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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/powerpc/platforms/powernv/opal-nvram.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/platforms/powernv/opal-nvram.c')
-rw-r--r--arch/powerpc/platforms/powernv/opal-nvram.c117
1 files changed, 117 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-nvram.c b/arch/powerpc/platforms/powernv/opal-nvram.c
new file mode 100644
index 000000000..5584247f5
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-nvram.c
@@ -0,0 +1,117 @@
+/*
+ * PowerNV nvram code.
+ *
+ * Copyright 2011 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.
+ */
+
+#define DEBUG
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of.h>
+
+#include <asm/opal.h>
+#include <asm/nvram.h>
+#include <asm/machdep.h>
+
+static unsigned int nvram_size;
+
+static ssize_t opal_nvram_size(void)
+{
+ return nvram_size;
+}
+
+static ssize_t opal_nvram_read(char *buf, size_t count, loff_t *index)
+{
+ s64 rc;
+ int off;
+
+ if (*index >= nvram_size)
+ return 0;
+ off = *index;
+ if ((off + count) > nvram_size)
+ count = nvram_size - off;
+ rc = opal_read_nvram(__pa(buf), count, off);
+ if (rc != OPAL_SUCCESS)
+ return -EIO;
+ *index += count;
+ return count;
+}
+
+/*
+ * This can be called in the panic path with interrupts off, so use
+ * mdelay in that case.
+ */
+static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index)
+{
+ s64 rc = OPAL_BUSY;
+ int off;
+
+ if (*index >= nvram_size)
+ return 0;
+ off = *index;
+ if ((off + count) > nvram_size)
+ count = nvram_size - off;
+
+ while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+ rc = opal_write_nvram(__pa(buf), count, off);
+ if (rc == OPAL_BUSY_EVENT) {
+ if (in_interrupt() || irqs_disabled())
+ mdelay(OPAL_BUSY_DELAY_MS);
+ else
+ msleep(OPAL_BUSY_DELAY_MS);
+ opal_poll_events(NULL);
+ } else if (rc == OPAL_BUSY) {
+ if (in_interrupt() || irqs_disabled())
+ mdelay(OPAL_BUSY_DELAY_MS);
+ else
+ msleep(OPAL_BUSY_DELAY_MS);
+ }
+ }
+
+ if (rc)
+ return -EIO;
+
+ *index += count;
+ return count;
+}
+
+static int __init opal_nvram_init_log_partitions(void)
+{
+ /* Scan nvram for partitions */
+ nvram_scan_partitions();
+ nvram_init_oops_partition(0);
+ return 0;
+}
+machine_arch_initcall(powernv, opal_nvram_init_log_partitions);
+
+void __init opal_nvram_init(void)
+{
+ struct device_node *np;
+ const __be32 *nbytes_p;
+
+ np = of_find_compatible_node(NULL, NULL, "ibm,opal-nvram");
+ if (np == NULL)
+ return;
+
+ nbytes_p = of_get_property(np, "#bytes", NULL);
+ if (!nbytes_p) {
+ of_node_put(np);
+ return;
+ }
+ nvram_size = be32_to_cpup(nbytes_p);
+
+ pr_info("OPAL nvram setup, %u bytes\n", nvram_size);
+ of_node_put(np);
+
+ ppc_md.nvram_read = opal_nvram_read;
+ ppc_md.nvram_write = opal_nvram_write;
+ ppc_md.nvram_size = opal_nvram_size;
+}
+