1628daa8dSBenjamin Herrenschmidt /* 2628daa8dSBenjamin Herrenschmidt * PowerNV nvram code. 3628daa8dSBenjamin Herrenschmidt * 4628daa8dSBenjamin Herrenschmidt * Copyright 2011 IBM Corp. 5628daa8dSBenjamin Herrenschmidt * 6628daa8dSBenjamin Herrenschmidt * This program is free software; you can redistribute it and/or 7628daa8dSBenjamin Herrenschmidt * modify it under the terms of the GNU General Public License 8628daa8dSBenjamin Herrenschmidt * as published by the Free Software Foundation; either version 9628daa8dSBenjamin Herrenschmidt * 2 of the License, or (at your option) any later version. 10628daa8dSBenjamin Herrenschmidt */ 11628daa8dSBenjamin Herrenschmidt 12628daa8dSBenjamin Herrenschmidt #define DEBUG 13628daa8dSBenjamin Herrenschmidt 14628daa8dSBenjamin Herrenschmidt #include <linux/kernel.h> 15628daa8dSBenjamin Herrenschmidt #include <linux/init.h> 16628daa8dSBenjamin Herrenschmidt #include <linux/of.h> 17628daa8dSBenjamin Herrenschmidt 18628daa8dSBenjamin Herrenschmidt #include <asm/opal.h> 19f7618299SHari Bathini #include <asm/nvram.h> 20628daa8dSBenjamin Herrenschmidt #include <asm/machdep.h> 21628daa8dSBenjamin Herrenschmidt 22628daa8dSBenjamin Herrenschmidt static unsigned int nvram_size; 23628daa8dSBenjamin Herrenschmidt 24628daa8dSBenjamin Herrenschmidt static ssize_t opal_nvram_size(void) 25628daa8dSBenjamin Herrenschmidt { 26628daa8dSBenjamin Herrenschmidt return nvram_size; 27628daa8dSBenjamin Herrenschmidt } 28628daa8dSBenjamin Herrenschmidt 29628daa8dSBenjamin Herrenschmidt static ssize_t opal_nvram_read(char *buf, size_t count, loff_t *index) 30628daa8dSBenjamin Herrenschmidt { 31628daa8dSBenjamin Herrenschmidt s64 rc; 32628daa8dSBenjamin Herrenschmidt int off; 33628daa8dSBenjamin Herrenschmidt 34628daa8dSBenjamin Herrenschmidt if (*index >= nvram_size) 35628daa8dSBenjamin Herrenschmidt return 0; 36628daa8dSBenjamin Herrenschmidt off = *index; 37628daa8dSBenjamin Herrenschmidt if ((off + count) > nvram_size) 38628daa8dSBenjamin Herrenschmidt count = nvram_size - off; 39628daa8dSBenjamin Herrenschmidt rc = opal_read_nvram(__pa(buf), count, off); 40628daa8dSBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) 41628daa8dSBenjamin Herrenschmidt return -EIO; 42628daa8dSBenjamin Herrenschmidt *index += count; 43628daa8dSBenjamin Herrenschmidt return count; 44628daa8dSBenjamin Herrenschmidt } 45628daa8dSBenjamin Herrenschmidt 46628daa8dSBenjamin Herrenschmidt static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index) 47628daa8dSBenjamin Herrenschmidt { 48628daa8dSBenjamin Herrenschmidt s64 rc = OPAL_BUSY; 49628daa8dSBenjamin Herrenschmidt int off; 50628daa8dSBenjamin Herrenschmidt 51628daa8dSBenjamin Herrenschmidt if (*index >= nvram_size) 52628daa8dSBenjamin Herrenschmidt return 0; 53628daa8dSBenjamin Herrenschmidt off = *index; 54628daa8dSBenjamin Herrenschmidt if ((off + count) > nvram_size) 55628daa8dSBenjamin Herrenschmidt count = nvram_size - off; 56628daa8dSBenjamin Herrenschmidt 57628daa8dSBenjamin Herrenschmidt while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { 58628daa8dSBenjamin Herrenschmidt rc = opal_write_nvram(__pa(buf), count, off); 59628daa8dSBenjamin Herrenschmidt if (rc == OPAL_BUSY_EVENT) 60628daa8dSBenjamin Herrenschmidt opal_poll_events(NULL); 61628daa8dSBenjamin Herrenschmidt } 62628daa8dSBenjamin Herrenschmidt *index += count; 63628daa8dSBenjamin Herrenschmidt return count; 64628daa8dSBenjamin Herrenschmidt } 65628daa8dSBenjamin Herrenschmidt 66f7618299SHari Bathini static int __init opal_nvram_init_log_partitions(void) 67f7618299SHari Bathini { 68f7618299SHari Bathini /* Scan nvram for partitions */ 69f7618299SHari Bathini nvram_scan_partitions(); 70f7618299SHari Bathini nvram_init_oops_partition(0); 71f7618299SHari Bathini return 0; 72f7618299SHari Bathini } 73f7618299SHari Bathini machine_arch_initcall(powernv, opal_nvram_init_log_partitions); 74f7618299SHari Bathini 75628daa8dSBenjamin Herrenschmidt void __init opal_nvram_init(void) 76628daa8dSBenjamin Herrenschmidt { 77628daa8dSBenjamin Herrenschmidt struct device_node *np; 7881063cddSBenjamin Herrenschmidt const __be32 *nbytes_p; 79628daa8dSBenjamin Herrenschmidt 80628daa8dSBenjamin Herrenschmidt np = of_find_compatible_node(NULL, NULL, "ibm,opal-nvram"); 81628daa8dSBenjamin Herrenschmidt if (np == NULL) 82628daa8dSBenjamin Herrenschmidt return; 83628daa8dSBenjamin Herrenschmidt 84628daa8dSBenjamin Herrenschmidt nbytes_p = of_get_property(np, "#bytes", NULL); 85628daa8dSBenjamin Herrenschmidt if (!nbytes_p) { 86628daa8dSBenjamin Herrenschmidt of_node_put(np); 87628daa8dSBenjamin Herrenschmidt return; 88628daa8dSBenjamin Herrenschmidt } 8981063cddSBenjamin Herrenschmidt nvram_size = be32_to_cpup(nbytes_p); 90628daa8dSBenjamin Herrenschmidt 919a4f5cd0SAnton Blanchard pr_info("OPAL nvram setup, %u bytes\n", nvram_size); 92628daa8dSBenjamin Herrenschmidt of_node_put(np); 93628daa8dSBenjamin Herrenschmidt 94628daa8dSBenjamin Herrenschmidt ppc_md.nvram_read = opal_nvram_read; 95628daa8dSBenjamin Herrenschmidt ppc_md.nvram_write = opal_nvram_write; 96628daa8dSBenjamin Herrenschmidt ppc_md.nvram_size = opal_nvram_size; 97628daa8dSBenjamin Herrenschmidt } 98628daa8dSBenjamin Herrenschmidt 99