1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Code shared between SPL and U-Boot proper
4 *
5 * Copyright (c) 2015 Google, Inc
6 * Written by Simon Glass <sjg@chromium.org>
7 */
8
9#include <common.h>
10#include <bootstage.h>
11#include <init.h>
12#include <asm/global_data.h>
13
14DECLARE_GLOBAL_DATA_PTR;
15
16/* Unfortunately x86 or ARM can't compile this code as gd cannot be assigned */
17#if !defined(CONFIG_X86) && !defined(CONFIG_ARM)
18__weak void arch_setup_gd(struct global_data *gd_ptr)
19{
20	gd = gd_ptr;
21}
22#endif /* !CONFIG_X86 && !CONFIG_ARM */
23
24/**
25 * This function is called from board_init_f_init_reserve to set up
26 * gd->start_addr_sp for stack protection if not already set otherwise
27 */
28__weak void board_init_f_init_stack_protection_addr(ulong base)
29{
30#if CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE)
31	/* set up stack pointer for stack usage if not set yet */
32	if (!gd->start_addr_sp)
33		gd->start_addr_sp = base;
34#endif
35}
36
37/**
38 * This function is called after the position of the initial stack is
39 * determined in gd->start_addr_sp. Boards can override it to set up
40 * stack-checking markers.
41 */
42__weak void board_init_f_init_stack_protection(void)
43{
44#if CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE)
45	ulong stack_bottom = gd->start_addr_sp -
46		CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK);
47
48	/* substact some safety margin (0x20) since stack is in use here */
49	memset((void *)stack_bottom, CONFIG_VAL(SYS_STACK_F_CHECK_BYTE),
50	       CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK) - 0x20);
51#endif
52}
53
54/*
55 * Allocate reserved space for use as 'globals' from 'top' address and
56 * return 'bottom' address of allocated space
57 *
58 * Notes:
59 *
60 * Actual reservation cannot be done from within this function as
61 * it requires altering the C stack pointer, so this will be done by
62 * the caller upon return from this function.
63 *
64 * IMPORTANT:
65 *
66 * Alignment constraints may differ for each 'chunk' allocated. For now:
67 *
68 * - GD is aligned down on a 16-byte boundary
69 *
70 *  - the early malloc arena is not aligned, therefore it follows the stack
71 *   alignment constraint of the architecture for which we are bulding.
72 *
73 *  - GD is allocated last, so that the return value of this functions is
74 *   both the bottom of the reserved area and the address of GD, should
75 *   the calling context need it.
76 */
77
78ulong board_init_f_alloc_reserve(ulong top)
79{
80	/* Reserve early malloc arena */
81#ifndef CFG_MALLOC_F_ADDR
82#if CONFIG_IS_ENABLED(SYS_MALLOC_F)
83	top -= CONFIG_VAL(SYS_MALLOC_F_LEN);
84#endif
85#endif
86	/* LAST : reserve GD (rounded up to a multiple of 16 bytes) */
87	top = rounddown(top-sizeof(struct global_data), 16);
88
89	return top;
90}
91
92/*
93 * Initialize reserved space (which has been safely allocated on the C
94 * stack from the C runtime environment handling code).
95 *
96 * Notes:
97 *
98 * Actual reservation was done by the caller; the locations from base
99 * to base+size-1 (where 'size' is the value returned by the allocation
100 * function above) can be accessed freely without risk of corrupting the
101 * C runtime environment.
102 *
103 * IMPORTANT:
104 *
105 * Upon return from the allocation function above, on some architectures
106 * the caller will set gd to the lowest reserved location. Therefore, in
107 * this initialization function, the global data MUST be placed at base.
108 *
109 * ALSO IMPORTANT:
110 *
111 * On some architectures, gd will already be good when entering this
112 * function. On others, it will only be good once arch_setup_gd() returns.
113 * Therefore, global data accesses must be done:
114 *
115 * - through gd_ptr if before the call to arch_setup_gd();
116 *
117 * - through gd once arch_setup_gd() has been called.
118 *
119 * Do not use 'gd->' until arch_setup_gd() has been called!
120 *
121 * IMPORTANT TOO:
122 *
123 * Initialization for each "chunk" (GD, early malloc arena...) ends with
124 * an incrementation line of the form 'base += <some size>'. The last of
125 * these incrementations seems useless, as base will not be used any
126 * more after this incrementation; but if/when a new "chunk" is appended,
127 * this increment will be essential as it will give base right value for
128 * this new chunk (which will have to end with its own incrementation
129 * statement). Besides, the compiler's optimizer will silently detect
130 * and remove the last base incrementation, therefore leaving that last
131 * (seemingly useless) incrementation causes no code increase.
132 */
133
134void board_init_f_init_reserve(ulong base)
135{
136	struct global_data *gd_ptr;
137
138	/*
139	 * clear GD entirely and set it up.
140	 * Use gd_ptr, as gd may not be properly set yet.
141	 */
142
143	gd_ptr = (struct global_data *)base;
144	/* zero the area */
145	memset(gd_ptr, '\0', sizeof(*gd));
146	/* set GD unless architecture did it already */
147#if !defined(CONFIG_ARM)
148	arch_setup_gd(gd_ptr);
149#endif
150
151	if (CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE))
152		board_init_f_init_stack_protection_addr(base);
153
154	/* next alloc will be higher by one GD plus 16-byte alignment */
155	base += roundup(sizeof(struct global_data), 16);
156
157	/*
158	 * record early malloc arena start.
159	 * Use gd as it is now properly set for all architectures.
160	 */
161
162#if CONFIG_IS_ENABLED(SYS_MALLOC_F)
163	/* go down one 'early malloc arena' */
164	gd->malloc_base = base;
165#if CONFIG_IS_ENABLED(ZERO_MEM_BEFORE_USE)
166	memset((void *)base, '\0', CONFIG_VAL(SYS_MALLOC_F_LEN));
167#endif
168#endif
169
170	if (CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE))
171		board_init_f_init_stack_protection();
172}
173
174#if CONFIG_IS_ENABLED(SHOW_BOOT_PROGRESS)
175/*
176 * Board-specific Platform code can reimplement show_boot_progress () if needed
177 */
178__weak void show_boot_progress(int val) {}
179#endif
180