diff options
Diffstat (limited to 'arch/powerpc/platforms/powernv/opal-secvar.c')
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal-secvar.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-secvar.c b/arch/powerpc/platforms/powernv/opal-secvar.c new file mode 100644 index 000000000..6ac410f4d --- /dev/null +++ b/arch/powerpc/platforms/powernv/opal-secvar.c @@ -0,0 +1,182 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PowerNV code for secure variables + * + * Copyright (C) 2019 IBM Corporation + * Author: Claudio Carvalho + * Nayna Jain + * + * APIs to access secure variables managed by OPAL. + */ + +#define pr_fmt(fmt) "secvar: "fmt + +#include <linux/types.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <asm/opal.h> +#include <asm/secvar.h> +#include <asm/secure_boot.h> + +static int opal_status_to_err(int rc) +{ + int err; + + switch (rc) { + case OPAL_SUCCESS: + err = 0; + break; + case OPAL_UNSUPPORTED: + err = -ENXIO; + break; + case OPAL_PARAMETER: + err = -EINVAL; + break; + case OPAL_RESOURCE: + err = -ENOSPC; + break; + case OPAL_HARDWARE: + err = -EIO; + break; + case OPAL_NO_MEM: + err = -ENOMEM; + break; + case OPAL_EMPTY: + err = -ENOENT; + break; + case OPAL_PARTIAL: + err = -EFBIG; + break; + default: + err = -EINVAL; + } + + return err; +} + +static int opal_get_variable(const char *key, u64 ksize, u8 *data, u64 *dsize) +{ + int rc; + + if (!key || !dsize) + return -EINVAL; + + *dsize = cpu_to_be64(*dsize); + + rc = opal_secvar_get(key, ksize, data, dsize); + + *dsize = be64_to_cpu(*dsize); + + return opal_status_to_err(rc); +} + +static int opal_get_next_variable(const char *key, u64 *keylen, u64 keybufsize) +{ + int rc; + + if (!key || !keylen) + return -EINVAL; + + *keylen = cpu_to_be64(*keylen); + + rc = opal_secvar_get_next(key, keylen, keybufsize); + + *keylen = be64_to_cpu(*keylen); + + return opal_status_to_err(rc); +} + +static int opal_set_variable(const char *key, u64 ksize, u8 *data, u64 dsize) +{ + int rc; + + if (!key || !data) + return -EINVAL; + + rc = opal_secvar_enqueue_update(key, ksize, data, dsize); + + return opal_status_to_err(rc); +} + +static ssize_t opal_secvar_format(char *buf, size_t bufsize) +{ + ssize_t rc = 0; + struct device_node *node; + const char *format; + + node = of_find_compatible_node(NULL, NULL, "ibm,secvar-backend"); + if (!of_device_is_available(node)) { + rc = -ENODEV; + goto out; + } + + rc = of_property_read_string(node, "format", &format); + if (rc) + goto out; + + rc = snprintf(buf, bufsize, "%s", format); + +out: + of_node_put(node); + + return rc; +} + +static int opal_secvar_max_size(u64 *max_size) +{ + int rc; + struct device_node *node; + + node = of_find_compatible_node(NULL, NULL, "ibm,secvar-backend"); + if (!node) + return -ENODEV; + + if (!of_device_is_available(node)) { + rc = -ENODEV; + goto out; + } + + rc = of_property_read_u64(node, "max-var-size", max_size); + +out: + of_node_put(node); + return rc; +} + +static const struct secvar_operations opal_secvar_ops = { + .get = opal_get_variable, + .get_next = opal_get_next_variable, + .set = opal_set_variable, + .format = opal_secvar_format, + .max_size = opal_secvar_max_size, +}; + +static int opal_secvar_probe(struct platform_device *pdev) +{ + if (!opal_check_token(OPAL_SECVAR_GET) + || !opal_check_token(OPAL_SECVAR_GET_NEXT) + || !opal_check_token(OPAL_SECVAR_ENQUEUE_UPDATE)) { + pr_err("OPAL doesn't support secure variables\n"); + return -ENODEV; + } + + return set_secvar_ops(&opal_secvar_ops); +} + +static const struct of_device_id opal_secvar_match[] = { + { .compatible = "ibm,secvar-backend",}, + {}, +}; + +static struct platform_driver opal_secvar_driver = { + .driver = { + .name = "secvar", + .of_match_table = opal_secvar_match, + }, +}; + +static int __init opal_secvar_init(void) +{ + return platform_driver_probe(&opal_secvar_driver, opal_secvar_probe); +} +device_initcall(opal_secvar_init); |