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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2023-09-25 20:31:44 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-10-19 17:12:46 +1100 |
| commit | 48cf93bb168d506a8278a6fb25c2f88c1c93ce6e (patch) | |
| tree | 5243af9b8254b0bccfdd9a5a6d64d4c3a332c0ed /arch/powerpc/kernel | |
| parent | 8e9bd41e4ce1001f5b89e4c9a69f870f39d56c12 (diff) | |
| download | linux-stable-48cf93bb168d506a8278a6fb25c2f88c1c93ce6e.tar.gz linux-stable-48cf93bb168d506a8278a6fb25c2f88c1c93ce6e.tar.bz2 linux-stable-48cf93bb168d506a8278a6fb25c2f88c1c93ce6e.zip | |
powerpc/e500: Introduce _PAGE_READ and remove _PAGE_USER
e500 MMU has 6 page protection bits:
- R, W, X for supervisor
- R, W, X for user
It means that it can support X without R.
To do that, _PAGE_READ flag is needed.
With 32 bits PTE there is no bit available for it in PTE. On the
other hand the only real use of _PAGE_USER is to implement PAGE_NONE
by clearing _PAGE_USER. As _PAGE_NONE can also be implemented by
clearing _PAGE_READ, remove _PAGE_USER and add _PAGE_READ. Move
_PAGE_PRESENT into bit 30 so that _PAGE_READ can match SR bit.
With 64 bits PTE _PAGE_USER is already the combination of SR and UR
so all we need to do is to rename it _PAGE_READ.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/0849ab6bf7ae2af23f94b0457fa40d0ea3983fe4.1695659959.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/head_85xx.S | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/head_85xx.S b/arch/powerpc/kernel/head_85xx.S index 1b122cba557b..39724ff5ae1f 100644 --- a/arch/powerpc/kernel/head_85xx.S +++ b/arch/powerpc/kernel/head_85xx.S @@ -485,10 +485,10 @@ END_BTB_FLUSH_SECTION */ mfspr r12,SPRN_ESR #ifdef CONFIG_PTE_64BIT - li r13,_PAGE_PRESENT + li r13,_PAGE_PRESENT|_PAGE_BAP_SR oris r13,r13,_PAGE_ACCESSED@h #else - li r13,_PAGE_PRESENT|_PAGE_ACCESSED + li r13,_PAGE_PRESENT|_PAGE_READ|_PAGE_ACCESSED #endif rlwimi r13,r12,11,29,29 @@ -783,15 +783,15 @@ BEGIN_MMU_FTR_SECTION mtspr SPRN_MAS7, r10 END_MMU_FTR_SECTION_IFSET(MMU_FTR_BIG_PHYS) #else - li r10, (_PAGE_EXEC | _PAGE_PRESENT) + li r10, (_PAGE_EXEC | _PAGE_READ) mr r13, r11 rlwimi r10, r11, 31, 29, 29 /* extract _PAGE_DIRTY into SW */ and r12, r11, r10 - andi. r10, r11, _PAGE_USER /* Test for _PAGE_USER */ + mcrf cr0, cr5 /* Test for user page */ slwi r10, r12, 1 or r10, r10, r12 rlwinm r10, r10, 0, ~_PAGE_EXEC /* Clear SX on user pages */ - iseleq r12, r12, r10 + isellt r12, r10, r12 rlwimi r13, r12, 0, 20, 31 /* Get RPN from PTE, merge w/ perms */ mtspr SPRN_MAS3, r13 #endif |