From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: David Gibson <dwg@au1.ibm.com>
Cc: paulus@samba.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org
Subject: Re: [PATCH -V5 08/25] powerpc: Decode the pte-lp-encoding bits correctly.
Date: Wed, 10 Apr 2013 23:19:48 +0530 [thread overview]
Message-ID: <87bo9mnumb.fsf@linux.vnet.ibm.com> (raw)
In-Reply-To: <87li8qolej.fsf@linux.vnet.ibm.com>
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> writes:
>>> static void hpte_decode(struct hash_pte *hpte, unsigned long slot,
>>> - int *psize, int *ssize, unsigned long *vpn)
>>> + int *psize, int *apsize, int *ssize, unsigned long *vpn)
>>> {
>>> unsigned long avpn, pteg, vpi;
>>> unsigned long hpte_r = hpte->r;
>>> unsigned long hpte_v = hpte->v;
>>> unsigned long vsid, seg_off;
>>> - int i, size, shift, penc;
>>> + int i, size, a_size, shift, penc;
>>>
>>> - if (!(hpte_v & HPTE_V_LARGE))
>>> - size = MMU_PAGE_4K;
>>> - else {
>>> + if (!(hpte_v & HPTE_V_LARGE)) {
>>> + size = MMU_PAGE_4K;
>>> + a_size = MMU_PAGE_4K;
>>> + } else {
>>> for (i = 0; i < LP_BITS; i++) {
>>> if ((hpte_r & LP_MASK(i+1)) == LP_MASK(i+1))
>>> break;
>>> @@ -388,19 +444,26 @@ static void hpte_decode(struct hash_pte *hpte, unsigned long slot,
>>> penc = LP_MASK(i+1) >> LP_SHIFT;
>>> for (size = 0; size < MMU_PAGE_COUNT; size++) {
>>
>>>
>>> - /* 4K pages are not represented by LP */
>>> - if (size == MMU_PAGE_4K)
>>> - continue;
>>> -
>>> /* valid entries have a shift value */
>>> if (!mmu_psize_defs[size].shift)
>>> continue;
>>> + for (a_size = 0; a_size < MMU_PAGE_COUNT; a_size++) {
>>
>> Can't you resize hpte_actual_psize() here instead of recoding the
>> lookup?
>
> I thought about that, but re-coding avoided some repeated check. But
> then, if I follow your review comments of avoiding hpte valid check etc, may
> be I can reuse the hpte_actual_psize. Will try this.
>
How about below ?
diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c
index 4427ca8..de235d5 100644
--- a/arch/powerpc/mm/hash_native_64.c
+++ b/arch/powerpc/mm/hash_native_64.c
@@ -271,19 +271,10 @@ static long native_hpte_remove(unsigned long hpte_group)
return i;
}
-static inline int hpte_actual_psize(struct hash_pte *hptep, int psize)
+static inline int __hpte_actual_psize(unsigned int lp, 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);
-
- if (!(hptep->v & HPTE_V_VALID))
- return -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++) {
@@ -310,6 +301,21 @@ static inline int hpte_actual_psize(struct hash_pte *hptep, int psize)
return -1;
}
+static inline int hpte_actual_psize(struct hash_pte *hptep, int psize)
+{
+ /* Look at the 8 bit LP value */
+ unsigned int lp = (hptep->r >> LP_SHIFT) & ((1 << LP_BITS) - 1);
+
+ if (!(hptep->v & HPTE_V_VALID))
+ return -1;
+
+ /* First check if it is large page */
+ if (!(hptep->v & HPTE_V_LARGE))
+ return MMU_PAGE_4K;
+
+ return __hpte_actual_psize(lp, psize);
+}
+
static long native_hpte_updatepp(unsigned long slot, unsigned long newpp,
unsigned long vpn, int psize, int ssize,
int local)
@@ -530,7 +536,7 @@ static void hpte_decode(struct hash_pte *hpte, unsigned long slot,
unsigned long avpn, pteg, vpi;
unsigned long hpte_v = hpte->v;
unsigned long vsid, seg_off;
- int size, a_size, shift, mask;
+ int size, a_size, shift;
/* Look at the 8 bit LP value */
unsigned int lp = (hpte->r >> LP_SHIFT) & ((1 << LP_BITS) - 1);
@@ -544,33 +550,11 @@ static void hpte_decode(struct hash_pte *hpte, unsigned long slot,
if (!mmu_psize_defs[size].shift)
continue;
- /* start from 1 ignoring MMU_PAGE_4K */
- for (a_size = 1; a_size < MMU_PAGE_COUNT; a_size++) {
-
- /* invalid penc */
- if (mmu_psize_defs[size].penc[a_size] == -1)
- 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[a_size].shift - LP_SHIFT;
- if (shift > LP_BITS)
- shift = LP_BITS;
- mask = (1 << shift) - 1;
- if ((lp & mask) ==
- mmu_psize_defs[size].penc[a_size]) {
- goto out;
- }
- }
+ a_size = __hpte_actual_psize(lp, size);
+ if (a_size != -1)
+ break;
}
}
-out:
/* This works for all page sizes, and for 256M and 1T segments */
*ssize = hpte_v >> HPTE_V_SSIZE_SHIFT;
shift = mmu_psize_defs[size].shift;
next prev parent reply other threads:[~2013-04-10 17:50 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-04 5:57 [PATCH -V5 00/25] THP support for PPC64 Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 01/25] powerpc: Use signed formatting when printing error Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 02/25] powerpc: Save DAR and DSISR in pt_regs on MCE Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 03/25] powerpc: Don't hard code the size of pte page Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 04/25] powerpc: Reduce the PTE_INDEX_SIZE Aneesh Kumar K.V
2013-04-11 7:10 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 05/25] powerpc: Move the pte free routines from common header Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 06/25] powerpc: Reduce PTE table memory wastage Aneesh Kumar K.V
2013-04-10 4:46 ` David Gibson
2013-04-10 6:29 ` Aneesh Kumar K.V
2013-04-10 7:04 ` David Gibson
2013-04-10 7:53 ` Aneesh Kumar K.V
2013-04-10 17:47 ` Aneesh Kumar K.V
2013-04-11 1:20 ` David Gibson
2013-04-11 1:12 ` David Gibson
2013-04-10 7:14 ` Michael Ellerman
2013-04-10 7:54 ` Aneesh Kumar K.V
2013-04-10 8:52 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 07/25] powerpc: Use encode avpn where we need only avpn values Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 08/25] powerpc: Decode the pte-lp-encoding bits correctly Aneesh Kumar K.V
2013-04-10 7:19 ` David Gibson
2013-04-10 8:11 ` Aneesh Kumar K.V
2013-04-10 17:49 ` Aneesh Kumar K.V [this message]
2013-04-11 1:28 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 09/25] powerpc: Fix hpte_decode to use the correct decoding for page sizes Aneesh Kumar K.V
2013-04-11 3:20 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 10/25] powerpc: print both base and actual page size on hash failure Aneesh Kumar K.V
2013-04-11 3:21 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 11/25] powerpc: Print page size info during boot Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 12/25] powerpc: Return all the valid pte ecndoing in KVM_PPC_GET_SMMU_INFO ioctl Aneesh Kumar K.V
2013-04-11 3:24 ` David Gibson
2013-04-11 5:11 ` Aneesh Kumar K.V
2013-04-11 5:57 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 13/25] powerpc: Update tlbie/tlbiel as per ISA doc Aneesh Kumar K.V
2013-04-11 3:30 ` David Gibson
2013-04-11 5:20 ` Aneesh Kumar K.V
2013-04-11 6:16 ` David Gibson
2013-04-11 6:36 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 14/25] mm/THP: HPAGE_SHIFT is not a #define on some arch Aneesh Kumar K.V
2013-04-11 3:36 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 15/25] mm/THP: Add pmd args to pgtable deposit and withdraw APIs Aneesh Kumar K.V
2013-04-11 3:40 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 16/25] mm/THP: withdraw the pgtable after pmdp related operations Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 17/25] powerpc/THP: Implement transparent hugepages for ppc64 Aneesh Kumar K.V
2013-04-11 5:38 ` David Gibson
2013-04-11 7:40 ` Aneesh Kumar K.V
2013-04-12 0:51 ` David Gibson
2013-04-12 5:06 ` Aneesh Kumar K.V
2013-04-12 5:39 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 18/25] powerpc/THP: Double the PMD table size for THP Aneesh Kumar K.V
2013-04-11 6:18 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 19/25] powerpc/THP: Differentiate THP PMD entries from HUGETLB PMD entries Aneesh Kumar K.V
2013-04-10 7:21 ` Michael Ellerman
2013-04-10 18:26 ` Aneesh Kumar K.V
2013-04-12 1:28 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 20/25] powerpc/THP: Add code to handle HPTE faults for large pages Aneesh Kumar K.V
2013-04-12 4:01 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 21/25] powerpc: Handle hugepage in perf callchain Aneesh Kumar K.V
2013-04-12 1:34 ` David Gibson
2013-04-12 5:05 ` Aneesh Kumar K.V
2013-04-04 5:58 ` [PATCH -V5 22/25] powerpc/THP: get_user_pages_fast changes Aneesh Kumar K.V
2013-04-12 1:41 ` David Gibson
2013-04-04 5:58 ` [PATCH -V5 23/25] powerpc/THP: Enable THP on PPC64 Aneesh Kumar K.V
2013-04-04 5:58 ` [PATCH -V5 24/25] powerpc: Optimize hugepage invalidate Aneesh Kumar K.V
2013-04-12 4:21 ` David Gibson
2013-04-14 10:02 ` Aneesh Kumar K.V
2013-04-15 1:18 ` David Gibson
2013-04-04 5:58 ` [PATCH -V5 25/25] powerpc: Handle hugepages in kvm Aneesh Kumar K.V
2013-04-04 6:00 ` [PATCH -V5 00/25] THP support for PPC64 Simon Jeons
2013-04-04 6:10 ` Aneesh Kumar K.V
2013-04-04 6:14 ` Simon Jeons
2013-04-04 8:38 ` Aneesh Kumar K.V
2013-04-19 1:55 ` Simon Jeons
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