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path: root/arch/powerpc/kernel/head_85xx.S
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2024-07-12powerpc/e500: use contiguous PMD instead of hugepdChristophe Leroy
e500 supports many page sizes among which the following size are implemented in the kernel at the time being: 4M, 16M, 64M, 256M, 1G. On e500, TLB miss for hugepages is exclusively handled by SW even on e6500 which has HW assistance for 4k pages, so there are no constraints like on the 8xx. On e500/32, all are at PGD/PMD level and can be handled as cont-PMD. On e500/64, smaller ones are on PMD while bigger ones are on PUD. Again, they can easily be handled as cont-PMD and cont-PUD instead of hugepd. On e500/32, use the pagesize bits in PTE to know if it is a PMD or a leaf entry. This works because the pagesize bits are in the last 12 bits and page tables are 4k aligned. On e500/64, use highest bit which is always 1 on PxD (Because PxD contains virtual address of a kernel memory) and always 0 on PTEs because not all bits of RPN are used/possible. Link: https://lkml.kernel.org/r/dd085987816ed2a0c70adb7e34966cb833fc03e1.1719928057.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12powerpc/e500: free r10 for FIND_PTEChristophe Leroy
Move r13 load after the call to FIND_PTE, and use r13 instead of r10 for storing fault address. This will allow using r10 freely in FIND_PTE in following patch to handle hugepage size. Link: https://lkml.kernel.org/r/a3ee563ad5b13c891a15d3aae6c136c44ce8aa63.1719928057.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12powerpc/e500: don't pre-check write access on data TLB errorChristophe Leroy
Don't pre-check write access on read-only pages on data TLB error. Load the TLB anyway and take a DSI exception when it happens. This avoids reading SPRN_ESR at every data TLB error exception. Link: https://lkml.kernel.org/r/8525518e1657d6032b7e980c1888102828d66950.1719928057.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12powerpc/e500: switch to 64 bits PGD on 85xx (32 bits)Christophe Leroy
At the time being when CONFIG_PTE_64BIT is selected, PTE entries are 64 bits but PGD entries are still 32 bits. In order to allow leaf PMD entries, switch the PGD to 64 bits entries. Link: https://lkml.kernel.org/r/ca85397df02564e5edc3a3c27b55cf43af3e4ef3.1719928057.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-19powerpc/e500: Introduce _PAGE_READ and remove _PAGE_USERChristophe Leroy
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
2023-10-19powerpc/nohash: Add _PAGE_WRITE to supplement _PAGE_RWChristophe Leroy
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 <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/1f79b88db54d030ada776dc9845e0e88345bfc28.1695659959.git.christophe.leroy@csgroup.eu
2023-10-10powerpc/85xx: Fix math emulation exceptionChristophe Leroy
Booting mpc85xx_defconfig kernel on QEMU leads to: Bad trap at PC: fe9bab0, SR: 2d000, vector=800 awk[82]: unhandled trap (5) at 0 nip fe9bab0 lr fe9e01c code 5 in libc-2.27.so[fe5a000+17a000] awk[82]: code: 3aa00000 3a800010 4bffe03c 9421fff0 7ca62b78 38a00000 93c10008 83c10008 awk[82]: code: 38210010 4bffdec8 9421ffc0 7c0802a6 <fc00048e> d8010008 4815190d 93810030 Trace/breakpoint trap WARNING: no useful console This is because allthough CONFIG_MATH_EMULATION is selected, Exception 800 calls unknown_exception(). Call emulation_assist_interrupt() instead. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/066caa6d9480365da9b8ed83692d7101e10ac5f8.1695657339.git.christophe.leroy@csgroup.eu
2023-08-16powerpc: remove unneeded #include <asm/export.h>Masahiro Yamada
There is no EXPORT_SYMBOL line there, hence #include <asm/export.h> is unneeded. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230806150954.394189-1-masahiroy@kernel.org
2023-01-30powerpc/85xx: Fix unannotated intra-function call warningSathvika Vasireddy
objtool throws the following warning: arch/powerpc/kernel/head_85xx.o: warning: objtool: .head.text+0x1a6c: unannotated intra-function call Fix the warning by annotating KernelSPE symbol with SYM_FUNC_START_LOCAL and SYM_FUNC_END macros. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230128124138.1066176-1-sv@linux.ibm.com
2022-12-08Merge branch 'topic/objtool' into nextMichael Ellerman
Merge the powerpc objtool support, which we were keeping in a topic branch in case of any merge conflicts.
2022-12-02powerpc: allow minimum sized kernel stack framesNicholas Piggin
This affects only 64-bit ELFv2 kernels, and reduces the minimum asm-created stack frame size from 112 to 32 byte on those kernels. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221127124942.1665522-16-npiggin@gmail.com
2022-12-02powerpc: add definition for pt_regs offset within an interrupt frameNicholas Piggin
This is a common offset that currently uses the overloaded STACK_FRAME_OVERHEAD constant. It's easier to read and more flexible to use a specific regs offset for this. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221127124942.1665522-8-npiggin@gmail.com
2022-11-18powerpc/32: Fix objtool unannotated intra-function call warningsChristophe Leroy
Fix several annotations in assembly files on PPC32. [Sathvika Vasireddy: Changed subject line and removed Kconfig change to enable objtool, as it is a part of "objtool/powerpc: Enable objtool to be built on ppc" patch in this series.] Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-7-sv@linux.ibm.com
2022-09-26powerpc: Change CONFIG_E500 to CONFIG_PPC_E500Christophe Leroy
It will be used outside arch/powerpc, make it clear its a powerpc configuration item. And we already have CONFIG_PPC_E500MC, so that will make it more consistent. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e63b22083c11c4300f4a82d3123a46e5fdd54fa6.1663606876.git.christophe.leroy@csgroup.eu
2022-09-26powerpc: Remove CONFIG_FSL_BOOKEChristophe Leroy
PPC_85xx is PPC32 only. PPC_85xx always selects E500 and is the only PPC32 that selects E500. FSL_BOOKE is selected when E500 and PPC32 are selected. So FSL_BOOKE is redundant with PPC_85xx. Remove FSL_BOOKE. And rename four files accordingly. cpu_setup_fsl_booke.S is not renamed because it is linked to PPC_FSL_BOOK3E and not to FSL_BOOKE as suggested by its name. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/08e3e15594e66d63b9e89c5b4f9c35153913c28f.1663606875.git.christophe.leroy@csgroup.eu
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