• Antonio Nino Diaz's avatar
    SPM: Deprecate the current implementation · 2d7b9e5e
    Antonio Nino Diaz authored
    
    The current SPM is a prototype that only supports one secure partition
    in EL0. The objective of SPM is to have multiple partitions. The current
    MM interface isn't adequate for this, so it is needed to modify heavily
    the code to add proper support for it.
    
    However, there are platforms which are already using this (like SGI) and
    removing the code would break it.  For this reason, the current SPM code
    has been duplicated in order to temporarily preserve compatibility. All
    new improvements/changes to SPM will be done in the non-deprecated copy,
    that may change without notice.
    
    The new build option SPM_DEPRECATED has been introduced to select the SPM
    implementation. It defaults to 1, that selects the deprecated SPM.
    
    Change-Id: Ic9f80b53b450e97b4d3f47e4ef4a138ee8d87443
    Signed-off-by: default avatarAntonio Nino Diaz <antonio.ninodiaz@arm.com>
    2d7b9e5e
sp_xlat.c 4.32 KB
/*
 * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <arch.h>
#include <arch_helpers.h>
#include <assert.h>
#include <errno.h>
#include <platform_def.h>
#include <platform.h>
#include <secure_partition.h>
#include <spm_svc.h>
#include <xlat_tables_v2.h>

#include "spm_private.h"
#include "spm_shim_private.h"

/* Place translation tables by default along with the ones used by BL31. */
#ifndef PLAT_SP_IMAGE_XLAT_SECTION_NAME
#define PLAT_SP_IMAGE_XLAT_SECTION_NAME	"xlat_table"
#endif

/* Allocate and initialise the translation context for the secure partitions. */
REGISTER_XLAT_CONTEXT2(sp,
		       PLAT_SP_IMAGE_MMAP_REGIONS,
		       PLAT_SP_IMAGE_MAX_XLAT_TABLES,
		       PLAT_VIRT_ADDR_SPACE_SIZE, PLAT_PHY_ADDR_SPACE_SIZE,
		       EL1_EL0_REGIME, PLAT_SP_IMAGE_XLAT_SECTION_NAME);

/* Lock used for SP_MEMORY_ATTRIBUTES_GET and SP_MEMORY_ATTRIBUTES_SET */
static spinlock_t mem_attr_smc_lock;

/* Get handle of Secure Partition translation context */
xlat_ctx_t *spm_get_sp_xlat_context(void)
{
	return &sp_xlat_ctx;
};

/*
 * Attributes are encoded using a different format in the SMC interface than in
 * the Trusted Firmware, where the mmap_attr_t enum type is used. This function
 * converts an attributes value from the SMC format to the mmap_attr_t format by
 * setting MT_RW/MT_RO, MT_USER/MT_PRIVILEGED and MT_EXECUTE/MT_EXECUTE_NEVER.
 * The other fields are left as 0 because they are ignored by the function
 * xlat_change_mem_attributes_ctx().
 */
static unsigned int smc_attr_to_mmap_attr(unsigned int attributes)
{
	unsigned int tf_attr = 0U;

	unsigned int access = (attributes & SP_MEMORY_ATTRIBUTES_ACCESS_MASK)
			      >> SP_MEMORY_ATTRIBUTES_ACCESS_SHIFT;

	if (access == SP_MEMORY_ATTRIBUTES_ACCESS_RW) {
		tf_attr |= MT_RW | MT_USER;
	} else if (access ==  SP_MEMORY_ATTRIBUTES_ACCESS_RO) {
		tf_attr |= MT_RO | MT_USER;
	} else {
		/* Other values are reserved. */
		assert(access ==  SP_MEMORY_ATTRIBUTES_ACCESS_NOACCESS);
		/* The only requirement is that there's no access from EL0 */
		tf_attr |= MT_RO | MT_PRIVILEGED;
	}

	if ((attributes & SP_MEMORY_ATTRIBUTES_NON_EXEC) == 0) {
		tf_attr |= MT_EXECUTE;
	} else {
		tf_attr |= MT_EXECUTE_NEVER;
	}

	return tf_attr;
}

/*
 * This function converts attributes from the Trusted Firmware format into the
 * SMC interface format.
 */
static unsigned int smc_mmap_to_smc_attr(unsigned int attr)
{
	unsigned int smc_attr = 0U;

	unsigned int data_access;

	if ((attr & MT_USER) == 0) {
		/* No access from EL0. */
		data_access = SP_MEMORY_ATTRIBUTES_ACCESS_NOACCESS;
	} else {
		if ((attr & MT_RW) != 0) {
			assert(MT_TYPE(attr) != MT_DEVICE);
			data_access = SP_MEMORY_ATTRIBUTES_ACCESS_RW;
		} else {
			data_access = SP_MEMORY_ATTRIBUTES_ACCESS_RO;
		}
	}

	smc_attr |= (data_access & SP_MEMORY_ATTRIBUTES_ACCESS_MASK)
		    << SP_MEMORY_ATTRIBUTES_ACCESS_SHIFT;

	if ((attr & MT_EXECUTE_NEVER) != 0U) {
		smc_attr |= SP_MEMORY_ATTRIBUTES_NON_EXEC;
	}

	return smc_attr;
}

int32_t spm_memory_attributes_get_smc_handler(sp_context_t *sp_ctx,
					      uintptr_t base_va)
{
	uint32_t attributes;

	spin_lock(&mem_attr_smc_lock);

	int rc = xlat_get_mem_attributes_ctx(sp_ctx->xlat_ctx_handle,
				     base_va, &attributes);

	spin_unlock(&mem_attr_smc_lock);

	/* Convert error codes of xlat_get_mem_attributes_ctx() into SPM. */
	assert((rc == 0) || (rc == -EINVAL));

	if (rc == 0) {
		return (int32_t) smc_mmap_to_smc_attr(attributes);
	} else {
		return SPM_INVALID_PARAMETER;
	}
}

int spm_memory_attributes_set_smc_handler(sp_context_t *sp_ctx,
					  u_register_t page_address,
					  u_register_t pages_count,
					  u_register_t smc_attributes)
{
	uintptr_t base_va = (uintptr_t) page_address;
	size_t size = (size_t) (pages_count * PAGE_SIZE);
	uint32_t attributes = (uint32_t) smc_attributes;

	INFO("  Start address  : 0x%lx\n", base_va);
	INFO("  Number of pages: %i (%zi bytes)\n", (int) pages_count, size);
	INFO("  Attributes     : 0x%x\n", attributes);

	spin_lock(&mem_attr_smc_lock);

	int ret = xlat_change_mem_attributes_ctx(sp_ctx->xlat_ctx_handle,
					base_va, size,
					smc_attr_to_mmap_attr(attributes));

	spin_unlock(&mem_attr_smc_lock);

	/* Convert error codes of xlat_change_mem_attributes_ctx() into SPM. */
	assert((ret == 0) || (ret == -EINVAL));

	return (ret == 0) ? SPM_SUCCESS : SPM_INVALID_PARAMETER;
}