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 14 #include <asm/fncpy.h> 15 #include <asm/tlb.h> 16 #include <asm/cacheflush.h> 17 #include <asm/set_memory.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(base, pages); 74 75 dst = fncpy(sram, funcp, size); 76 77 set_memory_ro(base, pages); 78 set_memory_x(base, pages); 79 80 return dst; 81 } 82 83 /* 84 * The amount of SRAM depends on the core type. 85 * Note that we cannot try to test for SRAM here because writes 86 * to secure SRAM will hang the system. Also the SRAM is not 87 * yet mapped at this point. 88 * Note that we cannot use ioremap for SRAM, as clock init needs SRAM early. 89 */ 90 static void __init omap_detect_and_map_sram(void) 91 { 92 unsigned long base; 93 int pages; 94 95 omap_sram_skip = SRAM_BOOTLOADER_SZ; 96 omap_sram_start = OMAP1_SRAM_PA; 97 98 if (cpu_is_omap7xx()) 99 omap_sram_size = 0x32000; /* 200K */ 100 else if (cpu_is_omap15xx()) 101 omap_sram_size = 0x30000; /* 192K */ 102 else if (cpu_is_omap1610() || cpu_is_omap1611() || 103 cpu_is_omap1621() || cpu_is_omap1710()) 104 omap_sram_size = 0x4000; /* 16K */ 105 else { 106 pr_err("Could not detect SRAM size\n"); 107 omap_sram_size = 0x4000; 108 } 109 110 omap_sram_start = ROUND_DOWN(omap_sram_start, PAGE_SIZE); 111 omap_sram_base = __arm_ioremap_exec(omap_sram_start, omap_sram_size, 1); 112 if (!omap_sram_base) { 113 pr_err("SRAM: Could not map\n"); 114 return; 115 } 116 117 omap_sram_ceil = omap_sram_base + omap_sram_size; 118 119 /* 120 * Looks like we need to preserve some bootloader code at the 121 * beginning of SRAM for jumping to flash for reboot to work... 122 */ 123 memset_io(omap_sram_base + omap_sram_skip, 0, 124 omap_sram_size - omap_sram_skip); 125 126 base = (unsigned long)omap_sram_base; 127 pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE; 128 129 set_memory_ro(base, pages); 130 set_memory_x(base, pages); 131 } 132 133 static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl); 134 135 void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl) 136 { 137 BUG_ON(!_omap_sram_reprogram_clock); 138 /* On 730, bit 13 must always be 1 */ 139 if (cpu_is_omap7xx()) 140 ckctl |= 0x2000; 141 _omap_sram_reprogram_clock(dpllctl, ckctl); 142 } 143 144 int __init omap1_sram_init(void) 145 { 146 omap_detect_and_map_sram(); 147 _omap_sram_reprogram_clock = 148 omap_sram_push(omap1_sram_reprogram_clock, 149 omap1_sram_reprogram_clock_sz); 150 151 return 0; 152 } 153