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kernel: tickless: Rename _Swap to allow creation of macro

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Future tickless kernel patches would be inserting some
code before call to Swap. To enable this it will create
a mcro named as the current _Swap which would call first
the tickless kernel code and then call the real __swap()

Jira: ZEP-339
Change-Id: Id778bfcee4f88982c958fcf22d7f04deb4bd572f
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
This commit is contained in:
Ramesh Thomas 2017-04-06 15:30:27 -07:00 • committed by Anas Nashif
commit 62eea121b3
9 changed files with 70 additions and 68 deletions
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26
arch/arc/core/swap.S
View file

@ -21,7 +21,7 @@
#include <v2/irq.h> #include <v2/irq.h>
#include <swap_macros.h> #include <swap_macros.h>
GTEXT(_Swap) GTEXT(__swap)
GDATA(_k_neg_eagain) GDATA(_k_neg_eagain)
GDATA(_kernel) GDATA(_kernel)
@ -29,25 +29,25 @@ GDATA(_kernel)
* *
* @brief Initiate a cooperative context switch * @brief Initiate a cooperative context switch
* *
* The _Swap() routine is invoked by various kernel services to effect * The __swap() routine is invoked by various kernel services to effect
* a cooperative context switch. Prior to invoking _Swap(), the caller * a cooperative context switch. Prior to invoking __swap(), the caller
* disables interrupts via irq_lock() and the return 'key' is passed as a * disables interrupts via irq_lock() and the return 'key' is passed as a
* parameter to _Swap(). The key is in fact the value stored in the register * parameter to __swap(). The key is in fact the value stored in the register
* operand of a CLRI instruction. * operand of a CLRI instruction.
* *
* It stores the intlock key parameter into current->intlock_key. * It stores the intlock key parameter into current->intlock_key.
* Given that _Swap() is called to effect a cooperative context switch, * Given that __swap() is called to effect a cooperative context switch,
* the caller-saved integer registers are saved on the stack by the function * the caller-saved integer registers are saved on the stack by the function
* call preamble to _Swap(). This creates a custom stack frame that will be * call preamble to __swap(). This creates a custom stack frame that will be
* popped when returning from _Swap(), but is not suitable for handling a return * popped when returning from __swap(), but is not suitable for handling a
* from an exception. Thus, the fact that the thread is pending because of a * return from an exception. Thus, the fact that the thread is pending because
* cooperative call to _Swap() has to be recorded via the _CAUSE_COOP code in * of a cooperative call to __swap() has to be recorded via the _CAUSE_COOP code
* the relinquish_cause of the thread's k_thread structure. The * in the relinquish_cause of the thread's k_thread structure. The
* _IrqExit()/_FirqExit() code will take care of doing the right thing to * _IrqExit()/_FirqExit() code will take care of doing the right thing to
* restore the thread status. * restore the thread status.
* *
* When _Swap() is invoked, we know the decision to perform a context switch or * When __swap() is invoked, we know the decision to perform a context switch or
* not has already been taken and a context switch must happen. * not has already been taken and a context switch must happen.
* *
* @return may contain a return value setup by a call to * @return may contain a return value setup by a call to
@ -55,11 +55,11 @@ GDATA(_kernel)
* *
* C function prototype: * C function prototype:
* *
* unsigned int _Swap (unsigned int key); * unsigned int __swap (unsigned int key);
* *
*/ */
SECTION_FUNC(TEXT, _Swap) SECTION_FUNC(TEXT, __swap)
/* interrupts are locked, interrupt key is in r0 */ /* interrupts are locked, interrupt key is in r0 */

20
arch/arm/core/swap.S
View file

@ -19,7 +19,7 @@
_ASM_FILE_PROLOGUE _ASM_FILE_PROLOGUE
GTEXT(_Swap) GTEXT(__swap)
#if defined(CONFIG_ARMV6_M) #if defined(CONFIG_ARMV6_M)
#elif defined(CONFIG_ARMV7_M) #elif defined(CONFIG_ARMV7_M)
GTEXT(__svc) GTEXT(__svc)
@ -186,7 +186,7 @@ _thread_irq_disabled:
* *
* @brief Service call handler * @brief Service call handler
* *
* The service call (svc) is only used in _Swap() to enter handler mode so we * The service call (svc) is only used in __swap() to enter handler mode so we
* can go through the PendSV exception to perform a context switch. * can go through the PendSV exception to perform a context switch.
* *
* @return N/A * @return N/A
@ -257,13 +257,13 @@ _oops:
* *
* @brief Initiate a cooperative context switch * @brief Initiate a cooperative context switch
* *
* The _Swap() routine is invoked by various kernel services to effect * The __swap() routine is invoked by various kernel services to effect
* a cooperative context context switch. Prior to invoking _Swap(), the caller * a cooperative context context switch. Prior to invoking __swap(), the caller
* disables interrupts via irq_lock() and the return 'key' is passed as a * 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 __swap(). The 'key' actually represents the BASEPRI register
* prior to disabling interrupts via the BASEPRI mechanism. * prior to disabling interrupts via the BASEPRI mechanism.
* *
* _Swap() itself does not do much. * __swap() itself does not do much.
* *
* It simply stores the intlock key (the BASEPRI value) parameter into * It simply stores the intlock key (the BASEPRI value) parameter into
* current->basepri, and then triggers a service call exception (svc) to setup * current->basepri, and then triggers a service call exception (svc) to setup
@ -273,7 +273,7 @@ _oops:
* __pendsv all come from handling an interrupt, which means we know the * __pendsv all come from handling an interrupt, which means we know the
* interrupts were not locked: in that case the BASEPRI value is 0. * 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 __swap() is called to effect a cooperative context switch,
* only the caller-saved integer registers need to be saved in the thread of the * 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 * outgoing thread. This is all performed by the hardware, which stores it in
* its exception stack frame, created when handling the svc exception. * its exception stack frame, created when handling the svc exception.
@ -286,18 +286,18 @@ _oops:
* *
* C function prototype: * C function prototype:
* *
* unsigned int _Swap (unsigned int basepri); * unsigned int __swap (unsigned int basepri);
* *
*/ */
SECTION_FUNC(TEXT, _Swap) SECTION_FUNC(TEXT, __swap)
ldr r1, =_kernel ldr r1, =_kernel
ldr r2, [r1, #_kernel_offset_to_current] ldr r2, [r1, #_kernel_offset_to_current]
str r0, [r2, #_thread_offset_to_basepri] str r0, [r2, #_thread_offset_to_basepri]
/* /*
* Set _Swap()'s default return code to -EAGAIN. This eliminates the need * Set __swap()'s default return code to -EAGAIN. This eliminates the need
* for the timeout code to set it itself. * for the timeout code to set it itself.
*/ */
ldr r1, =_k_neg_eagain ldr r1, =_k_neg_eagain

6
arch/nios2/core/exception.S
View file

@ -13,7 +13,7 @@ GTEXT(_exception)
/* import */ /* import */
GTEXT(_Fault) GTEXT(_Fault)
GTEXT(_Swap) GTEXT(__swap)
#ifdef CONFIG_IRQ_OFFLOAD #ifdef CONFIG_IRQ_OFFLOAD
GTEXT(_irq_do_offload) GTEXT(_irq_do_offload)
GTEXT(_offload_routine) GTEXT(_offload_routine)
@ -135,7 +135,7 @@ on_irq_stack:
/* /*
* A context reschedule is required: keep the volatile registers of * A context reschedule is required: keep the volatile registers of
* the interrupted thread on the context's stack. Utilize * the interrupted thread on the context's stack. Utilize
* the existing _Swap() primitive to save the remaining * the existing __swap() primitive to save the remaining
* thread's registers (including floating point) and perform * thread's registers (including floating point) and perform
* a switch to the new thread. * a switch to the new thread.
*/ */
@ -152,7 +152,7 @@ on_irq_stack:
*/ */
mov r4, et mov r4, et
call _Swap call __swap
jmpi _exception_exit jmpi _exception_exit
#else #else
jmpi no_reschedule jmpi no_reschedule

10
arch/nios2/core/swap.S
View file

@ -9,18 +9,18 @@
#include <offsets_short.h> #include <offsets_short.h>
/* exports */ /* exports */
GTEXT(_Swap) GTEXT(__swap)
GTEXT(_thread_entry_wrapper) GTEXT(_thread_entry_wrapper)
/* imports */ /* imports */
GTEXT(_sys_k_event_logger_context_switch) GTEXT(_sys_k_event_logger_context_switch)
GTEXT(_k_neg_eagain) GTEXT(_k_neg_eagain)
/* unsigned int _Swap(unsigned int key) /* unsigned int __swap(unsigned int key)
* *
* Always called with interrupts locked * Always called with interrupts locked
*/ */
SECTION_FUNC(exception.other, _Swap) SECTION_FUNC(exception.other, __swap)
/* Get a reference to _kernel in r10 */ /* Get a reference to _kernel in r10 */
movhi r10, %hi(_kernel) movhi r10, %hi(_kernel)
@ -30,7 +30,7 @@ SECTION_FUNC(exception.other, _Swap)
ldw r11, _kernel_offset_to_current(r10) ldw r11, _kernel_offset_to_current(r10)
/* Store all the callee saved registers. We either got here via /* 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 __swap() from C
* domain, so all the caller-saved registers have already been * domain, so all the caller-saved registers have already been
* saved by the exception asm or the calling C code already. * saved by the exception asm or the calling C code already.
*/ */
@ -93,7 +93,7 @@ SECTION_FUNC(exception.other, _Swap)
ldw sp, _thread_offset_to_sp(r2) ldw sp, _thread_offset_to_sp(r2)
/* We need to irq_unlock(current->coopReg.key); /* We need to irq_unlock(current->coopReg.key);
* key was supplied as argument to _Swap(). Fetch it. * key was supplied as argument to __swap(). Fetch it.
*/ */
ldw r3, _thread_offset_to_key(r2) ldw r3, _thread_offset_to_key(r2)

20
arch/riscv32/core/swap.S
View file

@ -9,18 +9,18 @@
#include <offsets_short.h> #include <offsets_short.h>
/* exports */ /* exports */
GTEXT(_Swap) GTEXT(__swap)
GTEXT(_thread_entry_wrapper) GTEXT(_thread_entry_wrapper)
/* Use ABI name of registers for the sake of simplicity */ /* Use ABI name of registers for the sake of simplicity */
/* /*
* unsigned int _Swap(unsigned int key) * unsigned int __swap(unsigned int key)
* *
* Always called with interrupts locked * Always called with interrupts locked
* key is stored in a0 register * key is stored in a0 register
*/ */
SECTION_FUNC(exception.other, _Swap) SECTION_FUNC(exception.other, __swap)
/* Make a system call to perform context switch */ /* Make a system call to perform context switch */
ecall ecall
@ -30,16 +30,16 @@ SECTION_FUNC(exception.other, _Swap)
* Restored register a0 contains IRQ lock state of thread. * Restored register a0 contains IRQ lock state of thread.
* *
* Prior to unlocking irq, load return value of * Prior to unlocking irq, load return value of
* _Swap to temp register t2 (from _thread_offset_to_swap_return_value). * __swap to temp register t2 (from
* Normally, it should be -EAGAIN, unless someone has previously * _thread_offset_to_swap_return_value). Normally, it should be -EAGAIN,
* called _set_thread_return_value(..). * unless someone has previously called _set_thread_return_value(..).
*/ */
la t0, _kernel la t0, _kernel
/* Get pointer to _kernel.current */ /* Get pointer to _kernel.current */
lw t1, _kernel_offset_to_current(t0) lw t1, _kernel_offset_to_current(t0)
/* Load return value of _Swap function in temp register t2 */ /* Load return value of __swap function in temp register t2 */
lw t2, _thread_offset_to_swap_return_value(t1) lw t2, _thread_offset_to_swap_return_value(t1)
/* /*
@ -62,9 +62,9 @@ SECTION_FUNC(exception.other, _Swap)
SECTION_FUNC(TEXT, _thread_entry_wrapper) SECTION_FUNC(TEXT, _thread_entry_wrapper)
/* /*
* _thread_entry_wrapper is called for every new thread upon the return * _thread_entry_wrapper is called for every new thread upon the return
* of _Swap or ISR. Its address, as well as its input function arguments * of __swap or ISR. Its address, as well as its input function
* thread_entry_t, void *, void *, void * are restored from the thread * arguments thread_entry_t, void *, void *, void * are restored from
* stack (initialized via function _thread). * the thread stack (initialized via function _thread).
* In this case, thread_entry_t, * void *, void * and void * are stored * In this case, thread_entry_t, * void *, void * and void * are stored
* in registers a0, a1, a2 and a3. These registers are used as arguments * in registers a0, a1, a2 and a3. These registers are used as arguments
* to function _thread_entry. Hence, just call _thread_entry with * to function _thread_entry. Hence, just call _thread_entry with

14
arch/x86/core/intstub.S
View file

@ -29,7 +29,7 @@
/* externs */ /* externs */
GTEXT(_Swap) GTEXT(__swap)
#ifdef CONFIG_SYS_POWER_MANAGEMENT #ifdef CONFIG_SYS_POWER_MANAGEMENT
GTEXT(_sys_power_save_idle_exit) GTEXT(_sys_power_save_idle_exit)
@ -123,7 +123,7 @@ SECTION_FUNC(TEXT, _interrupt_enter)
/* Push EDI as we will use it for scratch space. /* Push EDI as we will use it for scratch space.
* Rest of the callee-saved regs get saved by invocation of C * Rest of the callee-saved regs get saved by invocation of C
* functions (isr handler, _Swap(), etc) * functions (isr handler, __swap(), etc)
*/ */
pushl %edi pushl %edi
@ -289,7 +289,7 @@ alreadyOnIntStack:
/* /*
* Set the _INT_ACTIVE bit in the k_thread to allow the upcoming call to * Set the _INT_ACTIVE bit in the k_thread to allow the upcoming call to
* _Swap() to determine whether non-floating registers need to be * __swap() to determine whether non-floating registers need to be
* preserved using the lazy save/restore algorithm, or to indicate to * preserved using the lazy save/restore algorithm, or to indicate to
* debug tools that a preemptive context switch has occurred. * debug tools that a preemptive context switch has occurred.
*/ */
@ -301,7 +301,7 @@ alreadyOnIntStack:
/* /*
* A context reschedule is required: keep the volatile registers of * A context reschedule is required: keep the volatile registers of
* the interrupted thread on the context's stack. Utilize * the interrupted thread on the context's stack. Utilize
* the existing _Swap() primitive to save the remaining * the existing __swap() primitive to save the remaining
* thread's registers (including floating point) and perform * thread's registers (including floating point) and perform
* a switch to the new thread. * a switch to the new thread.
*/ */
@ -321,14 +321,14 @@ alreadyOnIntStack:
*/ */
popl %eax popl %eax
#endif #endif
call _Swap call __swap
#ifndef CONFIG_X86_IAMCU #ifndef CONFIG_X86_IAMCU
addl $4, %esp /* pop KERNEL_LOCK_KEY argument */ addl $4, %esp /* pop KERNEL_LOCK_KEY argument */
#endif #endif
/* /*
* The interrupted thread has now been scheduled, * The interrupted thread has now been scheduled,
* as the result of a _later_ invocation of _Swap(). * as the result of a _later_ invocation of __swap().
* *
* Now need to restore the interrupted thread's environment before * Now need to restore the interrupted thread's environment before
* returning control to it at the point where it was interrupted ... * returning control to it at the point where it was interrupted ...
@ -337,7 +337,7 @@ alreadyOnIntStack:
#if ( defined(CONFIG_FP_SHARING) || \ #if ( defined(CONFIG_FP_SHARING) || \
defined(CONFIG_GDB_INFO) ) defined(CONFIG_GDB_INFO) )
/* /*
* _Swap() has restored the floating point registers, if needed. * __swap() has restored the floating point registers, if needed.
* Clear the _INT_ACTIVE bit in the interrupted thread's state * Clear the _INT_ACTIVE bit in the interrupted thread's state
* since it has served its purpose. * since it has served its purpose.
*/ */

26
arch/x86/core/swap.S
View file

@ -8,10 +8,10 @@
* @file * @file
* @brief Kernel swapper code for IA-32 * @brief Kernel swapper code for IA-32
* *
* This module implements the _Swap() routine for the IA-32 architecture. * This module implements the __swap() routine for the IA-32 architecture.
* *
* Note that the file arch/x86/include/swapstk.h defines * Note that the file arch/x86/include/swapstk.h defines
* a representation of the save stack frame generated by _Swap() in order * a representation of the save stack frame generated by __swap() in order
* to generate offsets (in the form of absolute symbols) for consumption by * to generate offsets (in the form of absolute symbols) for consumption by
* host tools. Please update swapstk.h if changing the structure of the * host tools. Please update swapstk.h if changing the structure of the
* save frame on the stack. * save frame on the stack.
@ -23,7 +23,7 @@
/* exports (internal APIs) */ /* exports (internal APIs) */
GTEXT(_Swap) GTEXT(__swap)
/* externs */ /* externs */
GDATA(_k_neg_eagain) GDATA(_k_neg_eagain)
@ -32,13 +32,13 @@
* *
* @brief Initiate a cooperative context switch * @brief Initiate a cooperative context switch
* *
* The _Swap() routine is invoked by various kernel services to effect * The __swap() routine is invoked by various kernel services to effect
* a cooperative context switch. Prior to invoking _Swap(), the * a cooperative context switch. Prior to invoking __swap(), the
* caller disables interrupts (via irq_lock) and the return 'key' * 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 __swap(). The 'key' actually represents
* the EFLAGS register prior to disabling interrupts via a 'cli' instruction. * 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 __swap() is called to effect a cooperative context switch, only
* the non-volatile integer registers need to be saved in the TCS of the * 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 * outgoing thread. The restoration of the integer registers of the incoming
* thread depends on whether that thread was preemptively context switched out. * thread depends on whether that thread was preemptively context switched out.
@ -73,11 +73,11 @@
* *
* C function prototype: * C function prototype:
* *
* unsigned int _Swap (unsigned int eflags); * unsigned int __swap (unsigned int eflags);
* *
*/ */
SECTION_FUNC(TEXT, _Swap) SECTION_FUNC(TEXT, __swap)
#ifdef CONFIG_X86_IAMCU #ifdef CONFIG_X86_IAMCU
/* save EFLAGS on stack right before return address, just as SYSV would /* save EFLAGS on stack right before return address, just as SYSV would
* have done * have done
@ -305,24 +305,24 @@ CROHandlingDone:
/* /*
* %eax may contain one of these values: * %eax may contain one of these values:
* *
* - the return value for _Swap() that was set up by a call to * - the return value for __swap() that was set up by a call to
* _set_thread_return_value() * _set_thread_return_value()
* - in legacy kernel, same value as %ebx, which is non-volatile * - in legacy kernel, same value as %ebx, which is non-volatile
* - in unified kernel, -EINVAL * - in unified kernel, -EINVAL
*/ */
/* Utilize the 'eflags' parameter to _Swap() */ /* Utilize the 'eflags' parameter to __swap() */
pushl 4(%esp) pushl 4(%esp)
#ifdef CONFIG_INT_LATENCY_BENCHMARK #ifdef CONFIG_INT_LATENCY_BENCHMARK
testl $0x200, (%esp) testl $0x200, (%esp)
jz skipIntLatencyStop jz skipIntLatencyStop
/* save %eax since it used as the return value for _Swap */ /* save %eax since it used as the return value for __swap */
pushl %eax pushl %eax
/* interrupts are being reenabled, stop accumulating time */ /* interrupts are being reenabled, stop accumulating time */
call _int_latency_stop call _int_latency_stop
/* restore _Swap's %eax */ /* restore __swap's %eax */
popl %eax popl %eax
skipIntLatencyStop: skipIntLatencyStop:

12
arch/xtensa/core/swap.S
View file

@ -7,7 +7,7 @@
* @file * @file
* @brief kernel swapper code for Xtensa * @brief kernel swapper code for Xtensa
* *
* This module implements the _Swap() routine for the Xtensa architecture. * This module implements the __swap() routine for the Xtensa architecture.
*/ */
#include <xtensa_context.h> #include <xtensa_context.h>
@ -15,11 +15,11 @@
#include <offsets_short.h> #include <offsets_short.h>
.extern _kernel .extern _kernel
/* unsigned int _Swap (unsigned int basepri); */ /* unsigned int __swap (unsigned int basepri); */
.globl _Swap .globl __swap
.type _Swap,@function .type __swap,@function
.align 4 .align 4
_Swap: __swap:
#ifdef __XTENSA_CALL0_ABI__ #ifdef __XTENSA_CALL0_ABI__
addi sp, sp, -XT_SOL_FRMSZ addi sp, sp, -XT_SOL_FRMSZ
#else #else
@ -61,7 +61,7 @@ _Swap:
s32i a3, sp, XT_SOL_exit /* 0 to flag as solicited frame */ s32i a3, sp, XT_SOL_exit /* 0 to flag as solicited frame */
s32i sp, a4, THREAD_OFFSET(sp) /* current->arch.topOfStack := sp */ s32i sp, a4, THREAD_OFFSET(sp) /* current->arch.topOfStack := sp */
/* /*
* Set _Swap()'s default return code to -EAGAIN. This eliminates the * Set __swap()'s default return code to -EAGAIN. This eliminates the
* need for the timeout code to set it itself. * need for the timeout code to set it itself.
*/ */
movi a3, -11 /* a3 := -EAGAIN. TODO: Use a macro here insted of 11 */ movi a3, -11 /* a3 := -EAGAIN. TODO: Use a macro here insted of 11 */

4
kernel/include/nano_internal.h
View file

@ -50,7 +50,9 @@ extern void _new_thread(char *pStack, size_t stackSize,
/* context switching and scheduling-related routines */ /* context switching and scheduling-related routines */
extern unsigned int _Swap(unsigned int); extern unsigned int __swap(unsigned int key);
#define _Swap(x) __swap(x)
/* set and clear essential fiber/task flag */ /* set and clear essential fiber/task flag */