[PATCH V2 26/68] powerpc/mm/radix: Add radix pte defines
Balbir Singh
bsingharora at gmail.com
Thu Apr 21 14:12:12 AEST 2016
On 09/04/16 16:13, Aneesh Kumar K.V wrote:
> This add PowerISA 3.0 specific pte defines. We share most of the
> details with hash linux page table format. This patch indicate only
> things where we differ
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
> ---
> arch/powerpc/include/asm/book3s/64/pgtable.h | 1 +
> arch/powerpc/include/asm/book3s/64/radix-4k.h | 12 +++
> arch/powerpc/include/asm/book3s/64/radix-64k.h | 12 +++
> arch/powerpc/include/asm/book3s/64/radix.h | 128 +++++++++++++++++++++++++
> 4 files changed, 153 insertions(+)
> create mode 100644 arch/powerpc/include/asm/book3s/64/radix-4k.h
> create mode 100644 arch/powerpc/include/asm/book3s/64/radix-64k.h
> create mode 100644 arch/powerpc/include/asm/book3s/64/radix.h
>
> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
> index 2643487affac..c47c3f7fc4e0 100644
> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
> @@ -205,6 +205,7 @@ extern unsigned long __pgd_table_size;
> #endif /* __ASSEMBLY__ */
>
> #include <asm/book3s/64/hash.h>
> +#include <asm/book3s/64/radix.h>
> #include <asm/barrier.h>
>
> /*
> diff --git a/arch/powerpc/include/asm/book3s/64/radix-4k.h b/arch/powerpc/include/asm/book3s/64/radix-4k.h
> new file mode 100644
> index 000000000000..1966ee977206
> --- /dev/null
> +++ b/arch/powerpc/include/asm/book3s/64/radix-4k.h
> @@ -0,0 +1,12 @@
> +#ifndef _ASM_POWERPC_PGTABLE_RADIX_4K_H
> +#define _ASM_POWERPC_PGTABLE_RADIX_4K_H
> +
> +/*
> + * For 4K page size supported index is 13/9/9/9
> + */
> +#define R_PTE_INDEX_SIZE 9 /* 2MB huge page */
> +#define R_PMD_INDEX_SIZE 9 /* 1G huge page */
> +#define R_PUD_INDEX_SIZE 9
> +#define R_PGD_INDEX_SIZE 13
> +
> +#endif /* _ASM_POWERPC_PGTABLE_RADIX_4K_H */
> diff --git a/arch/powerpc/include/asm/book3s/64/radix-64k.h b/arch/powerpc/include/asm/book3s/64/radix-64k.h
> new file mode 100644
> index 000000000000..fe1cebe55e01
> --- /dev/null
> +++ b/arch/powerpc/include/asm/book3s/64/radix-64k.h
> @@ -0,0 +1,12 @@
> +#ifndef _ASM_POWERPC_PGTABLE_RADIX_64K_H
> +#define _ASM_POWERPC_PGTABLE_RADIX_64K_H
> +
> +/*
> + * For 64K page size supported index is 13/9/9/5
> + */
> +#define R_PTE_INDEX_SIZE 5 /* 2MB huge page */
> +#define R_PMD_INDEX_SIZE 9 /* 1G huge page */
> +#define R_PUD_INDEX_SIZE 9
> +#define R_PGD_INDEX_SIZE 13
> +
> +#endif /* _ASM_POWERPC_PGTABLE_RADIX_64K_H */
> diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
> new file mode 100644
> index 000000000000..72e18d5c96b4
> --- /dev/null
> +++ b/arch/powerpc/include/asm/book3s/64/radix.h
> @@ -0,0 +1,128 @@
> +#ifndef _ASM_POWERPC_PGTABLE_RADIX_H
> +#define _ASM_POWERPC_PGTABLE_RADIX_H
> +
> +#ifndef __ASSEMBLY__
> +#include <asm/cmpxchg.h>
> +#endif
> +
> +#ifdef CONFIG_PPC_64K_PAGES
> +#include <asm/book3s/64/radix-64k.h>
> +#else
> +#include <asm/book3s/64/radix-4k.h>
> +#endif
> +
> +/* An empty PTE can still have a R or C writeback */
> +#define R_PTE_NONE_MASK (_PAGE_DIRTY | _PAGE_ACCESSED)
> +
> +/* Bits to set in a RPMD/RPUD/RPGD */
> +#define R_PMD_VAL_BITS (0x8000000000000000UL | R_PTE_INDEX_SIZE)
> +#define R_PUD_VAL_BITS (0x8000000000000000UL | R_PMD_INDEX_SIZE)
> +#define R_PGD_VAL_BITS (0x8000000000000000UL | R_PUD_INDEX_SIZE)
> +
> +/* Don't have anything in the reserved bits and leaf bits */
> +#define R_PMD_BAD_BITS 0x60000000000000e0UL
> +#define R_PUD_BAD_BITS 0x60000000000000e0UL
> +#define R_PGD_BAD_BITS 0x60000000000000e0UL
> +
> +/*
> + * Size of EA range mapped by our pagetables.
> + */
> +#define R_PGTABLE_EADDR_SIZE (R_PTE_INDEX_SIZE + R_PMD_INDEX_SIZE + \
> + R_PUD_INDEX_SIZE + R_PGD_INDEX_SIZE + PAGE_SHIFT)
> +#define R_PGTABLE_RANGE (ASM_CONST(1) << R_PGTABLE_EADDR_SIZE)
> +
> +#ifndef __ASSEMBLY__
> +#define R_PTE_TABLE_SIZE (sizeof(pte_t) << R_PTE_INDEX_SIZE)
> +#define R_PMD_TABLE_SIZE (sizeof(pmd_t) << R_PMD_INDEX_SIZE)
> +#define R_PUD_TABLE_SIZE (sizeof(pud_t) << R_PUD_INDEX_SIZE)
> +#define R_PGD_TABLE_SIZE (sizeof(pgd_t) << R_PGD_INDEX_SIZE)
> +
> +static inline unsigned long rpte_update(struct mm_struct *mm,
> + unsigned long addr,
> + pte_t *ptep, unsigned long clr,
> + unsigned long set,
> + int huge)
> +{
> +
> + pte_t pte;
> + unsigned long old_pte, new_pte;
> +
> + do {
> + pte = READ_ONCE(*ptep);
> + old_pte = pte_val(pte);
> + new_pte = (old_pte | set) & ~clr;
> +
> + } while (cpu_to_be64(old_pte) != __cmpxchg_u64((unsigned long *)ptep,
> + cpu_to_be64(old_pte),
> + cpu_to_be64(new_pte)));
> + /* We already do a sync in cmpxchg, is ptesync needed ?*/
> + asm volatile("ptesync" : : : "memory");
Yes, I think ptesync is required after PTE changes
> + /* huge pages use the old page table lock */
> + if (!huge)
> + assert_pte_locked(mm, addr);
Are we passing huge, addr only for the assert? I think on most occasions huge is 0,
it is better to do it in the caller. It's probably worth refactoring at some point
for both types of *pte_update*
> +
> + return old_pte;
> +}
> +
> +/*
> + * Set the dirty and/or accessed bits atomically in a linux PTE, this
> + * function doesn't need to invalidate tlb.
> + */
> +static inline void __rptep_set_access_flags(pte_t *ptep, pte_t entry)
> +{
> + pte_t pte;
> + unsigned long old_pte, new_pte;
> + unsigned long set = pte_val(entry) & (_PAGE_DIRTY | _PAGE_ACCESSED |
> + _PAGE_RW | _PAGE_EXEC);
> + do {
> + pte = READ_ONCE(*ptep);
> + old_pte = pte_val(pte);
> + new_pte = old_pte | set;
> +
> + } while (cpu_to_be64(old_pte) != __cmpxchg_u64((unsigned long *)ptep,
> + cpu_to_be64(old_pte),
> + cpu_to_be64(new_pte)));
> + /* We already do a sync in cmpxchg, is ptesync needed ?*/
> + asm volatile("ptesync" : : : "memory");
Can this be implemented as
rpte_update(ptep, 0, set) if we refactored the code to remove mm, addr and huge
Making the code more legible and will remove duplication of code.
> +}
> +
> +static inline int rpte_same(pte_t pte_a, pte_t pte_b)
> +{
> + return ((pte_val(pte_a) == pte_val(pte_b)));
> +}
> +
> +static inline int rpte_none(pte_t pte)
> +{
> + return (pte_val(pte) & ~R_PTE_NONE_MASK) == 0;
> +}
> +
> +static inline void __set_rpte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, int percpu)
> +{
> + *ptep = pte;
Do we need WRITE_ONCE? I guess not since we have ptesync below
> + asm volatile("ptesync" : : : "memory");
> +}
> +
> +static inline int rpmd_bad(pmd_t pmd)
> +{
> + return !!(pmd_val(pmd) & R_PMD_BAD_BITS);
> +}
> +
> +static inline int rpmd_same(pmd_t pmd_a, pmd_t pmd_b)
> +{
> + return ((pmd_val(pmd_a) == pmd_val(pmd_b)));
> +}
> +
> +static inline int rpud_bad(pud_t pud)
> +{
> + return !!(pud_val(pud) & R_PUD_BAD_BITS);
> +}
> +
> +
> +static inline int rpgd_bad(pgd_t pgd)
> +{
> + return !!(pgd_val(pgd) & R_PGD_BAD_BITS);
> +}
> +
> +#endif /* __ASSEMBLY__ */
> +#endif
>
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