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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/platforms/powernv/opal-nvram.c | |
parent | Initial commit. (diff) | |
download | linux-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.c | 113 |
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; +} + |