arch/x86: (Intel64) use per-CPU parameter struct for CPU startup

A new 'struct x86_cpuboot' is created as well as an instance called
'x86_cpuboot[]' which contains per-CPU boot data (initial stack,
entry function/arg, selectors, etc.). The locore now consults this
table to set up per-CPU registers, etc. during early boot.

Also, rename tss.c to cpu.c as its scope is growing.

Signed-off-by: Charles E. Youse <charles.youse@intel.com>

arch/x86/core/intel64.cmake

@@ -10,7 +10,7 @@ set_property(SOURCE intel64/locore.S PROPERTY LANGUAGE ASM)
 
 zephyr_library_sources(
   intel64/locore.S
-  intel64/tss.c
+  intel64/cpu.c
   intel64/irq.c
   intel64/thread.c
   intel64/fatal.c

arch/x86/core/intel64/cpu.c

@@ -7,6 +7,9 @@
 #include <kernel_arch_data.h>
 #include <kernel_arch_func.h>
 #include <kernel_structs.h>
+#include <arch/x86/multiboot.h>
+
+extern FUNC_NORETURN void z_x86_prep_c(struct multiboot_info *);
 
 extern u8_t _exception_stack[];
 
@@ -15,6 +18,14 @@ struct x86_tss64 tss0 = {
 	.ist1 = (u64_t) _interrupt_stack + CONFIG_ISR_STACK_SIZE,
 	.ist7 = (u64_t) _exception_stack + CONFIG_EXCEPTION_STACK_SIZE,
 	.iomapb = 0xFFFF,	/* no I/O access bitmap */
-
 	.cpu = &(_kernel.cpus[0])
 };
+
+struct x86_cpuboot x86_cpuboot[] = {
+	{
+		.tr = X86_KERNEL_CPU0_TR,
+		.gs = X86_KERNEL_CPU0_GS,
+		.sp = (u64_t) _interrupt_stack + CONFIG_ISR_STACK_SIZE,
+		.fn = z_x86_prep_c
+	}
+};

arch/x86/core/intel64/locore.S

@@ -39,6 +39,9 @@ __start:
 	movl $__bss_num_dwords, %ecx
 	rep stosl
 
+	movl $x86_cpuboot, %ebp		/* BSP is always logical CPU id 0 */
+	movl %ebx, __x86_cpuboot_t_arg_OFFSET(%ebp)	/* multiboot info */
+
 	/*
 	 * transition to long mode, reload the segment registers,
 	 * and configure per-CPU stuff: GS, task register, stack.
@@ -71,12 +74,12 @@ __start:
 	movw %ax, %ss
 	movw %ax, %fs
 
-	movl $X86_KERNEL_CPU0_TR, %eax
+	movw __x86_cpuboot_t_tr_OFFSET(%rbp), %ax
 	ltr %ax
-	movl $X86_KERNEL_CPU0_GS, %eax
+	movw __x86_cpuboot_t_gs_OFFSET(%rbp), %ax
 	movw %ax, %gs
 
-	movl $(_interrupt_stack + CONFIG_ISR_STACK_SIZE), %esp
+	movq __x86_cpuboot_t_sp_OFFSET(%rbp), %rsp
 
 	/*
 	 * finally, complete environment for the C runtime and go.
@@ -86,7 +89,8 @@ __start:
 
 #ifdef CONFIG_INIT_STACKS
 	movq $0xAAAAAAAAAAAAAAAA, %rax
-	movq $_interrupt_stack, %rdi
+	movq %rsp, %rdi
+	subq $CONFIG_ISR_STACK_SIZE, %rdi
 	movq $(CONFIG_ISR_STACK_SIZE >> 3), %rcx
 	rep stosq
 #endif
@@ -100,8 +104,8 @@ __start:
 
 	/* don't replace CALL with JMP; honor the ABI stack alignment! */
 
-	movl %ebx, %edi		/* multiboot pointer (or NULL) */
+	movq __x86_cpuboot_t_arg_OFFSET(%rbp), %rdi
-	call z_x86_prep_c	/* enter kernel; never returns */
+	call *__x86_cpuboot_t_fn_OFFSET(%rbp) /* enter kernel; never return */
 
 /*
  * void x86_sse_init(struct k_thread *thread);
@@ -147,13 +151,13 @@ z_arch_switch:
 	movq %r14, _thread_offset_to_r14(%rsi)
 	movq %r15, _thread_offset_to_r15(%rsi)
 
-	movq $(_interrupt_stack + CONFIG_ISR_STACK_SIZE), %rsp
+	movq %gs:__x86_tss64_t_ist1_OFFSET, %rsp
 
 	/* fall through to __resume */
 
 /*
  * Entry:
- *   RSP = top of _interrupt_stack
+ *   RSP = top of CPU interrupt stack
  *   RDI = (struct k_thread *) thread to resume
  */
 

arch/x86/core/offsets/intel64_offsets.c

@@ -31,3 +31,10 @@ GEN_OFFSET_SYM(_thread_arch_t, sse);
 GEN_OFFSET_SYM(x86_tss64_t, ist1);
 GEN_OFFSET_SYM(x86_tss64_t, cpu);
 GEN_ABSOLUTE_SYM(__X86_TSS64_SIZEOF, sizeof(x86_tss64_t));
+
+GEN_OFFSET_SYM(x86_cpuboot_t, tr);
+GEN_OFFSET_SYM(x86_cpuboot_t, gs);
+GEN_OFFSET_SYM(x86_cpuboot_t, sp);
+GEN_OFFSET_SYM(x86_cpuboot_t, fn);
+GEN_OFFSET_SYM(x86_cpuboot_t, arg);
+GEN_ABSOLUTE_SYM(__X86_CPUBOOT_SIZEOF, sizeof(x86_cpuboot_t));

arch/x86/include/intel64/kernel_arch_data.h

@@ -72,6 +72,20 @@ struct x86_tss64 {
 
 typedef struct x86_tss64 x86_tss64_t;
 
+/*
+ * Per-CPU bootstrapping parameters. See locore.S and cpu.c.
+ */
+
+struct x86_cpuboot {
+	u16_t tr;		/* selector for task register */
+	u16_t gs;		/* selector for GS */
+	u64_t sp;		/* initial stack pointer */
+	void *fn;		/* kernel entry function */
+	void *arg;		/* argument for above function */
+};
+
+typedef struct x86_cpuboot x86_cpuboot_t;
+
 #endif /* _ASMLANGUAGE */
 
 #endif /* ZEPHYR_ARCH_X86_INCLUDE_INTEL64_KERNEL_ARCH_DATA_H_ */