On Fri, Apr 16, 2021 at 1:17 PM Anshuman Khandual <anshuman.khandual@xxxxxxx> wrote: > > Currently most platforms define FIRST_USER_ADDRESS as 0UL duplication the > same code all over. Instead just define a generic default value (i.e 0UL) > for FIRST_USER_ADDRESS and let the platforms override when required. This > makes it much cleaner with reduced code. > > The default FIRST_USER_ADDRESS here would be skipped in <linux/pgtable.h> > when the given platform overrides its value via <asm/pgtable.h>. > > Cc: Richard Henderson <rth@xxxxxxxxxxx> > Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Will Deacon <will@xxxxxxxxxx> > Cc: Guo Ren <guoren@xxxxxxxxxx> > Cc: Brian Cain <bcain@xxxxxxxxxxxxxx> > Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> > Cc: Michal Simek <monstr@xxxxxxxxx> > Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> > Cc: Ley Foon Tan <ley.foon.tan@xxxxxxxxx> > Cc: Jonas Bonn <jonas@xxxxxxxxxxxx> > Cc: Stefan Kristiansson <stefan.kristiansson@xxxxxxxxxxxxx> > Cc: Stafford Horne <shorne@xxxxxxxxx> > Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> > Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> > Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> > Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx> > Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx> > Cc: Heiko Carstens <hca@xxxxxxxxxxxxx> > Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> > Cc: Jeff Dike <jdike@xxxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Chris Zankel <chris@xxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: linux-arch@xxxxxxxxxxxxxxx > Cc: linux-mm@xxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> > --- > This applies on v5.12-rc7 and has been boot tested on arm64 platform. > But has been cross compiled on multiple other platforms. > > Changes in V2: > > - Dropped ARCH_HAS_FIRST_USER_ADDRESS construct > > Changes in V1: > > https://patchwork.kernel.org/project/linux-mm/patch/1618368899-20311-1-git-send-email-anshuman.khandual@xxxxxxx/ > > arch/alpha/include/asm/pgtable.h | 1 - > arch/arc/include/asm/pgtable.h | 6 ------ > arch/arm64/include/asm/pgtable.h | 2 -- > arch/csky/include/asm/pgtable.h | 1 - Acked-by: Guo Ren <guoren@xxxxxxxxxx> > arch/hexagon/include/asm/pgtable.h | 3 --- > arch/ia64/include/asm/pgtable.h | 1 - > arch/m68k/include/asm/pgtable_mm.h | 1 - > arch/microblaze/include/asm/pgtable.h | 2 -- > arch/mips/include/asm/pgtable-32.h | 1 - > arch/mips/include/asm/pgtable-64.h | 1 - > arch/nios2/include/asm/pgtable.h | 2 -- > arch/openrisc/include/asm/pgtable.h | 1 - > arch/parisc/include/asm/pgtable.h | 2 -- > arch/powerpc/include/asm/book3s/pgtable.h | 1 - > arch/powerpc/include/asm/nohash/32/pgtable.h | 1 - > arch/powerpc/include/asm/nohash/64/pgtable.h | 2 -- > arch/riscv/include/asm/pgtable.h | 2 -- > arch/s390/include/asm/pgtable.h | 2 -- > arch/sh/include/asm/pgtable.h | 2 -- > arch/sparc/include/asm/pgtable_32.h | 1 - > arch/sparc/include/asm/pgtable_64.h | 3 --- > arch/um/include/asm/pgtable-2level.h | 1 - > arch/um/include/asm/pgtable-3level.h | 1 - > arch/x86/include/asm/pgtable_types.h | 2 -- > arch/xtensa/include/asm/pgtable.h | 1 - > include/linux/pgtable.h | 9 +++++++++ > 26 files changed, 9 insertions(+), 43 deletions(-) > > diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h > index 8d856c62e22a..1a2fb0dc905b 100644 > --- a/arch/alpha/include/asm/pgtable.h > +++ b/arch/alpha/include/asm/pgtable.h > @@ -46,7 +46,6 @@ struct vm_area_struct; > #define PTRS_PER_PMD (1UL << (PAGE_SHIFT-3)) > #define PTRS_PER_PGD (1UL << (PAGE_SHIFT-3)) > #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) > -#define FIRST_USER_ADDRESS 0UL > > /* Number of pointers that fit on a page: this will go away. */ > #define PTRS_PER_PAGE (1UL << (PAGE_SHIFT-3)) > diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h > index 163641726a2b..a9fabfb70664 100644 > --- a/arch/arc/include/asm/pgtable.h > +++ b/arch/arc/include/asm/pgtable.h > @@ -228,12 +228,6 @@ > */ > #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) > > -/* > - * No special requirements for lowest virtual address we permit any user space > - * mapping to be mapped at. > - */ > -#define FIRST_USER_ADDRESS 0UL > - > > /**************************************************************** > * Bucket load of VM Helpers > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 47027796c2f9..f6ab8b64967e 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -26,8 +26,6 @@ > > #define vmemmap ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT)) > > -#define FIRST_USER_ADDRESS 0UL > - > #ifndef __ASSEMBLY__ > > #include <asm/cmpxchg.h> > diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h > index 0d60367b6bfa..151607ed5158 100644 > --- a/arch/csky/include/asm/pgtable.h > +++ b/arch/csky/include/asm/pgtable.h > @@ -14,7 +14,6 @@ > #define PGDIR_MASK (~(PGDIR_SIZE-1)) > > #define USER_PTRS_PER_PGD (PAGE_OFFSET/PGDIR_SIZE) > -#define FIRST_USER_ADDRESS 0UL > > /* > * C-SKY is two-level paging structure: > diff --git a/arch/hexagon/include/asm/pgtable.h b/arch/hexagon/include/asm/pgtable.h > index dbb22b80b8c4..e4979508cddf 100644 > --- a/arch/hexagon/include/asm/pgtable.h > +++ b/arch/hexagon/include/asm/pgtable.h > @@ -155,9 +155,6 @@ extern unsigned long _dflt_cache_att; > > extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* located in head.S */ > > -/* Seems to be zero even in architectures where the zero page is firewalled? */ > -#define FIRST_USER_ADDRESS 0UL > - > /* HUGETLB not working currently */ > #ifdef CONFIG_HUGETLB_PAGE > #define pte_mkhuge(pte) __pte((pte_val(pte) & ~0x3) | HVM_HUGEPAGE_SIZE) > diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h > index 9b4efe89e62d..b37381532c2f 100644 > --- a/arch/ia64/include/asm/pgtable.h > +++ b/arch/ia64/include/asm/pgtable.h > @@ -128,7 +128,6 @@ > #define PTRS_PER_PGD_SHIFT PTRS_PER_PTD_SHIFT > #define PTRS_PER_PGD (1UL << PTRS_PER_PGD_SHIFT) > #define USER_PTRS_PER_PGD (5*PTRS_PER_PGD/8) /* regions 0-4 are user regions */ > -#define FIRST_USER_ADDRESS 0UL > > /* > * All the normal masks have the "page accessed" bits on, as any time > diff --git a/arch/m68k/include/asm/pgtable_mm.h b/arch/m68k/include/asm/pgtable_mm.h > index aca22c2c1ee2..143ba7de9bda 100644 > --- a/arch/m68k/include/asm/pgtable_mm.h > +++ b/arch/m68k/include/asm/pgtable_mm.h > @@ -72,7 +72,6 @@ > #define PTRS_PER_PGD 128 > #endif > #define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE) > -#define FIRST_USER_ADDRESS 0UL > > /* Virtual address region for use by kernel_map() */ > #ifdef CONFIG_SUN3 > diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h > index 9ae8d2c17dd5..71cd547655d9 100644 > --- a/arch/microblaze/include/asm/pgtable.h > +++ b/arch/microblaze/include/asm/pgtable.h > @@ -25,8 +25,6 @@ extern int mem_init_done; > #include <asm/mmu.h> > #include <asm/page.h> > > -#define FIRST_USER_ADDRESS 0UL > - > extern unsigned long va_to_phys(unsigned long address); > extern pte_t *va_to_pte(unsigned long address); > > diff --git a/arch/mips/include/asm/pgtable-32.h b/arch/mips/include/asm/pgtable-32.h > index 6c0532d7b211..95df9c293d8d 100644 > --- a/arch/mips/include/asm/pgtable-32.h > +++ b/arch/mips/include/asm/pgtable-32.h > @@ -93,7 +93,6 @@ extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1, > #endif > > #define USER_PTRS_PER_PGD (0x80000000UL/PGDIR_SIZE) > -#define FIRST_USER_ADDRESS 0UL > > #define VMALLOC_START MAP_BASE > > diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h > index 1e7d6ce9d8d6..046465906c82 100644 > --- a/arch/mips/include/asm/pgtable-64.h > +++ b/arch/mips/include/asm/pgtable-64.h > @@ -137,7 +137,6 @@ > #define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t)) > > #define USER_PTRS_PER_PGD ((TASK_SIZE64 / PGDIR_SIZE)?(TASK_SIZE64 / PGDIR_SIZE):1) > -#define FIRST_USER_ADDRESS 0UL > > /* > * TLB refill handlers also map the vmalloc area into xuseg. Avoid > diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h > index 2600d76c310c..4a995fa628ee 100644 > --- a/arch/nios2/include/asm/pgtable.h > +++ b/arch/nios2/include/asm/pgtable.h > @@ -24,8 +24,6 @@ > #include <asm/pgtable-bits.h> > #include <asm-generic/pgtable-nopmd.h> > > -#define FIRST_USER_ADDRESS 0UL > - > #define VMALLOC_START CONFIG_NIOS2_KERNEL_MMU_REGION_BASE > #define VMALLOC_END (CONFIG_NIOS2_KERNEL_REGION_BASE - 1) > > diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h > index 9425bedab4fc..4ac591c9ca33 100644 > --- a/arch/openrisc/include/asm/pgtable.h > +++ b/arch/openrisc/include/asm/pgtable.h > @@ -73,7 +73,6 @@ extern void paging_init(void); > */ > > #define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE) > -#define FIRST_USER_ADDRESS 0UL > > /* > * Kernels own virtual memory area. > diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h > index 39017210dbf0..7f33c29764cc 100644 > --- a/arch/parisc/include/asm/pgtable.h > +++ b/arch/parisc/include/asm/pgtable.h > @@ -171,8 +171,6 @@ static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr) > * pgd entries used up by user/kernel: > */ > > -#define FIRST_USER_ADDRESS 0UL > - > /* NB: The tlb miss handlers make certain assumptions about the order */ > /* of the following bits, so be careful (One example, bits 25-31 */ > /* are moved together in one instruction). */ > diff --git a/arch/powerpc/include/asm/book3s/pgtable.h b/arch/powerpc/include/asm/book3s/pgtable.h > index 0e1263455d73..ad130e15a126 100644 > --- a/arch/powerpc/include/asm/book3s/pgtable.h > +++ b/arch/powerpc/include/asm/book3s/pgtable.h > @@ -8,7 +8,6 @@ > #include <asm/book3s/32/pgtable.h> > #endif > > -#define FIRST_USER_ADDRESS 0UL > #ifndef __ASSEMBLY__ > /* Insert a PTE, top-level function is out of line. It uses an inline > * low level function in the respective pgtable-* files > diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h > index 96522f7f0618..f06ae00f2a65 100644 > --- a/arch/powerpc/include/asm/nohash/32/pgtable.h > +++ b/arch/powerpc/include/asm/nohash/32/pgtable.h > @@ -54,7 +54,6 @@ extern int icache_44x_need_flush; > #define PGD_MASKED_BITS 0 > > #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) > -#define FIRST_USER_ADDRESS 0UL > > #define pte_ERROR(e) \ > pr_err("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \ > diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h > index 6cb8aa357191..e40fb54af7ef 100644 > --- a/arch/powerpc/include/asm/nohash/64/pgtable.h > +++ b/arch/powerpc/include/asm/nohash/64/pgtable.h > @@ -10,8 +10,6 @@ > #include <asm/barrier.h> > #include <asm/asm-const.h> > > -#define FIRST_USER_ADDRESS 0UL > - > /* > * Size of EA range mapped by our pagetables. > */ > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index ebf817c1bdf4..1893dc9f0974 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -490,8 +490,6 @@ void setup_bootmem(void); > void paging_init(void); > void misc_mem_init(void); > > -#define FIRST_USER_ADDRESS 0 > - > /* > * ZERO_PAGE is a global shared page that is always zero, > * used for zero-mapped memory areas, etc. > diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h > index 29c7ecd5ad1d..4ee49bb98f34 100644 > --- a/arch/s390/include/asm/pgtable.h > +++ b/arch/s390/include/asm/pgtable.h > @@ -65,8 +65,6 @@ extern unsigned long zero_page_mask; > > /* TODO: s390 cannot support io_remap_pfn_range... */ > > -#define FIRST_USER_ADDRESS 0UL > - > #define pte_ERROR(e) \ > printk("%s:%d: bad pte %p.\n", __FILE__, __LINE__, (void *) pte_val(e)) > #define pmd_ERROR(e) \ > diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h > index 27751e9470df..d7ddb1ec86a0 100644 > --- a/arch/sh/include/asm/pgtable.h > +++ b/arch/sh/include/asm/pgtable.h > @@ -59,8 +59,6 @@ static inline unsigned long long neff_sign_extend(unsigned long val) > /* Entries per level */ > #define PTRS_PER_PTE (PAGE_SIZE / (1 << PTE_MAGNITUDE)) > > -#define FIRST_USER_ADDRESS 0UL > - > #define PHYS_ADDR_MASK29 0x1fffffff > #define PHYS_ADDR_MASK32 0xffffffff > > diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h > index 632cdb959542..a732961da91d 100644 > --- a/arch/sparc/include/asm/pgtable_32.h > +++ b/arch/sparc/include/asm/pgtable_32.h > @@ -48,7 +48,6 @@ unsigned long __init bootmem_init(unsigned long *pages_avail); > #define PTRS_PER_PMD 64 > #define PTRS_PER_PGD 256 > #define USER_PTRS_PER_PGD PAGE_OFFSET / PGDIR_SIZE > -#define FIRST_USER_ADDRESS 0UL > #define PTE_SIZE (PTRS_PER_PTE*4) > > #define PAGE_NONE SRMMU_PAGE_NONE > diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h > index 550d3904de65..57460b7ada7b 100644 > --- a/arch/sparc/include/asm/pgtable_64.h > +++ b/arch/sparc/include/asm/pgtable_64.h > @@ -95,9 +95,6 @@ bool kern_addr_valid(unsigned long addr); > #define PTRS_PER_PUD (1UL << PUD_BITS) > #define PTRS_PER_PGD (1UL << PGDIR_BITS) > > -/* Kernel has a separate 44bit address space. */ > -#define FIRST_USER_ADDRESS 0UL > - > #define pmd_ERROR(e) \ > pr_err("%s:%d: bad pmd %p(%016lx) seen at (%pS)\n", \ > __FILE__, __LINE__, &(e), pmd_val(e), __builtin_return_address(0)) > diff --git a/arch/um/include/asm/pgtable-2level.h b/arch/um/include/asm/pgtable-2level.h > index 32106d31e4ab..8256ecc5b919 100644 > --- a/arch/um/include/asm/pgtable-2level.h > +++ b/arch/um/include/asm/pgtable-2level.h > @@ -23,7 +23,6 @@ > #define PTRS_PER_PTE 1024 > #define USER_PTRS_PER_PGD ((TASK_SIZE + (PGDIR_SIZE - 1)) / PGDIR_SIZE) > #define PTRS_PER_PGD 1024 > -#define FIRST_USER_ADDRESS 0UL > > #define pte_ERROR(e) \ > printk("%s:%d: bad pte %p(%08lx).\n", __FILE__, __LINE__, &(e), \ > diff --git a/arch/um/include/asm/pgtable-3level.h b/arch/um/include/asm/pgtable-3level.h > index 7e6a4180db9d..9289a86643a9 100644 > --- a/arch/um/include/asm/pgtable-3level.h > +++ b/arch/um/include/asm/pgtable-3level.h > @@ -41,7 +41,6 @@ > #endif > > #define USER_PTRS_PER_PGD ((TASK_SIZE + (PGDIR_SIZE - 1)) / PGDIR_SIZE) > -#define FIRST_USER_ADDRESS 0UL > > #define pte_ERROR(e) \ > printk("%s:%d: bad pte %p(%016lx).\n", __FILE__, __LINE__, &(e), \ > diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h > index f24d7ef8fffa..40497a9020c6 100644 > --- a/arch/x86/include/asm/pgtable_types.h > +++ b/arch/x86/include/asm/pgtable_types.h > @@ -7,8 +7,6 @@ > > #include <asm/page_types.h> > > -#define FIRST_USER_ADDRESS 0UL > - > #define _PAGE_BIT_PRESENT 0 /* is present */ > #define _PAGE_BIT_RW 1 /* writeable */ > #define _PAGE_BIT_USER 2 /* userspace addressable */ > diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h > index 4dc04e6c01d7..38aa57e34390 100644 > --- a/arch/xtensa/include/asm/pgtable.h > +++ b/arch/xtensa/include/asm/pgtable.h > @@ -59,7 +59,6 @@ > #define PTRS_PER_PGD 1024 > #define PGD_ORDER 0 > #define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE) > -#define FIRST_USER_ADDRESS 0UL > #define FIRST_USER_PGD_NR (FIRST_USER_ADDRESS >> PGDIR_SHIFT) > > #ifdef CONFIG_MMU > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index 5e772392a379..2fddfb188460 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -28,6 +28,15 @@ > #define USER_PGTABLES_CEILING 0UL > #endif > > +/* > + * This defines the first usable user address. Platforms > + * can override its value with custom FIRST_USER_ADDRESS > + * defined in their respective <asm/pgtable.h>. > + */ > +#ifndef FIRST_USER_ADDRESS > +#define FIRST_USER_ADDRESS 0UL > +#endif > + > /* > * A page table page can be thought of an array like this: pXd_t[PTRS_PER_PxD] > * > -- > 2.20.1 > -- Best Regards Guo Ren ML: https://lore.kernel.org/linux-csky/
