46 lines
1.1 KiB
C
46 lines
1.1 KiB
C
/*
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* Copyright (c) 2020 Intel Corporation
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <zephyr/kernel.h>
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#include <zephyr/kernel_structs.h>
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#include <kernel_internal.h>
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#include <kernel_tls.h>
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#include <zephyr/sys/util.h>
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size_t arch_tls_stack_setup(struct k_thread *new_thread, char *stack_ptr)
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{
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/*
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* TLS area for x86 and x86_64 has the data/bss first,
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* then a pointer pointing to itself. The address to
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* this pointer needs to be stored in register GS (x86)
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* or FS (x86_64). GCC generates code which reads this
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* pointer and offsets from this pointer are used to
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* access data.
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*/
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uintptr_t *self_ptr;
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/*
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* Since we are populating things backwards, store
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* the pointer to the TLS area at top of stack.
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*/
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stack_ptr -= sizeof(uintptr_t);
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self_ptr = (void *)stack_ptr;
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*self_ptr = POINTER_TO_UINT(stack_ptr);
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/*
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* Set thread TLS pointer as this is used to populate
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* FS/GS at context switch.
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*/
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new_thread->tls = POINTER_TO_UINT(self_ptr);
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/* Setup the TLS data */
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stack_ptr -= z_tls_data_size();
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z_tls_copy(stack_ptr);
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return (z_tls_data_size() + sizeof(uintptr_t));
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}
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