| Andres Salomon | fd699c7 | 2010-06-18 17:46:53 -0400 | [diff] [blame^] | 1 | #include <linux/kernel.h> |
| 2 | #include <linux/module.h> |
| 3 | #include <linux/init.h> |
| 4 | #include <asm/page.h> |
| 5 | #include <asm/setup.h> |
| 6 | #include <asm/io.h> |
| 7 | #include <asm/pgtable.h> |
| 8 | #include <asm/olpc_ofw.h> |
| 9 | |
| 10 | /* address of OFW callback interface; will be NULL if OFW isn't found */ |
| 11 | static int (*olpc_ofw_cif)(int *); |
| 12 | |
| 13 | /* page dir entry containing OFW's pgdir table; filled in by head_32.S */ |
| 14 | u32 olpc_ofw_pgd __initdata; |
| 15 | |
| 16 | static DEFINE_SPINLOCK(ofw_lock); |
| 17 | |
| 18 | #define MAXARGS 10 |
| 19 | |
| 20 | void __init setup_olpc_ofw_pgd(void) |
| 21 | { |
| 22 | pgd_t *base, *ofw_pde; |
| 23 | |
| 24 | if (!olpc_ofw_cif) |
| 25 | return; |
| 26 | |
| 27 | /* fetch OFW's PDE */ |
| 28 | base = early_ioremap(olpc_ofw_pgd, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD); |
| 29 | if (!base) { |
| 30 | printk(KERN_ERR "failed to remap OFW's pgd - disabling OFW!\n"); |
| 31 | olpc_ofw_cif = NULL; |
| 32 | return; |
| 33 | } |
| 34 | ofw_pde = &base[OLPC_OFW_PDE_NR]; |
| 35 | |
| 36 | /* install OFW's PDE permanently into the kernel's pgtable */ |
| 37 | set_pgd(&swapper_pg_dir[OLPC_OFW_PDE_NR], *ofw_pde); |
| 38 | early_iounmap(base, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD); |
| 39 | } |
| 40 | |
| 41 | int __olpc_ofw(const char *name, int nr_args, void **args, int nr_res, |
| 42 | void **res) |
| 43 | { |
| 44 | int ofw_args[MAXARGS + 3]; |
| 45 | unsigned long flags; |
| 46 | int ret, i, *p; |
| 47 | |
| 48 | BUG_ON(nr_args + nr_res > MAXARGS); |
| 49 | |
| 50 | if (!olpc_ofw_cif) |
| 51 | return -EIO; |
| 52 | |
| 53 | ofw_args[0] = (int)name; |
| 54 | ofw_args[1] = nr_args; |
| 55 | ofw_args[2] = nr_res; |
| 56 | |
| 57 | p = &ofw_args[3]; |
| 58 | for (i = 0; i < nr_args; i++, p++) |
| 59 | *p = (int)args[i]; |
| 60 | |
| 61 | /* call into ofw */ |
| 62 | spin_lock_irqsave(&ofw_lock, flags); |
| 63 | ret = olpc_ofw_cif(ofw_args); |
| 64 | spin_unlock_irqrestore(&ofw_lock, flags); |
| 65 | |
| 66 | if (!ret) { |
| 67 | for (i = 0; i < nr_res; i++, p++) |
| 68 | *((int *)res[i]) = *p; |
| 69 | } |
| 70 | |
| 71 | return ret; |
| 72 | } |
| 73 | EXPORT_SYMBOL_GPL(__olpc_ofw); |
| 74 | |
| 75 | /* OFW cif _should_ be above this address */ |
| 76 | #define OFW_MIN 0xff000000 |
| 77 | |
| 78 | /* OFW starts on a 1MB boundary */ |
| 79 | #define OFW_BOUND (1<<20) |
| 80 | |
| 81 | void __init olpc_ofw_detect(void) |
| 82 | { |
| 83 | struct olpc_ofw_header *hdr = &boot_params.olpc_ofw_header; |
| 84 | unsigned long start; |
| 85 | |
| 86 | /* ensure OFW booted us by checking for "OFW " string */ |
| 87 | if (hdr->ofw_magic != OLPC_OFW_SIG) |
| 88 | return; |
| 89 | |
| 90 | olpc_ofw_cif = (int (*)(int *))hdr->cif_handler; |
| 91 | |
| 92 | if ((unsigned long)olpc_ofw_cif < OFW_MIN) { |
| 93 | printk(KERN_ERR "OFW detected, but cif has invalid address 0x%lx - disabling.\n", |
| 94 | (unsigned long)olpc_ofw_cif); |
| 95 | olpc_ofw_cif = NULL; |
| 96 | return; |
| 97 | } |
| 98 | |
| 99 | /* determine where OFW starts in memory */ |
| 100 | start = round_down((unsigned long)olpc_ofw_cif, OFW_BOUND); |
| 101 | printk(KERN_INFO "OFW detected in memory, cif @ 0x%lx (reserving top %ldMB)\n", |
| 102 | (unsigned long)olpc_ofw_cif, (-start) >> 20); |
| 103 | reserve_top_address(-start); |
| 104 | } |