Finishing up what the commit c2febafc67734a ("mm: convert generic code to
5-level paging") started out while levelling up P4D huge mapping support
at par with PUD and PMD. A new arch call back arch_ioremap_p4d_supported()
is being added which just maintains status quo (P4D huge map not supported)
on x86, arm64 and powerpc.
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: x86@xxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> (powerpc)
---
Changes in V2:
- Added arch_ioremap_p4d_supported() definition for powerpc
- Changed commit message to add powerpc in the arch list
- Added tags from Michael Ellerman
Hello Andrew,
This applies and builds on linux-next (next-20190627) which contains
d909f9109c30 ("powerpc/64s/radix: Enable HAVE_ARCH_HUGE_VMAP")
but after
1. Reverting V1 of this patch
d31cf72b92ec ("mm/ioremap: probe platform for p4d huge map support")
2. Removing arch_ioremap_p4d_supported() definition which was added with
153083a99fe431 ("Merge branch 'akpm-current/current'")
- Anshuman
arch/arm64/mm/mmu.c | 5 +++++
arch/powerpc/mm/book3s64/radix_pgtable.c | 5 +++++
arch/x86/mm/ioremap.c | 5 +++++
include/linux/io.h | 1 +
lib/ioremap.c | 2 ++
5 files changed, 18 insertions(+)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 97ff0341..750a69d 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -942,6 +942,11 @@ void *__init fixmap_remap_fdt(phys_addr_t dt_phys)
return dt_virt;
}
+int __init arch_ioremap_p4d_supported(void)
+{
+ return 0;
+}
+
int __init arch_ioremap_pud_supported(void)
{
/*
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 22c0637..60c8fca 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -1120,6 +1120,11 @@ void radix__ptep_modify_prot_commit(struct vm_area_struct *vma,
set_pte_at(mm, addr, ptep, pte);
}
+int __init arch_ioremap_p4d_supported(void)
+{
+ return 0;
+}
+
int __init arch_ioremap_pud_supported(void)
{
/* HPT does not cope with large pages in the vmalloc area */
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index e500f1d..63e99f1 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -459,6 +459,11 @@ void iounmap(volatile void __iomem *addr)
}
EXPORT_SYMBOL(iounmap);
+int __init arch_ioremap_p4d_supported(void)
+{
+ return 0;
+}
+
int __init arch_ioremap_pud_supported(void)
{
#ifdef CONFIG_X86_64
diff --git a/include/linux/io.h b/include/linux/io.h
index 9876e58..accac82 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -33,6 +33,7 @@ static inline int ioremap_page_range(unsigned long addr, unsigned long end,
#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
void __init ioremap_huge_init(void);
+int arch_ioremap_p4d_supported(void);
int arch_ioremap_pud_supported(void);
int arch_ioremap_pmd_supported(void);
#else
diff --git a/lib/ioremap.c b/lib/ioremap.c
index a95161d..0a2ffad 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -30,6 +30,8 @@ early_param("nohugeiomap", set_nohugeiomap);
void __init ioremap_huge_init(void)
{
if (!ioremap_huge_disabled) {
+ if (arch_ioremap_p4d_supported())
+ ioremap_p4d_capable = 1;
if (arch_ioremap_pud_supported())
ioremap_pud_capable = 1;
if (arch_ioremap_pmd_supported())
--
2.7.4
