diff options
Diffstat (limited to 'arch/powerpc/platforms/powernv/opal-msglog.c')
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal-msglog.c | 71 |
1 files changed, 45 insertions, 26 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-msglog.c b/arch/powerpc/platforms/powernv/opal-msglog.c index 7a9cde0cfbd1..992a6b379a66 100644 --- a/arch/powerpc/platforms/powernv/opal-msglog.c +++ b/arch/powerpc/platforms/powernv/opal-msglog.c @@ -1,12 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * PowerNV OPAL in-memory console interface * * Copyright 2014 IBM Corp. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. */ #include <asm/io.h> @@ -16,6 +12,8 @@ #include <linux/types.h> #include <asm/barrier.h> +#include "powernv.h" + /* OPAL in-memory console. Defined in OPAL source at core/console.c */ struct memcons { __be64 magic; @@ -33,23 +31,23 @@ struct memcons { static struct memcons *opal_memcons = NULL; -ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count) +ssize_t memcons_copy(struct memcons *mc, char *to, loff_t pos, size_t count) { const char *conbuf; ssize_t ret; size_t first_read = 0; uint32_t out_pos, avail; - if (!opal_memcons) + if (!mc) return -ENODEV; - out_pos = be32_to_cpu(ACCESS_ONCE(opal_memcons->out_pos)); + out_pos = be32_to_cpu(READ_ONCE(mc->out_pos)); /* Now we've read out_pos, put a barrier in before reading the new * data it points to in conbuf. */ smp_rmb(); - conbuf = phys_to_virt(be64_to_cpu(opal_memcons->obuf_phys)); + conbuf = phys_to_virt(be64_to_cpu(mc->obuf_phys)); /* When the buffer has wrapped, read from the out_pos marker to the end * of the buffer, and then read the remaining data as in the un-wrapped @@ -57,7 +55,7 @@ ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count) if (out_pos & MEMCONS_OUT_POS_WRAP) { out_pos &= MEMCONS_OUT_POS_MASK; - avail = be32_to_cpu(opal_memcons->obuf_size) - out_pos; + avail = be32_to_cpu(mc->obuf_size) - out_pos; ret = memory_read_from_buffer(to, count, &pos, conbuf + out_pos, avail); @@ -75,7 +73,7 @@ ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count) } /* Sanity check. The firmware should not do this to us. */ - if (out_pos > be32_to_cpu(opal_memcons->obuf_size)) { + if (out_pos > be32_to_cpu(mc->obuf_size)) { pr_err("OPAL: memory console corruption. Aborting read.\n"); return -EINVAL; } @@ -90,44 +88,65 @@ out: return ret; } +ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count) +{ + return memcons_copy(opal_memcons, to, pos, count); +} + static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj, - struct bin_attribute *bin_attr, char *to, + const struct bin_attribute *bin_attr, char *to, loff_t pos, size_t count) { return opal_msglog_copy(to, pos, count); } -static struct bin_attribute opal_msglog_attr = { - .attr = {.name = "msglog", .mode = 0444}, +static struct bin_attribute opal_msglog_attr __ro_after_init = { + .attr = {.name = "msglog", .mode = 0400}, .read = opal_msglog_read }; -void __init opal_msglog_init(void) +struct memcons *__init memcons_init(struct device_node *node, const char *mc_prop_name) { u64 mcaddr; struct memcons *mc; - if (of_property_read_u64(opal_node, "ibm,opal-memcons", &mcaddr)) { - pr_warn("OPAL: Property ibm,opal-memcons not found, no message log\n"); - return; + if (of_property_read_u64(node, mc_prop_name, &mcaddr)) { + pr_warn("%s property not found, no message log\n", + mc_prop_name); + goto out_err; } mc = phys_to_virt(mcaddr); if (!mc) { - pr_warn("OPAL: memory console address is invalid\n"); - return; + pr_warn("memory console address is invalid\n"); + goto out_err; } if (be64_to_cpu(mc->magic) != MEMCONS_MAGIC) { - pr_warn("OPAL: memory console version is invalid\n"); - return; + pr_warn("memory console version is invalid\n"); + goto out_err; } - /* Report maximum size */ - opal_msglog_attr.size = be32_to_cpu(mc->ibuf_size) + - be32_to_cpu(mc->obuf_size); + return mc; + +out_err: + return NULL; +} + +u32 __init memcons_get_size(struct memcons *mc) +{ + return be32_to_cpu(mc->ibuf_size) + be32_to_cpu(mc->obuf_size); +} + +void __init opal_msglog_init(void) +{ + opal_memcons = memcons_init(opal_node, "ibm,opal-memcons"); + if (!opal_memcons) { + pr_warn("OPAL: memcons failed to load from ibm,opal-memcons\n"); + return; + } - opal_memcons = mc; + opal_msglog_attr.size = memcons_get_size(opal_memcons); } void __init opal_msglog_sysfs_init(void) |