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 143b807033SNicholas Piggin #include <linux/delay.h> 15628daa8dSBenjamin Herrenschmidt #include <linux/kernel.h> 16628daa8dSBenjamin Herrenschmidt #include <linux/init.h> 17628daa8dSBenjamin Herrenschmidt #include <linux/of.h> 18628daa8dSBenjamin Herrenschmidt 19628daa8dSBenjamin Herrenschmidt #include <asm/opal.h> 20f7618299SHari Bathini #include <asm/nvram.h> 21628daa8dSBenjamin Herrenschmidt #include <asm/machdep.h> 22628daa8dSBenjamin Herrenschmidt 23628daa8dSBenjamin Herrenschmidt static unsigned int nvram_size; 24628daa8dSBenjamin Herrenschmidt 25628daa8dSBenjamin Herrenschmidt static ssize_t opal_nvram_size(void) 26628daa8dSBenjamin Herrenschmidt { 27628daa8dSBenjamin Herrenschmidt return nvram_size; 28628daa8dSBenjamin Herrenschmidt } 29628daa8dSBenjamin Herrenschmidt 30628daa8dSBenjamin Herrenschmidt static ssize_t opal_nvram_read(char *buf, size_t count, loff_t *index) 31628daa8dSBenjamin Herrenschmidt { 32628daa8dSBenjamin Herrenschmidt s64 rc; 33628daa8dSBenjamin Herrenschmidt int off; 34628daa8dSBenjamin Herrenschmidt 35628daa8dSBenjamin Herrenschmidt if (*index >= nvram_size) 36628daa8dSBenjamin Herrenschmidt return 0; 37628daa8dSBenjamin Herrenschmidt off = *index; 38628daa8dSBenjamin Herrenschmidt if ((off + count) > nvram_size) 39628daa8dSBenjamin Herrenschmidt count = nvram_size - off; 40628daa8dSBenjamin Herrenschmidt rc = opal_read_nvram(__pa(buf), count, off); 41628daa8dSBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) 42628daa8dSBenjamin Herrenschmidt return -EIO; 43628daa8dSBenjamin Herrenschmidt *index += count; 44628daa8dSBenjamin Herrenschmidt return count; 45628daa8dSBenjamin Herrenschmidt } 46628daa8dSBenjamin Herrenschmidt 47c1d2a313SNicholas Piggin /* 48c1d2a313SNicholas Piggin * This can be called in the panic path with interrupts off, so use 49c1d2a313SNicholas Piggin * mdelay in that case. 50c1d2a313SNicholas Piggin */ 51628daa8dSBenjamin Herrenschmidt static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index) 52628daa8dSBenjamin Herrenschmidt { 53628daa8dSBenjamin Herrenschmidt s64 rc = OPAL_BUSY; 54628daa8dSBenjamin Herrenschmidt int off; 55628daa8dSBenjamin Herrenschmidt 56628daa8dSBenjamin Herrenschmidt if (*index >= nvram_size) 57628daa8dSBenjamin Herrenschmidt return 0; 58628daa8dSBenjamin Herrenschmidt off = *index; 59628daa8dSBenjamin Herrenschmidt if ((off + count) > nvram_size) 60628daa8dSBenjamin Herrenschmidt count = nvram_size - off; 61628daa8dSBenjamin Herrenschmidt 62628daa8dSBenjamin Herrenschmidt while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { 63628daa8dSBenjamin Herrenschmidt rc = opal_write_nvram(__pa(buf), count, off); 643b807033SNicholas Piggin if (rc == OPAL_BUSY_EVENT) { 65c1d2a313SNicholas Piggin if (in_interrupt() || irqs_disabled()) 66c1d2a313SNicholas Piggin mdelay(OPAL_BUSY_DELAY_MS); 67c1d2a313SNicholas Piggin else 683b807033SNicholas Piggin msleep(OPAL_BUSY_DELAY_MS); 69628daa8dSBenjamin Herrenschmidt opal_poll_events(NULL); 703b807033SNicholas Piggin } else if (rc == OPAL_BUSY) { 71c1d2a313SNicholas Piggin if (in_interrupt() || irqs_disabled()) 72c1d2a313SNicholas Piggin mdelay(OPAL_BUSY_DELAY_MS); 73c1d2a313SNicholas Piggin else 743b807033SNicholas Piggin msleep(OPAL_BUSY_DELAY_MS); 753b807033SNicholas Piggin } 76628daa8dSBenjamin Herrenschmidt } 77741de617SNicholas Piggin 78741de617SNicholas Piggin if (rc) 79741de617SNicholas Piggin return -EIO; 80741de617SNicholas Piggin 81628daa8dSBenjamin Herrenschmidt *index += count; 82628daa8dSBenjamin Herrenschmidt return count; 83628daa8dSBenjamin Herrenschmidt } 84628daa8dSBenjamin Herrenschmidt 85f7618299SHari Bathini static int __init opal_nvram_init_log_partitions(void) 86f7618299SHari Bathini { 87f7618299SHari Bathini /* Scan nvram for partitions */ 88f7618299SHari Bathini nvram_scan_partitions(); 89f7618299SHari Bathini nvram_init_oops_partition(0); 90f7618299SHari Bathini return 0; 91f7618299SHari Bathini } 92f7618299SHari Bathini machine_arch_initcall(powernv, opal_nvram_init_log_partitions); 93f7618299SHari Bathini 94628daa8dSBenjamin Herrenschmidt void __init opal_nvram_init(void) 95628daa8dSBenjamin Herrenschmidt { 96628daa8dSBenjamin Herrenschmidt struct device_node *np; 9781063cddSBenjamin Herrenschmidt const __be32 *nbytes_p; 98628daa8dSBenjamin Herrenschmidt 99628daa8dSBenjamin Herrenschmidt np = of_find_compatible_node(NULL, NULL, "ibm,opal-nvram"); 100628daa8dSBenjamin Herrenschmidt if (np == NULL) 101628daa8dSBenjamin Herrenschmidt return; 102628daa8dSBenjamin Herrenschmidt 103628daa8dSBenjamin Herrenschmidt nbytes_p = of_get_property(np, "#bytes", NULL); 104628daa8dSBenjamin Herrenschmidt if (!nbytes_p) { 105628daa8dSBenjamin Herrenschmidt of_node_put(np); 106628daa8dSBenjamin Herrenschmidt return; 107628daa8dSBenjamin Herrenschmidt } 10881063cddSBenjamin Herrenschmidt nvram_size = be32_to_cpup(nbytes_p); 109628daa8dSBenjamin Herrenschmidt 1109a4f5cd0SAnton Blanchard pr_info("OPAL nvram setup, %u bytes\n", nvram_size); 111628daa8dSBenjamin Herrenschmidt of_node_put(np); 112628daa8dSBenjamin Herrenschmidt 113628daa8dSBenjamin Herrenschmidt ppc_md.nvram_read = opal_nvram_read; 114628daa8dSBenjamin Herrenschmidt ppc_md.nvram_write = opal_nvram_write; 115628daa8dSBenjamin Herrenschmidt ppc_md.nvram_size = opal_nvram_size; 116628daa8dSBenjamin Herrenschmidt } 117628daa8dSBenjamin Herrenschmidt 118