tseg_region.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <assert.h>
#include <commonlib/helpers.h>
#include <console/console.h>
#include <cpu/x86/smm.h>
#include <stage_cache.h>
#include <types.h>
#include <inttypes.h>
 
/*
 *        Subregions within SMM
 *     +-------------------------+
 *     |          IED            | IED_REGION_SIZE
 *     +-------------------------+
 *     |  External Stage Cache   | SMM_RESERVED_SIZE
 *     +-------------------------+
 *     |      code and data      |
 *     |         (TSEG)          |
 *     +-------------------------+ TSEG
 */
int smm_subregion(int sub, uintptr_t *start, size_t *size)
{
        uintptr_t sub_base;
        size_t sub_size;
        const size_t ied_size = CONFIG_IED_REGION_SIZE;
        const size_t cache_size = CONFIG_SMM_RESERVED_SIZE;
 
        smm_region(&sub_base, &sub_size);
 
        ASSERT(IS_ALIGNED(sub_base, sub_size));
        ASSERT(sub_size > (cache_size + ied_size));
 
        switch (sub) {
        case SMM_SUBREGION_HANDLER:
                /* Handler starts at the base of TSEG. */
                sub_size -= ied_size;
                sub_size -= cache_size;
                break;
        case SMM_SUBREGION_CACHE:
                /* External cache is in the middle of TSEG. */
                sub_base += sub_size - (ied_size + cache_size);
                sub_size = cache_size;
                break;
        case SMM_SUBREGION_CHIPSET:
                /* IED is at the top. */
                sub_base += sub_size - ied_size;
                sub_size = ied_size;
                break;
        default:
                *start = 0;
                *size = 0;
                return -1;
        }
 
        *start = sub_base;
        *size = sub_size;
        return 0;
}
 
void stage_cache_external_region(void **base, size_t *size)
{
        if (smm_subregion(SMM_SUBREGION_CACHE, (uintptr_t *)base, size)) {
                printk(BIOS_ERR, "No cache SMM subregion.\n");
                *base = NULL;
                *size = 0;
        }
}
 
void smm_list_regions(void)
{
        uintptr_t base;
        size_t size;
        int i;
 
        smm_region(&base, &size);
        if (!size)
                return;
 
        printk(BIOS_DEBUG, "SMM Memory Map\n");
        printk(BIOS_DEBUG, "SMRAM       : 0x%" PRIxPTR " 0x%zx\n", base, size);
 
        for (i = 0; i < SMM_SUBREGION_NUM; i++) {
                if (smm_subregion(i, &base, &size))
                        continue;
                printk(BIOS_DEBUG, " Subregion %d: 0x%" PRIxPTR " 0x%zx\n", i, base, size);
        }
}