Thread (15 messages) 15 messages, 2 authors, 2023-12-11

Re: [PATCH v9 2/7] powerpc: mm: Implement p{m,u,4}d_leaf on all platforms

From: Christophe Leroy <hidden>
Date: 2023-11-30 06:38:05


Le 30/11/2023 à 03:53, Rohan McLure a écrit :
The check that a higher-level entry in multi-level pages contains a page
translation entry (pte) is performed by p{m,u,4}d_leaf stubs, which may
be specialised for each choice of mmu. In a prior commit, we replace
uses to the catch-all stubs, p{m,u,4}d_is_leaf with p{m,u,4}d_leaf.

Replace the catch-all stub definitions for p{m,u,4}d_is_leaf with
definitions for p{m,u,4}d_leaf. A future patch will assume that
p{m,u,4}d_leaf is defined on all platforms.

In particular, implement pud_leaf for Book3E-64, pmd_leaf for all Book3E
and Book3S-64 platforms, with a catch-all definition for p4d_leaf.
Is that needed ? There are fallback definitions of all pXd_leaf() in 
include/linux/pgtable.h
quoted hunk ↗ jump to hunk
Reviewed-by: Christophe Leroy <redacted>
Signed-off-by: Rohan McLure <redacted>
---
v9: No longer required in order implement page table check, just
refactoring.
---
  arch/powerpc/include/asm/book3s/32/pgtable.h |  5 +++++
  arch/powerpc/include/asm/book3s/64/pgtable.h | 10 ++++-----
  arch/powerpc/include/asm/nohash/64/pgtable.h |  6 ++++++
  arch/powerpc/include/asm/pgtable.h           | 22 ++------------------
  4 files changed, 17 insertions(+), 26 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 52971ee30717..9cc95a61d2a6 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -223,6 +223,11 @@ static inline void pmd_clear(pmd_t *pmdp)
  	*pmdp = __pmd(0);
  }
  
+#define pmd_leaf pmd_leaf
+static inline bool pmd_leaf(pmd_t pmd)
+{
+	return false;
+}
Is that needed ? There is a fallback definition of pmd_leaf() in 
include/linux/pgtable.h
quoted hunk ↗ jump to hunk
  
  /*
   * When flushing the tlb entry for a page, we also need to flush the hash
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index cb77eddca54b..8fdb7667c509 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -1459,16 +1459,14 @@ static inline bool is_pte_rw_upgrade(unsigned long old_val, unsigned long new_va
  /*
   * Like pmd_huge() and pmd_large(), but works regardless of config options
   */
-#define pmd_is_leaf pmd_is_leaf
-#define pmd_leaf pmd_is_leaf
-static inline bool pmd_is_leaf(pmd_t pmd)
+#define pmd_leaf pmd_leaf
+static inline bool pmd_leaf(pmd_t pmd)
  {
  	return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE));
  }
  
-#define pud_is_leaf pud_is_leaf
-#define pud_leaf pud_is_leaf
-static inline bool pud_is_leaf(pud_t pud)
+#define pud_leaf pud_leaf
+static inline bool pud_leaf(pud_t pud)
  {
  	return !!(pud_raw(pud) & cpu_to_be64(_PAGE_PTE));
  }
diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h
index 2202c78730e8..f58cbebde26e 100644
--- a/arch/powerpc/include/asm/nohash/64/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable.h
@@ -116,6 +116,12 @@ static inline void pud_clear(pud_t *pudp)
  	*pudp = __pud(0);
  }
  
+#define pud_leaf pud_leaf
+static inline bool pud_leaf(pud_t pud)
+{
+	return false;
+}
+
Is that needed ? There is a fallback definition of pud_leaf() in 
include/linux/pgtable.h
quoted hunk ↗ jump to hunk
  #define pud_none(pud)		(!pud_val(pud))
  #define	pud_bad(pud)		(!is_kernel_addr(pud_val(pud)) \
  				 || (pud_val(pud) & PUD_BAD_BITS))
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 9224f23065ff..db0231afca9d 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -180,29 +180,11 @@ static inline void pte_frag_set(mm_context_t *ctx, void *p)
  }
  #endif
  
-#ifndef pmd_is_leaf
-#define pmd_is_leaf pmd_is_leaf
-static inline bool pmd_is_leaf(pmd_t pmd)
+#define p4d_leaf p4d_leaf
+static inline bool p4d_leaf(p4d_t p4d)
  {
  	return false;
  }
Is that needed ? There is a fallback definition of p4d_leaf() in 
include/linux/pgtable.h
-#endif
-
-#ifndef pud_is_leaf
-#define pud_is_leaf pud_is_leaf
-static inline bool pud_is_leaf(pud_t pud)
-{
-	return false;
-}
-#endif
-
-#ifndef p4d_is_leaf
-#define p4d_is_leaf p4d_is_leaf
-static inline bool p4d_is_leaf(p4d_t p4d)
-{
-	return false;
-}
-#endif
  
  #define pmd_pgtable pmd_pgtable
  static inline pgtable_t pmd_pgtable(pmd_t pmd)
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