1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * OMAP SRAM detection and management
4 *
5 * Copyright (C) 2005 Nokia Corporation
6 * Written by Tony Lindgren <tony@atomide.com>
7 */
8
9#include <linux/module.h>
10#include <linux/kernel.h>
11#include <linux/init.h>
12#include <linux/io.h>
13#include <linux/set_memory.h>
14
15#include <asm/fncpy.h>
16#include <asm/tlb.h>
17#include <asm/cacheflush.h>
18
19#include <asm/mach/map.h>
20
21#include "soc.h"
22#include "sram.h"
23
24#define OMAP1_SRAM_PA		0x20000000
25#define SRAM_BOOTLOADER_SZ	0x80
26#define ROUND_DOWN(value, boundary)	((value) & (~((boundary) - 1)))
27
28static void __iomem *omap_sram_base;
29static unsigned long omap_sram_start;
30static unsigned long omap_sram_skip;
31static unsigned long omap_sram_size;
32static void __iomem *omap_sram_ceil;
33
34/*
35 * Memory allocator for SRAM: calculates the new ceiling address
36 * for pushing a function using the fncpy API.
37 *
38 * Note that fncpy requires the returned address to be aligned
39 * to an 8-byte boundary.
40 */
41static void *omap_sram_push_address(unsigned long size)
42{
43	unsigned long available, new_ceil = (unsigned long)omap_sram_ceil;
44
45	available = omap_sram_ceil - (omap_sram_base + omap_sram_skip);
46
47	if (size > available) {
48		pr_err("Not enough space in SRAM\n");
49		return NULL;
50	}
51
52	new_ceil -= size;
53	new_ceil = ROUND_DOWN(new_ceil, FNCPY_ALIGN);
54	omap_sram_ceil = IOMEM(new_ceil);
55
56	return (void __force *)omap_sram_ceil;
57}
58
59void *omap_sram_push(void *funcp, unsigned long size)
60{
61	void *sram;
62	unsigned long base;
63	int pages;
64	void *dst = NULL;
65
66	sram = omap_sram_push_address(size);
67	if (!sram)
68		return NULL;
69
70	base = (unsigned long)sram & PAGE_MASK;
71	pages = PAGE_ALIGN(size) / PAGE_SIZE;
72
73	set_memory_rw(base, pages);
74
75	dst = fncpy(sram, funcp, size);
76
77	set_memory_rox(base, pages);
78
79	return dst;
80}
81
82/*
83 * The amount of SRAM depends on the core type.
84 * Note that we cannot try to test for SRAM here because writes
85 * to secure SRAM will hang the system. Also the SRAM is not
86 * yet mapped at this point.
87 * Note that we cannot use ioremap for SRAM, as clock init needs SRAM early.
88 */
89static void __init omap_detect_and_map_sram(void)
90{
91	unsigned long base;
92	int pages;
93
94	omap_sram_skip = SRAM_BOOTLOADER_SZ;
95	omap_sram_start = OMAP1_SRAM_PA;
96
97	if (cpu_is_omap15xx())
98		omap_sram_size = 0x30000;	/* 192K */
99	else if (cpu_is_omap1610() || cpu_is_omap1611() ||
100			cpu_is_omap1621() || cpu_is_omap1710())
101		omap_sram_size = 0x4000;	/* 16K */
102	else {
103		pr_err("Could not detect SRAM size\n");
104		omap_sram_size = 0x4000;
105	}
106
107	omap_sram_start = ROUND_DOWN(omap_sram_start, PAGE_SIZE);
108	omap_sram_base = __arm_ioremap_exec(omap_sram_start, omap_sram_size, 1);
109	if (!omap_sram_base) {
110		pr_err("SRAM: Could not map\n");
111		return;
112	}
113
114	omap_sram_ceil = omap_sram_base + omap_sram_size;
115
116	/*
117	 * Looks like we need to preserve some bootloader code at the
118	 * beginning of SRAM for jumping to flash for reboot to work...
119	 */
120	memset_io(omap_sram_base + omap_sram_skip, 0,
121		  omap_sram_size - omap_sram_skip);
122
123	base = (unsigned long)omap_sram_base;
124	pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE;
125
126	set_memory_rox(base, pages);
127}
128
129static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl);
130
131void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl)
132{
133	BUG_ON(!_omap_sram_reprogram_clock);
134	_omap_sram_reprogram_clock(dpllctl, ckctl);
135}
136
137int __init omap1_sram_init(void)
138{
139	omap_detect_and_map_sram();
140	_omap_sram_reprogram_clock =
141			omap_sram_push(omap1_sram_reprogram_clock,
142					omap1_sram_reprogram_clock_sz);
143
144	return 0;
145}
146