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USIII and beyond CPUs have stricter requirements when it comes

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to synchronization needed after stores to internal ASIs in order
to make side-effects visible. This mainly requires the MEMBAR #Sync
after such stores to be replaced with a FLUSH. We use KERNBASE as
the address to FLUSH as it is guaranteed to not trap. Actually,
the USII synchronization rules also already require a FLUSH in
pretty much all of the cases changed.
We're also hitting an additional USIII synchronization rule which
requires stores to AA_IMMU_SFSR to be immediately followed by a DONE,
FLUSH or RETRY. Doing so triggers a RED state exception though so
leave the MEMBAR #Sync. Linux apparently also has gotten away with
doing the same for quite some time now, apart from the fact that
it's not clear to me why we need to clear the valid bit from the
SFSR in the first place.

Reviewed by:	nwhitehorn
This commit is contained in:
marius 2008-09-08 20:38:48 +00:00
parent 579a51f222
commit 45e57c6bd2
7 changed files with 31 additions and 14 deletions
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3
sys/boot/sparc64/loader/main.c
View File

@ -37,6 +37,7 @@ __FBSDID("$FreeBSD$");
#include <machine/tlb.h>
#include <machine/upa.h>
#include <machine/ver.h>
#include <machine/vmparam.h>
#include "bootstrap.h"
#include "libofw.h"
@ -461,7 +462,7 @@ itlb_enter_sun4u(u_long vpn, u_long data)
stxa(AA_IMMU_TAR, ASI_IMMU,
TLB_TAR_VA(vpn) | TLB_TAR_CTX(TLB_CTX_KERNEL));
stxa(0, ASI_ITLB_DATA_IN_REG, data);
membar(Sync);
flush(KERNBASE);
wrpr(pstate, reg, 0);
}

13
sys/sparc64/sparc64/exception.S
View File

@ -498,6 +498,11 @@ END(rsf_fatal)
wr %g0, ASI_IMMU, %asi
rdpr %tpc, %g3
ldxa [%g0 + AA_IMMU_SFSR] %asi, %g4
/*
* XXX in theory, a store to AA_IMMU_SFSR must be immediately
* followed by a DONE, FLUSH or RETRY for USIII. In practice,
* this triggers a RED state exception though.
*/
stxa %g0, [%g0 + AA_IMMU_SFSR] %asi
membar #Sync
ba %xcc, tl0_sfsr_trap
@ -716,8 +721,9 @@ ENTRY(tl0_immu_miss_trap)
* Put back the contents of the tag access register, in case we
* faulted.
*/
sethi %hi(KERNBASE), %g2
stxa %g1, [%g0 + AA_IMMU_TAR] %asi
membar #Sync
flush %g2
/*
* Switch to alternate globals.
@ -1213,6 +1219,11 @@ END(tl0_fp_restore)
wr %g0, ASI_IMMU, %asi
rdpr %tpc, %g3
ldxa [%g0 + AA_IMMU_SFSR] %asi, %g4
/*
* XXX in theory, a store to AA_IMMU_SFSR must be immediately
* followed by a DONE, FLUSH or RETRY for USIII. In practice,
* this triggers a RED state exception though.
*/
stxa %g0, [%g0 + AA_IMMU_SFSR] %asi
membar #Sync
ba %xcc, tl1_insn_exceptn_trap

12
sys/sparc64/sparc64/mp_exception.S
View File

@ -199,9 +199,10 @@ ENTRY(tl_ipi_tlb_page_demap)
ldx [%g5 + ITA_VA], %g2
or %g2, %g3, %g2
sethi %hi(KERNBASE), %g3
stxa %g0, [%g2] ASI_DMMU_DEMAP
stxa %g0, [%g2] ASI_IMMU_DEMAP
membar #Sync
flush %g3
IPI_DONE(%g5, %g1, %g2, %g3)
retry
@ -234,13 +235,13 @@ ENTRY(tl_ipi_tlb_range_demap)
ldx [%g5 + ITA_START], %g1
ldx [%g5 + ITA_END], %g2
set PAGE_SIZE, %g6
1: or %g1, %g3, %g4
sethi %hi(KERNBASE), %g6
stxa %g0, [%g4] ASI_DMMU_DEMAP
stxa %g0, [%g4] ASI_IMMU_DEMAP
membar #Sync
flush %g6
set PAGE_SIZE, %g6
add %g1, %g6, %g1
cmp %g1, %g2
blt,a,pt %xcc, 1b
@ -265,9 +266,10 @@ ENTRY(tl_ipi_tlb_context_demap)
#endif
mov TLB_DEMAP_PRIMARY | TLB_DEMAP_CONTEXT, %g1
sethi %hi(KERNBASE), %g3
stxa %g0, [%g1] ASI_DMMU_DEMAP
stxa %g0, [%g1] ASI_IMMU_DEMAP
membar #Sync
flush %g3
IPI_DONE(%g5, %g1, %g2, %g3)
retry

4
sys/sparc64/sparc64/pmap.c
View File

@ -556,7 +556,7 @@ pmap_map_tsb(void)
* FP block operations in the kernel).
*/
stxa(AA_DMMU_SCXR, ASI_DMMU, TLB_CTX_KERNEL);
membar(Sync);
flush(KERNBASE);
intr_restore(s);
}
@ -1980,7 +1980,7 @@ pmap_activate(struct thread *td)
stxa(AA_DMMU_TSB, ASI_DMMU, pm->pm_tsb);
stxa(AA_IMMU_TSB, ASI_IMMU, pm->pm_tsb);
stxa(AA_DMMU_PCXR, ASI_DMMU, context);
membar(Sync);
flush(KERNBASE);
mtx_unlock_spin(&sched_lock);
}

3
sys/sparc64/sparc64/support.S
View File

@ -780,8 +780,9 @@ ENTRY(openfirmware_exit)
sub %l0, SPOFF, %fp ! setup a stack in a locked page
sub %l0, SPOFF + CCFSZ, %sp
mov AA_DMMU_PCXR, %l3 ! force primary DMMU context 0
sethi %hi(KERNBASE), %l5
stxa %g0, [%l3] ASI_DMMU
membar #Sync
flush %l5
wrpr %g0, 0, %tl ! force trap level 0
call %l6
mov %i0, %o0

3
sys/sparc64/sparc64/swtch.S
View File

@ -237,8 +237,9 @@ ENTRY(cpu_switch)
mov AA_IMMU_TSB, %i5
stxa %i4, [%i5] ASI_IMMU
mov AA_DMMU_PCXR, %i5
sethi %hi(KERNBASE), %i4
stxa %i3, [%i5] ASI_DMMU
membar #Sync
flush %i4
/*
* Done, return and load the new process's window from the stack.

7
sys/sparc64/sparc64/tlb.c
View File

@ -45,6 +45,7 @@ __FBSDID("$FreeBSD$");
#include <machine/pmap.h>
#include <machine/smp.h>
#include <machine/tlb.h>
#include <machine/vmparam.h>
PMAP_STATS_VAR(tlb_ncontext_demap);
PMAP_STATS_VAR(tlb_npage_demap);
@ -85,7 +86,7 @@ tlb_context_demap(struct pmap *pm)
s = intr_disable();
stxa(TLB_DEMAP_PRIMARY | TLB_DEMAP_CONTEXT, ASI_DMMU_DEMAP, 0);
stxa(TLB_DEMAP_PRIMARY | TLB_DEMAP_CONTEXT, ASI_IMMU_DEMAP, 0);
membar(Sync);
flush(KERNBASE);
intr_restore(s);
}
ipi_wait(cookie);
@ -111,7 +112,7 @@ tlb_page_demap(struct pmap *pm, vm_offset_t va)
s = intr_disable();
stxa(TLB_DEMAP_VA(va) | flags, ASI_DMMU_DEMAP, 0);
stxa(TLB_DEMAP_VA(va) | flags, ASI_IMMU_DEMAP, 0);
membar(Sync);
flush(KERNBASE);
intr_restore(s);
}
ipi_wait(cookie);
@ -139,7 +140,7 @@ tlb_range_demap(struct pmap *pm, vm_offset_t start, vm_offset_t end)
for (va = start; va < end; va += PAGE_SIZE) {
stxa(TLB_DEMAP_VA(va) | flags, ASI_DMMU_DEMAP, 0);
stxa(TLB_DEMAP_VA(va) | flags, ASI_IMMU_DEMAP, 0);
membar(Sync);
flush(KERNBASE);
}
intr_restore(s);
}