1 files changed, 193 insertions, 0 deletions

diff --git a/drivers/platform/x86/dell-smbios.c b/drivers/platform/x86/dell-smbios.c
new file mode 100644
index 000000000000..d2412ab097da
--- /dev/null
+++ b/drivers/platform/x86/dell-smbios.c
@@ -0,0 +1,193 @@
+/*
+ *  Common functions for kernel modules using Dell SMBIOS
+ *
+ *  Copyright (c) Red Hat <mjg@redhat.com>
+ *  Copyright (c) 2014 Gabriele Mazzotta <gabriele.mzt@gmail.com>
+ *  Copyright (c) 2014 Pali Rohár <pali.rohar@gmail.com>
+ *
+ *  Based on documentation in the libsmbios package:
+ *  Copyright (C) 2005-2014 Dell Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/dmi.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include "../../firmware/dcdbas.h"
+#include "dell-smbios.h"
+
+struct calling_interface_structure {
+        struct dmi_header header;
+        u16 cmdIOAddress;
+        u8 cmdIOCode;
+        u32 supportedCmds;
+        struct calling_interface_token tokens[];
+} __packed;
+
+static struct calling_interface_buffer *buffer;
+static DEFINE_MUTEX(buffer_mutex);
+
+static int da_command_address;
+static int da_command_code;
+static int da_num_tokens;
+static struct calling_interface_token *da_tokens;
+
+int dell_smbios_error(int value)
+{
+        switch (value) {
+        case 0: /* Completed successfully */
+                return 0;
+        case -1: /* Completed with error */
+                return -EIO;
+        case -2: /* Function not supported */
+                return -ENXIO;
+        default: /* Unknown error */
+                return -EINVAL;
+        }
+}
+EXPORT_SYMBOL_GPL(dell_smbios_error);
+
+struct calling_interface_buffer *dell_smbios_get_buffer(void)
+{
+        mutex_lock(&buffer_mutex);
+        dell_smbios_clear_buffer();
+        return buffer;
+}
+EXPORT_SYMBOL_GPL(dell_smbios_get_buffer);
+
+void dell_smbios_clear_buffer(void)
+{
+        memset(buffer, 0, sizeof(struct calling_interface_buffer));
+}
+EXPORT_SYMBOL_GPL(dell_smbios_clear_buffer);
+
+void dell_smbios_release_buffer(void)
+{
+        mutex_unlock(&buffer_mutex);
+}
+EXPORT_SYMBOL_GPL(dell_smbios_release_buffer);
+
+void dell_smbios_send_request(int class, int select)
+{
+        struct smi_cmd command;
+
+        command.magic = SMI_CMD_MAGIC;
+        command.command_address = da_command_address;
+        command.command_code = da_command_code;
+        command.ebx = virt_to_phys(buffer);
+        command.ecx = 0x42534931;
+
+        buffer->class = class;
+        buffer->select = select;
+
+        dcdbas_smi_request(&command);
+}
+EXPORT_SYMBOL_GPL(dell_smbios_send_request);
+
+struct calling_interface_token *dell_smbios_find_token(int tokenid)
+{
+        int i;
+
+        for (i = 0; i < da_num_tokens; i++) {
+                if (da_tokens[i].tokenID == tokenid)
+                        return &da_tokens[i];
+        }
+
+        return NULL;
+}
+EXPORT_SYMBOL_GPL(dell_smbios_find_token);
+
+static void __init parse_da_table(const struct dmi_header *dm)
+{
+        /* Final token is a terminator, so we don't want to copy it */
+        int tokens = (dm->length-11)/sizeof(struct calling_interface_token)-1;
+        struct calling_interface_token *new_da_tokens;
+        struct calling_interface_structure *table =
+                container_of(dm, struct calling_interface_structure, header);
+
+        /* 4 bytes of table header, plus 7 bytes of Dell header, plus at least
+           6 bytes of entry */
+
+        if (dm->length < 17)
+                return;
+
+        da_command_address = table->cmdIOAddress;
+        da_command_code = table->cmdIOCode;
+
+        new_da_tokens = krealloc(da_tokens, (da_num_tokens + tokens) *
+                                 sizeof(struct calling_interface_token),
+                                 GFP_KERNEL);
+
+        if (!new_da_tokens)
+                return;
+        da_tokens = new_da_tokens;
+
+        memcpy(da_tokens+da_num_tokens, table->tokens,
+               sizeof(struct calling_interface_token) * tokens);
+
+        da_num_tokens += tokens;
+}
+
+static void __init find_tokens(const struct dmi_header *dm, void *dummy)
+{
+        switch (dm->type) {
+        case 0xd4: /* Indexed IO */
+        case 0xd5: /* Protected Area Type 1 */
+        case 0xd6: /* Protected Area Type 2 */
+                break;
+        case 0xda: /* Calling interface */
+                parse_da_table(dm);
+                break;
+        }
+}
+
+static int __init dell_smbios_init(void)
+{
+        int ret;
+
+        dmi_walk(find_tokens, NULL);
+
+        if (!da_tokens)  {
+                pr_info("Unable to find dmi tokens\n");
+                return -ENODEV;
+        }
+
+        /*
+         * Allocate buffer below 4GB for SMI data--only 32-bit physical addr
+         * is passed to SMI handler.
+         */
+        buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32);
+        if (!buffer) {
+                ret = -ENOMEM;
+                goto fail_buffer;
+        }
+
+        return 0;
+
+fail_buffer:
+        kfree(da_tokens);
+        return ret;
+}
+
+static void __exit dell_smbios_exit(void)
+{
+        kfree(da_tokens);
+        free_page((unsigned long)buffer);
+}
+
+subsys_initcall(dell_smbios_init);
+module_exit(dell_smbios_exit);
+
+MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
+MODULE_AUTHOR("Gabriele Mazzotta <gabriele.mzt@gmail.com>");
+MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
+MODULE_DESCRIPTION("Common functions for kernel modules using Dell SMBIOS");
+MODULE_LICENSE("GPL");