mm: remove devmap related functions and page table bits

Now that DAX and all other reference counts to ZONE_DEVICE pages are
managed normally there is no need for the special devmap PTE/PMD/PUD page
table bits.  So drop all references to these, freeing up a software
defined page table bit on architectures supporting it.

Link: https://lkml.kernel.org/r/6389398c32cc9daa3dfcaa9f79c7972525d310ce.1750323463.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Acked-by: Will Deacon <will@kernel.org> # arm64
Acked-by: David Hildenbrand <david@redhat.com>
Suggested-by: Chunyan Zhang <zhang.lyra@gmail.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Björn Töpel <bjorn@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Inki Dae <m.szyprowski@samsung.com>
Cc: John Groves <john@groves.net>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Alistair Popple
2025-06-19 18:58:03 +10:00
committed by Andrew Morton
parent 28dc88c39e
commit d438d27341
25 changed files with 17 additions and 319 deletions

View File

@@ -348,12 +348,6 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args)
vaddr &= HPAGE_PUD_MASK;
pud = pfn_pud(args->pud_pfn, args->page_prot);
/*
* Some architectures have debug checks to make sure
* huge pud mapping are only found with devmap entries
* For now test with only devmap entries.
*/
pud = pud_mkdevmap(pud);
set_pud_at(args->mm, vaddr, args->pudp, pud);
flush_dcache_page(page);
pudp_set_wrprotect(args->mm, vaddr, args->pudp);
@@ -366,7 +360,6 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args)
WARN_ON(!pud_none(pud));
#endif /* __PAGETABLE_PMD_FOLDED */
pud = pfn_pud(args->pud_pfn, args->page_prot);
pud = pud_mkdevmap(pud);
pud = pud_wrprotect(pud);
pud = pud_mkclean(pud);
set_pud_at(args->mm, vaddr, args->pudp, pud);
@@ -384,7 +377,6 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args)
#endif /* __PAGETABLE_PMD_FOLDED */
pud = pfn_pud(args->pud_pfn, args->page_prot);
pud = pud_mkdevmap(pud);
pud = pud_mkyoung(pud);
set_pud_at(args->mm, vaddr, args->pudp, pud);
flush_dcache_page(page);
@@ -693,53 +685,6 @@ static void __init pmd_protnone_tests(struct pgtable_debug_args *args)
static void __init pmd_protnone_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
static void __init pte_devmap_tests(struct pgtable_debug_args *args)
{
pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
pr_debug("Validating PTE devmap\n");
WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void __init pmd_devmap_tests(struct pgtable_debug_args *args)
{
pmd_t pmd;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PMD devmap\n");
pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
}
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static void __init pud_devmap_tests(struct pgtable_debug_args *args)
{
pud_t pud;
if (!has_transparent_pud_hugepage())
return;
pr_debug("Validating PUD devmap\n");
pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
}
#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#else
static void __init pte_devmap_tests(struct pgtable_debug_args *args) { }
static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
static void __init pte_soft_dirty_tests(struct pgtable_debug_args *args)
{
pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
@@ -1333,10 +1278,6 @@ static int __init debug_vm_pgtable(void)
pte_protnone_tests(&args);
pmd_protnone_tests(&args);
pte_devmap_tests(&args);
pmd_devmap_tests(&args);
pud_devmap_tests(&args);
pte_soft_dirty_tests(&args);
pmd_soft_dirty_tests(&args);
pte_swap_soft_dirty_tests(&args);