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 | |
28 | static void __iomem *omap_sram_base; |
29 | static unsigned long omap_sram_start; |
30 | static unsigned long omap_sram_skip; |
31 | static unsigned long omap_sram_size; |
32 | static 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 | */ |
41 | static 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 | |
59 | void *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(addr: base, numpages: pages); |
74 | |
75 | dst = fncpy(sram, funcp, size); |
76 | |
77 | set_memory_rox(addr: base, numpages: 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 | */ |
89 | static 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(addr: base, numpages: pages); |
127 | } |
128 | |
129 | static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl); |
130 | |
131 | void 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 | |
137 | int __init omap1_sram_init(void) |
138 | { |
139 | omap_detect_and_map_sram(); |
140 | _omap_sram_reprogram_clock = |
141 | omap_sram_push(funcp: omap1_sram_reprogram_clock, |
142 | size: omap1_sram_reprogram_clock_sz); |
143 | |
144 | return 0; |
145 | } |
146 | |