From: Mike Rapoport <rppt@xxxxxxxxxxxxx> Subject: nios2: add support for folded p4d page tables Implement primitives necessary for the 4th level folding, add walks of p4d level where appropriate and remove usage of __ARCH_USE_5LEVEL_HACK. Link: http://lkml.kernel.org/r/20200414153455.21744-7-rppt@xxxxxxxxxx Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Brian Cain <bcain@xxxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxx> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Cc: Guan Xuetao <gxt@xxxxxxxxxx> Cc: James Morse <james.morse@xxxxxxx> Cc: Jonas Bonn <jonas@xxxxxxxxxxxx> Cc: Julien Thierry <julien.thierry.kdev@xxxxxxxxx> Cc: Ley Foon Tan <ley.foon.tan@xxxxxxxxx> Cc: Marc Zyngier <maz@xxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Rich Felker <dalias@xxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxx> Cc: Stafford Horne <shorne@xxxxxxxxx> Cc: Stefan Kristiansson <stefan.kristiansson@xxxxxxxxxxxxx> Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx> Cc: Tony Luck <tony.luck@xxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/nios2/include/asm/pgtable.h | 3 +-- arch/nios2/mm/fault.c | 9 +++++++-- arch/nios2/mm/ioremap.c | 6 +++++- 3 files changed, 13 insertions(+), 5 deletions(-) --- a/arch/nios2/include/asm/pgtable.h~nios2-add-support-for-folded-p4d-page-tables +++ a/arch/nios2/include/asm/pgtable.h @@ -22,7 +22,6 @@ #include <asm/tlbflush.h> #include <asm/pgtable-bits.h> -#define __ARCH_USE_5LEVEL_HACK #include <asm-generic/pgtable-nopmd.h> #define FIRST_USER_ADDRESS 0UL @@ -100,7 +99,7 @@ extern pte_t invalid_pte_table[PAGE_SIZE */ static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval) { - pmdptr->pud.pgd.pgd = pmdval.pud.pgd.pgd; + *pmdptr = pmdval; } /* to find an entry in a page-table-directory */ --- a/arch/nios2/mm/fault.c~nios2-add-support-for-folded-p4d-page-tables +++ a/arch/nios2/mm/fault.c @@ -242,6 +242,7 @@ vmalloc_fault: */ int offset = pgd_index(address); pgd_t *pgd, *pgd_k; + p4d_t *p4d, *p4d_k; pud_t *pud, *pud_k; pmd_t *pmd, *pmd_k; pte_t *pte_k; @@ -253,8 +254,12 @@ vmalloc_fault: goto no_context; set_pgd(pgd, *pgd_k); - pud = pud_offset(pgd, address); - pud_k = pud_offset(pgd_k, address); + p4d = p4d_offset(pgd, address); + p4d_k = p4d_offset(pgd_k, address); + if (!p4d_present(*p4d_k)) + goto no_context; + pud = pud_offset(p4d, address); + pud_k = pud_offset(p4d_k, address); if (!pud_present(*pud_k)) goto no_context; pmd = pmd_offset(pud, address); --- a/arch/nios2/mm/ioremap.c~nios2-add-support-for-folded-p4d-page-tables +++ a/arch/nios2/mm/ioremap.c @@ -86,11 +86,15 @@ static int remap_area_pages(unsigned lon if (address >= end) BUG(); do { + p4d_t *p4d; pud_t *pud; pmd_t *pmd; error = -ENOMEM; - pud = pud_alloc(&init_mm, dir, address); + p4d = p4d_alloc(&init_mm, dir, address); + if (!p4d) + break; + pud = pud_alloc(&init_mm, p4d, address); if (!pud) break; pmd = pmd_alloc(&init_mm, pud, address); _
