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MFC locore.S:r.1.22, ofw_machdep.c:1.14

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>  Copy SPRG0-3 registers at boot-time and restore when calling into
>  OpenFirmware. FreeBSD/ppc uses SPRG0 as the per-cpu data area pointer,
>  and SPRG1-3 as temporary registers during exception handling. There
>  have been a few instances where OpenFirmware does require these to
>  be part of it's context, such as cd-booting an eMac.
This commit is contained in:
grehan 2005-11-11 05:21:08 +00:00
parent a4ba2270ec
commit f7e8320445
2 changed files with 57 additions and 6 deletions
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13
sys/powerpc/powerpc/locore.S
View File

@ -81,7 +81,7 @@ GLOBAL(esym)
.long 0 /* end of symbol table */
GLOBAL(ofmsr)
.long 0 /* msr used in Open Firmware */
.long 0, 0, 0, 0, 0 /* msr/sprg0-3 used in Open Firmware */
GLOBAL(powersave)
.long 0
@ -154,8 +154,17 @@ __start:
mfmsr 0
lis 9,ofmsr@ha
stw 0,ofmsr@l(9)
stwu 0,ofmsr@l(9)
mfsprg0 0 /* save SPRG0-3 */
stw 0,4(9) /* ofmsr[1] = sprg0 */
mfsprg1 0
stw 0,8(9) /* ofmsr[2] = sprg1 */
mfsprg2 0
stw 0,12(9) /* ofmsr[3] = sprg2 */
mfsprg3 0
stw 0,16(9) /* ofmsr[4] = sprg3 */
bl OF_init
lis 4,end@ha

50
sys/powerpc/powerpc/ofw_machdep.c
View File

@ -59,11 +59,49 @@ __FBSDID("$FreeBSD$");
static struct mem_region OFmem[OFMEM_REGIONS + 1], OFavail[OFMEM_REGIONS + 3];
static struct mem_region OFfree[OFMEM_REGIONS + 3];
extern long ofmsr;
extern register_t ofmsr[5];
extern struct pcpu __pcpu[MAXCPU];
extern struct pmap ofw_pmap;
extern int pmap_bootstrapped;
static int (*ofwcall)(void *);
/*
* Saved SPRG0-3 from OpenFirmware. Will be restored prior to the callback.
*/
register_t ofw_sprg0_save;
static __inline void
ofw_sprg_prepare(void)
{
/*
* Assume that interrupt are disabled at this point, or
* SPRG1-3 could be trashed
*/
__asm __volatile("mfsprg0 %0\n\t"
"mtsprg0 %1\n\t"
"mtsprg1 %2\n\t"
"mtsprg2 %3\n\t"
"mtsprg3 %4\n\t"
: "=&r"(ofw_sprg0_save)
: "r"(ofmsr[1]),
"r"(ofmsr[2]),
"r"(ofmsr[3]),
"r"(ofmsr[4]));
}
static __inline void
ofw_sprg_restore(void)
{
/*
* Note that SPRG1-3 contents are irrelevant. They are scratch
* registers used in the early portion of trap handling when
* interrupts are disabled.
*
* PCPU data cannot be used until this routine is called !
*/
__asm __volatile("mtsprg0 %0" :: "r"(ofw_sprg0_save));
}
/*
* Memory region utilities: determine if two regions overlap,
* and merge two overlapping regions into one
@ -173,9 +211,11 @@ openfirmware(void *args)
"mtmsr %1\n\t"
"isync\n"
: "=r" (oldmsr)
: "r" (ofmsr)
: "r" (ofmsr[0])
);
ofw_sprg_prepare();
if (pmap_bootstrapped) {
/*
* Swap the kernel's address space with Open Firmware's
@ -192,8 +232,8 @@ openfirmware(void *args)
"mtdbatu 3, %0" : : "r" (0));
isync();
}
result = ofwcall(args);
result = ofwcall(args);
if (pmap_bootstrapped) {
/*
@ -207,6 +247,8 @@ openfirmware(void *args)
}
}
ofw_sprg_restore();
__asm( "\t"
"mtmsr %0\n\t"
"isync\n"