diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/acpi/prmt.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c new file mode 100644 index 000000000..3d4c4620f --- /dev/null +++ b/drivers/acpi/prmt.c @@ -0,0 +1,344 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Author: Erik Kaneda <erik.kaneda@intel.com> + * Copyright 2020 Intel Corporation + * + * prmt.c + * + * Each PRM service is an executable that is run in a restricted environment + * that is invoked by writing to the PlatformRtMechanism OperationRegion from + * AML bytecode. + * + * init_prmt initializes the Platform Runtime Mechanism (PRM) services by + * processing data in the PRMT as well as registering an ACPI OperationRegion + * handler for the PlatformRtMechanism subtype. + * + */ +#include <linux/kernel.h> +#include <linux/efi.h> +#include <linux/acpi.h> +#include <linux/prmt.h> +#include <asm/efi.h> + +#pragma pack(1) +struct prm_mmio_addr_range { + u64 phys_addr; + u64 virt_addr; + u32 length; +}; + +struct prm_mmio_info { + u64 mmio_count; + struct prm_mmio_addr_range addr_ranges[]; +}; + +struct prm_buffer { + u8 prm_status; + u64 efi_status; + u8 prm_cmd; + guid_t handler_guid; +}; + +struct prm_context_buffer { + char signature[ACPI_NAMESEG_SIZE]; + u16 revision; + u16 reserved; + guid_t identifier; + u64 static_data_buffer; + struct prm_mmio_info *mmio_ranges; +}; +#pragma pack() + +static LIST_HEAD(prm_module_list); + +struct prm_handler_info { + guid_t guid; + void *handler_addr; + u64 static_data_buffer_addr; + u64 acpi_param_buffer_addr; + + struct list_head handler_list; +}; + +struct prm_module_info { + guid_t guid; + u16 major_rev; + u16 minor_rev; + u16 handler_count; + struct prm_mmio_info *mmio_info; + bool updatable; + + struct list_head module_list; + struct prm_handler_info handlers[]; +}; + +static u64 efi_pa_va_lookup(u64 pa) +{ + efi_memory_desc_t *md; + u64 pa_offset = pa & ~PAGE_MASK; + u64 page = pa & PAGE_MASK; + + for_each_efi_memory_desc(md) { + if (md->phys_addr < pa && pa < md->phys_addr + PAGE_SIZE * md->num_pages) + return pa_offset + md->virt_addr + page - md->phys_addr; + } + + return 0; +} + +#define get_first_handler(a) ((struct acpi_prmt_handler_info *) ((char *) (a) + a->handler_info_offset)) +#define get_next_handler(a) ((struct acpi_prmt_handler_info *) (sizeof(struct acpi_prmt_handler_info) + (char *) a)) + +static int __init +acpi_parse_prmt(union acpi_subtable_headers *header, const unsigned long end) +{ + struct acpi_prmt_module_info *module_info; + struct acpi_prmt_handler_info *handler_info; + struct prm_handler_info *th; + struct prm_module_info *tm; + u64 *mmio_count; + u64 cur_handler = 0; + u32 module_info_size = 0; + u64 mmio_range_size = 0; + void *temp_mmio; + + module_info = (struct acpi_prmt_module_info *) header; + module_info_size = struct_size(tm, handlers, module_info->handler_info_count); + tm = kmalloc(module_info_size, GFP_KERNEL); + if (!tm) + goto parse_prmt_out1; + + guid_copy(&tm->guid, (guid_t *) module_info->module_guid); + tm->major_rev = module_info->major_rev; + tm->minor_rev = module_info->minor_rev; + tm->handler_count = module_info->handler_info_count; + tm->updatable = true; + + if (module_info->mmio_list_pointer) { + /* + * Each module is associated with a list of addr + * ranges that it can use during the service + */ + mmio_count = (u64 *) memremap(module_info->mmio_list_pointer, 8, MEMREMAP_WB); + if (!mmio_count) + goto parse_prmt_out2; + + mmio_range_size = struct_size(tm->mmio_info, addr_ranges, *mmio_count); + tm->mmio_info = kmalloc(mmio_range_size, GFP_KERNEL); + if (!tm->mmio_info) + goto parse_prmt_out3; + + temp_mmio = memremap(module_info->mmio_list_pointer, mmio_range_size, MEMREMAP_WB); + if (!temp_mmio) + goto parse_prmt_out4; + memmove(tm->mmio_info, temp_mmio, mmio_range_size); + } else { + tm->mmio_info = kmalloc(sizeof(*tm->mmio_info), GFP_KERNEL); + if (!tm->mmio_info) + goto parse_prmt_out2; + + tm->mmio_info->mmio_count = 0; + } + + INIT_LIST_HEAD(&tm->module_list); + list_add(&tm->module_list, &prm_module_list); + + handler_info = get_first_handler(module_info); + do { + th = &tm->handlers[cur_handler]; + + guid_copy(&th->guid, (guid_t *)handler_info->handler_guid); + th->handler_addr = (void *)efi_pa_va_lookup(handler_info->handler_address); + th->static_data_buffer_addr = efi_pa_va_lookup(handler_info->static_data_buffer_address); + th->acpi_param_buffer_addr = efi_pa_va_lookup(handler_info->acpi_param_buffer_address); + } while (++cur_handler < tm->handler_count && (handler_info = get_next_handler(handler_info))); + + return 0; + +parse_prmt_out4: + kfree(tm->mmio_info); +parse_prmt_out3: + memunmap(mmio_count); +parse_prmt_out2: + kfree(tm); +parse_prmt_out1: + return -ENOMEM; +} + +#define GET_MODULE 0 +#define GET_HANDLER 1 + +static void *find_guid_info(const guid_t *guid, u8 mode) +{ + struct prm_handler_info *cur_handler; + struct prm_module_info *cur_module; + int i = 0; + + list_for_each_entry(cur_module, &prm_module_list, module_list) { + for (i = 0; i < cur_module->handler_count; ++i) { + cur_handler = &cur_module->handlers[i]; + if (guid_equal(guid, &cur_handler->guid)) { + if (mode == GET_MODULE) + return (void *)cur_module; + else + return (void *)cur_handler; + } + } + } + + return NULL; +} + +static struct prm_module_info *find_prm_module(const guid_t *guid) +{ + return (struct prm_module_info *)find_guid_info(guid, GET_MODULE); +} + +static struct prm_handler_info *find_prm_handler(const guid_t *guid) +{ + return (struct prm_handler_info *) find_guid_info(guid, GET_HANDLER); +} + +/* In-coming PRM commands */ + +#define PRM_CMD_RUN_SERVICE 0 +#define PRM_CMD_START_TRANSACTION 1 +#define PRM_CMD_END_TRANSACTION 2 + +/* statuses that can be passed back to ASL */ + +#define PRM_HANDLER_SUCCESS 0 +#define PRM_HANDLER_ERROR 1 +#define INVALID_PRM_COMMAND 2 +#define PRM_HANDLER_GUID_NOT_FOUND 3 +#define UPDATE_LOCK_ALREADY_HELD 4 +#define UPDATE_UNLOCK_WITHOUT_LOCK 5 + +/* + * This is the PlatformRtMechanism opregion space handler. + * @function: indicates the read/write. In fact as the PlatformRtMechanism + * message is driven by command, only write is meaningful. + * + * @addr : not used + * @bits : not used. + * @value : it is an in/out parameter. It points to the PRM message buffer. + * @handler_context: not used + */ +static acpi_status acpi_platformrt_space_handler(u32 function, + acpi_physical_address addr, + u32 bits, acpi_integer *value, + void *handler_context, + void *region_context) +{ + struct prm_buffer *buffer = ACPI_CAST_PTR(struct prm_buffer, value); + struct prm_handler_info *handler; + struct prm_module_info *module; + efi_status_t status; + struct prm_context_buffer context; + + if (!efi_enabled(EFI_RUNTIME_SERVICES)) { + pr_err_ratelimited("PRM: EFI runtime services no longer available\n"); + return AE_NO_HANDLER; + } + + /* + * The returned acpi_status will always be AE_OK. Error values will be + * saved in the first byte of the PRM message buffer to be used by ASL. + */ + switch (buffer->prm_cmd) { + case PRM_CMD_RUN_SERVICE: + + handler = find_prm_handler(&buffer->handler_guid); + module = find_prm_module(&buffer->handler_guid); + if (!handler || !module) + goto invalid_guid; + + ACPI_COPY_NAMESEG(context.signature, "PRMC"); + context.revision = 0x0; + context.reserved = 0x0; + context.identifier = handler->guid; + context.static_data_buffer = handler->static_data_buffer_addr; + context.mmio_ranges = module->mmio_info; + + status = efi_call_virt_pointer(handler, handler_addr, + handler->acpi_param_buffer_addr, + &context); + if (status == EFI_SUCCESS) { + buffer->prm_status = PRM_HANDLER_SUCCESS; + } else { + buffer->prm_status = PRM_HANDLER_ERROR; + buffer->efi_status = status; + } + break; + + case PRM_CMD_START_TRANSACTION: + + module = find_prm_module(&buffer->handler_guid); + if (!module) + goto invalid_guid; + + if (module->updatable) + module->updatable = false; + else + buffer->prm_status = UPDATE_LOCK_ALREADY_HELD; + break; + + case PRM_CMD_END_TRANSACTION: + + module = find_prm_module(&buffer->handler_guid); + if (!module) + goto invalid_guid; + + if (module->updatable) + buffer->prm_status = UPDATE_UNLOCK_WITHOUT_LOCK; + else + module->updatable = true; + break; + + default: + + buffer->prm_status = INVALID_PRM_COMMAND; + break; + } + + return AE_OK; + +invalid_guid: + buffer->prm_status = PRM_HANDLER_GUID_NOT_FOUND; + return AE_OK; +} + +void __init init_prmt(void) +{ + struct acpi_table_header *tbl; + acpi_status status; + int mc; + + status = acpi_get_table(ACPI_SIG_PRMT, 0, &tbl); + if (ACPI_FAILURE(status)) + return; + + mc = acpi_table_parse_entries(ACPI_SIG_PRMT, sizeof(struct acpi_table_prmt) + + sizeof (struct acpi_table_prmt_header), + 0, acpi_parse_prmt, 0); + acpi_put_table(tbl); + /* + * Return immediately if PRMT table is not present or no PRM module found. + */ + if (mc <= 0) + return; + + pr_info("PRM: found %u modules\n", mc); + + if (!efi_enabled(EFI_RUNTIME_SERVICES)) { + pr_err("PRM: EFI runtime services unavailable\n"); + return; + } + + status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT, + ACPI_ADR_SPACE_PLATFORM_RT, + &acpi_platformrt_space_handler, + NULL, NULL); + if (ACPI_FAILURE(status)) + pr_alert("PRM: OperationRegion handler could not be installed\n"); +} |