On Thu, Feb 11, 2016 at 6:06 PM, Andrew Donnellan
<andrew.donnel...@au1.ibm.com> wrote:
> Currently, the OPAL msglog/console buffer is exposed as a sysfs file, with
> the sysfs read handler responsible for retrieving the log from the OPAL
> buffer. We'd like to be able to use it in xmon as well.
>
> Refactor the OPAL msglog code to create a new function, opal_msglog_copy(),
> that copies to an arbitrary buffer. Separate the initialisation code into
> generic memcons init and sysfs file creation.
>
> Signed-off-by: Andrew Donnellan <andrew.donnel...@au1.ibm.com>
Reviewed-by: Joel Stanley <j...@jms.id.au>
>
> ---
>
> Changes V2->V3:
> - incorporate comments from Joel Stanley
> - opal_msglog_sysfs_init() now bails out if opal_memcons isn't set
>
> Changes V1->V2:
> - Incorporate comments from mpe
> - Move the memcons pointer out of the bin_attribute struct
> - Decouple memcons init from sysfs init
> ---
> arch/powerpc/include/asm/opal.h | 3 +++
> arch/powerpc/platforms/powernv/opal-msglog.c | 34
> ++++++++++++++++++++--------
> arch/powerpc/platforms/powernv/opal.c | 7 ++++--
> 3 files changed, 32 insertions(+), 12 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
> index 07a99e6..9d86c66 100644
> --- a/arch/powerpc/include/asm/opal.h
> +++ b/arch/powerpc/include/asm/opal.h
> @@ -248,6 +248,7 @@ extern int opal_elog_init(void);
> extern void opal_platform_dump_init(void);
> extern void opal_sys_param_init(void);
> extern void opal_msglog_init(void);
> +extern void opal_msglog_sysfs_init(void);
> extern int opal_async_comp_init(void);
> extern int opal_sensor_init(void);
> extern int opal_hmi_handler_init(void);
> @@ -273,6 +274,8 @@ void opal_free_sg_list(struct opal_sg_list *sg);
>
> extern int opal_error_code(int rc);
>
> +ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count);
> +
> #endif /* __ASSEMBLY__ */
>
> #endif /* _ASM_POWERPC_OPAL_H */
> diff --git a/arch/powerpc/platforms/powernv/opal-msglog.c
> b/arch/powerpc/platforms/powernv/opal-msglog.c
> index 44ed78a..c7a8f72 100644
> --- a/arch/powerpc/platforms/powernv/opal-msglog.c
> +++ b/arch/powerpc/platforms/powernv/opal-msglog.c
> @@ -31,26 +31,25 @@ struct memcons {
> __be32 in_cons;
> };
>
> -static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj,
> - struct bin_attribute *bin_attr, char *to,
> - loff_t pos, size_t count)
> +static struct memcons *opal_memcons = NULL;
> +
> +ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count)
> {
> - struct memcons *mc = bin_attr->private;
> const char *conbuf;
> ssize_t ret;
> size_t first_read = 0;
> uint32_t out_pos, avail;
>
> - if (!mc)
> + if (!opal_memcons)
> return -ENODEV;
>
> - out_pos = be32_to_cpu(ACCESS_ONCE(mc->out_pos));
> + out_pos = be32_to_cpu(ACCESS_ONCE(opal_memcons->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(mc->obuf_phys));
> + conbuf = phys_to_virt(be64_to_cpu(opal_memcons->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
> @@ -58,7 +57,7 @@ static ssize_t opal_msglog_read(struct file *file, struct
> kobject *kobj,
> if (out_pos & MEMCONS_OUT_POS_WRAP) {
>
> out_pos &= MEMCONS_OUT_POS_MASK;
> - avail = be32_to_cpu(mc->obuf_size) - out_pos;
> + avail = be32_to_cpu(opal_memcons->obuf_size) - out_pos;
>
> ret = memory_read_from_buffer(to, count, &pos,
> conbuf + out_pos, avail);
> @@ -76,7 +75,7 @@ static ssize_t opal_msglog_read(struct file *file, struct
> kobject *kobj,
> }
>
> /* Sanity check. The firmware should not do this to us. */
> - if (out_pos > be32_to_cpu(mc->obuf_size)) {
> + if (out_pos > be32_to_cpu(opal_memcons->obuf_size)) {
> pr_err("OPAL: memory console corruption. Aborting read.\n");
> return -EINVAL;
> }
> @@ -91,6 +90,13 @@ out:
> return ret;
> }
>
> +static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj,
> + 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},
> .read = opal_msglog_read
> @@ -117,8 +123,16 @@ void __init opal_msglog_init(void)
> return;
> }
>
> - opal_msglog_attr.private = mc;
> + opal_memcons = mc;
> +}
>
> +void __init opal_msglog_sysfs_init(void)
> +{
> + if (!opal_memcons) {
> + pr_warn("OPAL: message log initialisation failed, not
> creating sysfs entry\n");
> + return;
> + }
> +
> if (sysfs_create_bin_file(opal_kobj, &opal_msglog_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 4e0da5a..0256d07 100644
> --- a/arch/powerpc/platforms/powernv/opal.c
> +++ b/arch/powerpc/platforms/powernv/opal.c
> @@ -724,6 +724,9 @@ static int __init opal_init(void)
> of_node_put(leds);
> }
>
> + /* Initialise OPAL message log interface */
> + opal_msglog_init();
> +
> /* Create "opal" kobject under /sys/firmware */
> rc = opal_sysfs_init();
> if (rc == 0) {
> @@ -739,8 +742,8 @@ static int __init opal_init(void)
> opal_platform_dump_init();
> /* Setup system parameters interface */
> opal_sys_param_init();
> - /* Setup message log interface. */
> - opal_msglog_init();
> + /* Setup message log sysfs interface. */
> + opal_msglog_sysfs_init();
> }
>
> /* Initialize platform devices: IPMI backend, PRD & flash interface */
> --
> Andrew Donnellan Software Engineer, OzLabs
> andrew.donnel...@au1.ibm.com Australia Development Lab, Canberra
> +61 2 6201 8874 (work) IBM Australia Limited
>
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