From: Paul Mackerras <paulus@samba.org>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH -V2 10/26] powerpc: Decode the pte-lp-encoding bits correctly.
Date: Wed, 13 Mar 2013 15:09:59 +1100 [thread overview]
Message-ID: <20130313040959.GF21125@iris.ozlabs.ibm.com> (raw)
In-Reply-To: <1362550227-575-11-git-send-email-aneesh.kumar@linux.vnet.ibm.com>
On Wed, Mar 06, 2013 at 11:40:11AM +0530, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>
> We look at both the segment base page size and actual page size and store
> the pte-lp-encodings in an array per base page size.
>
> We also update all relevant functions to take actual page size argument
> so that we can use the correct PTE LP encoding in HPTE. This should also
> get the basic Multiple Page Size per Segment (MPSS) support. This is needed
> to enable THP on ppc64.
[snip]
> --- a/arch/powerpc/include/asm/mmu-hash64.h
> +++ b/arch/powerpc/include/asm/mmu-hash64.h
> @@ -154,7 +154,7 @@ extern unsigned long htab_hash_mask;
> struct mmu_psize_def
> {
> unsigned int shift; /* number of bits */
> - unsigned int penc; /* HPTE encoding */
> + unsigned int penc[MMU_PAGE_COUNT]; /* HPTE encoding */
Since we are using -1 as an invalid flag, it would be better to change
penc[] to be an array of int (or signed int) rather than unsigned
int. That would eliminate a few (signed int) casts in your subsequent
patches.
> +static inline int hpte_actual_psize(struct hash_pte *hptep, int psize)
> +{
> + int i, shift;
> + unsigned int mask;
> + /* Look at the 8 bit LP value */
> + unsigned int lp = (hptep->r >> LP_SHIFT) & ((1 << LP_BITS) - 1);
> +
> + /* First check if it is large page */
> + if (!(hptep->v & HPTE_V_LARGE))
> + return MMU_PAGE_4K;
> +
> + /* start from 1 ignoring MMU_PAGE_4K */
> + for (i = 1; i < MMU_PAGE_COUNT; i++) {
> + /* valid entries have a shift value */
> + if (!mmu_psize_defs[i].shift)
> + continue;
> + /*
> + * encoding bits per actual page size
> + * PTE LP actual page size
> + * rrrr rrrz ≥8KB
> + * rrrr rrzz ≥16KB
> + * rrrr rzzz ≥32KB
> + * rrrr zzzz ≥64KB
> + * .......
> + */
> + shift = mmu_psize_defs[i].shift -
> + mmu_psize_defs[MMU_PAGE_4K].shift;
The memory reference for mmu_psize_defs[MMU_PAGE_4K].shift seems
unnecessary here. Just use LP_SHIFT, same as when you calculated lp.
Paul.
next prev parent reply other threads:[~2013-03-13 4:09 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-06 6:10 [PATCH -V2 00/26]T HP support for PPC64 Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 01/26] powerpc: Use signed formatting when printing error Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 02/26] powerpc: Save DAR and DSISR in pt_regs on MCE Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 03/26] powerpc: Don't hard code the size of pte page Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 04/26] powerpc: Reduce the PTE_INDEX_SIZE Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 05/26] powerpc: Move the pte free routines from common header Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 06/26] powerpc: Reduce PTE table memory wastage Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 07/26] powerpc: Add size argument to pgtable_cache_add Aneesh Kumar K.V
2013-03-13 2:47 ` Paul Mackerras
2013-03-13 9:25 ` Aneesh Kumar K.V
2013-03-13 11:34 ` Paul Mackerras
2013-03-06 6:10 ` [PATCH -V2 08/26] powerpc: Clarify __pgtable_cache_add by renaming shift to index Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 09/26] powerpc: Use encode avpn where we need only avpn values Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 10/26] powerpc: Decode the pte-lp-encoding bits correctly Aneesh Kumar K.V
2013-03-13 4:09 ` Paul Mackerras [this message]
2013-03-06 6:10 ` [PATCH -V2 11/26] powerpc: Fix hpte_decode to use the correct decoding for page sizes Aneesh Kumar K.V
2013-03-13 2:56 ` Paul Mackerras
2013-03-06 6:10 ` [PATCH -V2 12/26] powerpc: Return all the valid pte ecndoing in KVM_PPC_GET_SMMU_INFO ioctl Aneesh Kumar K.V
2013-03-13 4:11 ` Paul Mackerras
2013-03-06 6:10 ` [PATCH -V2 13/26] powerpc: Update tlbie/tlbiel as per ISA doc Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 14/26] powerpc: print both base and actual page size on hash failure Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 15/26] powerpc: Print page size info during boot Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 16/26] mm/THP: HPAGE_SHIFT is not a #define on some arch Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 17/26] mm/THP: Add pmd args to pgtable deposit and withdraw APIs Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 18/26] mm/THP: withdraw the pgtable after pmdp related operations Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 19/26] powerpc/THP: Implement transparent huge pages for ppc64 Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 20/26] powerpc/THP: Differentiate THP PMD entries from HUGETLB PMD entries Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 21/26] powerpc/THP: Add code to handle HPTE faults for large pages Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 22/26] powerpc: Handle huge page in perf callchain Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 23/26] powerpc/THP: hypervisor require few WIMG bit set Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 24/26] powerpc/THP: get_user_pages_fast changes Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 25/26] powerpc/THP: Enable THP on PPC64 Aneesh Kumar K.V
2013-03-06 6:10 ` [PATCH -V2 26/26] powerpc: Optimize hugepage invalidate Aneesh Kumar K.V
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