parisc: flush pages through tmpalias space
The kernel has an 8M tmpailas space (originally designed for copying
and clearing pages but now only used for clearing). The idea is
to place zeros into the cache above a physical page rather than into
the physical page and flush the cache, because often the zeros end up
being replaced quickly anyway.
We can also use the tmpalias space for flushing a page. The difference
here is that we have to do tmpalias processing in the non access data and
instruction traps. The principle is the same: as long as we know the physical
address and have a virtual address congruent to the real one, the flush will
be effective.
In order to use the tmpalias space, the icache miss path has to be enhanced to
check for the alias region to make the fic instruction effective.
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index 6337ade..e8c119b 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -225,22 +225,13 @@
#ifndef CONFIG_64BIT
/*
* naitlb miss interruption handler (parisc 1.1 - 32 bit)
- *
- * Note: naitlb misses will be treated
- * as an ordinary itlb miss for now.
- * However, note that naitlb misses
- * have the faulting address in the
- * IOR/ISR.
*/
.macro naitlb_11 code
mfctl %isr,spc
- b itlb_miss_11
+ b naitlb_miss_11
mfctl %ior,va
- /* FIXME: If user causes a naitlb miss, the priv level may not be in
- * lower bits of va, where the itlb miss handler is expecting them
- */
.align 32
.endm
@@ -248,26 +239,17 @@
/*
* naitlb miss interruption handler (parisc 2.0)
- *
- * Note: naitlb misses will be treated
- * as an ordinary itlb miss for now.
- * However, note that naitlb misses
- * have the faulting address in the
- * IOR/ISR.
*/
.macro naitlb_20 code
mfctl %isr,spc
#ifdef CONFIG_64BIT
- b itlb_miss_20w
+ b naitlb_miss_20w
#else
- b itlb_miss_20
+ b naitlb_miss_20
#endif
mfctl %ior,va
- /* FIXME: If user causes a naitlb miss, the priv level may not be in
- * lower bits of va, where the itlb miss handler is expecting them
- */
.align 32
.endm
@@ -581,7 +563,24 @@
copy \va,\tmp1
depi 0,31,23,\tmp1
cmpb,COND(<>),n \tmp,\tmp1,\fault
- ldi (_PAGE_DIRTY|_PAGE_WRITE|_PAGE_READ),\prot
+ mfctl %cr19,\tmp /* iir */
+ /* get the opcode (first six bits) into \tmp */
+ extrw,u \tmp,5,6,\tmp
+ /*
+ * Only setting the T bit prevents data cache movein
+ * Setting access rights to zero prevents instruction cache movein
+ *
+ * Note subtlety here: _PAGE_GATEWAY, _PAGE_EXEC and _PAGE_WRITE go
+ * to type field and _PAGE_READ goes to top bit of PL1
+ */
+ ldi (_PAGE_REFTRAP|_PAGE_READ|_PAGE_WRITE),\prot
+ /*
+ * so if the opcode is one (i.e. this is a memory management
+ * instruction) nullify the next load so \prot is only T.
+ * Otherwise this is a normal data operation
+ */
+ cmpiclr,= 0x01,\tmp,%r0
+ ldi (_PAGE_DIRTY|_PAGE_READ|_PAGE_WRITE),\prot
depd,z \prot,8,7,\prot
/*
* OK, it is in the temp alias region, check whether "from" or "to".
@@ -631,11 +630,7 @@
def 13
def 14
dtlb_20 15
-#if 0
naitlb_20 16
-#else
- def 16
-#endif
nadtlb_20 17
def 18
def 19
@@ -678,11 +673,7 @@
def 13
def 14
dtlb_11 15
-#if 0
naitlb_11 16
-#else
- def 16
-#endif
nadtlb_11 17
def 18
def 19
@@ -1203,7 +1194,7 @@
get_pgd spc,ptp
space_check spc,t0,nadtlb_fault
- L3_ptep ptp,pte,t0,va,nadtlb_check_flush_20w
+ L3_ptep ptp,pte,t0,va,nadtlb_check_alias_20w
update_ptep ptp,pte,t0,t1
@@ -1214,6 +1205,14 @@
rfir
nop
+nadtlb_check_alias_20w:
+ do_alias spc,t0,t1,va,pte,prot,nadtlb_check_flush_20w
+
+ idtlbt pte,prot
+
+ rfir
+ nop
+
nadtlb_check_flush_20w:
bb,>=,n pte,_PAGE_FLUSH_BIT,nadtlb_emulate
@@ -1255,25 +1254,7 @@
nop
dtlb_check_alias_11:
-
- /* Check to see if fault is in the temporary alias region */
-
- cmpib,<>,n 0,spc,dtlb_fault /* forward */
- ldil L%(TMPALIAS_MAP_START),t0
- copy va,t1
- depwi 0,31,23,t1
- cmpb,<>,n t0,t1,dtlb_fault /* forward */
- ldi (_PAGE_DIRTY|_PAGE_WRITE|_PAGE_READ),prot
- depw,z prot,8,7,prot
-
- /*
- * OK, it is in the temp alias region, check whether "from" or "to".
- * Check "subtle" note in pacache.S re: r23/r26.
- */
-
- extrw,u,= va,9,1,r0
- or,tr %r23,%r0,pte /* If "from" use "from" page */
- or %r26,%r0,pte /* else "to", use "to" page */
+ do_alias spc,t0,t1,va,pte,prot,dtlb_fault
idtlba pte,(va)
idtlbp prot,(va)
@@ -1286,7 +1267,7 @@
space_check spc,t0,nadtlb_fault
- L2_ptep ptp,pte,t0,va,nadtlb_check_flush_11
+ L2_ptep ptp,pte,t0,va,nadtlb_check_alias_11
update_ptep ptp,pte,t0,t1
@@ -1304,6 +1285,15 @@
rfir
nop
+nadtlb_check_alias_11:
+ do_alias spc,t0,t1,va,pte,prot,nadtlb_check_flush_11
+
+ idtlba pte,(va)
+ idtlbp prot,(va)
+
+ rfir
+ nop
+
nadtlb_check_flush_11:
bb,>=,n pte,_PAGE_FLUSH_BIT,nadtlb_emulate
@@ -1359,7 +1349,7 @@
space_check spc,t0,nadtlb_fault
- L2_ptep ptp,pte,t0,va,nadtlb_check_flush_20
+ L2_ptep ptp,pte,t0,va,nadtlb_check_alias_20
update_ptep ptp,pte,t0,t1
@@ -1372,6 +1362,14 @@
rfir
nop
+nadtlb_check_alias_20:
+ do_alias spc,t0,t1,va,pte,prot,nadtlb_check_flush_20
+
+ idtlbt pte,prot
+
+ rfir
+ nop
+
nadtlb_check_flush_20:
bb,>=,n pte,_PAGE_FLUSH_BIT,nadtlb_emulate
@@ -1484,6 +1482,36 @@
rfir
nop
+naitlb_miss_20w:
+
+ /*
+ * I miss is a little different, since we allow users to fault
+ * on the gateway page which is in the kernel address space.
+ */
+
+ space_adjust spc,va,t0
+ get_pgd spc,ptp
+ space_check spc,t0,naitlb_fault
+
+ L3_ptep ptp,pte,t0,va,naitlb_check_alias_20w
+
+ update_ptep ptp,pte,t0,t1
+
+ make_insert_tlb spc,pte,prot
+
+ iitlbt pte,prot
+
+ rfir
+ nop
+
+naitlb_check_alias_20w:
+ do_alias spc,t0,t1,va,pte,prot,naitlb_fault
+
+ iitlbt pte,prot
+
+ rfir
+ nop
+
#else
itlb_miss_11:
@@ -1508,6 +1536,38 @@
rfir
nop
+naitlb_miss_11:
+ get_pgd spc,ptp
+
+ space_check spc,t0,naitlb_fault
+
+ L2_ptep ptp,pte,t0,va,naitlb_check_alias_11
+
+ update_ptep ptp,pte,t0,t1
+
+ make_insert_tlb_11 spc,pte,prot
+
+ mfsp %sr1,t0 /* Save sr1 so we can use it in tlb inserts */
+ mtsp spc,%sr1
+
+ iitlba pte,(%sr1,va)
+ iitlbp prot,(%sr1,va)
+
+ mtsp t0, %sr1 /* Restore sr1 */
+
+ rfir
+ nop
+
+naitlb_check_alias_11:
+ do_alias spc,t0,t1,va,pte,prot,itlb_fault
+
+ iitlba pte,(%sr0, va)
+ iitlbp prot,(%sr0, va)
+
+ rfir
+ nop
+
+
itlb_miss_20:
get_pgd spc,ptp
@@ -1526,6 +1586,32 @@
rfir
nop
+naitlb_miss_20:
+ get_pgd spc,ptp
+
+ space_check spc,t0,naitlb_fault
+
+ L2_ptep ptp,pte,t0,va,naitlb_check_alias_20
+
+ update_ptep ptp,pte,t0,t1
+
+ make_insert_tlb spc,pte,prot
+
+ f_extend pte,t0
+
+ iitlbt pte,prot
+
+ rfir
+ nop
+
+naitlb_check_alias_20:
+ do_alias spc,t0,t1,va,pte,prot,naitlb_fault
+
+ iitlbt pte,prot
+
+ rfir
+ nop
+
#endif
#ifdef CONFIG_64BIT
@@ -1662,6 +1748,10 @@
b intr_save
ldi 17,%r8
+naitlb_fault:
+ b intr_save
+ ldi 16,%r8
+
dtlb_fault:
b intr_save
ldi 15,%r8