drivers/wifi: Remove unnecessary data structure copy

[coreboot2.git] / src / cpu / x86 / smm / smm_module_loader.c

/* SPDX-License-Identifier: GPL-2.0-only */

#include <acpi/acpi_gnvs.h>
#include <cbmem.h>
#include <commonlib/helpers.h>
#include <commonlib/region.h>
#include <console/console.h>
#include <cpu/cpu.h>
#include <cpu/x86/smm.h>
#include <device/device.h>
#include <device/mmio.h>
#include <rmodule.h>
#include <smmstore.h>
#include <stdio.h>
#include <string.h>
#include <types.h>

#define SMM_CODE_SEGMENT_SIZE 0x10000

/*
 * Components that make up the SMRAM:
 * 1. Save state - the total save state memory used
 * 2. Stack - stacks for the CPUs in the SMM handler
 * 3. Stub - SMM stub code for calling into handler
 * 4. Handler - C-based SMM handler.
 *
 * The components are assumed to consist of one consecutive region.
 */

/*
 * The stub is the entry point that sets up protected mode and stacks for each
 * CPU. It then calls into the SMM handler module. It is encoded as an rmodule.
 */
extern unsigned char _binary_smmstub_start[];

/* Per CPU minimum stack size. */
#define SMM_MINIMUM_STACK_SIZE 32

struct cpu_smm_info {
        uint8_t active;
        uintptr_t smbase;
        struct region ss;
        struct region stub_code;
};
struct cpu_smm_info cpus[CONFIG_MAX_CPUS] = { 0 };

/*
 * This method creates a map of all the CPU entry points, save state locations
 * and the beginning and end of code segments for each CPU. This map is used
 * during relocation to properly align as many CPUs that can fit into the SMRAM
 * region. For more information on how SMRAM works, refer to the latest Intel
 * developer's manuals (volume 3, chapter 34). SMRAM is divided up into the
 * following regions:
 * +-----------------+ Top of SMRAM
 * |      MSEG       |
 * +-----------------+
 * |    common       |
 * |  smi handler    | 64K
 * |                 |
 * +-----------------+
 * | CPU 0 code  seg |
 * +-----------------+
 * | CPU 1 code seg  |
 * +-----------------+
 * | CPU x code seg  |
 * +-----------------+
 * |                 |
 * |                 |
 * +-----------------+
 * |    stacks       |
 * +-----------------+ <- START of SMRAM
 *
 * The code below checks when a code segment is full and begins placing the remainder
 * CPUs in the lower segments. The entry point for each CPU is smbase + 0x8000
 * and save state is smbase + 0x8000 + (0x8000 - state save size). Save state
 * area grows downward into the CPUs entry point.  Therefore staggering too many
 * CPUs in one 32K block will corrupt CPU0's entry code as the save states move
 * downward.
 * input : smbase of first CPU (all other CPUs
 *         will go below this address)
 * input : num_cpus in the system. The map will
 *         be created from 0 to num_cpus.
 */
static int smm_create_map(const uintptr_t smbase, const unsigned int num_cpus,
                          const struct smm_loader_params *params)
{
        struct rmodule smm_stub;

        if (ARRAY_SIZE(cpus) < num_cpus) {
                printk(BIOS_ERR, "%s: increase MAX_CPUS in Kconfig\n", __func__);
                return 0;
        }

        if (rmodule_parse(&_binary_smmstub_start, &smm_stub)) {
                printk(BIOS_ERR, "%s: unable to get SMM module size\n", __func__);
                return 0;
        }

        /*
         * How many CPUs can fit into one 64K segment?
         * Make sure that the first stub does not overlap with the last save state of a segment.
         */
        const size_t stub_size = rmodule_memory_size(&smm_stub);
        const size_t needed_ss_size = MAX(params->cpu_save_state_size, stub_size);
        const size_t cpus_per_segment =
                (SMM_CODE_SEGMENT_SIZE - SMM_ENTRY_OFFSET - stub_size) / needed_ss_size;

        if (cpus_per_segment == 0) {
                printk(BIOS_ERR, "%s: CPUs won't fit in segment. Broken stub or save state size\n",
                       __func__);
                return 0;
        }

        for (unsigned int i = 0; i < num_cpus; i++) {
                const size_t segment_number = i / cpus_per_segment;
                cpus[i].smbase = smbase - SMM_CODE_SEGMENT_SIZE * segment_number
                        - needed_ss_size * (i % cpus_per_segment);
                cpus[i].stub_code = region_create(cpus[i].smbase + SMM_ENTRY_OFFSET, stub_size);
                cpus[i].ss = region_create(
                                cpus[i].smbase + SMM_CODE_SEGMENT_SIZE - params->cpu_save_state_size,
                                params->cpu_save_state_size);
                cpus[i].active = 1;
        }

        return 1;
}

/*
 * This method expects the smm relocation map to be complete.
 * This method does not read any HW registers, it simply uses a
 * map that was created during SMM setup.
 * input: cpu_num - cpu number which is used as an index into the
 *       map to return the smbase
 */
u32 smm_get_cpu_smbase(unsigned int cpu_num)
{
        if (cpu_num < CONFIG_MAX_CPUS) {
                if (cpus[cpu_num].active)
                        return cpus[cpu_num].smbase;
        }
        return 0;
}

/*
 * This method assumes that at least 1 CPU has been set up from
 * which it will place other CPUs below its smbase ensuring that
 * save state does not clobber the first CPUs init code segment. The init
 * code which is the smm stub code is the same for all CPUs. They enter
 * smm, setup stacks (based on their apic id), enter protected mode
 * and then jump to the common smi handler.  The stack is allocated
 * at the beginning of smram (aka tseg base, not smbase). The stack
 * pointer for each CPU is calculated by using its apic id
 * (code is in smm_stub.s)
 * Each entry point will now have the same stub code which, sets up the CPU
 * stack, enters protected mode and then jumps to the smi handler. It is
 * important to enter protected mode before the jump because the "jump to
 * address" might be larger than the 20bit address supported by real mode.
 * SMI entry right now is in real mode.
 * input: num_cpus - number of cpus that need relocation including
 *        the first CPU (though its code is already loaded)
 */

static void smm_place_entry_code(const unsigned int num_cpus)
{
        unsigned int i;
        size_t size;

        /* start at 1, the first CPU stub code is already there */
        size = region_sz(&cpus[0].stub_code);
        for (i = 1; i < num_cpus; i++) {
                printk(BIOS_DEBUG,
                       "SMM Module: placing smm entry code at %zx,  cpu # 0x%x\n",
                       region_offset(&cpus[i].stub_code), i);
                memcpy((void *)region_offset(&cpus[i].stub_code),
                       (void *)region_offset(&cpus[0].stub_code), size);
                printk(BIOS_SPEW, "%s: copying from %zx to %zx 0x%zx bytes\n",
                       __func__, region_offset(&cpus[0].stub_code),
                       region_offset(&cpus[i].stub_code), size);
        }
}

static uintptr_t stack_top;
static size_t g_stack_size;

int smm_setup_stack(const uintptr_t perm_smbase, const size_t perm_smram_size,
                     const unsigned int total_cpus, const size_t stack_size)
{
        /* Need a minimum stack size and alignment. */
        if (stack_size <= SMM_MINIMUM_STACK_SIZE || (stack_size & 3) != 0) {
                printk(BIOS_ERR, "%s: need minimum stack size\n", __func__);
                return -1;
        }

        const size_t total_stack_size = total_cpus * stack_size;
        if (total_stack_size >= perm_smram_size) {
                printk(BIOS_ERR, "%s: Stack won't fit smram\n", __func__);
                return -1;
        }
        stack_top = perm_smbase + total_stack_size;
        g_stack_size = stack_size;
        return 0;
}

/*
 * Place the staggered entry points for each CPU. The entry points are
 * staggered by the per CPU SMM save state size extending down from
 * SMM_ENTRY_OFFSET.
 */
static void smm_stub_place_staggered_entry_points(const struct smm_loader_params *params)
{
        if (params->num_concurrent_save_states > 1)
                smm_place_entry_code(params->num_concurrent_save_states);
}

/*
 * The stub setup code assumes it is completely contained within the
 * default SMRAM size (0x10000) for the default SMI handler (entry at
 * 0x30000), but no assumption should be made for the permanent SMI handler.
 * The placement of CPU entry points for permanent handler are determined
 * by the number of CPUs in the system and the amount of SMRAM.
 * There are potentially 2 regions to place
 * within the default SMRAM size:
 * 1. Save state areas
 * 2. Stub code
 *
 * The save state always lives at the top of the CPUS smbase (and the entry
 * point is at offset 0x8000). This allows only a certain number of CPUs with
 * staggered entry points until the save state area comes down far enough to
 * overwrite/corrupt the entry code (stub code). Therefore, an SMM map is
 * created to avoid this corruption, see smm_create_map() above.
 * This module setup code works for the default (0x30000) SMM handler setup and the
 * permanent SMM handler.
 * The CPU stack is decided at runtime in the stub and is treaded as a continuous
 * region. As this might not fit the default SMRAM region, the same region used
 * by the permanent handler can be used during relocation.
 */
static int smm_module_setup_stub(const uintptr_t smbase, const size_t smm_size,
                                 struct smm_loader_params *params)
{
        struct rmodule smm_stub;
        if (rmodule_parse(&_binary_smmstub_start, &smm_stub)) {
                printk(BIOS_ERR, "%s: unable to parse smm stub\n", __func__);
                return -1;
        }
        const size_t stub_size = rmodule_memory_size(&smm_stub);

        /* Some sanity check */
        if (stub_size >= SMM_ENTRY_OFFSET) {
                printk(BIOS_ERR, "%s: Stub too large\n", __func__);
                return -1;
        }

        const uintptr_t smm_stub_loc = smbase + SMM_ENTRY_OFFSET;
        if (rmodule_load((void *)smm_stub_loc, &smm_stub)) {
                printk(BIOS_ERR, "%s: load module failed\n", __func__);
                return -1;
        }

        struct smm_stub_params *stub_params = rmodule_parameters(&smm_stub);
        stub_params->stack_top = stack_top;
        stub_params->stack_size = g_stack_size;
        stub_params->c_handler = (uintptr_t)params->handler;
        stub_params->cr3 = params->cr3;

        /* This runs on the BSP. All the APs are its siblings */
        struct cpu_info *info = cpu_info();
        if (!info || !info->cpu) {
                printk(BIOS_ERR, "%s: Failed to find BSP struct device\n", __func__);
                return -1;
        }
        int i = 0;
        for (struct device *dev = info->cpu; dev; dev = dev->sibling)
                if (dev->enabled)
                        stub_params->apic_id_to_cpu[i++] = dev->path.apic.initial_lapicid;

        if (i != params->num_cpus) {
                printk(BIOS_ERR, "%s: Failed to set up apic map correctly\n", __func__);
                return -1;
        }

        printk(BIOS_DEBUG, "%s: stack_top = 0x%x\n", __func__, stub_params->stack_top);
        printk(BIOS_DEBUG, "%s: per cpu stack_size = 0x%x\n", __func__,
               stub_params->stack_size);
        printk(BIOS_DEBUG, "%s: runtime.smm_size = 0x%zx\n", __func__, smm_size);

        smm_stub_place_staggered_entry_points(params);

        printk(BIOS_DEBUG, "SMM Module: stub loaded at %lx. Will call %p\n", smm_stub_loc,
               params->handler);
        return 0;
}

/*
 * smm_setup_relocation_handler assumes the callback is already loaded in
 * memory. i.e. Another SMM module isn't chained to the stub. The other
 * assumption is that the stub will be entered from the default SMRAM
 * location: 0x30000 -> 0x40000.
 */
int smm_setup_relocation_handler(struct smm_loader_params *params)
{
        uintptr_t smram = SMM_DEFAULT_BASE;
        printk(BIOS_SPEW, "%s: enter\n", __func__);
        /* There can't be more than 1 concurrent save state for the relocation
         * handler because all CPUs default to 0x30000 as SMBASE. */
        if (params->num_concurrent_save_states > 1)
                return -1;

        /* A handler has to be defined to call for relocation. */
        if (params->handler == NULL)
                return -1;

        /* Since the relocation handler always uses stack, adjust the number
         * of concurrent stack users to be CONFIG_MAX_CPUS. */
        if (params->num_cpus == 0)
                params->num_cpus = CONFIG_MAX_CPUS;

        printk(BIOS_SPEW, "%s: exit\n", __func__);
        return smm_module_setup_stub(smram, SMM_DEFAULT_SIZE, params);
}

static void setup_smihandler_params(struct smm_runtime *mod_params,
                                    struct smm_loader_params *loader_params)
{
        uintptr_t tseg_base;
        size_t tseg_size;

        smm_region(&tseg_base, &tseg_size);

        mod_params->smbase = tseg_base;
        mod_params->smm_size = tseg_size;
        mod_params->save_state_size = loader_params->cpu_save_state_size;
        mod_params->num_cpus = loader_params->num_cpus;
        mod_params->gnvs_ptr = (uint32_t)(uintptr_t)acpi_get_gnvs();
        const struct cbmem_entry *cbmemc;
        if (CONFIG(CONSOLE_CBMEM) && (cbmemc = cbmem_entry_find(CBMEM_ID_CONSOLE))) {
                mod_params->cbmemc = cbmem_entry_start(cbmemc);
                mod_params->cbmemc_size = cbmem_entry_size(cbmemc);
        } else {
                mod_params->cbmemc = 0;
                mod_params->cbmemc_size = 0;
        }

        for (int i = 0; i < loader_params->num_cpus; i++)
                mod_params->save_state_top[i] = region_last(&cpus[i].ss) + 1;

        if (CONFIG(RUNTIME_CONFIGURABLE_SMM_LOGLEVEL))
                mod_params->smm_log_level = mainboard_set_smm_log_level();
        else
                mod_params->smm_log_level = 0;

        if (CONFIG(SMM_PCI_RESOURCE_STORE))
                smm_pci_resource_store_init(mod_params);

        if (CONFIG(SMMSTORE_V2)) {
                struct smmstore_params_info info;
                if (smmstore_get_info(&info) < 0) {
                        printk(BIOS_INFO, "SMMSTORE: Failed to get meta data\n");
                        return;
                }

                void *ptr = cbmem_add(CBMEM_ID_SMM_COMBUFFER, info.block_size);
                if (!ptr) {
                        printk(BIOS_ERR, "SMMSTORE: Failed to add com buffer\n");
                        return;
                }
                mod_params->smmstore_com_buffer_base = (uintptr_t)ptr;
                mod_params->smmstore_com_buffer_size = info.block_size;
        }
}

static void print_region(const char *name, const struct region region)
{
        printk(BIOS_DEBUG, "%-12s [0x%zx-0x%zx]\n", name, region_offset(&region),
               region_last(&region));
}

/* STM + Handler + (Stub + Save state) * CONFIG_MAX_CPUS + stacks + page tables*/
#define SMM_REGIONS_ARRAY_SIZE (1  + 1 + CONFIG_MAX_CPUS * 2 + 1 + 1)

static int append_and_check_region(const struct region smram,
                                   const struct region region,
                                   struct region *region_list,
                                   const char *name)
{
        unsigned int region_counter = 0;
        for (; region_counter < SMM_REGIONS_ARRAY_SIZE; region_counter++)
                if (region_sz(&region_list[region_counter]) == 0)
                        break;

        if (region_counter >= SMM_REGIONS_ARRAY_SIZE) {
                printk(BIOS_ERR, "Array used to check regions too small\n");
                return 1;
        }

        if (!region_is_subregion(&smram, &region)) {
                printk(BIOS_ERR, "%s not in SMM\n", name);
                return 1;
        }

        print_region(name, region);
        for (unsigned int i = 0; i < region_counter; i++) {
                if (region_overlap(&region_list[i], &region)) {
                        printk(BIOS_ERR, "%s overlaps with a previous region\n", name);
                        return 1;
                }
        }

        region_list[region_counter] = region;

        return 0;
}

#define _PRES (1ULL << 0)
#define _RW   (1ULL << 1)
#define _US   (1ULL << 2)
#define _A    (1ULL << 5)
#define _D    (1ULL << 6)
#define _PS   (1ULL << 7)
#define _GEN_DIR(a) (_PRES + _RW + _US + _A + (a))
#define _GEN_PAGE(a) (_PRES + _RW + _US + _PS + _A +  _D + (a))
#define PAGE_SIZE 8

/* Return the PM4LE */
static uintptr_t install_page_table(const uintptr_t handler_base)
{
        const bool one_g_pages = !!(cpuid_edx(0x80000001) & (1 << 26));
        /* 4 1G pages or 4 PDPE entries with 512 * 2M pages */
        const size_t pages_needed = one_g_pages ? 4 : 2048 + 4;
        const uintptr_t pages_base = ALIGN_DOWN(handler_base - pages_needed * PAGE_SIZE, 4096);
        const uintptr_t pm4le = ALIGN_DOWN(pages_base - 8, 4096);

        if (one_g_pages) {
                for (size_t i = 0; i < 4; i++)
                        write64p(pages_base + i * PAGE_SIZE, _GEN_PAGE(1ull * GiB * i));
                write64p(pm4le, _GEN_DIR(pages_base));
        } else {
                for (size_t i = 0; i < 2048; i++)
                        write64p(pages_base + i * PAGE_SIZE, _GEN_PAGE(2ull * MiB * i));
                write64p(pm4le, _GEN_DIR(pages_base + 2048 * PAGE_SIZE));
                for (size_t i = 0; i < 4; i++)
                        write64p(pages_base + (2048 + i) * PAGE_SIZE, _GEN_DIR(pages_base + 4096 * i));
        }
        return pm4le;
}

/*
 *The SMM module is placed within the provided region in the following
 * manner:
 * +-----------------+ <- smram + size
 * | BIOS resource   |
 * | list (STM)      |
 * +-----------------+
 * |  smi handler    |
 * |      ...        |
 * +-----------------+
 * |  page tables    |
 * +-----------------+ <- cpu0
 * |    stub code    | <- cpu1
 * |    stub code    | <- cpu2
 * |    stub code    | <- cpu3, etc
 * |                 |
 * |                 |
 * |                 |
 * |    stacks       |
 * +-----------------+ <- smram start
 *
 * With CONFIG(SMM_TSEG) the stubs will be placed in the same segment as the
 * permanent handler and the stacks.
 */
int smm_load_module(const uintptr_t smram_base, const size_t smram_size,
                    struct smm_loader_params *params)
{
        /*
         * Place in .bss to reduce stack usage.
         * TODO: once CPU_INFO_V2 is used everywhere, use smaller stack for APs and move
         * this back to the BSP stack.
         */
        static struct region region_list[SMM_REGIONS_ARRAY_SIZE] = {};

        struct rmodule smi_handler;
        if (rmodule_parse(&_binary_smm_start, &smi_handler))
                return -1;

        const struct region smram = region_create(smram_base, smram_size);
        const uintptr_t smram_top = region_last(&smram) + 1;

        const size_t stm_size =
                CONFIG(STM) ? CONFIG_MSEG_SIZE + CONFIG_BIOS_RESOURCE_LIST_SIZE : 0;

        if (CONFIG(STM)) {
                struct region stm = region_create(smram_top - stm_size, stm_size);
                if (append_and_check_region(smram, stm, region_list, "STM"))
                        return -1;
                printk(BIOS_DEBUG, "MSEG size     0x%x\n", CONFIG_MSEG_SIZE);
                printk(BIOS_DEBUG, "BIOS res list 0x%x\n", CONFIG_BIOS_RESOURCE_LIST_SIZE);
        }

        const size_t handler_size = rmodule_memory_size(&smi_handler);
        const size_t handler_alignment = rmodule_load_alignment(&smi_handler);
        const uintptr_t handler_base =
                ALIGN_DOWN(smram_top - stm_size - handler_size,
                           handler_alignment);
        struct region handler = region_create(handler_base, handler_size);
        if (append_and_check_region(smram, handler, region_list, "HANDLER"))
                return -1;

        uintptr_t stub_segment_base;
        if (ENV_X86_64) {
                uintptr_t pt_base = install_page_table(handler_base);
                struct region page_tables = region_create(pt_base, handler_base - pt_base);
                if (append_and_check_region(smram, page_tables, region_list, "PAGE TABLES"))
                        return -1;
                params->cr3 = pt_base;
                stub_segment_base = pt_base - SMM_CODE_SEGMENT_SIZE;
        } else {
                stub_segment_base = handler_base - SMM_CODE_SEGMENT_SIZE;
        }

        if (!smm_create_map(stub_segment_base, params->num_concurrent_save_states, params)) {
                printk(BIOS_ERR, "%s: Error creating CPU map\n", __func__);
                return -1;
        }
        for (unsigned int i = 0; i < params->num_concurrent_save_states; i++) {
                printk(BIOS_DEBUG, "\nCPU %u\n", i);
                char string[13];
                snprintf(string, sizeof(string), "  ss%d", i);
                if (append_and_check_region(smram, cpus[i].ss, region_list, string))
                        return -1;
                snprintf(string, sizeof(string), "  stub%d", i);
                if (append_and_check_region(smram, cpus[i].stub_code, region_list, string))
                        return -1;
        }

        struct region stacks = region_create(smram_base,
                        params->num_concurrent_save_states * CONFIG_SMM_MODULE_STACK_SIZE);
        printk(BIOS_DEBUG, "\n");
        if (append_and_check_region(smram, stacks, region_list, "stacks"))
                return -1;

        if (rmodule_load((void *)handler_base, &smi_handler))
                return -1;

        struct smm_runtime *smihandler_params = rmodule_parameters(&smi_handler);
        params->handler = rmodule_entry(&smi_handler);
        setup_smihandler_params(smihandler_params, params);

        return smm_module_setup_stub(stub_segment_base, smram_size, params);
}