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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/platforms/powernv/opal-nvram.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
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.c113
1 files changed, 113 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..380bc2d7e
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-nvram.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PowerNV nvram code.
+ *
+ * Copyright 2011 IBM Corp.
+ */
+
+#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;
+}
+