diff options
| -rw-r--r-- | src/cpu/x86/smm/smm_module_loader.c | 74 |
1 files changed, 32 insertions, 42 deletions
diff --git a/src/cpu/x86/smm/smm_module_loader.c b/src/cpu/x86/smm/smm_module_loader.c index 9068435d20..00c6cf9b47 100644 --- a/src/cpu/x86/smm/smm_module_loader.c +++ b/src/cpu/x86/smm/smm_module_loader.c @@ -1,5 +1,6 @@ /* SPDX-License-Identifier: GPL-2.0-only */ +#include "assert.h" #include <acpi/acpi_gnvs.h> #include <stddef.h> #include <stdint.h> @@ -85,65 +86,54 @@ struct cpu_smm_info cpus[CONFIG_MAX_CPUS] = { 0 }; * input : num_cpus in the system. The map will * be created from 0 to num_cpus. */ -static int smm_create_map(uintptr_t smbase, unsigned int num_cpus, - const struct smm_loader_params *params) +static int smm_create_map(const uintptr_t smbase, const unsigned int num_cpus, + const struct smm_loader_params *params) { - unsigned int i; struct rmodule smm_stub; - unsigned int ss_size = params->per_cpu_save_state_size, stub_size; - unsigned int smm_entry_offset = SMM_ENTRY_OFFSET; - unsigned int seg_count = 0, segments = 0, available; - unsigned int cpus_in_segment = 0; - unsigned int base = smbase; - if (rmodule_parse(&_binary_smmstub_start, &smm_stub)) { - printk(BIOS_ERR, "%s: unable to get SMM module size\n", __func__); + if (ARRAY_SIZE(cpus) < num_cpus) { + printk(BIOS_ERR, "%s: increase MAX_CPUS in Kconfig\n", __func__); return 0; } - stub_size = rmodule_memory_size(&smm_stub); - /* How many CPUs can fit into one 64K segment? */ - available = 0xFFFF - smm_entry_offset - ss_size - stub_size; - if (available > 0) { - cpus_in_segment = available / ss_size; - /* minimum segments needed will always be 1 */ - segments = num_cpus / cpus_in_segment + 1; - printk(BIOS_DEBUG, - "%s: cpus allowed in one segment %d\n", __func__, cpus_in_segment); - printk(BIOS_DEBUG, - "%s: min # of segments needed %d\n", __func__, segments); - } else { - printk(BIOS_ERR, "%s: not enough space in SMM to setup all CPUs\n", __func__); - printk(BIOS_ERR, " save state & stub size need to be reduced\n"); - printk(BIOS_ERR, " or increase SMRAM size\n"); + if (rmodule_parse(&_binary_smmstub_start, &smm_stub)) { + printk(BIOS_ERR, "%s: unable to get SMM module size\n", __func__); return 0; } - if (ARRAY_SIZE(cpus) < num_cpus) { - printk(BIOS_ERR, - "%s: increase MAX_CPUS in Kconfig\n", __func__); + /* + * 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->real_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 (i = 0; i < num_cpus; i++) { + for (unsigned int i = 0; i < num_cpus; i++) { + if (i % cpus_per_segment == 0) + printk(BIOS_DEBUG, "-------------NEW CODE SEGMENT --------------\n"); printk(BIOS_DEBUG, "CPU 0x%x\n", i); - cpus[i].smbase = base; - cpus[i].entry = base + smm_entry_offset; - printk(BIOS_DEBUG, " smbase %lx entry %lx\n", cpus[i].smbase, - cpus[i].entry); - cpus[i].ss_start = cpus[i].entry + (smm_entry_offset - ss_size); + /* We copy the same stub for each CPU so they all need the same 'smbase'. */ + 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].entry = cpus[i].smbase + SMM_ENTRY_OFFSET; + cpus[i].ss_start = cpus[i].smbase + SMM_CODE_SEGMENT_SIZE - needed_ss_size; cpus[i].code_start = cpus[i].entry; cpus[i].code_end = cpus[i].entry + stub_size; - printk(BIOS_DEBUG, " ss_start %lx code_end %lx\n", cpus[i].ss_start, + printk(BIOS_DEBUG, " Stub [0x%lx-0x%lx[\n", cpus[i].code_start, cpus[i].code_end); + printk(BIOS_DEBUG, " Save state [0x%lx-0x%lx[\n", + cpus[i].ss_start + needed_ss_size - params->real_cpu_save_state_size, + cpus[i].ss_start + needed_ss_size); cpus[i].active = 1; - base -= ss_size; - seg_count++; - if (seg_count >= cpus_in_segment) { - base -= smm_entry_offset; - seg_count = 0; - printk(BIOS_DEBUG, "-------------NEW CODE SEGMENT --------------\n"); - } } return 1; |