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113 lines
2.2 KiB
113 lines
2.2 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* PowerNV nvram code. |
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* |
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* Copyright 2011 IBM Corp. |
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*/ |
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#define DEBUG |
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#include <linux/delay.h> |
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#include <linux/kernel.h> |
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#include <linux/init.h> |
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#include <linux/of.h> |
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#include <asm/opal.h> |
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#include <asm/nvram.h> |
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#include <asm/machdep.h> |
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static unsigned int nvram_size; |
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static ssize_t opal_nvram_size(void) |
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{ |
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return nvram_size; |
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} |
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static ssize_t opal_nvram_read(char *buf, size_t count, loff_t *index) |
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{ |
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s64 rc; |
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int off; |
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if (*index >= nvram_size) |
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return 0; |
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off = *index; |
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if ((off + count) > nvram_size) |
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count = nvram_size - off; |
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rc = opal_read_nvram(__pa(buf), count, off); |
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if (rc != OPAL_SUCCESS) |
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return -EIO; |
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*index += count; |
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return count; |
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} |
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/* |
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* This can be called in the panic path with interrupts off, so use |
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* mdelay in that case. |
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*/ |
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static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index) |
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{ |
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s64 rc = OPAL_BUSY; |
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int off; |
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if (*index >= nvram_size) |
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return 0; |
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off = *index; |
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if ((off + count) > nvram_size) |
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count = nvram_size - off; |
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while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { |
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rc = opal_write_nvram(__pa(buf), count, off); |
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if (rc == OPAL_BUSY_EVENT) { |
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if (in_interrupt() || irqs_disabled()) |
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mdelay(OPAL_BUSY_DELAY_MS); |
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else |
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msleep(OPAL_BUSY_DELAY_MS); |
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opal_poll_events(NULL); |
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} else if (rc == OPAL_BUSY) { |
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if (in_interrupt() || irqs_disabled()) |
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mdelay(OPAL_BUSY_DELAY_MS); |
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else |
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msleep(OPAL_BUSY_DELAY_MS); |
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} |
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} |
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if (rc) |
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return -EIO; |
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*index += count; |
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return count; |
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} |
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static int __init opal_nvram_init_log_partitions(void) |
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{ |
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/* Scan nvram for partitions */ |
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nvram_scan_partitions(); |
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nvram_init_oops_partition(0); |
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return 0; |
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} |
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machine_arch_initcall(powernv, opal_nvram_init_log_partitions); |
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void __init opal_nvram_init(void) |
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{ |
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struct device_node *np; |
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const __be32 *nbytes_p; |
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np = of_find_compatible_node(NULL, NULL, "ibm,opal-nvram"); |
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if (np == NULL) |
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return; |
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nbytes_p = of_get_property(np, "#bytes", NULL); |
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if (!nbytes_p) { |
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of_node_put(np); |
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return; |
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} |
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nvram_size = be32_to_cpup(nbytes_p); |
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pr_info("OPAL nvram setup, %u bytes\n", nvram_size); |
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of_node_put(np); |
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ppc_md.nvram_read = opal_nvram_read; |
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ppc_md.nvram_write = opal_nvram_write; |
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ppc_md.nvram_size = opal_nvram_size; |
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} |
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