linux_dsm_epyc7002/arch/powerpc/mm/pgtable-book3s64.c
Reza Arbab 32b53c012e powerpc/mm: Fix memory hotplug BUG() on radix
Memory hotplug is leading to hash page table calls, even on radix:

  arch_add_memory
    create_section_mapping
      htab_bolt_mapping
        BUG_ON(!ppc_md.hpte_insert);

To fix, refactor {create,remove}_section_mapping() into hash__ and
radix__ variants. Leave the radix versions stubbed for now.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-01-17 10:05:43 +11:00

147 lines
4.0 KiB
C

/*
* Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/sched.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include "mmu_decl.h"
#include <trace/events/thp.h>
int (*register_process_table)(unsigned long base, unsigned long page_size,
unsigned long tbl_size);
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/*
* This is called when relaxing access to a hugepage. It's also called in the page
* fault path when we don't hit any of the major fault cases, ie, a minor
* update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
* handled those two for us, we additionally deal with missing execute
* permission here on some processors
*/
int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp, pmd_t entry, int dirty)
{
int changed;
#ifdef CONFIG_DEBUG_VM
WARN_ON(!pmd_trans_huge(*pmdp));
assert_spin_locked(&vma->vm_mm->page_table_lock);
#endif
changed = !pmd_same(*(pmdp), entry);
if (changed) {
__ptep_set_access_flags(vma->vm_mm, pmdp_ptep(pmdp),
pmd_pte(entry), address);
flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
}
return changed;
}
int pmdp_test_and_clear_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
}
/*
* set a new huge pmd. We should not be called for updating
* an existing pmd entry. That should go via pmd_hugepage_update.
*/
void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
#ifdef CONFIG_DEBUG_VM
WARN_ON(pte_present(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
assert_spin_locked(&mm->page_table_lock);
WARN_ON(!pmd_trans_huge(pmd));
#endif
trace_hugepage_set_pmd(addr, pmd_val(pmd));
return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
}
/*
* We use this to invalidate a pmdp entry before switching from a
* hugepte to regular pmd entry.
*/
void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, 0);
flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
/*
* This ensures that generic code that rely on IRQ disabling
* to prevent a parallel THP split work as expected.
*/
kick_all_cpus_sync();
}
static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
{
return __pmd(pmd_val(pmd) | pgprot_val(pgprot));
}
pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
{
unsigned long pmdv;
pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK;
return pmd_set_protbits(__pmd(pmdv), pgprot);
}
pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
{
return pfn_pmd(page_to_pfn(page), pgprot);
}
pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
{
unsigned long pmdv;
pmdv = pmd_val(pmd);
pmdv &= _HPAGE_CHG_MASK;
return pmd_set_protbits(__pmd(pmdv), newprot);
}
/*
* This is called at the end of handling a user page fault, when the
* fault has been handled by updating a HUGE PMD entry in the linux page tables.
* We use it to preload an HPTE into the hash table corresponding to
* the updated linux HUGE PMD entry.
*/
void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd)
{
return;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
/* For use by kexec */
void mmu_cleanup_all(void)
{
if (radix_enabled())
radix__mmu_cleanup_all();
else if (mmu_hash_ops.hpte_clear_all)
mmu_hash_ops.hpte_clear_all();
}
#ifdef CONFIG_MEMORY_HOTPLUG
int create_section_mapping(unsigned long start, unsigned long end)
{
if (radix_enabled())
return -ENODEV;
return hash__create_section_mapping(start, end);
}
int remove_section_mapping(unsigned long start, unsigned long end)
{
if (radix_enabled())
return -ENODEV;
return hash__remove_section_mapping(start, end);
}
#endif /* CONFIG_MEMORY_HOTPLUG */