Joel Stanley <j...@jms.id.au> writes: > OPAL provides an in-memory circular buffer containing a message log > populated with various runtime messages produced by the firmware. > > Provide a sysfs interface /sys/firmware/opal/messages for userspace to > view the messages.
Acked-by: Stewart Smith <stew...@linux.vnet.ibm.com> > Signed-off-by: Joel Stanley <j...@jms.id.au> > --- > arch/powerpc/include/asm/opal.h | 4 ++ > arch/powerpc/platforms/powernv/Makefile | 1 + > arch/powerpc/platforms/powernv/opal-messages.c | 97 > ++++++++++++++++++++++++++ > arch/powerpc/platforms/powernv/opal.c | 4 +- > 4 files changed, 105 insertions(+), 1 deletion(-) > create mode 100644 arch/powerpc/platforms/powernv/opal-messages.c > > diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h > index ffafab0..6aa757e 100644 > --- a/arch/powerpc/include/asm/opal.h > +++ b/arch/powerpc/include/asm/opal.h > @@ -729,6 +729,9 @@ typedef struct oppanel_line { > /* /sys/firmware/opal */ > extern struct kobject *opal_kobj; > > +/* /ibm,opal */ > +extern struct device_node *opal_node; > + > /* API functions */ > int64_t opal_console_write(int64_t term_number, __be64 *length, > const uint8_t *buffer); > @@ -918,6 +921,7 @@ extern void opal_flash_init(void); > extern int opal_elog_init(void); > extern void opal_platform_dump_init(void); > extern void opal_sys_param_init(void); > +extern void opal_messages_init(void); > > extern int opal_machine_check(struct pt_regs *regs); > extern bool opal_mce_check_early_recovery(struct pt_regs *regs); > diff --git a/arch/powerpc/platforms/powernv/Makefile > b/arch/powerpc/platforms/powernv/Makefile > index f324ea0..e2ba418 100644 > --- a/arch/powerpc/platforms/powernv/Makefile > +++ b/arch/powerpc/platforms/powernv/Makefile > @@ -1,6 +1,7 @@ > obj-y += setup.o opal-takeover.o opal-wrappers.o > opal.o opal-async.o > obj-y += opal-rtc.o opal-nvram.o opal-lpc.o > opal-flash.o > obj-y += rng.o opal-elog.o opal-dump.o > opal-sysparam.o opal-sensor.o > +obj-y += opal-messages.o > > obj-$(CONFIG_SMP) += smp.o > obj-$(CONFIG_PCI) += pci.o pci-p5ioc2.o pci-ioda.o > diff --git a/arch/powerpc/platforms/powernv/opal-messages.c > b/arch/powerpc/platforms/powernv/opal-messages.c > new file mode 100644 > index 0000000..3a863e8 > --- /dev/null > +++ b/arch/powerpc/platforms/powernv/opal-messages.c > @@ -0,0 +1,97 @@ > +/* > + * 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> > +#include <asm/opal.h> > +#include <linux/debugfs.h> > +#include <linux/of.h> > +#include <linux/types.h> > + > +/* OPAL in-memory console. Defined in OPAL source at core/console.c */ > +struct memcons { > + __be64 magic; > +#define MEMCONS_MAGIC 0x6630696567726173L > + __be64 obuf_phys; > + __be64 ibuf_phys; > + __be32 obuf_size; > + __be32 ibuf_size; > + __be32 out_pos; > +#define MEMCONS_OUT_POS_WRAP 0x80000000u > +#define MEMCONS_OUT_POS_MASK 0x00ffffffu > + __be32 in_prod; > + __be32 in_cons; > +}; > + > +static ssize_t opal_messages_read(struct file *file, struct kobject *kobj, > + struct bin_attribute *bin_attr, char *to, loff_t pos, size_t count) > +{ > + struct memcons *mc = bin_attr->private; > + const char *conbuf; > + bool wrapped; > + size_t num_read; > + int out_pos; > + > + if (!mc) > + return -ENODEV; > + > + conbuf = phys_to_virt(be64_to_cpu(mc->obuf_phys)); > + wrapped = be32_to_cpu(mc->out_pos) & MEMCONS_OUT_POS_WRAP; > + out_pos = be32_to_cpu(mc->out_pos) & MEMCONS_OUT_POS_MASK; > + > + if (!wrapped) { > + num_read = memory_read_from_buffer(to, count, &pos, conbuf, > + out_pos); > + } else { > + num_read = memory_read_from_buffer(to, count, &pos, > + conbuf + out_pos, > + be32_to_cpu(mc->obuf_size) - out_pos); > + > + if (num_read < 0) > + goto out; > + > + num_read += memory_read_from_buffer(to + num_read, > + count - num_read, &pos, conbuf, out_pos); > + } > +out: > + return num_read; > +} > + > +static struct bin_attribute messages_attr = { > + .attr = {.name = "messages", .mode = 0444}, > + .read = opal_messages_read > +}; > + > +void __init opal_messages_init(void) > +{ > + 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; > + } > + > + mc = phys_to_virt(mcaddr); > + if (!mc) { > + pr_warn("OPAL: memory console address is invalid\n"); > + return; > + } > + > + if (be64_to_cpu(mc->magic) != MEMCONS_MAGIC) { > + pr_warn("OPAL: memory console version is invalid\n"); > + return; > + } > + > + messages_attr.private = mc; > + > + if (sysfs_create_bin_file(opal_kobj, &messages_attr) != 0) > + pr_warn("OPAL: sysfs file creation failed\n"); > +} > diff --git a/arch/powerpc/platforms/powernv/opal.c > b/arch/powerpc/platforms/powernv/opal.c > index e92f2f6..2bc032a 100644 > --- a/arch/powerpc/platforms/powernv/opal.c > +++ b/arch/powerpc/platforms/powernv/opal.c > @@ -46,7 +46,7 @@ struct mcheck_recoverable_range { > static struct mcheck_recoverable_range *mc_recoverable_range; > static int mc_recoverable_range_len; > > -static struct device_node *opal_node; > +struct device_node *opal_node; > static DEFINE_SPINLOCK(opal_write_lock); > extern u64 opal_mc_secondary_handler[]; > static unsigned int *opal_irqs; > @@ -574,6 +574,8 @@ static int __init opal_init(void) > opal_platform_dump_init(); > /* Setup system parameters interface */ > opal_sys_param_init(); > + /* Setup message log interface. */ > + opal_messages_init(); > } > > return 0; > -- > 1.9.1 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev