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(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 */ 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_omap7xx()) 98 omap_sram_size = 0x32000; /* 200K */ 99 else if (cpu_is_omap15xx()) 100 omap_sram_size = 0x30000; /* 192K */ 101 else if (cpu_is_omap1610() || cpu_is_omap1611() || 102 cpu_is_omap1621() || cpu_is_omap1710()) 103 omap_sram_size = 0x4000; /* 16K */ 104 else { 105 pr_err("Could not detect SRAM size\n"); 106 omap_sram_size = 0x4000; 107 } 108 109 omap_sram_start = ROUND_DOWN(omap_sram_start, PAGE_SIZE); 110 omap_sram_base = __arm_ioremap_exec(omap_sram_start, omap_sram_size, 1); 111 if (!omap_sram_base) { 112 pr_err("SRAM: Could not map\n"); 113 return; 114 } 115 116 omap_sram_ceil = omap_sram_base + omap_sram_size; 117 118 /* 119 * Looks like we need to preserve some bootloader code at the 120 * beginning of SRAM for jumping to flash for reboot to work... 121 */ 122 memset_io(omap_sram_base + omap_sram_skip, 0, 123 omap_sram_size - omap_sram_skip); 124 125 base = (unsigned long)omap_sram_base; 126 pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE; 127 128 set_memory_rox(base, pages); 129 } 130 131 static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl); 132 133 void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl) 134 { 135 BUG_ON(!_omap_sram_reprogram_clock); 136 /* On 730, bit 13 must always be 1 */ 137 if (cpu_is_omap7xx()) 138 ckctl |= 0x2000; 139 _omap_sram_reprogram_clock(dpllctl, ckctl); 140 } 141 142 int __init omap1_sram_init(void) 143 { 144 omap_detect_and_map_sram(); 145 _omap_sram_reprogram_clock = 146 omap_sram_push(omap1_sram_reprogram_clock, 147 omap1_sram_reprogram_clock_sz); 148 149 return 0; 150 } 151