[PATCH 6.4 491/800] powerpc/book3s64/mm: Fix DirectMap stats in /proc/meminfo

Greg Kroah-Hartman
2023-07-16T20:16:11Z

From: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>

[ Upstream commit 0da90af431abc3f497a38ec9ef6e43b0d0dabe80 ]

On memory unplug reduce DirectMap page count correctly.
root@ubuntu-guest:# grep Direct /proc/meminfo
DirectMap4k: 0 kB
DirectMap64k: 0 kB
DirectMap2M: 115343360 kB
DirectMap1G: 0 kB

Before fix:
root@ubuntu-guest:# ndctl disable-namespace all
disabled 1 namespace
root@ubuntu-guest:# grep Direct /proc/meminfo
DirectMap4k: 0 kB
DirectMap64k: 0 kB
DirectMap2M: 115343360 kB
DirectMap1G: 0 kB

After fix:
root@ubuntu-guest:# ndctl disable-namespace all
disabled 1 namespace
root@ubuntu-guest:# grep Direct /proc/meminfo
DirectMap4k: 0 kB
DirectMap64k: 0 kB
DirectMap2M: 104857600 kB
DirectMap1G: 0 kB

Fixes: a2dc009afa9a ("powerpc/mm/book3s/radix: Add mapping statistics")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com <mailto:sachinp@linux.ibm.com>>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230616110826.344417-4-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/mm/book3s64/radix_pgtable.c | 34 +++++++++++++++---------
1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 2297aa764ecdb..e8db8c8efe359 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -745,9 +745,9 @@ static void free_pud_table(pud_t *pud_start, p4d_t *p4d)
}

static void remove_pte_table(pte_t *pte_start, unsigned long addr,
- unsigned long end)
+ unsigned long end, bool direct)
{
- unsigned long next;
+ unsigned long next, pages = 0;
pte_t *pte;

pte = pte_start + pte_index(addr);
@@ -769,13 +769,16 @@ static void remove_pte_table(pte_t *pte_start, unsigned long addr,
}

pte_clear(&init_mm, addr, pte);
+ pages++;
}
+ if (direct)
+ update_page_count(mmu_virtual_psize, -pages);
}

static void __meminit remove_pmd_table(pmd_t *pmd_start, unsigned long addr,
- unsigned long end)
+ unsigned long end, bool direct)
{
- unsigned long next;
+ unsigned long next, pages = 0;
pte_t *pte_base;
pmd_t *pmd;

@@ -793,19 +796,22 @@ static void __meminit remove_pmd_table(pmd_t *pmd_start, unsigned long addr,
continue;
}
pte_clear(&init_mm, addr, (pte_t *)pmd);
+ pages++;
continue;
}

pte_base = (pte_t *)pmd_page_vaddr(*pmd);
- remove_pte_table(pte_base, addr, next);
+ remove_pte_table(pte_base, addr, next, direct);
free_pte_table(pte_base, pmd);
}
+ if (direct)
+ update_page_count(MMU_PAGE_2M, -pages);
}

static void __meminit remove_pud_table(pud_t *pud_start, unsigned long addr,
- unsigned long end)
+ unsigned long end, bool direct)
{
- unsigned long next;
+ unsigned long next, pages = 0;
pmd_t *pmd_base;
pud_t *pud;

@@ -823,16 +829,20 @@ static void __meminit remove_pud_table(pud_t *pud_start, unsigned long addr,
continue;
}
pte_clear(&init_mm, addr, (pte_t *)pud);
+ pages++;
continue;
}

pmd_base = pud_pgtable(*pud);
- remove_pmd_table(pmd_base, addr, next);
+ remove_pmd_table(pmd_base, addr, next, direct);
free_pmd_table(pmd_base, pud);
}
+ if (direct)
+ update_page_count(MMU_PAGE_1G, -pages);
}

-static void __meminit remove_pagetable(unsigned long start, unsigned long end)
+static void __meminit remove_pagetable(unsigned long start, unsigned long end,
+ bool direct)
{
unsigned long addr, next;
pud_t *pud_base;
@@ -861,7 +871,7 @@ static void __meminit remove_pagetable(unsigned long start, unsigned long end)
}

pud_base = p4d_pgtable(*p4d);
- remove_pud_table(pud_base, addr, next);
+ remove_pud_table(pud_base, addr, next, direct);
free_pud_table(pud_base, p4d);
}

@@ -884,7 +894,7 @@ int __meminit radix__create_section_mapping(unsigned long start,

int __meminit radix__remove_section_mapping(unsigned long start, unsigned long end)
{
- remove_pagetable(start, end);
+ remove_pagetable(start, end, true);
return 0;
}
#endif /* CONFIG_MEMORY_HOTPLUG */
@@ -920,7 +930,7 @@ int __meminit radix__vmemmap_create_mapping(unsigned long start,
#ifdef CONFIG_MEMORY_HOTPLUG
void __meminit radix__vmemmap_remove_mapping(unsigned long start, unsigned long page_size)
{
- remove_pagetable(start, start + page_size);
+ remove_pagetable(start, start + page_size, false);
}
#endif
#endif
--
2.39.2