From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 671E71A0CF0 for ; Fri, 5 Dec 2014 20:40:54 +1100 (AEDT) In-Reply-To: <1417753577.4741.52.camel@kernel.crashing.org> To: Benjamin Herrenschmidt , "linuxppc-dev@ozlabs.org list" From: Michael Ellerman Subject: Re: [v2] powerpc/powernv: Expose OPAL firmware symbol map Message-Id: <20141205094054.4536E140120@ozlabs.org> Date: Fri, 5 Dec 2014 20:40:54 +1100 (AEDT) Cc: Anton Blanchard List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2014-05-12 at 04:26:17 UTC, Benjamin Herrenschmidt wrote: > Newer versions of OPAL will provide this, so let's expose it to user > space so tools like perf can use it to properly decode samples in > firmware space. > > diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c > index 06d9076..98f50e8 100644 > --- a/arch/powerpc/platforms/powernv/opal.c > +++ b/arch/powerpc/platforms/powernv/opal.c > @@ -61,6 +61,8 @@ static DEFINE_SPINLOCK(opal_notifier_lock); > static uint64_t last_notified_mask = 0x0ul; > static atomic_t opal_notifier_hold = ATOMIC_INIT(0); > static uint32_t opal_heartbeat; > +static void *opal_symmap; > +static uint64_t opal_symmap_size; We shouldn't need these. The bin_attribute has a size (you set it), you just need to use it in symbol_map_read(). And the attribute also has a private pointer, which you can use for opal_symmap. > @@ -608,6 +610,40 @@ static int opal_sysfs_init(void) > return 0; > } > > +static ssize_t symbol_map_read(struct file *fp, struct kobject *kobj, > + struct bin_attribute *bin_attr, > + char *buf, loff_t off, size_t count) > +{ > + return memory_read_from_buffer(buf, count, &off, > + opal_symmap, opal_symmap_size); So this would be: return memory_read_from_buffer(buf, count, &off, bin_attr->private, bin_attr->size); > +} > + > +static BIN_ATTR_RO(symbol_map, 0); > + > +static void opal_export_symmap(void) > +{ > + const __be64 *syms; > + unsigned int size; > + struct device_node *fw; > + int rc; > + > + fw = of_find_node_by_path("/ibm,opal/firmware"); > + if (!fw) > + return; > + syms = of_get_property(fw, "symbol-map", &size); > + if (!syms || size != 2 * sizeof(__be64)) > + return; > + > + opal_symmap = __va(be64_to_cpu(syms[0])); > + opal_symmap_size = be64_to_cpu(syms[1]); I was going to tell you to use of_property_read_u64_index(), but it doesn't exist - we can add it one day and clean this up then. > + /* Setup attributes */ > + bin_attr_symbol_map.size = opal_symmap_size; > + rc = sysfs_create_bin_file(opal_kobj, &bin_attr_symbol_map); > + if (rc) > + pr_warn("Error %d creating OPAL symbols file\n", rc); Can you prefix it please, so: pr_warn("opal: Error .." Or add to the very top of the file: #define pr_fmt(fmt) "opal: " fmt cheers