--- /dev/null
+// 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()
+
+
+LIST_HEAD(prm_module_list);
+
+struct prm_handler_info {
+ guid_t guid;
+ u64 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 = 0;
+ 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);
+
+ 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);
+ mmio_range_size = struct_size(tm->mmio_info, addr_ranges, mmio_count);
+ tm->mmio_info = kmalloc(mmio_range_size, GFP_KERNEL);
+ temp_mmio = memremap(module_info->mmio_list_pointer, mmio_range_size, MEMREMAP_WB);
+ memmove(tm->mmio_info, temp_mmio, mmio_range_size);
+ } else {
+ mmio_range_size = struct_size(tm->mmio_info, addr_ranges, mmio_count);
+ tm->mmio_info = kmalloc(mmio_range_size, GFP_KERNEL);
+ 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 = 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;
+}
+
+#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;
+
+ /*
+ * 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)
+{
+ acpi_status status;
+ int mc = acpi_table_parse_entries(ACPI_SIG_PRMT, sizeof(struct acpi_table_prmt) +
+ sizeof (struct acpi_table_prmt_header),
+ 0, acpi_parse_prmt, 0);
+ pr_info("PRM: found %u modules\n", mc);
+
+ 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");
+}
projects / linux-2.6-microblaze.git / commitdiff