leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

powerpc/603: let's handle PAGE_DIRTY directly

Browse Source 
PAGE_DIRTY corresponds to the C bit. If writing on
a page for which the C bit is not set, a DataStoreTLBMiss
is generated. No need to check it in DataLoadTLBMiss.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Christophe Leroy 2019-02-21 10:38:00 +00:00 committed by Michael Ellerman
parent 54a05a30c8
commit f8b58c64ea
1 changed files with 2 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/powerpc/kernel/head_32.S
View File

@ -595,12 +595,10 @@ DataLoadTLBMiss:
stw r0,0(r2) /* update PTE (accessed bit) */ stw r0,0(r2) /* update PTE (accessed bit) */
/* Convert linux-style PTE to low word of PPC-style PTE */ /* Convert linux-style PTE to low word of PPC-style PTE */
rlwinm r1,r0,32-10,31,31 /* _PAGE_RW -> PP lsb */ rlwinm r1,r0,32-10,31,31 /* _PAGE_RW -> PP lsb */
rlwinm r2,r0,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
and r1,r1,r2 /* writable if _RW and _DIRTY */
rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */ rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */ rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */
ori r1,r1,0xe04 /* clear out reserved bits */ ori r1,r1,0xe04 /* clear out reserved bits */
andc r1,r0,r1 /* PP = user? (rw&dirty? 2: 3): 0 */ andc r1,r0,r1 /* PP = user? rw? 2: 3: 0 */
BEGIN_FTR_SECTION BEGIN_FTR_SECTION
rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */ rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT) END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
@ -669,7 +667,7 @@ DataStoreTLBMiss:
lwz r0,0(r2) /* get linux-style pte */ lwz r0,0(r2) /* get linux-style pte */
andc. r1,r1,r0 /* check access & ~permission */ andc. r1,r1,r0 /* check access & ~permission */
bne- DataAddressInvalid /* return if access not permitted */ bne- DataAddressInvalid /* return if access not permitted */
ori r0,r0,_PAGE_ACCESSED|_PAGE_DIRTY ori r0,r0,_PAGE_ACCESSED
/* /*
* NOTE! We are assuming this is not an SMP system, otherwise * NOTE! We are assuming this is not an SMP system, otherwise
* we would need to update the pte atomically with lwarx/stwcx. * we would need to update the pte atomically with lwarx/stwcx.