- 11 May, 2016 1 commit
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Michael Ellerman authored
Follow the example of the cpu feature code, and add a mask of possible MMU features, MMU_FTRS_POSSIBLE. This is used in mmu_has_feature(), which allows the possible mask to act as a shortcut for any features that are not possible, but still allows the feature bit itself to be defined. We will use this in the next commit to allow MMU_FTR_RADIX checks to be elided when MMU_FTR_RADIX is not possible. Signed-off-by:Michael Ellerman <mpe@ellerman.id.au>
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- 01 May, 2016 39 commits
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Aneesh Kumar K.V authored
Core kernel doesn't track the page size of the VA range that we are invalidating. Hence we end up flushing TLB for the entire mm here. Later patches will improve this. We also don't flush page walk cache separetly instead use RIC=2 when flushing TLB, because we do a MMU gather flush after freeing page table. MMU_NO_CONTEXT is updated for hash. Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
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Aneesh Kumar K.V authored
This file now contains both hash and radix specific code. Rename it to indicate this better. Signed-off-by:
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Aneesh Kumar K.V authored
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Aneesh Kumar K.V authored
How we switch MMU context differs between hash and radix. For hash we need to switch the SLB details and for radix we need to switch the PID SPR. Signed-off-by:
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Aneesh Kumar K.V authored
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Aneesh Kumar K.V authored
For hash we create vmemmap mapping using bolted hash page table entries. For radix we fill the radix page table. The next patch will add the radix details for creating vmemmap mappings. Signed-off-by:
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Aneesh Kumar K.V authored
This adds routines for early setup for radix. We use device tree property "ibm,processor-radix-AP-encodings" to find supported page sizes. If we don't find the above we consider 64K and 4K as supported page sizes. We do map vmemap using 2M page size if we can. The linear mapping is done such that we use required page size for that range. For example memory of 3.5G is mapped such that we use 1G mapping till 3G range and use 2M mapping for the rest. Signed-off-by:
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Aneesh Kumar K.V authored
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Aneesh Kumar K.V authored
This only does 64K Linux page support for now. 64K hash Linux config THP needs to differentiate it from hugetlb huge page because with THP we need to track hash pte slot information with respect to each subpage. This is not needed with hugetlb hugepage, because we don't do MPSS with hugetlb. Radix doesn't have any such restrictions. Signed-off-by:
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Aneesh Kumar K.V authored
Here we create pgtable-64/4k.h and move pmd accessors that are common between hash and radix there. We can't do much sharing with 4K Linux page size because 4K Linux page size with hash config doesn't support THP. So for now it is empty. In later patches we will add functions that does conditional hash/radix accessors there. Signed-off-by:
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Aneesh Kumar K.V authored
For those pte accessors, that operate on a different set of pte bits between hash/radix, we add a generic variant that does a conditional to hash linux or radix variant. Signed-off-by:
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Aneesh Kumar K.V authored
In this patch we add the radix Kconfig and conditional check. radix_enabled() is written to always return 0 here. Once we have all needed radix changes added, we will update this to an mmu_feature check. We need to add this early so that we can get it all build in the early stage. Signed-off-by:
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Aneesh Kumar K.V authored
This adds Power ISA 3.0 specific pte defines. We share most of the details with hash Linux page table format. This patch indicates only things where we differ. Signed-off-by:
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Aneesh Kumar K.V authored
Only code movement. No functionality change. Signed-off-by:
Balbir Singh <bsingharora@gmail.com> Signed-off-by:
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Aneesh Kumar K.V authored
Now that the page table size is a variable, we can move these to generic pgtable.h. Signed-off-by:
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Aneesh Kumar K.V authored
Radix and hash MMU models support different page table sizes. Make the #defines a variable so that existing code can work with variable sizes. Slice related code is only used by hash, so use hash constants there. We will replicate some of the boundary conditions with resepct to TASK_SIZE using radix values too. Right now we do boundary condition check using hash constants. Swapper pgdir size is initialized in asm code. We select the max pgd size to keep it simple. For now we select hash pgdir. When adding radix we will switch that to radix pgdir which is 64K. BUILD_BUG_ON check which is removed is already done in hugepage_init() using MAYBE_BUILD_BUG_ON(). Signed-off-by:
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Aneesh Kumar K.V authored
These pte functions will remain the same between radix and hash. Move them to pgtable.h. Signed-off-by:
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Aneesh Kumar K.V authored
Now that we have moved book3s hash64 Linux pte bits to match Power ISA 3.0 radix pte bit positions, we move the matching pte bits to a common header. Only code movement in this patch. No functionality change. Signed-off-by:
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Aneesh Kumar K.V authored
I am splitting this as a separate patch to get better review. If ok we should merge this with previous patch. Signed-off-by:
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Aneesh Kumar K.V authored
This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by:
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Aneesh Kumar K.V authored
This patch reduces the number of #ifdefs in C code and will also help in adding radix changes later. Only code movement in this patch. Signed-off-by:
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Aneesh Kumar K.V authored
PowerISA 3.0 adds a parition table indexed by LPID. Parition table allows us to specify the MMU model that will be used for guest and host translation. This patch adds support with SLB based hash model (UPRT = 0). What is required with this model is to support the new hash page table entry format and also setup partition table such that we use hash table for address translation. We don't have segment table support yet. In order to make sure we don't load KVM module on Power9 (since we don't have kvm support yet) this patch also disables KVM on Power9. Signed-off-by:
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Aneesh Kumar K.V authored
Add structs and #defines related to the radix MMU partition table format. We also add a ppc_md callback for updating a partition table entry. Signed-off-by:
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Aneesh Kumar K.V authored
Start moving code that is generic between radix and hash to book3s64 specific headers from the book3s64 hash specific one. Signed-off-by:
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Aneesh Kumar K.V authored
The radix variant is going to require a flush_tlb_range(). With flush_tlb_range() added, ptep_clear_flush_young() is the same as the generic version. So drop the powerpc specific variant. Signed-off-by:
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Aneesh Kumar K.V authored
The radix variant is going to require a flush_pmd_tlb_range(). With flush_pmd_tlb_range() added, pmdp_clear_flush_young() is the same as the generic version. So drop the powerpc specific variant. Signed-off-by:
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Aneesh Kumar K.V authored
PowerISA 3.0 introduces two pte bits with the below meaning for radix: 00 -> Normal Memory 01 -> Strong Access Order (SAO) 10 -> Non idempotent I/O (Cache inhibited and guarded) 11 -> Tolerant I/O (Cache inhibited) We drop the existing WIMG bits in the Linux page table in favour of the above constants. We loose _PAGE_WRITETHRU with this conversion. We only use writethru via pgprot_cached_wthru() which is used by fbdev/controlfb.c which is Apple control display and also PPC32. With respect to _PAGE_COHERENCE, we have been marking hpte always coherent for some time now. htab_convert_pte_flags() always added HPTE_R_M. NOTE: KVM changes need closer review. Signed-off-by:
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Aneesh Kumar K.V authored
Use a helper instead of open coding with constants. A later patch will drop the WIMG bits and use PowerISA 3.0 defines. Signed-off-by:
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Aneesh Kumar K.V authored
PS3 had used a PPP bit hack to implement a read only mapping in the kernel area. Since we are bolting the ioremap area, it used the pte flags _PAGE_PRESENT | _PAGE_USER to get a PPP value of 0x3 there by resulting in a read only mapping. This means the area can be accessed by user space, but kernel will never return such an address to user space. But we can do better by implementing a read only kernel mapping using PPP bits 0b110. This also allows us to do read only kernel mapping for radix in later patches. Signed-off-by:
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Aneesh Kumar K.V authored
PTE_RPN_SHIFT is actually page size dependent. Even though PowerISA 3.0 expects only the lower 12 bits to be zero, we will always find the pages to be PAGE_SHIFT aligned. In case of hash config, this also allows us to use the additional 3 bits to track pte specific information. We need to make sure we use these bits only for hash specific pte flags. For both 4K and 64K config, pte now can hold 57 bits address. Inorder to keep things simpler, drop PTE_RPN_SHIFT and PTE_RPN_SIZE and specify the 57 bit detail explicitly. Signed-off-by:
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Aneesh Kumar K.V authored
_PAGE_PRIVILEGED means the page can be accessed only by the kernel. This is done to keep pte bits similar to PowerISA 3.0 Radix PTE format. User pages are now marked by clearing _PAGE_PRIVILEGED bit. Previously we allowed the kernel to have a privileged page in the lower address range (USER_REGION). With this patch such access is denied. We also prevent a kernel access to a non-privileged page in higher address range (ie, REGION_ID != 0). Both the above access scenarios should never happen. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by:
Ian Munsie <imunsie@au1.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
We have a common declaration in pte-common.h Add a book3s specific one and switch to pte_user() in callchain.c. In a subsequent patch we will switch _PAGE_USER to _PAGE_PRIVILEGED in the book3s version only. Signed-off-by:
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Michael Ellerman authored
In a subsequent patch we want to add a second definition of pte_user(). Before we do that, make the signature clear, ie. it takes a pte_t and returns bool. We move it up inside the existing #ifndef __ASSEMBLY__ block, but otherwise it's a straight conversion. Convert the call in settlbcam(), which passes an unsigned long, to pass a pte_t. Signed-off-by: -
Aneesh Kumar K.V authored
Subpage protection used to depend on the _PAGE_USER bit to implement no access mode. This patch switches that to use _PAGE_RWX. We clear Read, Write and Execute access from the pte instead of clearing _PAGE_USER now. This was done so that we can switch to _PAGE_PRIVILEGED in a later patch. subpage_protection() returns pte bits that need to be cleared. Instead of updating the interface to handle no-access in a separate way, it appears simpler to clear RWX acecss to indicate no access. We still don't insert hash ptes for no access implied by !_PAGE_RWX. Hence we should not get PROT_FAULT with change. Signed-off-by:
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Aneesh Kumar K.V authored
This splits the _PAGE_RW bit into _PAGE_READ and _PAGE_WRITE. It also removes the dependency on _PAGE_USER for implying read only. Few things to note here is that, we have read implied with write and execute permission. Hence we should always find _PAGE_READ set on hash pte fault. We still can't switch PROT_NONE to !(_PAGE_RWX). Auto numa depends on marking a prot none pte _PAGE_WRITE. (For more details look at b191f9b1 "mm: numa: preserve PTE write permissions across a NUMA hinting fault") Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by:
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Michael Ellerman authored
We can avoid doing endian conversions by using pte_raw() in pxx_same(). The swap of the constant (_PAGE_HPTEFLAGS) should be done at compile time by the compiler. Signed-off-by: -
Aneesh Kumar K.V authored
Traditionally Power server machines have used the Hashed Page Table MMU mode. In this mode Linux manages its own tree of nested page tables, aka. "the Linux page tables", which are not used by the hardware directly, and software loads translations into the hash page table for use by the hardware. Power ISA 3.0 defines a new MMU mode, known as Radix Tree Translation, where the hardware can directly operate on the Linux page tables. However the hardware requires that the page tables be in big endian format. To accommodate this, switch the pgtable types to __be64 and add appropriate endian conversions. Because we will be supporting a single kernel binary that boots using either radix or hash mode, we always store the Linux page tables big endian, even in hash mode where they are not actually used by the hardware. Signed-off-by:
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Michael Ellerman authored
We have five locations in 64-bit hash MMU code that do a cmpxchg() of a PTE. Currently doing it inline OK, but in a future patch we will be converting the PTEs to __be64 in some configs. In that case we will need casts at every cmpxchg() site in order to keep sparse happy. So move the logic into a helper, this is a reasonably nice cleanup on its own. Signed-off-by:
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