linux/arch/mips/fw/sni/sniprom.c
Maciej W. Rozycki 824122a319 MIPS: DEC/SNI: O32 wrapper stack switching fixes
Commit 231a35d372 [[MIPS] RM: Collected
changes] broke DECstation support by introducing an incompatible copy of
arch/mips/dec/prom/call_o32.S in arch/mips/fw/lib/, built unconditionally.
The copy happens to land earlier of the two among the modules used in the
link and is therefore chosen for the DECstation rather than the intended
original.  As a result random kernel data is corrupted because a pointer
to the "%s" formatted output template is used as a temporary stack pointer
rather than being passed down to prom_printf.  This also explains why
prom_printf still works, up to a point -- the next argument is the actual
string to output so it works just fine as the output template until enough
kernel data has been corrupted to cause a crash.

This change adjusts the modified wrapper in arch/mips/fw/lib/call_o32.S to
let callers request no stack switching by passing a null temporary stack
pointer in $a1, reworks the DECstation callers to work with the updated
interface and removes the old copy from arch/mips/dec/prom/call_o32.S.  A
few minor readability adjustments are included as well, most importantly
O32_SZREG is now used throughout where applicable rather than hardcoded
multiplies of 4 and $fp is used to access the argument save area as a more
usual register to operate the stack with rather than $s0.

Finally an update is made to the temporary stack space used by the SNI
platform to guarantee 8-byte alignment as per o32 requirements.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6668/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-13 00:29:35 +02:00

153 lines
3.8 KiB
C

/*
* Big Endian PROM code for SNI RM machines
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2005-2006 Florian Lohoff (flo@rfc822.org)
* Copyright (C) 2005-2006 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/console.h>
#include <asm/addrspace.h>
#include <asm/sni.h>
#include <asm/mipsprom.h>
#include <asm/mipsregs.h>
#include <asm/bootinfo.h>
/* special SNI prom calls */
/*
* This does not exist in all proms - SINIX compares
* the prom env variable "version" against "2.0008"
* or greater. If lesser it tries to probe interesting
* registers
*/
#define PROM_GET_MEMCONF 58
#define PROM_GET_HWCONF 61
#define PROM_VEC (u64 *)CKSEG1ADDR(0x1fc00000)
#define PROM_ENTRY(x) (PROM_VEC + (x))
#define ___prom_putchar ((int *(*)(int))PROM_ENTRY(PROM_PUTCHAR))
#define ___prom_getenv ((char *(*)(char *))PROM_ENTRY(PROM_GETENV))
#define ___prom_get_memconf ((void (*)(void *))PROM_ENTRY(PROM_GET_MEMCONF))
#define ___prom_get_hwconf ((u32 (*)(void))PROM_ENTRY(PROM_GET_HWCONF))
#ifdef CONFIG_64BIT
/* O32 stack has to be 8-byte aligned. */
static u64 o32_stk[4096];
#define O32_STK &o32_stk[sizeof(o32_stk)]
#define __PROM_O32(fun, arg) fun arg __asm__(#fun); \
__asm__(#fun " = call_o32")
int __PROM_O32(__prom_putchar, (int *(*)(int), void *, int));
char *__PROM_O32(__prom_getenv, (char *(*)(char *), void *, char *));
void __PROM_O32(__prom_get_memconf, (void (*)(void *), void *, void *));
u32 __PROM_O32(__prom_get_hwconf, (u32 (*)(void), void *));
#define _prom_putchar(x) __prom_putchar(___prom_putchar, O32_STK, x)
#define _prom_getenv(x) __prom_getenv(___prom_getenv, O32_STK, x)
#define _prom_get_memconf(x) __prom_get_memconf(___prom_get_memconf, O32_STK, x)
#define _prom_get_hwconf() __prom_get_hwconf(___prom_get_hwconf, O32_STK)
#else
#define _prom_putchar(x) ___prom_putchar(x)
#define _prom_getenv(x) ___prom_getenv(x)
#define _prom_get_memconf(x) ___prom_get_memconf(x)
#define _prom_get_hwconf(x) ___prom_get_hwconf(x)
#endif
void prom_putchar(char c)
{
_prom_putchar(c);
}
char *prom_getenv(char *s)
{
return _prom_getenv(s);
}
void *prom_get_hwconf(void)
{
u32 hwconf = _prom_get_hwconf();
if (hwconf == 0xffffffff)
return NULL;
return (void *)CKSEG1ADDR(hwconf);
}
void __init prom_free_prom_memory(void)
{
}
/*
* /proc/cpuinfo system type
*
*/
char *system_type = "Unknown";
const char *get_system_type(void)
{
return system_type;
}
static void __init sni_mem_init(void)
{
int i, memsize;
struct membank {
u32 size;
u32 base;
u32 size2;
u32 pad1;
u32 pad2;
} memconf[8];
int brd_type = *(unsigned char *)SNI_IDPROM_BRDTYPE;
/* MemSIZE from prom in 16MByte chunks */
memsize = *((unsigned char *) SNI_IDPROM_MEMSIZE) * 16;
pr_debug("IDProm memsize: %u MByte\n", memsize);
/* get memory bank layout from prom */
_prom_get_memconf(&memconf);
pr_debug("prom_get_mem_conf memory configuration:\n");
for (i = 0; i < 8 && memconf[i].size; i++) {
if (brd_type == SNI_BRD_PCI_TOWER ||
brd_type == SNI_BRD_PCI_TOWER_CPLUS) {
if (memconf[i].base >= 0x20000000 &&
memconf[i].base < 0x30000000)
memconf[i].base -= 0x20000000;
}
pr_debug("Bank%d: %08x @ %08x\n", i,
memconf[i].size, memconf[i].base);
add_memory_region(memconf[i].base, memconf[i].size,
BOOT_MEM_RAM);
}
}
void __init prom_init(void)
{
int argc = fw_arg0;
u32 *argv = (u32 *)CKSEG0ADDR(fw_arg1);
int i;
sni_mem_init();
/* copy prom cmdline parameters to kernel cmdline */
for (i = 1; i < argc; i++) {
strcat(arcs_cmdline, (char *)CKSEG0ADDR(argv[i]));
if (i < (argc - 1))
strcat(arcs_cmdline, " ");
}
}