arch: all: Remove not used struct _caller_saved

The struct _caller_saved is not used. Most architectures put
automatically the registers onto stack, in others architectures the
exception code does it.

Signed-off-by: Flavio Ceolin <[email protected]>

Author: Flavio Ceolin

arch/arc/include/kernel_arch_thread.h

@@ -12,7 +12,6 @@
  *
  *  struct _thread_arch
  *  struct _callee_saved
- *  struct _caller_saved
  *
  * necessary to instantiate instances of struct k_thread.
  */
@@ -32,15 +31,6 @@
 #ifndef _ASMLANGUAGE
 #include <zephyr/types.h>
 
-struct _caller_saved {
-	/*
-	 * Saved on the stack as part of handling a regular IRQ or by the
-	 * kernel when calling the FIRQ return code.
-	 */
-};
-
-typedef struct _caller_saved _caller_saved_t;
-
 struct _callee_saved {
 	u32_t sp; /* r28 */
 };

arch/arm/include/kernel_arch_thread.h

@@ -12,8 +12,7 @@
  *
  *  struct _thread_arch
  *  struct _callee_saved
- *  struct _caller_saved
- *
+  *
  * necessary to instantiate instances of struct k_thread.
  */
 
@@ -23,26 +22,6 @@
 #ifndef _ASMLANGUAGE
 #include <zephyr/types.h>
 
-struct _caller_saved {
-	/*
-	 * Unused for Cortex-M, which automatically saves the necessary
-	 * registers in its exception stack frame.
-	 *
-	 * For Cortex-A, this may be:
-	 *
-	 * u32_t a1;       r0
-	 * u32_t a2;       r1
-	 * u32_t a3;       r2
-	 * u32_t a4;       r3
-	 * u32_t ip;       r12
-	 * u32_t lr;       r14
-	 * u32_t pc;       r15
-	 * u32_t xpsr;
-	 */
-};
-
-typedef struct _caller_saved _caller_saved_t;
-
 struct _callee_saved {
 	u32_t v1;  /* r4 */
 	u32_t v2;  /* r5 */

arch/nios2/include/kernel_arch_thread.h

@@ -12,7 +12,6 @@
  *
  *  struct _thread_arch
  *  struct _callee_saved
- *  struct _caller_saved
  *
  * necessary to instantiate instances of struct k_thread.
  */
@@ -23,15 +22,6 @@
 #ifndef _ASMLANGUAGE
 #include <zephyr/types.h>
 
-struct _caller_saved {
-	/*
-	 * Nothing here, the exception code puts all the caller-saved
-	 * registers onto the stack.
-	 */
-};
-
-typedef struct _caller_saved _caller_saved_t;
-
 struct _callee_saved {
 	/* General purpose callee-saved registers */
 	u32_t r16;

arch/posix/include/kernel_arch_thread.h

@@ -13,7 +13,6 @@
  *
  *  struct _thread_arch
  *  struct _callee_saved
- *  struct _caller_saved
  *
  * necessary to instantiate instances of struct k_thread.
  */
@@ -24,13 +23,6 @@
 #ifndef _ASMLANGUAGE
 #include <zephyr/types.h>
 
-struct _caller_saved {
-	/*
-	 * Nothing here
-	 */
-};
-
-
 struct _callee_saved {
 	/* IRQ status before irq_lock() and call to z_swap() */
 	u32_t key;

arch/riscv32/include/kernel_arch_thread.h

@@ -12,7 +12,6 @@
  *
  *  struct _thread_arch
  *  struct _callee_saved
- *  struct _caller_saved
  *
  * necessary to instantiate instances of struct k_thread.
  */
@@ -45,15 +44,6 @@ struct _callee_saved {
 };
 typedef struct _callee_saved _callee_saved_t;
 
-struct _caller_saved {
-	/*
-	 * Nothing here, the exception code puts all the caller-saved
-	 * registers onto the stack.
-	 */
-};
-
-typedef struct _caller_saved _caller_saved_t;
-
 struct _thread_arch {
 	u32_t swap_return_value; /* Return value of z_swap() */
 };

arch/x86/include/kernel_arch_thread.h

@@ -12,7 +12,6 @@
  *
  *  struct _thread_arch
  *  struct _callee_saved
- *  struct _caller_saved
  *
  * necessary to instantiate instances of struct k_thread.
  */
@@ -37,32 +36,6 @@
 #ifndef _ASMLANGUAGE
 #include <stdint.h>
 
-/*
- * The following structure defines the set of 'volatile' integer registers.
- * These registers need not be preserved by a called C function.  Given that
- * they are not preserved across function calls, they must be save/restored
- * (along with the struct _caller_saved) when a preemptive context switch
- * occurs.
- */
-
-struct _caller_saved {
-
-	/*
-	 * The volatile registers 'eax', 'ecx' and 'edx' area not included in
-	 * the definition of 'tPreempReg' since the interrupt and exception
-	 * handling routunes use the stack to save and restore the values of
-	 * these registers in order to support interrupt nesting.  The stubs
-	 * do _not_ copy the saved values from the stack into the TCS.
-	 *
-	 * unsigned long eax;
-	 * unsigned long ecx;
-	 * unsigned long edx;
-	 */
-
-};
-
-typedef struct _caller_saved _caller_saved_t;
-
 /*
  * The following structure defines the set of 'non-volatile' integer registers.
  * These registers must be preserved by a called C function.  These are the

arch/x86_64/include/kernel_arch_thread.h

@@ -11,7 +11,6 @@
  * Zephyr thread struct.  But we don't need that for this arch.
  */
 
-struct _caller_saved { };
 struct _callee_saved { };
 struct _thread_arch { };
 

arch/xtensa/core/offsets/offsets.c

@@ -50,9 +50,6 @@ GEN_OFFSET_SYM(__esf_t, pc);
 /* size of the entire __esf_t structure */
 GEN_ABSOLUTE_SYM(____esf_t_SIZEOF, sizeof(__esf_t));
 
-/* size of the entire preempt registers structure */
-GEN_ABSOLUTE_SYM(__tPreempt_SIZEOF, sizeof(_caller_saved_t));
-
 /* size of the struct k_thread structure without save area for coproc regs */
 GEN_ABSOLUTE_SYM(_K_THREAD_NO_FLOAT_SIZEOF,
 		 sizeof(struct k_thread) - sizeof(tCoopCoprocReg) -

arch/xtensa/include/kernel_arch_thread.h

@@ -12,7 +12,6 @@
  *
  *  struct _thread_arch
  *  struct _callee_saved
- *  struct _caller_saved
  *
  * necessary to instantiate instances of struct k_thread.
  */
@@ -24,28 +23,6 @@
 #include <zephyr/types.h>
 #include <xtensa_context.h>
 
-/*
- * The following structure defines the set of 'volatile' integer registers.
- * These registers need not be preserved by a called C function.  Given that
- * they are not preserved across function calls, they must be save/restored
- * (along with the struct _caller_saved) when a preemptive context switch
- * occurs.
- */
-
-struct _caller_saved {
-
-	/*
-	 * The volatile registers area not included in the definition of
-	 * 'tPreempReg' since the interrupt stubs (_IntEnt/_IntExit)
-	 * and exception stubs (_ExcEnt/_ExcEnter) use the stack to save and
-	 * restore the values of these registers in order to support interrupt
-	 * nesting.  The stubs do _not_ copy the saved values from the stack
-	 * into the k_thread.
-	 */
-};
-
-typedef struct _caller_saved _caller_saved_t;
-
 /*
  * The following structure defines the set of 'non-volatile' integer registers.
  * These registers must be preserved by a called C function.  These are the

include/kernel.h

@@ -513,8 +513,6 @@ struct k_thread {
 
 	struct _thread_base base;
 
-	/** defined by the architecture, but all archs need these */
-	struct _caller_saved caller_saved;
 	/** defined by the architecture, but all archs need these */
 	struct _callee_saved callee_saved;