rsi_cmds.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Copyright (C) 2023 ARM Ltd.
  4 */
  5
  6#ifndef __ASM_RSI_CMDS_H
  7#define __ASM_RSI_CMDS_H
  8
  9#include <linux/arm-smccc.h>
 10#include <linux/string.h>
 11#include <asm/memory.h>
 12
 13#include <asm/rsi_smc.h>
 14
 15#define RSI_GRANULE_SHIFT		12
 16#define RSI_GRANULE_SIZE		(_AC(1, UL) << RSI_GRANULE_SHIFT)
 17
 18enum ripas {
 19	RSI_RIPAS_EMPTY = 0,
 20	RSI_RIPAS_RAM = 1,
 21	RSI_RIPAS_DESTROYED = 2,
 22	RSI_RIPAS_DEV = 3,
 23};
 24
 25static inline unsigned long rsi_request_version(unsigned long req,
 26						unsigned long *out_lower,
 27						unsigned long *out_higher)
 28{
 29	struct arm_smccc_res res;
 30
 31	arm_smccc_smc(SMC_RSI_ABI_VERSION, req, 0, 0, 0, 0, 0, 0, &res);
 32
 33	if (out_lower)
 34		*out_lower = res.a1;
 35	if (out_higher)
 36		*out_higher = res.a2;
 37
 38	return res.a0;
 39}
 40
 41static inline unsigned long rsi_get_realm_config(struct realm_config *cfg)
 42{
 43	struct arm_smccc_res res;
 44
 45	arm_smccc_smc(SMC_RSI_REALM_CONFIG, virt_to_phys(cfg),
 46		      0, 0, 0, 0, 0, 0, &res);
 47	return res.a0;
 48}
 49
 50static inline unsigned long rsi_ipa_state_get(phys_addr_t start,
 51					      phys_addr_t end,
 52					      enum ripas *state,
 53					      phys_addr_t *top)
 54{
 55	struct arm_smccc_res res;
 56
 57	arm_smccc_smc(SMC_RSI_IPA_STATE_GET,
 58		      start, end, 0, 0, 0, 0, 0,
 59		      &res);
 60
 61	if (res.a0 == RSI_SUCCESS) {
 62		if (top)
 63			*top = res.a1;
 64		if (state)
 65			*state = res.a2;
 66	}
 67
 68	return res.a0;
 69}
 70
 71static inline long rsi_set_addr_range_state(phys_addr_t start,
 72					    phys_addr_t end,
 73					    enum ripas state,
 74					    unsigned long flags,
 75					    phys_addr_t *top)
 76{
 77	struct arm_smccc_res res;
 78
 79	arm_smccc_smc(SMC_RSI_IPA_STATE_SET, start, end, state,
 80		      flags, 0, 0, 0, &res);
 81
 82	if (top)
 83		*top = res.a1;
 84
 85	if (res.a2 != RSI_ACCEPT)
 86		return -EPERM;
 87
 88	return res.a0;
 89}
 90
 91/**
 92 * rsi_attestation_token_init - Initialise the operation to retrieve an
 93 * attestation token.
 94 *
 95 * @challenge:	The challenge data to be used in the attestation token
 96 *		generation.
 97 * @size:	Size of the challenge data in bytes.
 98 *
 99 * Initialises the attestation token generation and returns an upper bound
100 * on the attestation token size that can be used to allocate an adequate
101 * buffer. The caller is expected to subsequently call
102 * rsi_attestation_token_continue() to retrieve the attestation token data on
103 * the same CPU.
104 *
105 * Returns:
106 *  On success, returns the upper limit of the attestation report size.
107 *  Otherwise, -EINVAL
108 */
109static inline long
110rsi_attestation_token_init(const u8 *challenge, unsigned long size)
111{
112	struct arm_smccc_1_2_regs regs = { 0 };
113
114	/* The challenge must be at least 32bytes and at most 64bytes */
115	if (!challenge || size < 32 || size > 64)
116		return -EINVAL;
117
118	regs.a0 = SMC_RSI_ATTESTATION_TOKEN_INIT;
119	memcpy(&regs.a1, challenge, size);
120	arm_smccc_1_2_smc(&regs, &regs);
121
122	if (regs.a0 == RSI_SUCCESS)
123		return regs.a1;
124
125	return -EINVAL;
126}
127
128/**
129 * rsi_attestation_token_continue - Continue the operation to retrieve an
130 * attestation token.
131 *
132 * @granule: {I}PA of the Granule to which the token will be written.
133 * @offset:  Offset within Granule to start of buffer in bytes.
134 * @size:    The size of the buffer.
135 * @len:     The number of bytes written to the buffer.
136 *
137 * Retrieves up to a RSI_GRANULE_SIZE worth of token data per call. The caller
138 * is expected to call rsi_attestation_token_init() before calling this
139 * function to retrieve the attestation token.
140 *
141 * Return:
142 * * %RSI_SUCCESS     - Attestation token retrieved successfully.
143 * * %RSI_INCOMPLETE  - Token generation is not complete.
144 * * %RSI_ERROR_INPUT - A parameter was not valid.
145 * * %RSI_ERROR_STATE - Attestation not in progress.
146 */
147static inline unsigned long rsi_attestation_token_continue(phys_addr_t granule,
148							   unsigned long offset,
149							   unsigned long size,
150							   unsigned long *len)
151{
152	struct arm_smccc_res res;
153
154	arm_smccc_1_1_invoke(SMC_RSI_ATTESTATION_TOKEN_CONTINUE,
155			     granule, offset, size, 0, &res);
156
157	if (len)
158		*len = res.a1;
159	return res.a0;
160}
161
162#endif /* __ASM_RSI_CMDS_H */