1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * linux/arch/arm/plat-omap/sram.c
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * OMAP SRAM detection and management
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Copyright (C) 2005 Nokia Corporation
8*4882a593Smuzhiyun * Written by Tony Lindgren <tony@atomide.com>
9*4882a593Smuzhiyun *
10*4882a593Smuzhiyun * Copyright (C) 2009-2012 Texas Instruments
11*4882a593Smuzhiyun * Added OMAP4/5 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
12*4882a593Smuzhiyun */
13*4882a593Smuzhiyun #undef DEBUG
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #include <linux/module.h>
16*4882a593Smuzhiyun #include <linux/kernel.h>
17*4882a593Smuzhiyun #include <linux/init.h>
18*4882a593Smuzhiyun #include <linux/io.h>
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun #include <asm/fncpy.h>
21*4882a593Smuzhiyun #include <asm/tlb.h>
22*4882a593Smuzhiyun #include <asm/cacheflush.h>
23*4882a593Smuzhiyun #include <asm/set_memory.h>
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun #include <asm/mach/map.h>
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun #include <plat/sram.h>
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun #define ROUND_DOWN(value,boundary) ((value) & (~((boundary)-1)))
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun static void __iomem *omap_sram_base;
32*4882a593Smuzhiyun static unsigned long omap_sram_skip;
33*4882a593Smuzhiyun static unsigned long omap_sram_size;
34*4882a593Smuzhiyun static void __iomem *omap_sram_ceil;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun /*
37*4882a593Smuzhiyun * Memory allocator for SRAM: calculates the new ceiling address
38*4882a593Smuzhiyun * for pushing a function using the fncpy API.
39*4882a593Smuzhiyun *
40*4882a593Smuzhiyun * Note that fncpy requires the returned address to be aligned
41*4882a593Smuzhiyun * to an 8-byte boundary.
42*4882a593Smuzhiyun */
omap_sram_push_address(unsigned long size)43*4882a593Smuzhiyun static void *omap_sram_push_address(unsigned long size)
44*4882a593Smuzhiyun {
45*4882a593Smuzhiyun unsigned long available, new_ceil = (unsigned long)omap_sram_ceil;
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun available = omap_sram_ceil - (omap_sram_base + omap_sram_skip);
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun if (size > available) {
50*4882a593Smuzhiyun pr_err("Not enough space in SRAM\n");
51*4882a593Smuzhiyun return NULL;
52*4882a593Smuzhiyun }
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun new_ceil -= size;
55*4882a593Smuzhiyun new_ceil = ROUND_DOWN(new_ceil, FNCPY_ALIGN);
56*4882a593Smuzhiyun omap_sram_ceil = IOMEM(new_ceil);
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun return (void *)omap_sram_ceil;
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun
omap_sram_push(void * funcp,unsigned long size)61*4882a593Smuzhiyun void *omap_sram_push(void *funcp, unsigned long size)
62*4882a593Smuzhiyun {
63*4882a593Smuzhiyun void *sram;
64*4882a593Smuzhiyun unsigned long base;
65*4882a593Smuzhiyun int pages;
66*4882a593Smuzhiyun void *dst = NULL;
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun sram = omap_sram_push_address(size);
69*4882a593Smuzhiyun if (!sram)
70*4882a593Smuzhiyun return NULL;
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun base = (unsigned long)sram & PAGE_MASK;
73*4882a593Smuzhiyun pages = PAGE_ALIGN(size) / PAGE_SIZE;
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun set_memory_rw(base, pages);
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun dst = fncpy(sram, funcp, size);
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun set_memory_ro(base, pages);
80*4882a593Smuzhiyun set_memory_x(base, pages);
81*4882a593Smuzhiyun
82*4882a593Smuzhiyun return dst;
83*4882a593Smuzhiyun }
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun /*
86*4882a593Smuzhiyun * The SRAM context is lost during off-idle and stack
87*4882a593Smuzhiyun * needs to be reset.
88*4882a593Smuzhiyun */
omap_sram_reset(void)89*4882a593Smuzhiyun void omap_sram_reset(void)
90*4882a593Smuzhiyun {
91*4882a593Smuzhiyun omap_sram_ceil = omap_sram_base + omap_sram_size;
92*4882a593Smuzhiyun }
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun /*
95*4882a593Smuzhiyun * Note that we cannot use ioremap for SRAM, as clock init needs SRAM early.
96*4882a593Smuzhiyun */
omap_map_sram(unsigned long start,unsigned long size,unsigned long skip,int cached)97*4882a593Smuzhiyun void __init omap_map_sram(unsigned long start, unsigned long size,
98*4882a593Smuzhiyun unsigned long skip, int cached)
99*4882a593Smuzhiyun {
100*4882a593Smuzhiyun unsigned long base;
101*4882a593Smuzhiyun int pages;
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun if (size == 0)
104*4882a593Smuzhiyun return;
105*4882a593Smuzhiyun
106*4882a593Smuzhiyun start = ROUND_DOWN(start, PAGE_SIZE);
107*4882a593Smuzhiyun omap_sram_size = size;
108*4882a593Smuzhiyun omap_sram_skip = skip;
109*4882a593Smuzhiyun omap_sram_base = __arm_ioremap_exec(start, size, cached);
110*4882a593Smuzhiyun if (!omap_sram_base) {
111*4882a593Smuzhiyun pr_err("SRAM: Could not map\n");
112*4882a593Smuzhiyun return;
113*4882a593Smuzhiyun }
114*4882a593Smuzhiyun
115*4882a593Smuzhiyun omap_sram_reset();
116*4882a593Smuzhiyun
117*4882a593Smuzhiyun /*
118*4882a593Smuzhiyun * Looks like we need to preserve some bootloader code at the
119*4882a593Smuzhiyun * beginning of SRAM for jumping to flash for reboot to work...
120*4882a593Smuzhiyun */
121*4882a593Smuzhiyun memset_io(omap_sram_base + omap_sram_skip, 0,
122*4882a593Smuzhiyun omap_sram_size - omap_sram_skip);
123*4882a593Smuzhiyun
124*4882a593Smuzhiyun base = (unsigned long)omap_sram_base;
125*4882a593Smuzhiyun pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE;
126*4882a593Smuzhiyun
127*4882a593Smuzhiyun set_memory_ro(base, pages);
128*4882a593Smuzhiyun set_memory_x(base, pages);
129*4882a593Smuzhiyun }
130