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Use the PROM provided SUNW,set-trap-table to take over the trap

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table. This is required in order to set obp-control-relinquished
within the PROM, allowing to safely read the OFW translations node.
Without this, f.e. a `ofwdump -ap` triggers a fatal reset error or
worse things on machines based on USIII and beyond.
In theory this should allow to remove touching %tba in cpu_setregs(),
in practice we seem to currently face a chicken and egg problem when
doing so however.
This commit is contained in:
Marius Strobl 2008-09-04 20:52:54 +00:00
parent f083c6eb98
commit e5858aa9d5
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=182773
3 changed files with 35 additions and 0 deletions
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1
sys/sparc64/include/trap.h
View File

@ -90,6 +90,7 @@
#define T_KERNEL 64
#ifndef LOCORE
void sun4u_set_traptable(void *tba_addr);
extern const char *trap_msg[];
#endif

10
sys/sparc64/sparc64/machdep.c
View File

@ -436,6 +436,16 @@ sparc64_init(caddr_t mdp, u_long o1, u_long o2, u_long o3, ofw_vec_t *vec)
*/
cpu_setregs(pc);
/*
* Take over the trap table via the PROM. Using the PROM for this
* is necessary in order to set obp-control-relinquished to true
* within the PROM so obtaining /virtual-memory/translations doesn't
* trigger a fatal reset error or worse things further down the road.
* XXX it should be possible to use this soley instead of writing
* %tba in cpu_setregs(). Doing so causes a hang however.
*/
sun4u_set_traptable(tl0_base);
/*
* It's now safe to use the real DELAY().
*/

24
sys/sparc64/sparc64/trap.c
View File

@ -70,6 +70,8 @@ __FBSDID("$FreeBSD$");
#endif
#include <security/audit/audit.h>
#include <dev/ofw/openfirm.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
@ -227,6 +229,28 @@ int debugger_on_signal = 0;
SYSCTL_INT(_debug, OID_AUTO, debugger_on_signal, CTLFLAG_RW,
&debugger_on_signal, 0, "");
/*
* SUNW,set-trap-table allows to take over %tba from the PROM, which
* will turn off interrupts and handle outstanding ones while doing so,
* in a safe way.
*/
void
sun4u_set_traptable(void *tba_addr)
{
static struct {
cell_t name;
cell_t nargs;
cell_t nreturns;
cell_t tba_addr;
} args = {
(cell_t)"SUNW,set-trap-table",
2,
};
args.tba_addr = (cell_t)tba_addr;
openfirmware(&args);
}
void
trap(struct trapframe *tf)
{