arch/arm/mach-omap1/sram-init.c

   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_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
 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(omap1_sram_reprogram_clock,
 142                                         omap1_sram_reprogram_clock_sz);
 143
 144         return 0;
 145 }