Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1688108

[RFC v6 03/62] powerpc: introduce pte_set_hash_slot() helper

From Ram Pai <linuxram@us.ibm.com>
Newsgroups linux.kernel
Subject [RFC v6 03/62] powerpc: introduce pte_set_hash_slot() helper
Date 2017-07-16 06:20 +0200
Message-ID <u3Jce-2ea-23@gated-at.bofh.it> (permalink)
References <u3ISR-1St-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

Introduce pte_set_hash_slot().It  sets the (H_PAGE_F_SECOND|H_PAGE_F_GIX)
bits at  the   appropriate   location   in   the   PTE  of  4K  PTE.  For
64K PTE, it  sets  the  bits  in  the  second  part  of  the  PTE. Though
the implementation  for the former just needs the slot parameter, it does
take some additional parameters to keep the prototype consistent.

This function  will  be  handy  as  we   work   towards  re-arranging the
bits in the later patches.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/hash-4k.h  |   15 +++++++++++++++
 arch/powerpc/include/asm/book3s/64/hash-64k.h |   25 +++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h b/arch/powerpc/include/asm/book3s/64/hash-4k.h
index d2cf949..dc153c6 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h
@@ -53,6 +53,21 @@ static inline int hash__hugepd_ok(hugepd_t hpd)
 }
 #endif
 
+/*
+ * 4k pte format is  different  from  64k  pte  format.  Saving  the
+ * hash_slot is just a matter of returning the pte bits that need to
+ * be modified. On 64k pte, things are a  little  more  involved and
+ * hence  needs   many   more  parameters  to  accomplish  the  same.
+ * However we  want  to abstract this out from the caller by keeping
+ * the prototype consistent across the two formats.
+ */
+static inline unsigned long pte_set_hash_slot(pte_t *ptep, real_pte_t rpte,
+			unsigned int subpg_index, unsigned long slot)
+{
+	return (slot << H_PAGE_F_GIX_SHIFT) &
+		(H_PAGE_F_SECOND | H_PAGE_F_GIX);
+}
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 
 static inline char *get_hpte_slot_array(pmd_t *pmdp)
diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h b/arch/powerpc/include/asm/book3s/64/hash-64k.h
index c281f18..89ef5a9 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-64k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h
@@ -67,6 +67,31 @@ static inline unsigned long __rpte_to_hidx(real_pte_t rpte, unsigned long index)
 	return ((rpte.hidx >> (index<<2)) & 0xfUL);
 }
 
+/*
+ * Commit the hash slot and return pte bits that needs to be modified.
+ * The caller is expected to modify the pte bits accordingly and
+ * commit the pte to memory.
+ */
+static inline unsigned long pte_set_hash_slot(pte_t *ptep, real_pte_t rpte,
+		unsigned int subpg_index, unsigned long slot)
+{
+	unsigned long *hidxp = (unsigned long *)(ptep + PTRS_PER_PTE);
+
+	rpte.hidx &= ~(0xfUL << (subpg_index << 2));
+	*hidxp = rpte.hidx  | (slot << (subpg_index << 2));
+	/*
+	 * Commit the hidx bits to memory before returning.
+	 * Anyone reading  pte  must  ensure hidx bits are
+	 * read  only  after  reading the pte by using the
+	 * read-side  barrier  smp_rmb(). __real_pte() can
+	 * help ensure that.
+	 */
+	smp_wmb();
+
+	/* no pte bits to be modified, return 0x0UL */
+	return 0x0UL;
+}
+
 #define __rpte_to_pte(r)	((r).pte)
 extern bool __rpte_sub_valid(real_pte_t rpte, unsigned long index);
 /*
-- 
1.7.1

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[RFC v6 00/62] powerpc: Memory Protection Keys Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 11/62] powerpc: initial pkey plumbing Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 31/62] powerpc: Handle exceptions caused by pkey violation Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 15/62] powerpc: helper functions to initialize AMR, IAMR and UMOR registers Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 06/62] powerpc: use helper functions in __hash_page_64K() for 64K PTE Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 33/62] powerpc: introduce get_pte_pkey() helper Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 26/62] powerpc: Program HPTE key protection bits Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 49/62] selftest/vm: fix alloc_random_pkey() to make it really random Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 45/62] selftest/vm: generics function to handle shadow key register Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 53/62] selftest/vm: powerpc implementation for generic abstraction Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 51/62] selftest/vm: pkey register should match shadow pkey Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 38/62] powerpc: implementation for arch_pkeys_enabled() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 37/62] x86: implementation for arch_pkeys_enabled() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 46/62] selftest/vm: fix the wrong assert in pkey_disable_set() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 62/62] Documentation/vm: PowerPC specific updates to memory protection keys Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 22/62] powerpc: ability to associate pkey to a vma Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 27/62] powerpc: helper to validate key-access permissions of a pte Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 30/62] powerpc: implementation for arch_vma_access_permitted() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 44/62] selftest/vm: typecast the pkey register Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 24/62] powerpc: map vma key-protection bits to pte key bits. Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 55/62] selftest/vm: associate key on a mapped page and detect access violation Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 58/62] selftest/vm: detect no write key-violation on a freed key Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 61/62] Documentation/x86: Move protecton key documentation to arch neutral directory Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 52/62] selftest/vm: generic cleanup Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 54/62] selftest/vm: fix an assertion in test_pkey_alloc_exhaust() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 60/62] selftest/vm: sub-page allocator Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 32/62] powerpc: capture AMR register content on pkey violation Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 34/62] powerpc: capture the violated protection key on fault Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 50/62] selftest/vm: introduce two arch independent abstraction Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 25/62] powerpc: sys_pkey_mprotect() system call Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 59/62] selftest/vm: detect write violation on a mapped access-denied-key page Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 57/62] selftest/vm: associate key on a mapped page and detect write violation Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 36/62] mm: introduce arch_pkeys_enabled() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 40/62] x86: delete arch_show_smap() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 29/62] powerpc: Macro the mask used for checking DSI exception Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 47/62] selftest/vm: fixed bugs in pkey_disable_clear() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 28/62] powerpc: check key protection for user page access Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 48/62] selftest/vm: clear the bits in shadow reg when a pkey is freed. Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 56/62] selftest/vm: detect no key violation on a freed key Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 39/62] mm: display pkey in smaps if arch_pkeys_enabled() is true Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 42/62] selftest/vm: rename all references to pkru to a generic name Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 07/62] powerpc: use helper functions in __hash_page_huge() for 64K PTE Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 12/62] mm: introduce an additional vma bit for powerpc pkey Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 13/62] powerpc: track allocation status of all pkeys Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 09/62] powerpc: use helper functions in __hash_page_4K() for 4K PTE Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 01/62] powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 08/62] powerpc: use helper functions in __hash_page_4K() for 64K PTE Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 05/62] powerpc: capture the PTE format changes in the dump pte report Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 02/62] powerpc: Free up four 64K PTE bits in 64K backed HPTE pages Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 14/62] powerpc: helper function to read,write AMR,IAMR,UAMOR registers Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 18/62] powerpc: sys_pkey_alloc() and sys_pkey_free() system calls Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 03/62] powerpc: introduce pte_set_hash_slot() helper Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 21/62] powerpc: introduce execute-only pkey Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 10/62] powerpc: use helper functions in flush_hash_page() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 16/62] powerpc: cleaup AMR,iAMR when a key is allocated or freed Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 20/62] powerpc: store and restore the pkey state across context switches Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200

csiph-web