--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * xen/arch/arm/tee/ffa.c
+ *
+ * Arm Firmware Framework for ARMv8-A (FF-A) mediator
+ *
+ * Copyright (C) 2023 Linaro Limited
+ */
+
+#include <xen/bitops.h>
+#include <xen/domain_page.h>
+#include <xen/errno.h>
+#include <xen/init.h>
+#include <xen/lib.h>
+#include <xen/sched.h>
+#include <xen/sizes.h>
+#include <xen/types.h>
+
+#include <asm/event.h>
+#include <asm/regs.h>
+#include <asm/smccc.h>
+#include <asm/tee/ffa.h>
+#include <asm/tee/tee.h>
+
+/* Error codes */
+#define FFA_RET_OK 0
+#define FFA_RET_NOT_SUPPORTED -1
+#define FFA_RET_INVALID_PARAMETERS -2
+#define FFA_RET_NO_MEMORY -3
+#define FFA_RET_BUSY -4
+#define FFA_RET_INTERRUPTED -5
+#define FFA_RET_DENIED -6
+#define FFA_RET_RETRY -7
+#define FFA_RET_ABORTED -8
+
+/* FFA_VERSION helpers */
+#define FFA_VERSION_MAJOR_SHIFT 16U
+#define FFA_VERSION_MAJOR_MASK 0x7FFFU
+#define FFA_VERSION_MINOR_SHIFT 0U
+#define FFA_VERSION_MINOR_MASK 0xFFFFU
+#define MAKE_FFA_VERSION(major, minor) \
+ ((((major) & FFA_VERSION_MAJOR_MASK) << FFA_VERSION_MAJOR_SHIFT) | \
+ ((minor) & FFA_VERSION_MINOR_MASK))
+
+#define FFA_VERSION_1_0 MAKE_FFA_VERSION(1, 0)
+#define FFA_VERSION_1_1 MAKE_FFA_VERSION(1, 1)
+/* The minimal FF-A version of the SPMC that can be supported */
+#define FFA_MIN_SPMC_VERSION FFA_VERSION_1_1
+
+/*
+ * This is the version we want to use in communication with guests and SPs.
+ * During negotiation with a guest or a SP we may need to lower it for
+ * that particular guest or SP.
+ */
+#define FFA_MY_VERSION_MAJOR 1U
+#define FFA_MY_VERSION_MINOR 1U
+#define FFA_MY_VERSION MAKE_FFA_VERSION(FFA_MY_VERSION_MAJOR, \
+ FFA_MY_VERSION_MINOR)
+
+/* Function IDs */
+#define FFA_ERROR 0x84000060U
+#define FFA_SUCCESS_32 0x84000061U
+#define FFA_VERSION 0x84000063U
+
+struct ffa_ctx {
+ /* FF-A version used by the guest */
+ uint32_t guest_vers;
+};
+
+/* Negotiated FF-A version to use with the SPMC */
+static uint32_t __ro_after_init ffa_version;
+
+static bool ffa_get_version(uint32_t *vers)
+{
+ const struct arm_smccc_1_2_regs arg = {
+ .a0 = FFA_VERSION,
+ .a1 = FFA_MY_VERSION,
+ };
+ struct arm_smccc_1_2_regs resp;
+
+ arm_smccc_1_2_smc(&arg, &resp);
+ if ( resp.a0 == FFA_RET_NOT_SUPPORTED )
+ {
+ gprintk(XENLOG_ERR, "ffa: FFA_VERSION returned not supported\n");
+ return false;
+ }
+
+ *vers = resp.a0;
+
+ return true;
+}
+
+static void set_regs(struct cpu_user_regs *regs, register_t v0, register_t v1,
+ register_t v2, register_t v3, register_t v4, register_t v5,
+ register_t v6, register_t v7)
+{
+ set_user_reg(regs, 0, v0);
+ set_user_reg(regs, 1, v1);
+ set_user_reg(regs, 2, v2);
+ set_user_reg(regs, 3, v3);
+ set_user_reg(regs, 4, v4);
+ set_user_reg(regs, 5, v5);
+ set_user_reg(regs, 6, v6);
+ set_user_reg(regs, 7, v7);
+}
+
+static void handle_version(struct cpu_user_regs *regs)
+{
+ struct domain *d = current->domain;
+ struct ffa_ctx *ctx = d->arch.tee;
+ uint32_t vers = get_user_reg(regs, 1);
+
+ if ( vers < FFA_VERSION_1_1 )
+ vers = FFA_VERSION_1_0;
+ else
+ vers = FFA_VERSION_1_1;
+
+ ctx->guest_vers = vers;
+ set_regs(regs, vers, 0, 0, 0, 0, 0, 0, 0);
+}
+
+static bool ffa_handle_call(struct cpu_user_regs *regs)
+{
+ uint32_t fid = get_user_reg(regs, 0);
+ struct domain *d = current->domain;
+ struct ffa_ctx *ctx = d->arch.tee;
+
+ if ( !ctx )
+ return false;
+
+ switch ( fid )
+ {
+ case FFA_VERSION:
+ handle_version(regs);
+ return true;
+
+ default:
+ gprintk(XENLOG_ERR, "ffa: unhandled fid 0x%x\n", fid);
+ return false;
+ }
+}
+
+static int ffa_domain_init(struct domain *d)
+{
+ struct ffa_ctx *ctx;
+
+ if ( !ffa_version )
+ return -ENODEV;
+
+ ctx = xzalloc(struct ffa_ctx);
+ if ( !ctx )
+ return -ENOMEM;
+
+ d->arch.tee = ctx;
+
+ return 0;
+}
+
+/* This function is supposed to undo what ffa_domain_init() has done */
+static int ffa_domain_teardown(struct domain *d)
+{
+ struct ffa_ctx *ctx = d->arch.tee;
+
+ if ( !ctx )
+ return 0;
+
+ XFREE(d->arch.tee);
+
+ return 0;
+}
+
+static int ffa_relinquish_resources(struct domain *d)
+{
+ return 0;
+}
+
+static bool ffa_probe(void)
+{
+ uint32_t vers;
+ unsigned int major_vers;
+ unsigned int minor_vers;
+
+ /*
+ * psci_init_smccc() updates this value with what's reported by EL-3
+ * or secure world.
+ */
+ if ( smccc_ver < ARM_SMCCC_VERSION_1_2 )
+ {
+ printk(XENLOG_ERR
+ "ffa: unsupported SMCCC version %#x (need at least %#x)\n",
+ smccc_ver, ARM_SMCCC_VERSION_1_2);
+ return false;
+ }
+
+ if ( !ffa_get_version(&vers) )
+ return false;
+
+ if ( vers < FFA_MIN_SPMC_VERSION || vers > FFA_MY_VERSION )
+ {
+ printk(XENLOG_ERR "ffa: Incompatible version %#x found\n", vers);
+ return false;
+ }
+
+ major_vers = (vers >> FFA_VERSION_MAJOR_SHIFT) & FFA_VERSION_MAJOR_MASK;
+ minor_vers = vers & FFA_VERSION_MINOR_MASK;
+ printk(XENLOG_INFO "ARM FF-A Mediator version %u.%u\n",
+ FFA_MY_VERSION_MAJOR, FFA_MY_VERSION_MINOR);
+ printk(XENLOG_INFO "ARM FF-A Firmware version %u.%u\n",
+ major_vers, minor_vers);
+
+ ffa_version = vers;
+
+ return true;
+}
+
+static const struct tee_mediator_ops ffa_ops =
+{
+ .probe = ffa_probe,
+ .domain_init = ffa_domain_init,
+ .domain_teardown = ffa_domain_teardown,
+ .relinquish_resources = ffa_relinquish_resources,
+ .handle_call = ffa_handle_call,
+};
+
+REGISTER_TEE_MEDIATOR(ffa, "FF-A", XEN_DOMCTL_CONFIG_TEE_FFA, &ffa_ops);
projects / people / aperard / xen-unstable.git / commitdiff