arch/ppc/boot/simple/mpc10x_memory.c

   1 /*
   2  * A routine to find out how much memory the machine has.
   3  *
   4  * Based on:
   5  * arch/ppc/kernel/mpc10x_common.c
   6  *
   7  * Author: Mark A. Greer
   8  *         mgreer@mvista.com
   9  *
  10  * 2001-2002 (c) MontaVista, Software, Inc.  This file is licensed under
  11  * the terms of the GNU General Public License version 2.  This program
  12  * is licensed "as is" without any warranty of any kind, whether express
  13  * or implied.
  14  */
  15
  16 #include <linux/pci.h>
  17 #include <asm/types.h>
  18 #include <asm/io.h>
  19 #include "mpc10x.h"
  20
  21 /*
  22  * *** WARNING - A BAT MUST be set to access the PCI config addr/data regs ***
  23  */
  24
  25 /*
  26  * PCI config space macros, similar to indirect_xxx and early_xxx macros.
  27  * We assume bus 0.
  28  */
  29 #define MPC10X_CFG_read(val, addr, type, op)    *val = op((type)(addr))
  30 #define MPC10X_CFG_write(val, addr, type, op)   op((type *)(addr), (val))
  31
  32 #define MPC10X_PCI_OP(rw, size, type, op, mask)                         \
  33 static void                                                             \
  34 mpc10x_##rw##_config_##size(unsigned int __iomem *cfg_addr,                     \
  35                 unsigned int *cfg_data, int devfn, int offset,          \
  36                 type val)                                               \
  37 {                                                                       \
  38         out_be32(cfg_addr,                                              \
  39                  ((offset & 0xfc) << 24) | (devfn << 16)                \
  40                  | (0 << 8) | 0x80);                                    \
  41         MPC10X_CFG_##rw(val, cfg_data + (offset & mask), type, op);     \
  42         return;                                                         \
  43 }
  44
  45 MPC10X_PCI_OP(read, byte,  u8 *, in_8, 3)
  46 MPC10X_PCI_OP(read, dword, u32 *, in_le32, 0)
  47
  48 /*
  49  * Read the memory controller registers to determine the amount of memory in
  50  * the system.  This assumes that the firmware has correctly set up the memory
  51  * controller registers.  On CONFIG_PPC_PREP, we know we are being called
  52  * under a PReP memory map. On all other machines, we assume we are under
  53  * a CHRP memory map.  Further, on CONFIG_PPC_PREP we must rename
  54  * this function.
  55  */
  56 #ifdef CONFIG_PPC_PREP
  57 #define get_mem_size mpc10x_get_mem_size
  58 #endif
  59 unsigned long
  60 get_mem_size(void)
  61 {
  62         unsigned int *config_addr, *config_data, val;
  63         unsigned long start, end, total, offset;
  64         int i;
  65         unsigned char bank_enables;
  66
  67 #ifdef CONFIG_PPC_PREP
  68         config_addr = (unsigned int *)MPC10X_MAPA_CNFG_ADDR;
  69         config_data = (unsigned int *)MPC10X_MAPA_CNFG_DATA;
  70 #else
  71         config_addr = (unsigned int *)MPC10X_MAPB_CNFG_ADDR;
  72         config_data = (unsigned int *)MPC10X_MAPB_CNFG_DATA;
  73 #endif
  74
  75         mpc10x_read_config_byte(config_addr, config_data, PCI_DEVFN(0,0),
  76                         MPC10X_MCTLR_MEM_BANK_ENABLES, &bank_enables);
  77
  78         total = 0;
  79
  80         for (i = 0; i < 8; i++) {
  81                 if (bank_enables & (1 << i)) {
  82                         offset = MPC10X_MCTLR_MEM_START_1 + ((i > 3) ? 4 : 0);
  83                         mpc10x_read_config_dword(config_addr, config_data,
  84                                         PCI_DEVFN(0,0), offset, &val);
  85                         start = (val >> ((i & 3) << 3)) & 0xff;
  86
  87                         offset = MPC10X_MCTLR_EXT_MEM_START_1 + ((i>3) ? 4 : 0);
  88                         mpc10x_read_config_dword(config_addr, config_data,
  89                                         PCI_DEVFN(0,0), offset, &val);
  90                         val = (val >> ((i & 3) << 3)) & 0x03;
  91                         start = (val << 28) | (start << 20);
  92
  93                         offset = MPC10X_MCTLR_MEM_END_1 + ((i > 3) ? 4 : 0);
  94                         mpc10x_read_config_dword(config_addr, config_data,
  95                                         PCI_DEVFN(0,0), offset, &val);
  96                         end = (val >> ((i & 3) << 3)) & 0xff;
  97
  98                         offset = MPC10X_MCTLR_EXT_MEM_END_1 + ((i > 3) ? 4 : 0);
  99                         mpc10x_read_config_dword(config_addr, config_data,
 100                                         PCI_DEVFN(0,0), offset, &val);
 101                         val = (val >> ((i & 3) << 3)) & 0x03;
 102                         end = (val << 28) | (end << 20) | 0xfffff;
 103
 104                         total += (end - start + 1);
 105                 }
 106         }
 107
 108         return total;
 109 }