linux_dsm_epyc7002/arch/sparc/include/asm/oplib_64.h
David S. Miller ef3e035c3a sparc64: Fix register corruption in top-most kernel stack frame during boot.
Meelis Roos reported that kernels built with gcc-4.9 do not boot, we
eventually narrowed this down to only impacting machines using
UltraSPARC-III and derivitive cpus.

The crash happens right when the first user process is spawned:

[   54.451346] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
[   54.451346]
[   54.571516] CPU: 1 PID: 1 Comm: init Not tainted 3.16.0-rc2-00211-gd7933ab #96
[   54.666431] Call Trace:
[   54.698453]  [0000000000762f8c] panic+0xb0/0x224
[   54.759071]  [000000000045cf68] do_exit+0x948/0x960
[   54.823123]  [000000000042cbc0] fault_in_user_windows+0xe0/0x100
[   54.902036]  [0000000000404ad0] __handle_user_windows+0x0/0x10
[   54.978662] Press Stop-A (L1-A) to return to the boot prom
[   55.050713] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004

Further investigation showed that compiling only per_cpu_patch() with
an older compiler fixes the boot.

Detailed analysis showed that the function is not being miscompiled by
gcc-4.9, but it is using a different register allocation ordering.

With the gcc-4.9 compiled function, something during the code patching
causes some of the %i* input registers to get corrupted.  Perhaps
we have a TLB miss path into the firmware that is deep enough to
cause a register window spill and subsequent restore when we get
back from the TLB miss trap.

Let's plug this up by doing two things:

1) Stop using the firmware stack for client interface calls into
   the firmware.  Just use the kernel's stack.

2) As soon as we can, call into a new function "start_early_boot()"
   to put a one-register-window buffer between the firmware's
   deepest stack frame and the top-most initial kernel one.

Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-24 09:52:49 -07:00

252 lines
8.1 KiB
C

/* oplib.h: Describes the interface and available routines in the
* Linux Prom library.
*
* Copyright (C) 1995, 2007 David S. Miller (davem@davemloft.net)
* Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#ifndef __SPARC64_OPLIB_H
#define __SPARC64_OPLIB_H
#include <asm/openprom.h>
/* OBP version string. */
extern char prom_version[];
/* Root node of the prom device tree, this stays constant after
* initialization is complete.
*/
extern phandle prom_root_node;
/* PROM stdout */
extern int prom_stdout;
/* /chosen node of the prom device tree, this stays constant after
* initialization is complete.
*/
extern phandle prom_chosen_node;
/* Helper values and strings in arch/sparc64/kernel/head.S */
extern const char prom_peer_name[];
extern const char prom_compatible_name[];
extern const char prom_root_compatible[];
extern const char prom_cpu_compatible[];
extern const char prom_finddev_name[];
extern const char prom_chosen_path[];
extern const char prom_cpu_path[];
extern const char prom_getprop_name[];
extern const char prom_mmu_name[];
extern const char prom_callmethod_name[];
extern const char prom_translate_name[];
extern const char prom_map_name[];
extern const char prom_unmap_name[];
extern int prom_mmu_ihandle_cache;
extern unsigned int prom_boot_mapped_pc;
extern unsigned int prom_boot_mapping_mode;
extern unsigned long prom_boot_mapping_phys_high, prom_boot_mapping_phys_low;
struct linux_mlist_p1275 {
struct linux_mlist_p1275 *theres_more;
unsigned long start_adr;
unsigned long num_bytes;
};
struct linux_mem_p1275 {
struct linux_mlist_p1275 **p1275_totphys;
struct linux_mlist_p1275 **p1275_prommap;
struct linux_mlist_p1275 **p1275_available; /* What we can use */
};
/* The functions... */
/* You must call prom_init() before using any of the library services,
* preferably as early as possible. Pass it the romvec pointer.
*/
void prom_init(void *cif_handler);
void prom_init_report(void);
/* Boot argument acquisition, returns the boot command line string. */
char *prom_getbootargs(void);
/* Miscellaneous routines, don't really fit in any category per se. */
/* Reboot the machine with the command line passed. */
void prom_reboot(const char *boot_command);
/* Evaluate the forth string passed. */
void prom_feval(const char *forth_string);
/* Enter the prom, with possibility of continuation with the 'go'
* command in newer proms.
*/
void prom_cmdline(void);
/* Enter the prom, with no chance of continuation for the stand-alone
* which calls this.
*/
void prom_halt(void) __attribute__ ((noreturn));
/* Halt and power-off the machine. */
void prom_halt_power_off(void) __attribute__ ((noreturn));
/* Acquire the IDPROM of the root node in the prom device tree. This
* gets passed a buffer where you would like it stuffed. The return value
* is the format type of this idprom or 0xff on error.
*/
unsigned char prom_get_idprom(char *idp_buffer, int idpbuf_size);
/* Write a buffer of characters to the console. */
void prom_console_write_buf(const char *buf, int len);
/* Prom's internal routines, don't use in kernel/boot code. */
__printf(1, 2) void prom_printf(const char *fmt, ...);
void prom_write(const char *buf, unsigned int len);
/* Multiprocessor operations... */
#ifdef CONFIG_SMP
/* Start the CPU with the given device tree node at the passed program
* counter with the given arg passed in via register %o0.
*/
void prom_startcpu(int cpunode, unsigned long pc, unsigned long arg);
/* Start the CPU with the given cpu ID at the passed program
* counter with the given arg passed in via register %o0.
*/
void prom_startcpu_cpuid(int cpuid, unsigned long pc, unsigned long arg);
/* Stop the CPU with the given cpu ID. */
void prom_stopcpu_cpuid(int cpuid);
/* Stop the current CPU. */
void prom_stopself(void);
/* Idle the current CPU. */
void prom_idleself(void);
/* Resume the CPU with the passed device tree node. */
void prom_resumecpu(int cpunode);
#endif
/* Power management interfaces. */
/* Put the current CPU to sleep. */
void prom_sleepself(void);
/* Put the entire system to sleep. */
int prom_sleepsystem(void);
/* Initiate a wakeup event. */
int prom_wakeupsystem(void);
/* MMU and memory related OBP interfaces. */
/* Get unique string identifying SIMM at given physical address. */
int prom_getunumber(int syndrome_code,
unsigned long phys_addr,
char *buf, int buflen);
/* Retain physical memory to the caller across soft resets. */
int prom_retain(const char *name, unsigned long size,
unsigned long align, unsigned long *paddr);
/* Load explicit I/D TLB entries into the calling processor. */
long prom_itlb_load(unsigned long index,
unsigned long tte_data,
unsigned long vaddr);
long prom_dtlb_load(unsigned long index,
unsigned long tte_data,
unsigned long vaddr);
/* Map/Unmap client program address ranges. First the format of
* the mapping mode argument.
*/
#define PROM_MAP_WRITE 0x0001 /* Writable */
#define PROM_MAP_READ 0x0002 /* Readable - sw */
#define PROM_MAP_EXEC 0x0004 /* Executable - sw */
#define PROM_MAP_LOCKED 0x0010 /* Locked, use i/dtlb load calls for this instead */
#define PROM_MAP_CACHED 0x0020 /* Cacheable in both L1 and L2 caches */
#define PROM_MAP_SE 0x0040 /* Side-Effects */
#define PROM_MAP_GLOB 0x0080 /* Global */
#define PROM_MAP_IE 0x0100 /* Invert-Endianness */
#define PROM_MAP_DEFAULT (PROM_MAP_WRITE | PROM_MAP_READ | PROM_MAP_EXEC | PROM_MAP_CACHED)
int prom_map(int mode, unsigned long size,
unsigned long vaddr, unsigned long paddr);
void prom_unmap(unsigned long size, unsigned long vaddr);
/* PROM device tree traversal functions... */
/* Get the child node of the given node, or zero if no child exists. */
phandle prom_getchild(phandle parent_node);
/* Get the next sibling node of the given node, or zero if no further
* siblings exist.
*/
phandle prom_getsibling(phandle node);
/* Get the length, at the passed node, of the given property type.
* Returns -1 on error (ie. no such property at this node).
*/
int prom_getproplen(phandle thisnode, const char *property);
/* Fetch the requested property using the given buffer. Returns
* the number of bytes the prom put into your buffer or -1 on error.
*/
int prom_getproperty(phandle thisnode, const char *property,
char *prop_buffer, int propbuf_size);
/* Acquire an integer property. */
int prom_getint(phandle node, const char *property);
/* Acquire an integer property, with a default value. */
int prom_getintdefault(phandle node, const char *property, int defval);
/* Acquire a boolean property, 0=FALSE 1=TRUE. */
int prom_getbool(phandle node, const char *prop);
/* Acquire a string property, null string on error. */
void prom_getstring(phandle node, const char *prop, char *buf,
int bufsize);
/* Does the passed node have the given "name"? YES=1 NO=0 */
int prom_nodematch(phandle thisnode, const char *name);
/* Search all siblings starting at the passed node for "name" matching
* the given string. Returns the node on success, zero on failure.
*/
phandle prom_searchsiblings(phandle node_start, const char *name);
/* Return the first property type, as a string, for the given node.
* Returns a null string on error. Buffer should be at least 32B long.
*/
char *prom_firstprop(phandle node, char *buffer);
/* Returns the next property after the passed property for the given
* node. Returns null string on failure. Buffer should be at least 32B long.
*/
char *prom_nextprop(phandle node, const char *prev_property, char *buf);
/* Returns 1 if the specified node has given property. */
int prom_node_has_property(phandle node, const char *property);
/* Returns phandle of the path specified */
phandle prom_finddevice(const char *name);
/* Set the indicated property at the given node with the passed value.
* Returns the number of bytes of your value that the prom took.
*/
int prom_setprop(phandle node, const char *prop_name, char *prop_value,
int value_size);
phandle prom_inst2pkg(int);
void prom_sun4v_guest_soft_state(void);
int prom_ihandle2path(int handle, char *buffer, int bufsize);
/* Client interface level routines. */
void p1275_cmd_direct(unsigned long *);
#endif /* !(__SPARC64_OPLIB_H) */