kernel: rename __swap

This is part of the core kernel -> architecture API and
has been renamed to z_arch_swap().

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>

arch/arm/core/swap.c

@@ -17,13 +17,13 @@ extern const int _k_neg_eagain;
  *
  * @brief Initiate a cooperative context switch
  *
- * The __swap() routine is invoked by various kernel services to effect
- * a cooperative context context switch.  Prior to invoking __swap(), the caller
+ * The z_arch_swap() routine is invoked by various kernel services to effect
+ * a cooperative context context switch.  Prior to invoking z_arch_swap(), the caller
  * disables interrupts via irq_lock() and the return 'key' is passed as a
- * parameter to __swap().  The 'key' actually represents the BASEPRI register
+ * parameter to z_arch_swap().  The 'key' actually represents the BASEPRI register
  * prior to disabling interrupts via the BASEPRI mechanism.
  *
- * __swap() itself does not do much.
+ * z_arch_swap() itself does not do much.
  *
  * It simply stores the intlock key (the BASEPRI value) parameter into
  * current->basepri, and then triggers a PendSV exception, which does
@@ -33,7 +33,7 @@ extern const int _k_neg_eagain;
  * __pendsv all come from handling an interrupt, which means we know the
  * interrupts were not locked: in that case the BASEPRI value is 0.
  *
- * Given that __swap() is called to effect a cooperative context switch,
+ * Given that z_arch_swap() is called to effect a cooperative context switch,
  * only the caller-saved integer registers need to be saved in the thread of the
  * outgoing thread. This is all performed by the hardware, which stores it in
  * its exception stack frame, created when handling the __pendsv exception.
@@ -45,7 +45,7 @@ extern const int _k_neg_eagain;
  * z_arch_thread_return_value_set()
  *
  */
-int __swap(int key)
+int z_arch_swap(unsigned int key)
 {
 #ifdef CONFIG_EXECUTION_BENCHMARKING
 	read_timer_start_of_swap();

arch/arm/core/swap_helper.S

@@ -118,7 +118,7 @@ out_fp_endif:
     isb /* Make the effect of disabling interrupts be realized immediately */
 #elif defined(CONFIG_ARMV7_R)
     /*
-     * Interrupts are still disabled from __swap so empty clause
+     * Interrupts are still disabled from z_arch_swap so empty clause
      * here to avoid the preprocessor error below
      */
 #else

arch/nios2/core/exception.S

@@ -12,7 +12,7 @@ GTEXT(_exception)
 
 /* import */
 GTEXT(_Fault)
-GTEXT(__swap)
+GTEXT(z_arch_swap)
 #ifdef CONFIG_IRQ_OFFLOAD
 GTEXT(z_irq_do_offload)
 GTEXT(_offload_routine)
@@ -126,7 +126,7 @@ on_irq_stack:
 	/*
 	 * A context reschedule is required: keep the volatile registers of
 	 * the interrupted thread on the context's stack.  Utilize
-	 * the existing __swap() primitive to save the remaining
+	 * the existing z_arch_swap() primitive to save the remaining
 	 * thread's registers (including floating point) and perform
 	 * a switch to the new thread.
 	 */
@@ -143,7 +143,7 @@ on_irq_stack:
 	 */
 	mov r4, et
 
-	call __swap
+	call z_arch_swap
 	jmpi _exception_exit
 #else
 	jmpi no_reschedule

arch/nios2/core/swap.S

@@ -8,18 +8,18 @@
 #include <offsets_short.h>
 
 /* exports */
-GTEXT(__swap)
+GTEXT(z_arch_swap)
 GTEXT(z_thread_entry_wrapper)
 
 /* imports */
 GTEXT(sys_trace_thread_switched_in)
 GTEXT(_k_neg_eagain)
 
-/* unsigned int __swap(unsigned int key)
+/* unsigned int z_arch_swap(unsigned int key)
  *
  * Always called with interrupts locked
  */
-SECTION_FUNC(exception.other, __swap)
+SECTION_FUNC(exception.other, z_arch_swap)
 
 #ifdef CONFIG_EXECUTION_BENCHMARKING
 	/* Get a reference to _kernel in r10 */
@@ -56,7 +56,7 @@ SECTION_FUNC(exception.other, __swap)
 	ldw  r11, _kernel_offset_to_current(r10)
 
 	/* Store all the callee saved registers. We either got here via
-	 * an exception or from a cooperative invocation of __swap() from C
+	 * an exception or from a cooperative invocation of z_arch_swap() from C
 	 * domain, so all the caller-saved registers have already been
 	 * saved by the exception asm or the calling C code already.
 	 */
@@ -114,7 +114,7 @@ SECTION_FUNC(exception.other, __swap)
 	ldw sp,  _thread_offset_to_sp(r2)
 
 	/* We need to irq_unlock(current->coopReg.key);
-	 * key was supplied as argument to __swap(). Fetch it.
+	 * key was supplied as argument to z_arch_swap(). Fetch it.
 	 */
 	ldw r3, _thread_offset_to_key(r2)
 

arch/posix/core/posix_core.c

@@ -187,7 +187,7 @@ static void posix_preexit_cleanup(void)
 /**
  * Let the ready thread run and block this thread until it is allowed again
  *
- * called from __swap() which does the picking from the kernel structures
+ * called from z_arch_swap() which does the picking from the kernel structures
  */
 void posix_swap(int next_allowed_thread_nbr, int this_th_nbr)
 {
@@ -256,7 +256,7 @@ static void posix_cleanup_handler(void *arg)
 
 /**
  * Helper function to start a Zephyr thread as a POSIX thread:
- *  It will block the thread until a __swap() is called for it
+ *  It will block the thread until a z_arch_swap() is called for it
  *
  * Spawned from posix_new_thread() below
  */

arch/posix/core/swap.c

@@ -9,7 +9,7 @@
  * @file
  * @brief Kernel swapper code for POSIX
  *
- * This module implements the __swap() routine for the POSIX architecture.
+ * This module implements the z_arch_swap() routine for the POSIX architecture.
  *
  */
 
@@ -23,10 +23,10 @@
  *
  * @brief Initiate a cooperative context switch
  *
- * The __swap() routine is invoked by various kernel services to effect
- * a cooperative context switch.  Prior to invoking __swap(), the
+ * The z_arch_swap() routine is invoked by various kernel services to effect
+ * a cooperative context switch.  Prior to invoking z_arch_swap(), the
  * caller disables interrupts (via irq_lock) and the return 'key'
- * is passed as a parameter to __swap().
+ * is passed as a parameter to z_arch_swap().
  *
  *
  * @return -EAGAIN, or a return value set by a call to
@@ -34,7 +34,7 @@
  *
  */
 
-int __swap(unsigned int key)
+int z_arch_swap(unsigned int key)
 {
 /*
  * struct k_thread * _kernel.current is the currently runnig thread
@@ -80,7 +80,7 @@ int __swap(unsigned int key)
 
 #ifdef CONFIG_ARCH_HAS_CUSTOM_SWAP_TO_MAIN
 /**
- * This is just a version of __swap() in which we do not save anything about the
+ * This is just a version of z_arch_swap() in which we do not save anything about the
  * current thread.
  *
  * Note that we will never come back to this thread:

arch/riscv/core/swap.S

@@ -9,18 +9,18 @@
 #include <offsets_short.h>
 
 /* exports */
-GTEXT(__swap)
+GTEXT(z_arch_swap)
 GTEXT(z_thread_entry_wrapper)
 
 /* Use ABI name of registers for the sake of simplicity */
 
 /*
- * unsigned int __swap(unsigned int key)
+ * unsigned int z_arch_swap(unsigned int key)
  *
  * Always called with interrupts locked
  * key is stored in a0 register
  */
-SECTION_FUNC(exception.other, __swap)
+SECTION_FUNC(exception.other, z_arch_swap)
 
 	/* Make a system call to perform context switch */
 #ifdef CONFIG_EXECUTION_BENCHMARKING
@@ -76,7 +76,7 @@ SECTION_FUNC(exception.other, __swap)
 	 * Restored register a0 contains IRQ lock state of thread.
 	 *
 	 * Prior to unlocking irq, load return value of
-	 * __swap to temp register t2 (from
+	 * z_arch_swap to temp register t2 (from
 	 * _thread_offset_to_swap_return_value). Normally, it should be -EAGAIN,
 	 * unless someone has previously called z_arch_thread_return_value_set(..).
 	 */
@@ -85,7 +85,7 @@ SECTION_FUNC(exception.other, __swap)
 	/* Get pointer to _kernel.current */
 	RV_OP_LOADREG t1, _kernel_offset_to_current(t0)
 
-	/* Load return value of __swap function in temp register t2 */
+	/* Load return value of z_arch_swap function in temp register t2 */
 	lw t2, _thread_offset_to_swap_return_value(t1)
 
 	/*
@@ -108,7 +108,7 @@ SECTION_FUNC(exception.other, __swap)
 SECTION_FUNC(TEXT, z_thread_entry_wrapper)
 	/*
 	 * z_thread_entry_wrapper is called for every new thread upon the return
-	 * of __swap or ISR. Its address, as well as its input function
+	 * of z_arch_swap or ISR. Its address, as well as its input function
 	 * arguments thread_entry_t, void *, void *, void * are restored from
 	 * the thread stack (initialized via function _thread).
 	 * In this case, thread_entry_t, * void *, void * and void * are stored

arch/x86/core/ia32/intstub.S

@@ -30,7 +30,7 @@
 
 	/* externs */
 
-	GTEXT(__swap)
+	GTEXT(z_arch_swap)
 
 #ifdef CONFIG_SYS_POWER_MANAGEMENT
 	GTEXT(z_sys_power_save_idle_exit)
@@ -126,7 +126,7 @@ SECTION_FUNC(TEXT, _interrupt_enter)
 
 	/* Push EDI as we will use it for scratch space.
 	 * Rest of the callee-saved regs get saved by invocation of C
-	 * functions (isr handler, __swap(), etc)
+	 * functions (isr handler, z_arch_swap(), etc)
 	 */
 	pushl	%edi
 
@@ -228,7 +228,7 @@ alreadyOnIntStack:
 
 	/*
 	 * Set X86_THREAD_FLAG_INT bit in k_thread to allow the upcoming call
-	 * to __swap() to determine whether non-floating registers need to be
+	 * to z_arch_swap() to determine whether non-floating registers need to be
 	 * preserved using the lazy save/restore algorithm, or to indicate to
 	 * debug tools that a preemptive context switch has occurred.
 	 */
@@ -240,7 +240,7 @@ alreadyOnIntStack:
 	/*
 	 * A context reschedule is required: keep the volatile registers of
 	 * the interrupted thread on the context's stack.  Utilize
-	 * the existing __swap() primitive to save the remaining
+	 * the existing z_arch_swap() primitive to save the remaining
 	 * thread's registers (including floating point) and perform
 	 * a switch to the new thread.
 	 */
@@ -251,12 +251,12 @@ alreadyOnIntStack:
 	call	z_check_stack_sentinel
 #endif
 	pushfl			/* push KERNEL_LOCK_KEY argument */
-	call	__swap
+	call	z_arch_swap
 	addl 	$4, %esp	/* pop KERNEL_LOCK_KEY argument */
 
 	/*
 	 * The interrupted thread has now been scheduled,
-	 * as the result of a _later_ invocation of __swap().
+	 * as the result of a _later_ invocation of z_arch_swap().
 	 *
 	 * Now need to restore the interrupted thread's environment before
 	 * returning control to it at the point where it was interrupted ...
@@ -264,7 +264,7 @@ alreadyOnIntStack:
 
 #if defined(CONFIG_LAZY_FP_SHARING)
 	/*
-	 * __swap() has restored the floating point registers, if needed.
+	 * z_arch_swap() has restored the floating point registers, if needed.
 	 * Clear X86_THREAD_FLAG_INT in the interrupted thread's state
 	 * since it has served its purpose.
 	 */

arch/x86/core/ia32/swap.S

@@ -8,7 +8,7 @@
  * @file
  * @brief Kernel swapper code for IA-32
  *
- * This module implements the __swap() routine for the IA-32 architecture.
+ * This module implements the z_arch_swap() routine for the IA-32 architecture.
  */
 
 #include <kernel_structs.h>
@@ -17,7 +17,7 @@
 
 	/* exports (internal APIs) */
 
-	GTEXT(__swap)
+	GTEXT(z_arch_swap)
 	GTEXT(z_x86_thread_entry_wrapper)
 	GTEXT(_x86_user_thread_entry_wrapper)
 
@@ -31,13 +31,13 @@
  *
  * @brief Initiate a cooperative context switch
  *
- * The __swap() routine is invoked by various kernel services to effect
- * a cooperative context switch.  Prior to invoking __swap(), the
+ * The z_arch_swap() routine is invoked by various kernel services to effect
+ * a cooperative context switch.  Prior to invoking z_arch_swap(), the
  * caller disables interrupts (via irq_lock) and the return 'key'
- * is passed as a parameter to __swap().  The 'key' actually represents
+ * is passed as a parameter to z_arch_swap().  The 'key' actually represents
  * the EFLAGS register prior to disabling interrupts via a 'cli' instruction.
  *
- * Given that __swap() is called to effect a cooperative context switch, only
+ * Given that z_arch_swap() is called to effect a cooperative context switch, only
  * the non-volatile integer registers need to be saved in the TCS of the
  * outgoing thread.  The restoration of the integer registers of the incoming
  * thread depends on whether that thread was preemptively context switched out.
@@ -72,7 +72,7 @@
  *
  * C function prototype:
  *
- * unsigned int __swap (unsigned int eflags);
+ * unsigned int z_arch_swap (unsigned int eflags);
  *
  */
 
@@ -85,7 +85,7 @@
 	pop %edx
 	pop %eax
 .endm
-SECTION_FUNC(TEXT, __swap)
+SECTION_FUNC(TEXT, z_arch_swap)
 #ifdef CONFIG_EXECUTION_BENCHMARKING
 	/* Save the eax and edx registers before reading the time stamp
 	* once done pop the values.
@@ -356,12 +356,12 @@ CROHandlingDone:
 	/*
 	 * %eax may contain one of these values:
 	 *
-	 * - the return value for __swap() that was set up by a call to
+	 * - the return value for z_arch_swap() that was set up by a call to
 	 * z_arch_thread_return_value_set()
 	 * - -EINVAL
 	 */
 
-	/* Utilize the 'eflags' parameter to __swap() */
+	/* Utilize the 'eflags' parameter to z_arch_swap() */
 
 	pushl	4(%esp)
 	popfl

kernel/Kconfig

@@ -695,13 +695,13 @@ config MAX_DOMAIN_PARTITIONS
 menu "SMP Options"
 
 config USE_SWITCH
-	bool "Use new-style _arch_switch instead of __swap"
+	bool "Use new-style _arch_switch instead of z_arch_swap"
 	depends on USE_SWITCH_SUPPORTED
 	help
 	  The _arch_switch() API is a lower level context switching
-	  primitive than the original __swap mechanism.  It is required
+	  primitive than the original z_arch_swap mechanism.  It is required
 	  for an SMP-aware scheduler, or if the architecture does not
-	  provide __swap.  In uniprocess situations where the
+	  provide z_arch_swap.  In uniprocess situations where the
 	  architecture provides both, _arch_switch incurs more somewhat
 	  overhead and may be slower.
 

kernel/include/kernel_internal.h

@@ -275,6 +275,8 @@ extern int z_stack_adjust_initialized;
 extern void z_arch_busy_wait(u32_t usec_to_wait);
 #endif
 
+int z_arch_swap(unsigned int key);
+
 /**
  * TODO: document
  */

kernel/include/kswap.h

@@ -113,7 +113,7 @@ static inline void z_swap_unlocked(void)
 
 #else /* !CONFIG_USE_SWITCH */
 
-extern int __swap(unsigned int key);
+extern int z_arch_swap(unsigned int key);
 
 static inline int z_swap_irqlock(unsigned int key)
 {
@@ -123,7 +123,7 @@ static inline int z_swap_irqlock(unsigned int key)
 #ifndef CONFIG_ARM
 	sys_trace_thread_switched_out();
 #endif
-	ret = __swap(key);
+	ret = z_arch_swap(key);
 #ifndef CONFIG_ARM
 	sys_trace_thread_switched_in();
 #endif

soc/posix/inf_clock/soc.c

@@ -14,7 +14,7 @@
  *
  * The HW models raising an interrupt will "awake the cpu" by calling
  * poisix_interrupt_raised() which will transfer control to the irq handler,
- * which will run inside SW/Zephyr contenxt. After which a __swap() to whatever
+ * which will run inside SW/Zephyr contenxt. After which a z_arch_swap() to whatever
  * Zephyr thread may follow.
  * Again, once Zephyr is done, control is given back to the HW models.
  *
@@ -143,7 +143,7 @@ void posix_halt_cpu(void)
 	 * => let the "irq handler" check if/what interrupt was raised
 	 * and call the appropriate irq handler.
 	 *
-	 * Note that, the interrupt handling may trigger a __swap() to another
+	 * Note that, the interrupt handling may trigger a z_arch_swap() to another
 	 * Zephyr thread. When posix_irq_handler() returns, the Zephyr
 	 * kernel has swapped back to this thread again
 	 */

tests/arch/arm/arm_thread_swap/README.txt

@@ -20,7 +20,7 @@ Notes:
   The test verifies the correct behavior of the thread contex-switch,
   when it is triggered indirectly (by setting the PendSV interrupt
   to pending state), as well as when the thread itself triggers its
-  swap-out (by calling __swap(.)).
+  swap-out (by calling z_arch_swap(.)).
 
   The test is currently supported only in ARMv7-M and ARMv8-M Mainline
   targets.

tests/arch/arm/arm_thread_swap/src/arm_thread_arch.c

@@ -9,7 +9,7 @@
 #include <arch/arm/cortex_m/cmsis.h>
 #include <kernel_structs.h>
 #include <offsets_short_arch.h>
-
+#include <ksched.h>
 
 #if !defined(__GNUC__)
 #error __FILE__ goes only with Cortex-M GCC
@@ -20,7 +20,6 @@
 #define BASEPRI_MODIFIED_2 0x40
 #define SWAP_RETVAL        0x1234
 
-extern int __swap(unsigned int key);
 extern void z_move_thread_to_end_of_prio_q(struct k_thread *thread);
 
 static struct k_thread alt_thread;
@@ -200,7 +199,7 @@ static void alt_thread_entry(void)
 	zassert_true(p_ztest_thread->arch.basepri == BASEPRI_MODIFIED_1,
 		"ztest thread basepri not preserved in swap-out\n");
 
-	/* Verify original swap return value (set by __swap() */
+	/* Verify original swap return value (set by z_arch_swap() */
 	zassert_true(p_ztest_thread->arch.swap_return_value == -EAGAIN,
 		"ztest thread swap-return-value not preserved in swap-out\n");
 #endif
@@ -420,7 +419,7 @@ void test_arm_thread_swap(void)
 	 * This will be verified by the alternative test thread.
 	 */
 	register int swap_return_val __asm__("r0") =
-		__swap(BASEPRI_MODIFIED_1);
+		z_arch_swap(BASEPRI_MODIFIED_1);
 
 #endif /* CONFIG_NO_OPTIMIZATIONS */