arch/powerpc/kernel/proc_powerpc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen IBM Corporation
   4  */
   5
   6 #include <linux/init.h>
   7 #include <linux/memblock.h>
   8 #include <linux/mm.h>
   9 #include <linux/proc_fs.h>
  10 #include <linux/kernel.h>
  11 #include <linux/of.h>
  12
  13 #include <asm/machdep.h>
  14 #include <asm/vdso_datapage.h>
  15 #include <asm/rtas.h>
  16 #include <asm/systemcfg.h>
  17 #include <linux/uaccess.h>
  18
  19 #ifdef CONFIG_PPC64_PROC_SYSTEMCFG
  20
  21 static loff_t page_map_seek(struct file *file, loff_t off, int whence)
  22 {
  23         return fixed_size_llseek(file, off, whence, PAGE_SIZE);
  24 }
  25
  26 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
  27                               loff_t *ppos)
  28 {
  29         return simple_read_from_buffer(buf, nbytes, ppos,
  30                         pde_data(file_inode(file)), PAGE_SIZE);
  31 }
  32
  33 static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
  34 {
  35         if ((vma->vm_end - vma->vm_start) > PAGE_SIZE)
  36                 return -EINVAL;
  37
  38         return remap_pfn_range(vma, vma->vm_start,
  39                                __pa(pde_data(file_inode(file))) >> PAGE_SHIFT,
  40                                PAGE_SIZE, vma->vm_page_prot);
  41 }
  42
  43 static const struct proc_ops page_map_proc_ops = {
  44         .proc_lseek     = page_map_seek,
  45         .proc_read      = page_map_read,
  46         .proc_mmap      = page_map_mmap,
  47 };
  48
  49 static union {
  50         struct systemcfg        data;
  51         u8                      page[PAGE_SIZE];
  52 } systemcfg_data_store __page_aligned_data;
  53 struct systemcfg *systemcfg = &systemcfg_data_store.data;
  54
  55 static int __init proc_ppc64_init(void)
  56 {
  57         struct proc_dir_entry *pde;
  58
  59         strcpy((char *)systemcfg->eye_catcher, "SYSTEMCFG:PPC64");
  60         systemcfg->version.major = SYSTEMCFG_MAJOR;
  61         systemcfg->version.minor = SYSTEMCFG_MINOR;
  62         systemcfg->processor = mfspr(SPRN_PVR);
  63         /*
  64          * Fake the old platform number for pSeries and add
  65          * in LPAR bit if necessary
  66          */
  67         systemcfg->platform = 0x100;
  68         if (firmware_has_feature(FW_FEATURE_LPAR))
  69                 systemcfg->platform |= 1;
  70         systemcfg->physicalMemorySize = memblock_phys_mem_size();
  71         systemcfg->dcache_size = ppc64_caches.l1d.size;
  72         systemcfg->dcache_line_size = ppc64_caches.l1d.line_size;
  73         systemcfg->icache_size = ppc64_caches.l1i.size;
  74         systemcfg->icache_line_size = ppc64_caches.l1i.line_size;
  75
  76         pde = proc_create_data("powerpc/systemcfg", S_IFREG | 0444, NULL,
  77                                &page_map_proc_ops, systemcfg);
  78         if (!pde)
  79                 return 1;
  80         proc_set_size(pde, PAGE_SIZE);
  81
  82         return 0;
  83 }
  84 __initcall(proc_ppc64_init);
  85
  86 #endif /* CONFIG_PPC64_PROC_SYSTEMCFG */
  87
  88 /*
  89  * Create the ppc64 and ppc64/rtas directories early. This allows us to
  90  * assume that they have been previously created in drivers.
  91  */
  92 static int __init proc_ppc64_create(void)
  93 {
  94         struct proc_dir_entry *root;
  95
  96         root = proc_mkdir("powerpc", NULL);
  97         if (!root)
  98                 return 1;
  99
 100 #ifdef CONFIG_PPC64
 101         if (!proc_symlink("ppc64", NULL, "powerpc"))
 102                 pr_err("Failed to create link /proc/ppc64 -> /proc/powerpc\n");
 103 #endif
 104
 105         if (!of_find_node_by_path("/rtas"))
 106                 return 0;
 107
 108         if (!proc_mkdir("rtas", root))
 109                 return 1;
 110
 111         if (!proc_symlink("rtas", NULL, "powerpc/rtas"))
 112                 return 1;
 113
 114         return 0;
 115 }
 116 core_initcall(proc_ppc64_create);