summaryrefslogtreecommitdiffstats
path: root/kernel/arch/powerpc/platforms/powernv/opal-msglog.c
diff options
context:
space:
mode:
authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/powerpc/platforms/powernv/opal-msglog.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/powerpc/platforms/powernv/opal-msglog.c')
-rw-r--r--kernel/arch/powerpc/platforms/powernv/opal-msglog.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/platforms/powernv/opal-msglog.c b/kernel/arch/powerpc/platforms/powernv/opal-msglog.c
new file mode 100644
index 000000000..44ed78af1
--- /dev/null
+++ b/kernel/arch/powerpc/platforms/powernv/opal-msglog.c
@@ -0,0 +1,124 @@
+/*
+ * 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>
+#include <asm/barrier.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_msglog_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;
+ ssize_t ret;
+ size_t first_read = 0;
+ uint32_t out_pos, avail;
+
+ if (!mc)
+ return -ENODEV;
+
+ out_pos = be32_to_cpu(ACCESS_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(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
+ * case. */
+ if (out_pos & MEMCONS_OUT_POS_WRAP) {
+
+ out_pos &= MEMCONS_OUT_POS_MASK;
+ avail = be32_to_cpu(mc->obuf_size) - out_pos;
+
+ ret = memory_read_from_buffer(to, count, &pos,
+ conbuf + out_pos, avail);
+
+ if (ret < 0)
+ goto out;
+
+ first_read = ret;
+ to += first_read;
+ count -= first_read;
+ pos -= avail;
+
+ if (count <= 0)
+ goto out;
+ }
+
+ /* Sanity check. The firmware should not do this to us. */
+ if (out_pos > be32_to_cpu(mc->obuf_size)) {
+ pr_err("OPAL: memory console corruption. Aborting read.\n");
+ return -EINVAL;
+ }
+
+ ret = memory_read_from_buffer(to, count, &pos, conbuf, out_pos);
+
+ if (ret < 0)
+ goto out;
+
+ ret += first_read;
+out:
+ return ret;
+}
+
+static struct bin_attribute opal_msglog_attr = {
+ .attr = {.name = "msglog", .mode = 0444},
+ .read = opal_msglog_read
+};
+
+void __init opal_msglog_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;
+ }
+
+ opal_msglog_attr.private = mc;
+
+ if (sysfs_create_bin_file(opal_kobj, &opal_msglog_attr) != 0)
+ pr_warn("OPAL: sysfs file creation failed\n");
+}