99a8155914
In the current implementation both SPSR and ELR registers are saved with the callee-saved registers and restored by the context-switch routine. To support nested IRQs we have to save those on the stack when entering and exiting from an ISR. Since the values are now carried on the stack we can now add those to the ESF and the initial stack and take care to restore them for new threads using the new thread wrapper routine. Signed-off-by: Carlo Caione <ccaione@baylibre.com>
106 lines
2.9 KiB
C
106 lines
2.9 KiB
C
/*
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* Copyright (c) 2019 Carlo Caione <ccaione@baylibre.com>
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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/**
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* @file
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* @brief New thread creation for ARM64 Cortex-A
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*
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* Core thread related primitives for the ARM64 Cortex-A
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*/
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#include <kernel.h>
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#include <ksched.h>
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#include <wait_q.h>
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#include <arch/cpu.h>
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/**
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*
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* @brief Initialize a new thread from its stack space
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*
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* The control structure (thread) is put at the lower address of the stack. An
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* initial context, to be "restored" by z_arm64_context_switch(), is put at the
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* other end of the stack, and thus reusable by the stack when not needed
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* anymore.
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*
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* <options> is currently unused.
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*
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* @param stack pointer to the aligned stack memory
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* @param stackSize size of the available stack memory in bytes
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* @param pEntry the entry point
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* @param parameter1 entry point to the first param
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* @param parameter2 entry point to the second param
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* @param parameter3 entry point to the third param
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* @param priority thread priority
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* @param options thread options: K_ESSENTIAL, K_FP_REGS
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*
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* @return N/A
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*/
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void z_thread_entry_wrapper(k_thread_entry_t k, void *p1, void *p2, void *p3);
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struct init_stack_frame {
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/* top of the stack / most recently pushed */
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/* SPSL_ELn and ELR_ELn */
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u64_t spsr;
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u64_t elr;
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/*
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* Used by z_thread_entry_wrapper. pulls these off the stack and
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* into argument registers before calling z_thread_entry()
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*/
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u64_t entry_point;
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u64_t arg1;
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u64_t arg2;
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u64_t arg3;
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/* least recently pushed */
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};
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void arch_new_thread(struct k_thread *thread, k_thread_stack_t *stack,
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size_t stackSize, k_thread_entry_t pEntry,
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void *parameter1, void *parameter2, void *parameter3,
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int priority, unsigned int options)
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{
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char *pStackMem = Z_THREAD_STACK_BUFFER(stack);
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char *stackEnd;
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struct init_stack_frame *pInitCtx;
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stackEnd = pStackMem + stackSize;
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z_new_thread_init(thread, pStackMem, stackSize, priority, options);
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pInitCtx = (struct init_stack_frame *)(STACK_ROUND_DOWN(stackEnd -
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sizeof(struct init_stack_frame)));
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pInitCtx->entry_point = (u64_t)pEntry;
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pInitCtx->arg1 = (u64_t)parameter1;
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pInitCtx->arg2 = (u64_t)parameter2;
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pInitCtx->arg3 = (u64_t)parameter3;
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/*
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* - ELR_ELn: to be used by eret in z_thread_entry_wrapper() to return
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* to z_thread_entry() with pEntry in x0(entry_point) and the parameters
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* already in place in x1(arg1), x2(arg2), x3(arg3).
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* - SPSR_ELn: to enable IRQs (we are masking debug exceptions, SError
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* interrupts and FIQs).
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*/
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pInitCtx->elr = (u64_t)z_thread_entry;
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pInitCtx->spsr = SPSR_MODE_EL1H | DAIF_FIQ;
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/*
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* We are saving:
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*
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* - SP: to pop out pEntry and parameters when going through
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* z_thread_entry_wrapper().
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* - x30: to be used by ret in z_arm64_context_switch() when the new
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* task is first scheduled.
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*/
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thread->callee_saved.sp = (u64_t)pInitCtx;
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thread->callee_saved.x30 = (u64_t)z_thread_entry_wrapper;
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}
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