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 } 62741de617SNicholas Piggin 63741de617SNicholas Piggin if (rc) 64741de617SNicholas Piggin return -EIO; 65741de617SNicholas Piggin 66628daa8dSBenjamin Herrenschmidt *index += count; 67628daa8dSBenjamin Herrenschmidt return count; 68628daa8dSBenjamin Herrenschmidt } 69628daa8dSBenjamin Herrenschmidt 70f7618299SHari Bathini static int __init opal_nvram_init_log_partitions(void) 71f7618299SHari Bathini { 72f7618299SHari Bathini /* Scan nvram for partitions */ 73f7618299SHari Bathini nvram_scan_partitions(); 74f7618299SHari Bathini nvram_init_oops_partition(0); 75f7618299SHari Bathini return 0; 76f7618299SHari Bathini } 77f7618299SHari Bathini machine_arch_initcall(powernv, opal_nvram_init_log_partitions); 78f7618299SHari Bathini 79628daa8dSBenjamin Herrenschmidt void __init opal_nvram_init(void) 80628daa8dSBenjamin Herrenschmidt { 81628daa8dSBenjamin Herrenschmidt struct device_node *np; 8281063cddSBenjamin Herrenschmidt const __be32 *nbytes_p; 83628daa8dSBenjamin Herrenschmidt 84628daa8dSBenjamin Herrenschmidt np = of_find_compatible_node(NULL, NULL, "ibm,opal-nvram"); 85628daa8dSBenjamin Herrenschmidt if (np == NULL) 86628daa8dSBenjamin Herrenschmidt return; 87628daa8dSBenjamin Herrenschmidt 88628daa8dSBenjamin Herrenschmidt nbytes_p = of_get_property(np, "#bytes", NULL); 89628daa8dSBenjamin Herrenschmidt if (!nbytes_p) { 90628daa8dSBenjamin Herrenschmidt of_node_put(np); 91628daa8dSBenjamin Herrenschmidt return; 92628daa8dSBenjamin Herrenschmidt } 9381063cddSBenjamin Herrenschmidt nvram_size = be32_to_cpup(nbytes_p); 94628daa8dSBenjamin Herrenschmidt 959a4f5cd0SAnton Blanchard pr_info("OPAL nvram setup, %u bytes\n", nvram_size); 96628daa8dSBenjamin Herrenschmidt of_node_put(np); 97628daa8dSBenjamin Herrenschmidt 98628daa8dSBenjamin Herrenschmidt ppc_md.nvram_read = opal_nvram_read; 99628daa8dSBenjamin Herrenschmidt ppc_md.nvram_write = opal_nvram_write; 100628daa8dSBenjamin Herrenschmidt ppc_md.nvram_size = opal_nvram_size; 101628daa8dSBenjamin Herrenschmidt } 102628daa8dSBenjamin Herrenschmidt 103