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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 | // SPDX-License-Identifier: GPL-2.0-or-later /* * PowerNV nvram code. * * Copyright 2011 IBM Corp. */ #define DEBUG #include <linux/delay.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/of.h> #include <asm/opal.h> #include <asm/nvram.h> #include <asm/machdep.h> static unsigned int nvram_size; static ssize_t opal_nvram_size(void) { return nvram_size; } static ssize_t opal_nvram_read(char *buf, size_t count, loff_t *index) { s64 rc; int off; if (*index >= nvram_size) return 0; off = *index; if ((off + count) > nvram_size) count = nvram_size - off; rc = opal_read_nvram(__pa(buf), count, off); if (rc != OPAL_SUCCESS) return -EIO; *index += count; return count; } /* * This can be called in the panic path with interrupts off, so use * mdelay in that case. */ static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index) { s64 rc = OPAL_BUSY; int off; if (*index >= nvram_size) return 0; off = *index; if ((off + count) > nvram_size) count = nvram_size - off; while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { rc = opal_write_nvram(__pa(buf), count, off); if (rc == OPAL_BUSY_EVENT) { if (in_interrupt() || irqs_disabled()) mdelay(OPAL_BUSY_DELAY_MS); else msleep(OPAL_BUSY_DELAY_MS); opal_poll_events(NULL); } else if (rc == OPAL_BUSY) { if (in_interrupt() || irqs_disabled()) mdelay(OPAL_BUSY_DELAY_MS); else msleep(OPAL_BUSY_DELAY_MS); } } if (rc) return -EIO; *index += count; return count; } static int __init opal_nvram_init_log_partitions(void) { /* Scan nvram for partitions */ nvram_scan_partitions(); nvram_init_oops_partition(0); return 0; } machine_arch_initcall(powernv, opal_nvram_init_log_partitions); void __init opal_nvram_init(void) { struct device_node *np; const __be32 *nbytes_p; np = of_find_compatible_node(NULL, NULL, "ibm,opal-nvram"); if (np == NULL) return; nbytes_p = of_get_property(np, "#bytes", NULL); if (!nbytes_p) { of_node_put(np); return; } nvram_size = be32_to_cpup(nbytes_p); pr_info("OPAL nvram setup, %u bytes\n", nvram_size); of_node_put(np); ppc_md.nvram_read = opal_nvram_read; ppc_md.nvram_write = opal_nvram_write; ppc_md.nvram_size = opal_nvram_size; } |