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|
struct syscall_result {
long val;
int errno;
};
static struct syscall_result syscall_return(long result)
{
struct syscall_result res;
if (((unsigned long)result) >= ((unsigned long)-125)) {
res.errno = - result;
res.val = -1;
} else {
res.errno = 0;
res.val = result;
}
return res;
}
static struct syscall_result syscall0(unsigned long nr)
{
long res;
asm volatile(
"int $0x80"
: "=a" (res)
: "a" (nr));
return syscall_return(res);
}
static struct syscall_result syscall1(unsigned long nr, unsigned long arg1)
{
long res;
asm volatile(
"int $0x80"
: "=a" (res)
: "a" (nr), "b" (arg1));
return syscall_return(res);
}
static struct syscall_result syscall2(unsigned long nr, unsigned long arg1, unsigned long arg2)
{
long res;
asm volatile(
"int $0x80"
: "=a" (res)
: "a" (nr), "b" (arg1), "c" (arg2));
return syscall_return(res);
}
static struct syscall_result syscall3(unsigned long nr, unsigned long arg1, unsigned long arg2,
unsigned long arg3)
{
long res;
asm volatile(
"int $0x80"
: "=a" (res)
: "a" (nr), "b" (arg1), "c" (arg2), "d" (arg3));
return syscall_return(res);
}
static struct syscall_result syscall4(unsigned long nr, unsigned long arg1, unsigned long arg2,
unsigned long arg3, unsigned long arg4)
{
long res;
asm volatile(
"int $0x80"
: "=a" (res)
: "a" (nr), "b" (arg1), "c" (arg2), "d" (arg3), "S" (arg4));
return syscall_return(res);
}
static struct syscall_result syscall5(unsigned long nr, unsigned long arg1, unsigned long arg2,
unsigned long arg3, unsigned long arg4, unsigned long arg5)
{
long res;
asm volatile(
"int $0x80"
: "=a" (res)
: "a" (nr), "b" (arg1), "c" (arg2), "d" (arg3),
"S" (arg4), "D" (arg5));
return syscall_return(res);
}
#define NR_exit 1
#define NR_fork 2
#define NR_read 3
#define NR_write 4
#define NR_open 5
#define NR_close 6
#define NR_waitpid 7
#define NR_creat 8
#define NR_link 9
#define NR_unlink 10
#define NR_execve 11
#define NR_chdir 12
#define NR_time 13
#define NR_mknod 14
#define NR_chmod 15
#define NR_lchown 16
#define NR_break 17
#define NR_oldstat 18
#define NR_lseek 19
#define NR_getpid 20
#define NR_mount 21
#define NR_umount 22
#define NR_setuid 23
#define NR_getuid 24
#define NR_stime 25
#define NR_ptrace 26
#define NR_alarm 27
#define NR_oldfstat 28
#define NR_pause 29
#define NR_utime 30
#define NR_stty 31
#define NR_gtty 32
#define NR_access 33
#define NR_nice 34
#define NR_ftime 35
#define NR_sync 36
#define NR_kill 37
#define NR_rename 38
#define NR_mkdir 39
#define NR_rmdir 40
#define NR_dup 41
#define NR_pipe 42
#define NR_times 43
#define NR_prof 44
#define NR_brk 45
#define NR_setgid 46
#define NR_getgid 47
#define NR_signal 48
#define NR_geteuid 49
#define NR_getegid 50
#define NR_acct 51
#define NR_umount2 52
#define NR_lock 53
#define NR_ioctl 54
#define NR_fcntl 55
#define NR_mpx 56
#define NR_setpgid 57
#define NR_ulimit 58
#define NR_oldolduname 59
#define NR_umask 60
#define NR_chroot 61
#define NR_ustat 62
#define NR_dup2 63
#define NR_getppid 64
#define NR_getpgrp 65
#define NR_setsid 66
#define NR_sigaction 67
#define NR_sgetmask 68
#define NR_ssetmask 69
#define NR_setreuid 70
#define NR_setregid 71
#define NR_sigsuspend 72
#define NR_sigpending 73
#define NR_sethostname 74
#define NR_setrlimit 75
#define NR_getrlimit 76
#define NR_getrusage 77
#define NR_gettimeofday 78
#define NR_settimeofday 79
#define NR_getgroups 80
#define NR_setgroups 81
#define NR_select 82
#define NR_symlink 83
#define NR_oldlstat 84
#define NR_readlink 85
#define NR_uselib 86
#define NR_swapon 87
#define NR_reboot 88
#define NR_readdir 89
#define NR_mmap 90
#define NR_munmap 91
#define NR_truncate 92
#define NR_ftruncate 93
#define NR_fchmod 94
#define NR_fchown 95
#define NR_getpriority 96
#define NR_setpriority 97
#define NR_profil 98
#define NR_statfs 99
#define NR_fstatfs 100
#define NR_ioperm 101
#define NR_socketcall 102
#define NR_syslog 103
#define NR_setitimer 104
#define NR_getitimer 105
#define NR_stat 106
#define NR_lstat 107
#define NR_fstat 108
#define NR_olduname 109
#define NR_iopl 110
#define NR_vhangup 111
#define NR_idle 112
#define NR_vm86old 113
#define NR_wait4 114
#define NR_swapoff 115
#define NR_sysinfo 116
#define NR_ipc 117
#define NR_fsync 118
#define NR_sigreturn 119
#define NR_clone 120
#define NR_setdomainname 121
#define NR_uname 122
#define NR_modify_ldt 123
#define NR_adjtimex 124
#define NR_mprotect 125
#define NR_sigprocmask 126
#define NR_create_module 127
#define NR_init_module 128
#define NR_delete_module 129
#define NR_get_kernel_syms 130
#define NR_quotactl 131
#define NR_getpgid 132
#define NR_fchdir 133
#define NR_bdflush 134
#define NR_sysfs 135
#define NR_personality 136
#define NR_afs_syscall 137 /* Syscall for Andrew File System */
#define NR_setfsuid 138
#define NR_setfsgid 139
#define NR__llseek 140
#define NR_getdents 141
#define NR__newselect 142
#define NR_flock 143
#define NR_msync 144
#define NR_readv 145
#define NR_writev 146
#define NR_getsid 147
#define NR_fdatasync 148
#define NR__sysctl 149
#define NR_mlock 150
#define NR_munlock 151
#define NR_mlockall 152
#define NR_munlockall 153
#define NR_sched_setparam 154
#define NR_sched_getparam 155
#define NR_sched_setscheduler 156
#define NR_sched_getscheduler 157
#define NR_sched_yield 158
#define NR_sched_get_priority_max 159
#define NR_sched_get_priority_min 160
#define NR_sched_rr_get_interval 161
#define NR_nanosleep 162
#define NR_mremap 163
#define NR_setresuid 164
#define NR_getresuid 165
#define NR_vm86 166
#define NR_query_module 167
#define NR_poll 168
#define NR_nfsservctl 169
#define NR_setresgid 170
#define NR_getresgid 171
#define NR_prctl 172
#define NR_rt_sigreturn 173
#define NR_rt_sigaction 174
#define NR_rt_sigprocmask 175
#define NR_rt_sigpending 176
#define NR_rt_sigtimedwait 177
#define NR_rt_sigqueueinfo 178
#define NR_rt_sigsuspend 179
#define NR_pread 180
#define NR_pwrite 181
#define NR_chown 182
#define NR_getcwd 183
#define NR_capget 184
#define NR_capset 185
#define NR_sigaltstack 186
#define NR_sendfile 187
#define NR_getpmsg 188 /* some people actually want streams */
#define NR_putpmsg 189 /* some people actually want streams */
#define NR_vfork 190
typedef long ssize_t;
typedef unsigned long size_t;
/* Standard file descriptors */
#define STDIN_FILENO 0 /* Standard input */
#define STDOUT_FILENO 1 /* Standard output */
#define STDERR_FILENO 2 /* Standard error output */
static ssize_t write(int fd, const void *buf, size_t count)
{
struct syscall_result res;
res = syscall3(NR_write, fd, (unsigned long)buf, count);
return res.val;
}
static void _exit(int status)
{
struct syscall_result res;
res = syscall1(NR_exit, status);
}
static const char *addr_of_char(unsigned char ch)
{
static const char byte[] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
};
return byte + ch;
}
static void console_tx_byte(unsigned char ch)
{
write(STDOUT_FILENO, addr_of_char(ch), 1);
}
static void console_tx_nibble(unsigned nibble)
{
unsigned char digit;
digit = nibble + '0';
if (digit > '9') {
digit += 39;
}
console_tx_byte(digit);
}
static void console_tx_char(unsigned char byte)
{
console_tx_byte(byte);
}
static void console_tx_hex8(unsigned char value)
{
console_tx_nibble((value >> 4U) & 0x0fU);
console_tx_nibble(value & 0x0fU);
}
static void console_tx_hex16(unsigned short value)
{
console_tx_nibble((value >> 12U) & 0x0FU);
console_tx_nibble((value >> 8U) & 0x0FU);
console_tx_nibble((value >> 4U) & 0x0FU);
console_tx_nibble(value & 0x0FU);
}
static void console_tx_hex32(unsigned short value)
{
console_tx_nibble((value >> 28U) & 0x0FU);
console_tx_nibble((value >> 24U) & 0x0FU);
console_tx_nibble((value >> 20U) & 0x0FU);
console_tx_nibble((value >> 16U) & 0x0FU);
console_tx_nibble((value >> 12U) & 0x0FU);
console_tx_nibble((value >> 8U) & 0x0FU);
console_tx_nibble((value >> 4U) & 0x0FU);
console_tx_nibble(value & 0x0FU);
}
static void console_tx_string(const char *str)
{
unsigned char ch;
while((ch = *str++) != '\0') {
console_tx_byte(ch);
}
}
static void print_emerg_char(unsigned char byte) { console_tx_char(byte); }
static void print_emerg_hex8(unsigned char value) { console_tx_hex8(value); }
static void print_emerg_hex16(unsigned short value){ console_tx_hex16(value); }
static void print_emerg_hex32(unsigned int value) { console_tx_hex32(value); }
static void print_emerg(const char *str) { console_tx_string(str); }
static void print_debug_char(unsigned char byte) { console_tx_char(byte); }
static void print_debug_hex8(unsigned char value) { console_tx_hex8(value); }
static void print_debug_hex16(unsigned short value){ console_tx_hex16(value); }
static void print_debug_hex32(unsigned int value) { console_tx_hex32(value); }
static void print_debug(const char *str) { console_tx_string(str); }
int log2(int value)
{
/* __builtin_bsr is a exactly equivalent to the x86 machine
* instruction with the exception that it returns -1
* when the value presented to it is zero.
* Otherwise __builtin_bsr returns the zero based index of
* the highest bit set.
*/
return __builtin_bsr(value);
}
static void die(const char *str)
{
print_emerg(str);
do {
asm(" ");
} while(1);
}
static int smbus_read_byte(unsigned device, unsigned address)
{
static const unsigned char dimm[] = {
0x80, 0x08, 0x07, 0x0d, 0x0a, 0x02, 0x48, 0x00, 0x04, 0x60, 0x70, 0x02, 0x82, 0x08, 0x08, 0x01,
0x0e, 0x04, 0x0c, 0x01, 0x02, 0x20, 0x00, 0x75, 0x70, 0x00, 0x00, 0x48, 0x30, 0x48, 0x2a, 0x40,
0x80, 0x80, 0x45, 0x45, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x33,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0x80, 0x08, 0x07, 0x0d, 0x0a, 0x02, 0x48, 0x00, 0x04, 0x60, 0x70, 0x02, 0x82, 0x08, 0x08, 0x01,
0x0e, 0x04, 0x0c, 0x01, 0x02, 0x20, 0x00, 0x75, 0x70, 0x00, 0x00, 0x48, 0x30, 0x48, 0x2a, 0x40,
0x80, 0x80, 0x45, 0x45, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x33,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
};
return dimm[(device << 8) + address];
}
#define SMBUS_MEM_DEVICE_START 0x00
#define SMBUS_MEM_DEVICE_END 0x01
#define SMBUS_MEM_DEVICE_INC 1
/* Function 2 */
#define DRAM_CONFIG_HIGH 0x94
#define DCH_MEMCLK_SHIFT 20
#define DCH_MEMCLK_MASK 7
#define DCH_MEMCLK_100MHZ 0
#define DCH_MEMCLK_133MHZ 2
#define DCH_MEMCLK_166MHZ 5
#define DCH_MEMCLK_200MHZ 7
/* Function 3 */
#define NORTHBRIDGE_CAP 0xE8
#define NBCAP_128Bit 0x0001
#define NBCAP_MP 0x0002
#define NBCAP_BIG_MP 0x0004
#define NBCAP_ECC 0x0004
#define NBCAP_CHIPKILL_ECC 0x0010
#define NBCAP_MEMCLK_SHIFT 5
#define NBCAP_MEMCLK_MASK 3
#define NBCAP_MEMCLK_100MHZ 3
#define NBCAP_MEMCLK_133MHZ 2
#define NBCAP_MEMCLK_166MHZ 1
#define NBCAP_MEMCLK_200MHZ 0
#define NBCAP_MEMCTRL 0x0100
typedef unsigned char uint8_t;
typedef unsigned int uint32_t;
static unsigned spd_to_dimm(unsigned device)
{
return (device - SMBUS_MEM_DEVICE_START);
}
static void disable_dimm(unsigned index)
{
print_debug("disabling dimm");
print_debug_hex8(index);
print_debug("\r\n");
#if 0
pci_write_config32(PCI_DEV(0, 0x18, 2), DRAM_CSBASE + (((index << 1)+0)<<2), 0);
pci_write_config32(PCI_DEV(0, 0x18, 2), DRAM_CSBASE + (((index << 1)+1)<<2), 0);
#endif
}
struct mem_param {
uint8_t cycle_time;
uint32_t dch_memclk;
};
static const struct mem_param *get_mem_param(unsigned min_cycle_time)
{
static const struct mem_param speed[] = {
{
.cycle_time = 0xa0,
.dch_memclk = DCH_MEMCLK_100MHZ << DCH_MEMCLK_SHIFT,
},
{
.cycle_time = 0x75,
.dch_memclk = DCH_MEMCLK_133MHZ << DCH_MEMCLK_SHIFT,
},
{
.cycle_time = 0x60,
.dch_memclk = DCH_MEMCLK_166MHZ << DCH_MEMCLK_SHIFT,
},
{
.cycle_time = 0x50,
.dch_memclk = DCH_MEMCLK_200MHZ << DCH_MEMCLK_SHIFT,
},
{
.cycle_time = 0x00,
},
};
const struct mem_param *param;
for(param = &speed[0]; param->cycle_time ; param++) {
if (min_cycle_time > (param+1)->cycle_time) {
break;
}
}
if (!param->cycle_time) {
die("min_cycle_time to low");
}
return param;
}
#if 1
static void debug(int c)
{
print_debug_char(c);
print_debug_char('\r');
print_debug_char('\n');
}
#endif
static const struct mem_param *spd_set_memclk(void)
{
/* Compute the minimum cycle time for these dimms */
const struct mem_param *param;
unsigned min_cycle_time, min_latency;
unsigned device;
uint32_t value;
static const int latency_indices[] = { 26, 23, 9 };
static const unsigned char min_cycle_times[] = {
[NBCAP_MEMCLK_200MHZ] = 0x50, /* 5ns */
[NBCAP_MEMCLK_166MHZ] = 0x60, /* 6ns */
[NBCAP_MEMCLK_133MHZ] = 0x75, /* 7.5ns */
[NBCAP_MEMCLK_100MHZ] = 0xa0, /* 10ns */
};
#if 0
value = pci_read_config32(PCI_DEV(0, 0x18, 3), NORTHBRIDGE_CAP);
#else
value = 0x50;
#endif
min_cycle_time = min_cycle_times[(value >> NBCAP_MEMCLK_SHIFT) & NBCAP_MEMCLK_MASK];
min_latency = 2;
#if 1
print_debug("min_cycle_time: ");
print_debug_hex8(min_cycle_time);
print_debug(" min_latency: ");
print_debug_hex8(min_latency);
print_debug("\r\n");
#endif
/* Compute the least latency with the fastest clock supported
* by both the memory controller and the dimms.
*/
for(device = SMBUS_MEM_DEVICE_START;
device <= SMBUS_MEM_DEVICE_END;
device += SMBUS_MEM_DEVICE_INC)
{
int new_cycle_time, new_latency;
int index;
int latencies;
int latency;
debug('A');
/* First find the supported CAS latencies
* Byte 18 for DDR SDRAM is interpreted:
* bit 0 == CAS Latency = 1.0
* bit 1 == CAS Latency = 1.5
* bit 2 == CAS Latency = 2.0
* bit 3 == CAS Latency = 2.5
* bit 4 == CAS Latency = 3.0
* bit 5 == CAS Latency = 3.5
* bit 6 == TBD
* bit 7 == TBD
*/
new_cycle_time = 0xa0;
new_latency = 5;
latencies = smbus_read_byte(device, 18);
if (latencies <= 0) continue;
debug('B');
/* Compute the lowest cas latency supported */
latency = log2(latencies) -2;
/* Loop through and find a fast clock with a low latency */
for(index = 0; index < 3; index++, latency++) {
int value;
debug('C');
if ((latency < 2) || (latency > 4) ||
(!(latencies & (1 << latency)))) {
continue;
}
debug('D');
value = smbus_read_byte(device, latency_indices[index]);
if (value < 0) continue;
debug('E');
/* Only increase the latency if we decreas the clock */
if ((value >= min_cycle_time) && (value < new_cycle_time)) {
new_cycle_time = value;
new_latency = latency;
#if 1
print_debug("device: ");
print_debug_hex8(device);
print_debug(" new_cycle_time: ");
print_debug_hex8(new_cycle_time);
print_debug(" new_latency: ");
print_debug_hex8(new_latency);
print_debug("\r\n");
#endif
}
debug('G');
}
debug('H');
#if 1
print_debug("device: ");
print_debug_hex8(device);
print_debug(" new_cycle_time: ");
print_debug_hex8(new_cycle_time);
print_debug(" new_latency: ");
print_debug_hex8(new_latency);
print_debug("\r\n");
#endif
if (new_latency > 4){
continue;
}
debug('I');
/* Does min_latency need to be increased? */
if (new_cycle_time > min_cycle_time) {
min_cycle_time = new_cycle_time;
}
/* Does min_cycle_time need to be increased? */
if (new_latency > min_latency) {
min_latency = new_latency;
}
#if 1
print_debug("device: ");
print_debug_hex8(device);
print_debug(" min_cycle_time: ");
print_debug_hex8(min_cycle_time);
print_debug(" min_latency: ");
print_debug_hex8(min_latency);
print_debug("\r\n");
#endif
}
/* Make a second pass through the dimms and disable
* any that cannot support the selected memclk and cas latency.
*/
for(device = SMBUS_MEM_DEVICE_START;
device <= SMBUS_MEM_DEVICE_END;
device += SMBUS_MEM_DEVICE_INC)
{
int latencies;
int latency;
int index;
int value;
int dimm;
latencies = smbus_read_byte(device, 18);
if (latencies <= 0) {
goto dimm_err;
}
/* Compute the lowest cas latency supported */
latency = log2(latencies) -2;
/* Walk through searching for the selected latency */
for(index = 0; index < 3; index++, latency++) {
if (!(latencies & (1 << latency))) {
continue;
}
if (latency == min_latency)
break;
}
/* If I can't find the latency or my index is bad error */
if ((latency != min_latency) || (index >= 3)) {
goto dimm_err;
}
/* Read the min_cycle_time for this latency */
value = smbus_read_byte(device, latency_indices[index]);
/* All is good if the selected clock speed
* is what I need or slower.
*/
if (value <= min_cycle_time) {
continue;
}
/* Otherwise I have an error, disable the dimm */
dimm_err:
disable_dimm(spd_to_dimm(device));
}
#if 1
print_debug("min_cycle_time: ");
print_debug_hex8(min_cycle_time);
print_debug(" min_latency: ");
print_debug_hex8(min_latency);
print_debug("\r\n");
#endif
/* Now that I know the minimum cycle time lookup the memory parameters */
param = get_mem_param(min_cycle_time);
#if 0
/* Update DRAM Config High with our selected memory speed */
value = pci_read_config32(PCI_DEV(0, 0x18, 2), DRAM_CONFIG_HIGH);
value &= ~(DCH_MEMCLK_MASK << DCH_MEMCLK_SHIFT);
value |= param->dch_memclk;
pci_write_config32(PCI_DEV(0, 0x18, 2), DRAM_CONFIG_HIGH, value);
static const unsigned latencies[] = { 1, 5, 2 };
/* Update DRAM Timing Low wiht our selected cas latency */
value = pci_read_config32(PCI_DEV(0, 0x18, 2), DRAM_CONFIG_LOW);
value &= ~7;
value |= latencies[min_latency - 2];
pci_write_config32(PCI_DEV(0, 0x18, 2), DRAM_CONFIG_LOW, value);
#endif
return param;
}
static void main(void)
{
const struct mem_param *param;
param = spd_set_memclk();
_exit(0);
}
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