.cc
 SRC_CC  += opregion_io_mem.cc
 SRC_C   += dummies.c
 SRC_C   += lx_emul.c

repos/pc/src/drivers/framebuffer/intel/pc/time.cc

@@ -0,0 +1,25 @@
+/*
+ * \brief  Lx_emul udelay function for very short delays
+ * \author Stefan Kalkowski
+ * \date   2021-07-10
+ */
+
+/*
+ * Copyright (C) 2021 Genode Labs GmbH
+ *
+ * This file is distributed under the terms of the GNU General Public License
+ * version 2.
+ */
+
+#include <base/log.h>
+#include <lx_kit/env.h>
+
+extern "C" void lx_emul_time_udelay(unsigned long usec);
+extern "C" void lx_emul_time_udelay(unsigned long usec)
+{
+	if (usec > 100)
+		Genode::error("Cannot delay that long ", usec, " microseconds");
+
+	unsigned long long start = Lx_kit::env().timer.curr_time().trunc_to_plain_us().value;
+	while (Lx_kit::env().timer.curr_time().trunc_to_plain_us().value < (start + usec)) { ; }
+}

repos/pc/src/drivers/usb_host/pc/spec/x86_32/source.list

@@ -1,4 +1,3 @@
-arch/x86/lib/delay.c
 arch/x86/lib/hweight.S
 arch/x86/pci/legacy.c
 drivers/base/bus.c

repos/pc/src/drivers/usb_host/pc/spec/x86_64/source.list

@@ -1,4 +1,3 @@
-arch/x86/lib/delay.c
 arch/x86/lib/hweight.S
 arch/x86/pci/legacy.c
 drivers/base/bus.c

repos/pc/src/drivers/usb_host/pc/target.inc

@@ -8,6 +8,7 @@ LIBS    := base pc_lx_emul jitterentropy
 INC_DIR += $(REL_PRG_DIR)
 SRC_CC  += main.cc
 SRC_CC  += misc.cc
+SRC_CC  += time.cc
 SRC_CC  += lx_emul/shared_dma_buffer.cc
 SRC_C   += dummies.c
 SRC_C   += lx_emul.c

repos/pc/src/drivers/usb_host/pc/time.cc

@@ -0,0 +1,25 @@
+/*
+ * \brief  Lx_emul udelay function for very short delays
+ * \author Stefan Kalkowski
+ * \date   2021-07-10
+ */
+
+/*
+ * Copyright (C) 2021 Genode Labs GmbH
+ *
+ * This file is distributed under the terms of the GNU General Public License
+ * version 2.
+ */
+
+#include <base/log.h>
+#include <lx_kit/env.h>
+
+extern "C" void lx_emul_time_udelay(unsigned long usec);
+extern "C" void lx_emul_time_udelay(unsigned long usec)
+{
+	if (usec > 100)
+		Genode::error("Cannot delay that long ", usec, " microseconds");
+
+	unsigned long long start = Lx_kit::env().timer.curr_time().trunc_to_plain_us().value;
+	while (Lx_kit::env().timer.curr_time().trunc_to_plain_us().value < (start + usec)) { ; }
+}

repos/pc/src/lib/pc/lx_emul/common_dummies.c

@@ -47,11 +47,6 @@ const struct trace_print_flags pageflag_names[] = { {0,NULL}};
 
 struct kernel_stat kstat;
 
-#include <linux/delay.h>
-
-/* support for arch/x86/lib/delay.c, normally defined in init/main.c */
-unsigned long loops_per_jiffy = (1<<12);
-
 
 #include <asm/processor.h>
 
@@ -70,11 +65,6 @@ struct cpuinfo_x86 boot_cpu_data =
 unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
 
 
-#include <linux/delay.h>
-
-unsigned long lpj_fine = 0;
-
-
 /*
  * Generate_dummies.c will otherwise pull in <linux/rcutree.h>
  * that clashes with rcutiny.h.

repos/pc/src/lib/pc/lx_emul/delay.c

@@ -0,0 +1,34 @@
+/*
+ * \brief  Supplement for emulation for linux/include/asm-generic/delay.h
+ * \author Josef Soentgen
+ * \date   2022-05-05
+ */
+
+/*
+ * Copyright (C) 2022 Genode Labs GmbH
+ *
+ * This file is distributed under the terms of the GNU General Public License
+ * version 2.
+ */
+
+
+#include <asm-generic/delay.h>
+#include <linux/delay.h>
+
+#include <lx_emul.h>
+
+
+void __const_udelay(unsigned long xloops)
+{
+       unsigned long usecs = xloops / 0x10C7UL;
+       if (usecs < 100)
+               lx_emul_time_udelay(usecs);
+       else
+               usleep_range(usecs, usecs * 10);
+}
+
+
+void __udelay(unsigned long usecs)
+{
+	lx_emul_time_udelay(usecs);
+}

repos/pc/src/lib/wifi/lx_emul.c

@@ -18,20 +18,6 @@
 #include <lx_emul/alloc.h>
 #include <lx_emul/io_mem.h>
 
-
-#include <asm-generic/delay.h>
-#include <linux/delay.h>
-
-void __const_udelay(unsigned long xloops)
-{
-       unsigned long usecs = xloops / 0x10C7UL;
-       if (usecs < 100)
-               lx_emul_time_udelay(usecs);
-       else
-               usleep_range(usecs, usecs * 10);
-}
-
-
 #include <linux/slab.h>
 
 struct kmem_cache * kmem_cache_create_usercopy(const char * name,