| /* 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/x86/smm.h> |
| #include <rmodule.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <types.h> |
| |
| #define FXSAVE_SIZE 512 |
| #define SMM_CODE_SEGMENT_SIZE 0x10000 |
| /* FXSAVE area during relocation. While it may not be strictly needed the |
| SMM stub code relies on the FXSAVE area being non-zero to enable SSE |
| instructions within SMM mode. */ |
| static uint8_t fxsave_area_relocation[CONFIG_MAX_CPUS][FXSAVE_SIZE] |
| __attribute__((aligned(16))); |
| |
| /* |
| * 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, FXSAVE |
| * +-----------------+ |
| * | 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.offset = cpus[i].smbase + SMM_ENTRY_OFFSET; |
| cpus[i].stub_code.size = stub_size; |
| cpus[i].ss.offset = cpus[i].smbase + SMM_CODE_SEGMENT_SIZE |
| - params->cpu_save_state_size; |
| cpus[i].ss.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, |
| void *const fxsave_area) |
| { |
| 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->fxsave_area = (uintptr_t)fxsave_area; |
| stub_params->fxsave_area_size = FXSAVE_SIZE; |
| |
| /* Initialize the APIC id to CPU number table to be 1:1 */ |
| for (int i = 0; i < params->num_cpus; i++) |
| stub_params->apic_id_to_cpu[i] = i; |
| |
| /* Allow the initiator to manipulate SMM stub parameters. */ |
| params->stub_params = stub_params; |
| |
| 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.start32_offset = 0x%x\n", __func__, |
| stub_params->start32_offset); |
| 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, fxsave_area_relocation); |
| } |
| |
| static void setup_smihandler_params(struct smm_runtime *mod_params, |
| uintptr_t smram_base, |
| uintptr_t smram_size, |
| struct smm_loader_params *loader_params) |
| { |
| mod_params->smbase = smram_base; |
| mod_params->smm_size = smram_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_end(&cpus[i].ss); |
| } |
| |
| static void print_region(const char *name, const struct region region) |
| { |
| printk(BIOS_DEBUG, "%-12s [0x%zx-0x%zx]\n", name, region_offset(®ion), |
| region_end(®ion)); |
| } |
| |
| /* STM + FX_SAVE + Handler + (Stub + Save state) * CONFIG_MAX_CPUS + stacks */ |
| #define SMM_REGIONS_ARRAY_SIZE (1 + 1 + 1 + CONFIG_MAX_CPUS * 2 + 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_list[region_counter].size == 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, ®ion)) { |
| 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(®ion_list[i], ®ion)) { |
| printk(BIOS_ERR, "%s overlaps with a previous region\n", name); |
| return 1; |
| } |
| } |
| |
| region_list[region_counter] = region; |
| |
| return 0; |
| } |
| |
| /* |
| *The SMM module is placed within the provided region in the following |
| * manner: |
| * +-----------------+ <- smram + size |
| * | BIOS resource | |
| * | list (STM) | |
| * +-----------------+ |
| * | fxsave area | |
| * +-----------------+ |
| * | smi handler | |
| * | ... | |
| * +-----------------+ <- 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 = { .offset = smram_base, .size = smram_size }; |
| const uintptr_t smram_top = region_end(&smram); |
| |
| const size_t stm_size = |
| CONFIG(STM) ? CONFIG_MSEG_SIZE + CONFIG_BIOS_RESOURCE_LIST_SIZE : 0; |
| |
| if (CONFIG(STM)) { |
| struct region stm = {}; |
| stm.offset = smram_top - stm_size; |
| 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 fx_save_area_size = CONFIG(SSE) ? FXSAVE_SIZE * params->num_cpus : 0; |
| struct region fx_save = {}; |
| if (CONFIG(SSE)) { |
| fx_save.offset = smram_top - stm_size - fx_save_area_size; |
| fx_save.size = fx_save_area_size; |
| if (append_and_check_region(smram, fx_save, region_list, "FX_SAVE")) |
| return -1; |
| } |
| |
| 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 - fx_save_area_size - handler_size, |
| handler_alignment); |
| struct region handler = { |
| .offset = handler_base, |
| .size = handler_size |
| }; |
| if (append_and_check_region(smram, handler, region_list, "HANDLER")) |
| return -1; |
| |
| uintptr_t stub_segment_base; |
| |
| if (CONFIG(SMM_TSEG)) { |
| stub_segment_base = handler_base - SMM_CODE_SEGMENT_SIZE; |
| } else if (CONFIG(SMM_ASEG)) { |
| stub_segment_base = smram_base; |
| if (smram_base != SMM_BASE || smram_size != SMM_CODE_SEGMENT_SIZE) { |
| printk(BIOS_ERR, "SMM base & size are 0x%lx, 0x%zx, but must be 0x%x, 0x%x\n", |
| smram_base, smram_size, SMM_BASE, SMM_CODE_SEGMENT_SIZE); |
| return -1; |
| } |
| } |
| |
| 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 = { |
| .offset = smram_base, |
| .size = 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, smram_base, smram_size, params); |
| |
| return smm_module_setup_stub(stub_segment_base, smram_size, params, |
| (void *)region_offset(&fx_save)); |
| } |