Re: [PATCH v4 08/14] powerpc: add support for folded p4d page tables

2020-06-04 Thread Qian Cai 



> On Jun 3, 2020, at 3:05 PM, Andrew Morton  wrote:
> 
> A bunch of new material just landed in linux-next/powerpc.
> 
> The timing is awkward!  I trust this will be going into mainline during
> this merge window?  If not, please drop it and repull after -rc1.

I have noticed the same pattern over and over again, i.e., many powerpc new 
material has only shown up in linux-next for only a few days before sending for 
a pull request to Linus.

There are absolutely no safe net for this kind of practice. The main problem is 
that Linus seems totally fine with it.

Re: [PATCH v4 08/14] powerpc: add support for folded p4d page tables

2020-06-03 Thread Andrew Morton 
On Tue, 14 Apr 2020 18:34:49 +0300 Mike Rapoport  wrote:

> Implement primitives necessary for the 4th level folding, add walks of p4d
> level where appropriate and replace 5level-fixup.h with pgtable-nop4d.h.

A bunch of new material just landed in linux-next/powerpc.

The timing is awkward!  I trust this will be going into mainline during
this merge window?  If not, please drop it and repull after -rc1.

arch/powerpc/mm/ptdump/ptdump.c:walk_pagetables() was a problem. 
Here's what I ended up with - please check.

static void walk_pagetables(struct pg_state *st)
{
unsigned int i;
unsigned long addr = st->start_address & PGDIR_MASK;
pgd_t *pgd = pgd_offset_k(addr);

/*
 * Traverse the linux pagetable structure and dump pages that are in
 * the hash pagetable.
 */
for (i = pgd_index(addr); i < PTRS_PER_PGD; i++, pgd++, addr += 
PGDIR_SIZE) {
p4d_t *p4d = p4d_offset(pgd, 0);

if (pgd_none(*pgd) || pgd_is_leaf(*pgd))
note_page(st, addr, 1, p4d_val(*p4d), PGDIR_SIZE);
else if (is_hugepd(__hugepd(p4d_val(*p4d
walk_hugepd(st, (hugepd_t *)pgd, addr, PGDIR_SHIFT, 1);
else
/* pgd exists */
walk_pud(st, p4d, addr);
}
}

Mike's series "mm: consolidate definitions of page table accessors"
took quite a lot of damage as well.  Patches which needed rework as a
result of this were:

powerpc-add-support-for-folded-p4d-page-tables-fix.patch
mm-introduce-include-linux-pgtableh.patch
mm-reorder-includes-after-introduction-of-linux-pgtableh.patch
mm-pgtable-add-shortcuts-for-accessing-kernel-pmd-and-pte.patch
mm-pgtable-add-shortcuts-for-accessing-kernel-pmd-and-pte-fix-2.patch
mm-consolidate-pte_index-and-pte_offset_-definitions.patch
mm-consolidate-pmd_index-and-pmd_offset-definitions.patch
mm-consolidate-pud_index-and-pud_offset-definitions.patch
mm-consolidate-pgd_index-and-pgd_offset_k-definitions.patch

[PATCH v4 08/14] powerpc: add support for folded p4d page tables

2020-04-14 Thread Mike Rapoport 
From: Mike Rapoport 

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate and replace 5level-fixup.h with pgtable-nop4d.h.

Signed-off-by: Mike Rapoport 
Tested-by: Christophe Leroy  # 8xx and 83xx
---
 arch/powerpc/include/asm/book3s/32/pgtable.h  |  1 -
 arch/powerpc/include/asm/book3s/64/hash.h |  4 +-
 arch/powerpc/include/asm/book3s/64/pgalloc.h  |  4 +-
 arch/powerpc/include/asm/book3s/64/pgtable.h  | 60 ++-
 arch/powerpc/include/asm/book3s/64/radix.h|  6 +-
 arch/powerpc/include/asm/nohash/32/pgtable.h  |  1 -
 arch/powerpc/include/asm/nohash/64/pgalloc.h  |  2 +-
 .../include/asm/nohash/64/pgtable-4k.h| 32 +-
 arch/powerpc/include/asm/nohash/64/pgtable.h  |  6 +-
 arch/powerpc/include/asm/pgtable.h| 10 ++--
 arch/powerpc/kvm/book3s_64_mmu_radix.c| 32 ++
 arch/powerpc/lib/code-patching.c  |  7 ++-
 arch/powerpc/mm/book3s64/hash_pgtable.c   |  4 +-
 arch/powerpc/mm/book3s64/radix_pgtable.c  | 26 +---
 arch/powerpc/mm/book3s64/subpage_prot.c   |  6 +-
 arch/powerpc/mm/hugetlbpage.c | 28 +
 arch/powerpc/mm/nohash/book3e_pgtable.c   | 15 ++---
 arch/powerpc/mm/pgtable.c | 30 ++
 arch/powerpc/mm/pgtable_64.c  | 10 ++--
 arch/powerpc/mm/ptdump/hashpagetable.c| 20 ++-
 arch/powerpc/mm/ptdump/ptdump.c   | 14 +++--
 arch/powerpc/xmon/xmon.c  | 18 +++---
 22 files changed, 197 insertions(+), 139 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h 
b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 7549393c4c43..6052b72216a6 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -2,7 +2,6 @@
 #ifndef _ASM_POWERPC_BOOK3S_32_PGTABLE_H
 #define _ASM_POWERPC_BOOK3S_32_PGTABLE_H
 
-#define __ARCH_USE_5LEVEL_HACK
 #include 
 
 #include 
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h 
b/arch/powerpc/include/asm/book3s/64/hash.h
index 6fc4520092c7..73ad038ed10b 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -134,9 +134,9 @@ static inline int get_region_id(unsigned long ea)
 
 #definehash__pmd_bad(pmd)  (pmd_val(pmd) & H_PMD_BAD_BITS)
 #definehash__pud_bad(pud)  (pud_val(pud) & H_PUD_BAD_BITS)
-static inline int hash__pgd_bad(pgd_t pgd)
+static inline int hash__p4d_bad(p4d_t p4d)
 {
-   return (pgd_val(pgd) == 0);
+   return (p4d_val(p4d) == 0);
 }
 #ifdef CONFIG_STRICT_KERNEL_RWX
 extern void hash__mark_rodata_ro(void);
diff --git a/arch/powerpc/include/asm/book3s/64/pgalloc.h 
b/arch/powerpc/include/asm/book3s/64/pgalloc.h
index a41e91bd0580..69c5b051734f 100644
--- a/arch/powerpc/include/asm/book3s/64/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/64/pgalloc.h
@@ -85,9 +85,9 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
 }
 
-static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
+static inline void p4d_populate(struct mm_struct *mm, p4d_t *pgd, pud_t *pud)
 {
-   *pgd =  __pgd(__pgtable_ptr_val(pud) | PGD_VAL_BITS);
+   *pgd =  __p4d(__pgtable_ptr_val(pud) | PGD_VAL_BITS);
 }
 
 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h 
b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 368b136517e0..bc047514724c 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -2,7 +2,7 @@
 #ifndef _ASM_POWERPC_BOOK3S_64_PGTABLE_H_
 #define _ASM_POWERPC_BOOK3S_64_PGTABLE_H_
 
-#include 
+#include 
 
 #ifndef __ASSEMBLY__
 #include 
@@ -251,7 +251,7 @@ extern unsigned long __pmd_frag_size_shift;
 /* Bits to mask out from a PUD to get to the PMD page */
 #define PUD_MASKED_BITS0xc0ffUL
 /* Bits to mask out from a PGD to get to the PUD page */
-#define PGD_MASKED_BITS0xc0ffUL
+#define P4D_MASKED_BITS0xc0ffUL
 
 /*
  * Used as an indicator for rcu callback functions
@@ -949,54 +949,60 @@ static inline bool pud_access_permitted(pud_t pud, bool 
write)
return pte_access_permitted(pud_pte(pud), write);
 }
 
-#define pgd_write(pgd) pte_write(pgd_pte(pgd))
+#define __p4d_raw(x)   ((p4d_t) { __pgd_raw(x) })
+static inline __be64 p4d_raw(p4d_t x)
+{
+   return pgd_raw(x.pgd);
+}
+
+#define p4d_write(p4d) pte_write(p4d_pte(p4d))
 
-static inline void pgd_clear(pgd_t *pgdp)
+static inline void p4d_clear(p4d_t *p4dp)
 {
-   *pgdp = __pgd(0);
+   *p4dp = __p4d(0);
 }
 
-static inline int pgd_none(pgd_t pgd)
+static inline int p4d_none(p4d_t p4d)
 {
-   return !pgd_raw(pgd);
+   return !p4d_raw(p4d);
 }
 
-static inline int pgd_pre