kernel/linux.git/arch/powerpc/include/asm/book3s, branch v6.7

powerpc/32s: Implement local_flush_tlb_page_psize()

2023-10-23T09:33:19+00:00

There's a single call to local_flush_tlb_page_psize() in the code patching code. That call is never executed on 32-bit Book3S, because it's guarded by mm_patch_enabled() which is essentially a radix_enabled() check, which is always false on 32s. However depending on how the optimiser sees things it may still trip over the BUILD_BUG() in the 32s stub of local_flush_tlb_page_psize(). To avoid that, implement it in terms of flush_range() so that if it ever becomes called it should function, even if not optimally. Note that flush_range() deals with page aligning the address and so on, and that 32s doesn't support huge pages so there should be no issue with non-standard page sizes needing to be flushed. Signed-off-by: Michael Ellerman Link: https://msgid.link/20231023092319.1507325-1-mpe@ellerman.id.au

powerpc: Annotate endianness of various variables and functions

2023-10-19T06:12:47+00:00

Sparse reports several endianness warnings on variables and functions that are consistently treated as big endian. There are no multi-endianness shenanigans going on here so fix these low hanging fruit up in one patch. All changes are just type annotations; no endianness switching operations are introduced by this patch. Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://msgid.link/20231011053711.93427-7-bgray@linux.ibm.com

powerpc: Support execute-only on all powerpc

2023-10-19T06:12:47+00:00

Introduce PAGE_EXECONLY_X macro which provides exec-only rights. The _X may be seen as redundant with the EXECONLY but it helps keep consistency, all macros having the EXEC right have _X. And put it next to PAGE_NONE as PAGE_EXECONLY_X is somehow PAGE_NONE + EXEC just like all other SOMETHING_X are just SOMETHING + EXEC. On book3s/64 PAGE_EXECONLY becomes PAGE_READONLY_X. On book3s/64, as PAGE_EXECONLY is only valid for Radix add VM_READ flag in vm_get_page_prot() for non-Radix. And update access_error() so that a non exec fault on a VM_EXEC only mapping is always invalid, even when the underlying layer don't always generate a fault for that. For 8xx, set PAGE_EXECONLY_X as _PAGE_NA | _PAGE_EXEC. For others, only set it as just _PAGE_EXEC With that change, 8xx, e500 and 44x fully honor execute-only protection. On 40x that is a partial implementation of execute-only. The implementation won't be complete because once a TLB has been loaded via the Instruction TLB miss handler, it will be possible to read the page. But at least it can't be read unless it is executed first. On 603 MMU, TLB missed are handled by SW and there are separate DTLB and ITLB. Execute-only is therefore now supported by not loading DTLB when read access is not permitted. On hash (604) MMU it is more tricky because hash table is common to load/store and execute. Nevertheless it is still possible to check whether _PAGE_READ is set before loading hash table for a load/store access. At least it can't be read unless it is executed first. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/4283ea9cbef9ff2fbee468904800e1962bc8fc18.1695659959.git.christophe.leroy@csgroup.eu

powerpc/32s: Introduce _PAGE_READ and remove _PAGE_USER

2023-10-19T06:12:47+00:00

On 603 MMU, TLB missed are handled by SW and there are separated DTLB and ITLB. It is therefore possible to implement execute-only protection by not loading DTLB when read access is not permitted. To do that, _PAGE_READ flag is needed but 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. Then use the virtual address to know whether user rights or kernel rights are to be used. With that change, 603 MMU now honors execute-only protection. For hash (604) MMU it is more tricky because hash table is common to load/store and execute. Nevertheless it is still possible to check whether _PAGE_READ is set before loading hash table for a load/store access. At least it can't be read unless it is executed first. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/b7702dd5a041ec59055ed2880f4952e94c087a2e.1695659959.git.christophe.leroy@csgroup.eu

powerpc/32s: Add _PAGE_WRITE to supplement _PAGE_RW

2023-10-19T06:12:47+00:00

Several places, _PAGE_RW maps to write permission and don't always imply read. To make it more clear, do as book3s/64 in commit c7d54842deb1 ("powerpc/mm: Use _PAGE_READ to indicate Read access") and use _PAGE_WRITE when more relevant. For the time being _PAGE_WRITE is equivalent to _PAGE_RW but that will change when _PAGE_READ gets added in following patches. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/5798782869fe4d2698f104948dabd17657b89395.1695659959.git.christophe.leroy@csgroup.eu

powerpc/64s: Use generic permission masks

2023-10-19T06:12:46+00:00

book3s64 need specific masks because it needs _PAGE_PRIVILEGED for PAGE_NONE. book3s64 already has _PAGE_RW and _PAGE_RWX. So add _PAGE_NA, _PAGE_RO and _PAGE_ROX and remove specific permission masks. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/d37a418de52e2c950cad6797e81663b56991366f.1695659959.git.christophe.leroy@csgroup.eu

powerpc: Remove pte_mkuser() and pte_mkpriviledged()

2023-10-19T06:12:46+00:00

pte_mkuser() is never used. Remove it. pte_mkpriviledged() is not used anymore. Remove it too. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/1a1dc18816456c637dc8a9c38d532f7598b60ac4.1695659959.git.christophe.leroy@csgroup.eu

powerpc: Untangle fixmap.h and pgtable.h and mmu.h

2023-10-19T06:12:44+00:00

fixmap.h need pgtable.h for [un]map_kernel_page() pgtable.h need fixmap.h for FIXADDR_TOP. Untangle the two files by moving FIXADDR_TOP into pgtable.h Also move VIRT_IMMR_BASE to fixmap.h to avoid fixmap.h in mmu.h Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/5eba12392a018be28ad0a02ed844767b132589e7.1695659959.git.christophe.leroy@csgroup.eu

powerpc: Refactor update_mmu_cache_range()

2023-10-19T06:12:44+00:00

On nohash, this function voids except for E500 with hugepages. On book3s, this function is for hash MMUs only. Combine those tests and rename E500 update_mmu_cache_range() as __update_mmu_cache() which gets called by update_mmu_cache_range(). Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/b029842cb6783cbeb43d202e69a90341d65295a4.1695659959.git.christophe.leroy@csgroup.eu

powerpc: Deduplicate prototypes of ptep_set_access_flags() and phys_mem_access_prot()

2023-10-19T06:12:44+00:00

Prototypes of ptep_set_access_flags() and phys_mem_access_prot() are identical for book3s and nohash. Deduplicate them. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/b846832cce842a2852615b7356937fb9507e436d.1695659959.git.christophe.leroy@csgroup.eu