mm: define default value for FIRST_USER_ADDRESS

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>.

Link: https://lkml.kernel.org/r/1620615725-24623-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Acked-by: Guo Ren <guoren@kernel.org>			[csky]
Acked-by: Stafford Horne <shorne@gmail.com>		[openrisc]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>	[RISC-V]
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h
index e1757b7..ff69084 100644 (file)
--- 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 5878846..577682e 100644 (file)
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -222,12 +222,6 @@
  */
 #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 0b10204..25f5c04 100644 (file)
--- 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 0d60367..151607e 100644 (file)
--- 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 dbb22b8..e497950 100644 (file)
--- 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 d765fd9..3f5dbbd 100644 (file)
--- 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 aca22c2..143ba7d 100644 (file)
--- 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 9ae8d2c..71cd547 100644 (file)
--- 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 6c0532d..95df9c2 100644 (file)
--- 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 1e7d6ce..0464659 100644 (file)
--- 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 2600d76..4a995fa 100644 (file)
--- 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 9425bed..4ac591c 100644 (file)
--- 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 3901721..7f33c29 100644 (file)
--- 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 0e12634..ad130e1 100644 (file)
--- 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 96522f7..f06ae00 100644 (file)
--- 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 57cd389..53fbfdf 100644 (file)
--- a/arch/powerpc/include/asm/nohash/64/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable.h
@@ -12,8 +12,6 @@
 #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 380cd3a..62f3fe7 100644 (file)
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -536,8 +536,6 @@ 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 b38f7b7..7c86bf0 100644 (file)
--- 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 27751e9..d7ddb1e 100644 (file)
--- 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 a5cf79c..0888bda 100644 (file)
--- 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 2cd80a0..a400e0f 100644 (file)
--- 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 32106d3..8256ecc 100644 (file)
--- 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 7e6a418..9289a86 100644 (file)
--- 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 f24d7ef..40497a9 100644 (file)
--- 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 d7fc45c..bd5aeb7 100644 (file)
--- 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 2b0d022..69700e3 100644 (file)
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -29,6 +29,15 @@
 #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]
  *
  * The pXx_index() functions return the index of the entry in the page