89 lines
2.6 KiB
C
89 lines
2.6 KiB
C
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/* Copyright 2011 The Chromium OS Authors. All rights reserved.
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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/*
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* Shared memory interface for Chrome EC.
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*
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* This is intended to supply a relatively large block of memory for use by a
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* task for a relatively short amount of time. For example, verified boot may
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* need a buffer to hold signature data during a verification operation. It is
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* NOT intended for allocating long-term buffers; those should in general be
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* static variables allocated at compile-time. It is NOT a full-featured
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* replacement for malloc() / free().
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*/
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#ifndef __CROS_EC_SHARED_MEM_H
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#define __CROS_EC_SHARED_MEM_H
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#include "common.h"
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#include <stddef.h>
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/**
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* Returns the maximum amount of shared memory which can be acquired, in
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* bytes.
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*/
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int shared_mem_size(void);
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#define SHARED_MEM_CHECK_SIZE(size) \
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BUILD_ASSERT((size) <= CONFIG_SHAREDMEM_MINIMUM_SIZE)
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/*
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* Acquires a shared memory area of the requested size in bytes.
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*
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* Doing a sysjump between images will corrupt and/or erase shared memory as
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* jump tags are added and .bss is reinitialized. Due to the way jump tags are
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* added to the end of RAM, shared memory must not be allocated, accessed, or
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* freed after the start of a sysjump (for example, in HOOK_SYSJUMP).
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*
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* @param size Number of bytes requested
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* @param dest_ptr If successful, set on return to the start of the
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* granted memory buffer.
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*
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* @return EC_SUCCESS if successful, EC_ERROR_BUSY if buffer in use, or
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* other non-zero error code.
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*/
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int shared_mem_acquire(int size, char **dest_ptr);
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#define SHARED_MEM_ACQUIRE_CHECK(size, dest_ptr) \
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({ \
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SHARED_MEM_CHECK_SIZE(size); \
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shared_mem_acquire((size), (dest_ptr)); \
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})
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/**
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* Releases a shared memory area previously allocated via shared_mem_acquire().
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*/
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void shared_mem_release(void *ptr);
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/*
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* This structure is allocated at the base of the free memory chunk and every
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* allocated buffer.
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*/
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struct shm_buffer {
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struct shm_buffer *next_buffer;
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struct shm_buffer *prev_buffer;
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size_t buffer_size;
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};
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#ifdef TEST_SHMALLOC
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/*
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* When in test mode, all possible paths in the allocation/free functions set
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* unique bits in an integer bitmap.
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*
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* The test function generates random allocation and free requests and
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* monitors the bitmap until all bits have been set, which indicates that all
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* possible paths have been executed.
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*/
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#define MAX_MASK_BIT 24
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#define ALL_PATHS_MASK ((1 << (MAX_MASK_BIT + 1)) - 1)
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void set_map_bit(uint32_t mask);
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extern struct shm_buffer *free_buf_chain;
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extern struct shm_buffer *allocced_buf_chain;
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#endif
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#endif /* __CROS_EC_SHARED_MEM_H */
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