[PATCH] powerpc/powernv: add hdat attribute to sysfs
From: Matt Brown <hidden>
Date: 2017-02-23 02:30:06
From: Matt Brown <redacted> The HDAT data area is consumed by skiboot and turned into a device-tree. In some cases we would like to look directly at the HDAT, so this patch adds a sysfs node to allow it to be viewed. This is not possible through /dev/mem as it is reserved memory which is stopped by the /dev/mem filter. Signed-off-by: Matt Brown <redacted> --- arch/powerpc/include/asm/opal.h | 1 + arch/powerpc/platforms/powernv/opal-msglog.c | 49 ++++++++++++++++++++++++++++ arch/powerpc/platforms/powernv/opal.c | 2 ++ 3 files changed, 52 insertions(+)
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 5c7db0f..b26944e 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h@@ -277,6 +277,7 @@ extern int opal_async_comp_init(void); extern int opal_sensor_init(void); extern int opal_hmi_handler_init(void); extern int opal_event_init(void); +extern void opal_hdat_sysfs_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/opal-msglog.c b/arch/powerpc/platforms/powernv/opal-msglog.c
index 39d6ff9..a637055 100644
--- a/arch/powerpc/platforms/powernv/opal-msglog.c
+++ b/arch/powerpc/platforms/powernv/opal-msglog.c@@ -31,7 +31,13 @@ struct memcons { __be32 in_cons; }; +struct hdatInfo { + char *base; + u64 size; +}; + static struct memcons *opal_memcons = NULL; +static struct hdatInfo hdat_inf; ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count) {
@@ -136,3 +142,46 @@ void __init opal_msglog_sysfs_init(void) if (sysfs_create_bin_file(opal_kobj, &opal_msglog_attr) != 0) pr_warn("OPAL: sysfs file creation failed\n"); } + + + +/* Read function for HDAT attribute in sysfs */ +static ssize_t hdat_read(struct file *file, struct kobject *kobj, + struct bin_attribute *bin_attr, char *to, + loff_t pos, size_t count) +{ + if (!hdat_inf.base) + return -ENODEV; + + return memory_read_from_buffer(to, count, &pos, hdat_inf.base, + hdat_inf.size); +} + + +/* HDAT attribute for sysfs */ +static struct bin_attribute hdat_attr = { + .attr = {.name = "hdat", .mode = 0444}, + .read = hdat_read +}; + +void __init opal_hdat_sysfs_init(void) +{ + u64 hdatAddr[2]; + + /* Check for the hdat-map prop in device-tree */ + if (of_property_read_u64_array(opal_node, "hdat-map", hdatAddr, 2)) { + pr_debug("OPAL: Property hdat-map not found.\n"); + return; + } + + /* Print out hdat-map values. [0]: base, [1]: size */ + pr_debug("HDAT Base address: %#llx\n", hdatAddr[0]); + pr_debug("HDAT Size: %#llx\n", hdatAddr[1]); + + hdat_inf.base = phys_to_virt(hdatAddr[0]); + hdat_inf.size = hdatAddr[1]; + + if (sysfs_create_bin_file(opal_kobj, &hdat_attr) != 0) + pr_debug("OPAL: sysfs file creation for HDAT failed"); + +}
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 2822935..cae3745 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c@@ -740,6 +740,8 @@ static int __init opal_init(void) opal_sys_param_init(); /* Setup message log sysfs interface. */ opal_msglog_sysfs_init(); + /* Create hdat object under sys/firmware/opal */ + opal_hdat_sysfs_init(); } /* Initialize platform devices: IPMI backend, PRD & flash interface */
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2.9.3