From 9155e2341aa8b5df057dc1c77633b33d1a4f17d2 Mon Sep 17 00:00:00 2001 From: Nayna Jain Date: Sun, 10 Nov 2019 21:10:33 -0600 Subject: powerpc/powernv: Add OPAL API interface to access secure variable The X.509 certificates trusted by the platform and required to secure boot the OS kernel are wrapped in secure variables, which are controlled by OPAL. This patch adds firmware/kernel interface to read and write OPAL secure variables based on the unique key. This support can be enabled using CONFIG_OPAL_SECVAR. Signed-off-by: Claudio Carvalho Signed-off-by: Nayna Jain Signed-off-by: Eric Richter [mpe: Make secvar_ops __ro_after_init, only build opal-secvar.c if PPC_SECURE_BOOT=y] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1573441836-3632-2-git-send-email-nayna@linux.ibm.com --- arch/powerpc/platforms/powernv/Makefile | 1 + arch/powerpc/platforms/powernv/opal-call.c | 3 + arch/powerpc/platforms/powernv/opal-secvar.c | 140 +++++++++++++++++++++++++++ arch/powerpc/platforms/powernv/opal.c | 3 + 4 files changed, 147 insertions(+) create mode 100644 arch/powerpc/platforms/powernv/opal-secvar.c (limited to 'arch/powerpc/platforms') diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile index a3ac9646119d..c0f8120045c3 100644 --- a/arch/powerpc/platforms/powernv/Makefile +++ b/arch/powerpc/platforms/powernv/Makefile @@ -20,3 +20,4 @@ obj-$(CONFIG_PPC_MEMTRACE) += memtrace.o obj-$(CONFIG_PPC_VAS) += vas.o vas-window.o vas-debug.o obj-$(CONFIG_OCXL_BASE) += ocxl.o obj-$(CONFIG_SCOM_DEBUGFS) += opal-xscom.o +obj-$(CONFIG_PPC_SECURE_BOOT) += opal-secvar.o diff --git a/arch/powerpc/platforms/powernv/opal-call.c b/arch/powerpc/platforms/powernv/opal-call.c index a2aa5e433ac8..5cd0f52d258f 100644 --- a/arch/powerpc/platforms/powernv/opal-call.c +++ b/arch/powerpc/platforms/powernv/opal-call.c @@ -290,3 +290,6 @@ OPAL_CALL(opal_nx_coproc_init, OPAL_NX_COPROC_INIT); OPAL_CALL(opal_mpipl_update, OPAL_MPIPL_UPDATE); OPAL_CALL(opal_mpipl_register_tag, OPAL_MPIPL_REGISTER_TAG); OPAL_CALL(opal_mpipl_query_tag, OPAL_MPIPL_QUERY_TAG); +OPAL_CALL(opal_secvar_get, OPAL_SECVAR_GET); +OPAL_CALL(opal_secvar_get_next, OPAL_SECVAR_GET_NEXT); +OPAL_CALL(opal_secvar_enqueue_update, OPAL_SECVAR_ENQUEUE_UPDATE); diff --git a/arch/powerpc/platforms/powernv/opal-secvar.c b/arch/powerpc/platforms/powernv/opal-secvar.c new file mode 100644 index 000000000000..14133e120bdd --- /dev/null +++ b/arch/powerpc/platforms/powernv/opal-secvar.c @@ -0,0 +1,140 @@ +// 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 +#include +#include +#include +#include +#include + +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, uint64_t ksize, + u8 *data, uint64_t *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, uint64_t *keylen, + uint64_t 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, uint64_t ksize, u8 *data, + uint64_t dsize) +{ + int rc; + + if (!key || !data) + return -EINVAL; + + rc = opal_secvar_enqueue_update(key, ksize, data, dsize); + + return opal_status_to_err(rc); +} + +static const struct secvar_operations opal_secvar_ops = { + .get = opal_get_variable, + .get_next = opal_get_next_variable, + .set = opal_set_variable, +}; + +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; + } + + set_secvar_ops(&opal_secvar_ops); + + return 0; +} + +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); diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index 38e90270280b..8355bcd00f93 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -1002,6 +1002,9 @@ static int __init opal_init(void) /* Initialise OPAL Power control interface */ opal_power_control_init(); + /* Initialize OPAL secure variables */ + opal_pdev_init("ibm,secvar-backend"); + return 0; } machine_subsys_initcall(powernv, opal_init); -- cgit v1.2.3-59-g8ed1b