![Christoph Hellwig](/assets/img/avatar_default.png)
... and __initconst if applicable. Based on similar work for an older kernel in the Grsecurity patch. [JD: fix toshiba-wmi build] [JD: add htcpen] [JD: move __initconst where checkscript wants it] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jean Delvare <jdelvare@suse.de>
942 lines
24 KiB
C
942 lines
24 KiB
C
/*
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* Copyright 2010 Google Inc. All Rights Reserved.
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* Author: dlaurie@google.com (Duncan Laurie)
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*
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* Re-worked to expose sysfs APIs by mikew@google.com (Mike Waychison)
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*
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* EFI SMI interface for Google platforms
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/device.h>
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#include <linux/platform_device.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/spinlock.h>
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#include <linux/dma-mapping.h>
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#include <linux/dmapool.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/ioctl.h>
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#include <linux/acpi.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#include <linux/dmi.h>
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#include <linux/kdebug.h>
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#include <linux/reboot.h>
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#include <linux/efi.h>
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#include <linux/module.h>
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#include <linux/ucs2_string.h>
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#define GSMI_SHUTDOWN_CLEAN 0 /* Clean Shutdown */
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/* TODO(mikew@google.com): Tie in HARDLOCKUP_DETECTOR with NMIWDT */
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#define GSMI_SHUTDOWN_NMIWDT 1 /* NMI Watchdog */
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#define GSMI_SHUTDOWN_PANIC 2 /* Panic */
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#define GSMI_SHUTDOWN_OOPS 3 /* Oops */
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#define GSMI_SHUTDOWN_DIE 4 /* Die -- No longer meaningful */
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#define GSMI_SHUTDOWN_MCE 5 /* Machine Check */
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#define GSMI_SHUTDOWN_SOFTWDT 6 /* Software Watchdog */
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#define GSMI_SHUTDOWN_MBE 7 /* Uncorrected ECC */
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#define GSMI_SHUTDOWN_TRIPLE 8 /* Triple Fault */
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#define DRIVER_VERSION "1.0"
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#define GSMI_GUID_SIZE 16
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#define GSMI_BUF_SIZE 1024
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#define GSMI_BUF_ALIGN sizeof(u64)
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#define GSMI_CALLBACK 0xef
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/* SMI return codes */
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#define GSMI_SUCCESS 0x00
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#define GSMI_UNSUPPORTED2 0x03
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#define GSMI_LOG_FULL 0x0b
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#define GSMI_VAR_NOT_FOUND 0x0e
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#define GSMI_HANDSHAKE_SPIN 0x7d
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#define GSMI_HANDSHAKE_CF 0x7e
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#define GSMI_HANDSHAKE_NONE 0x7f
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#define GSMI_INVALID_PARAMETER 0x82
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#define GSMI_UNSUPPORTED 0x83
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#define GSMI_BUFFER_TOO_SMALL 0x85
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#define GSMI_NOT_READY 0x86
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#define GSMI_DEVICE_ERROR 0x87
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#define GSMI_NOT_FOUND 0x8e
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#define QUIRKY_BOARD_HASH 0x78a30a50
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/* Internally used commands passed to the firmware */
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#define GSMI_CMD_GET_NVRAM_VAR 0x01
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#define GSMI_CMD_GET_NEXT_VAR 0x02
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#define GSMI_CMD_SET_NVRAM_VAR 0x03
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#define GSMI_CMD_SET_EVENT_LOG 0x08
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#define GSMI_CMD_CLEAR_EVENT_LOG 0x09
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#define GSMI_CMD_CLEAR_CONFIG 0x20
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#define GSMI_CMD_HANDSHAKE_TYPE 0xC1
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/* Magic entry type for kernel events */
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#define GSMI_LOG_ENTRY_TYPE_KERNEL 0xDEAD
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/* SMI buffers must be in 32bit physical address space */
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struct gsmi_buf {
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u8 *start; /* start of buffer */
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size_t length; /* length of buffer */
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dma_addr_t handle; /* dma allocation handle */
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u32 address; /* physical address of buffer */
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};
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struct gsmi_device {
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struct platform_device *pdev; /* platform device */
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struct gsmi_buf *name_buf; /* variable name buffer */
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struct gsmi_buf *data_buf; /* generic data buffer */
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struct gsmi_buf *param_buf; /* parameter buffer */
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spinlock_t lock; /* serialize access to SMIs */
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u16 smi_cmd; /* SMI command port */
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int handshake_type; /* firmware handler interlock type */
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struct dma_pool *dma_pool; /* DMA buffer pool */
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} gsmi_dev;
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/* Packed structures for communicating with the firmware */
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struct gsmi_nvram_var_param {
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efi_guid_t guid;
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u32 name_ptr;
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u32 attributes;
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u32 data_len;
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u32 data_ptr;
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} __packed;
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struct gsmi_get_next_var_param {
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u8 guid[GSMI_GUID_SIZE];
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u32 name_ptr;
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u32 name_len;
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} __packed;
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struct gsmi_set_eventlog_param {
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u32 data_ptr;
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u32 data_len;
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u32 type;
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} __packed;
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/* Event log formats */
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struct gsmi_log_entry_type_1 {
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u16 type;
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u32 instance;
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} __packed;
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/*
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* Some platforms don't have explicit SMI handshake
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* and need to wait for SMI to complete.
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*/
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#define GSMI_DEFAULT_SPINCOUNT 0x10000
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static unsigned int spincount = GSMI_DEFAULT_SPINCOUNT;
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module_param(spincount, uint, 0600);
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MODULE_PARM_DESC(spincount,
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"The number of loop iterations to use when using the spin handshake.");
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static struct gsmi_buf *gsmi_buf_alloc(void)
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{
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struct gsmi_buf *smibuf;
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smibuf = kzalloc(sizeof(*smibuf), GFP_KERNEL);
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if (!smibuf) {
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printk(KERN_ERR "gsmi: out of memory\n");
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return NULL;
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}
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/* allocate buffer in 32bit address space */
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smibuf->start = dma_pool_alloc(gsmi_dev.dma_pool, GFP_KERNEL,
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&smibuf->handle);
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if (!smibuf->start) {
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printk(KERN_ERR "gsmi: failed to allocate name buffer\n");
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kfree(smibuf);
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return NULL;
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}
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/* fill in the buffer handle */
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smibuf->length = GSMI_BUF_SIZE;
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smibuf->address = (u32)virt_to_phys(smibuf->start);
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return smibuf;
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}
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static void gsmi_buf_free(struct gsmi_buf *smibuf)
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{
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if (smibuf) {
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if (smibuf->start)
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dma_pool_free(gsmi_dev.dma_pool, smibuf->start,
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smibuf->handle);
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kfree(smibuf);
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}
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}
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/*
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* Make a call to gsmi func(sub). GSMI error codes are translated to
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* in-kernel errnos (0 on success, -ERRNO on error).
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*/
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static int gsmi_exec(u8 func, u8 sub)
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{
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u16 cmd = (sub << 8) | func;
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u16 result = 0;
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int rc = 0;
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/*
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* AH : Subfunction number
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* AL : Function number
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* EBX : Parameter block address
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* DX : SMI command port
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*
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* Three protocols here. See also the comment in gsmi_init().
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*/
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if (gsmi_dev.handshake_type == GSMI_HANDSHAKE_CF) {
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/*
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* If handshake_type == HANDSHAKE_CF then set CF on the
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* way in and wait for the handler to clear it; this avoids
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* corrupting register state on those chipsets which have
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* a delay between writing the SMI trigger register and
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* entering SMM.
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*/
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asm volatile (
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"stc\n"
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"outb %%al, %%dx\n"
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"1: jc 1b\n"
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: "=a" (result)
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: "0" (cmd),
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"d" (gsmi_dev.smi_cmd),
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"b" (gsmi_dev.param_buf->address)
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: "memory", "cc"
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);
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} else if (gsmi_dev.handshake_type == GSMI_HANDSHAKE_SPIN) {
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/*
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* If handshake_type == HANDSHAKE_SPIN we spin a
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* hundred-ish usecs to ensure the SMI has triggered.
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*/
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asm volatile (
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"outb %%al, %%dx\n"
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"1: loop 1b\n"
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: "=a" (result)
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: "0" (cmd),
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"d" (gsmi_dev.smi_cmd),
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"b" (gsmi_dev.param_buf->address),
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"c" (spincount)
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: "memory", "cc"
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);
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} else {
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/*
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* If handshake_type == HANDSHAKE_NONE we do nothing;
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* either we don't need to or it's legacy firmware that
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* doesn't understand the CF protocol.
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*/
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asm volatile (
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"outb %%al, %%dx\n\t"
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: "=a" (result)
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: "0" (cmd),
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"d" (gsmi_dev.smi_cmd),
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"b" (gsmi_dev.param_buf->address)
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: "memory", "cc"
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);
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}
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/* check return code from SMI handler */
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switch (result) {
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case GSMI_SUCCESS:
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break;
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case GSMI_VAR_NOT_FOUND:
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/* not really an error, but let the caller know */
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rc = 1;
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break;
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case GSMI_INVALID_PARAMETER:
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printk(KERN_ERR "gsmi: exec 0x%04x: Invalid parameter\n", cmd);
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rc = -EINVAL;
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break;
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case GSMI_BUFFER_TOO_SMALL:
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printk(KERN_ERR "gsmi: exec 0x%04x: Buffer too small\n", cmd);
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rc = -ENOMEM;
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break;
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case GSMI_UNSUPPORTED:
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case GSMI_UNSUPPORTED2:
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if (sub != GSMI_CMD_HANDSHAKE_TYPE)
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printk(KERN_ERR "gsmi: exec 0x%04x: Not supported\n",
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cmd);
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rc = -ENOSYS;
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break;
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case GSMI_NOT_READY:
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printk(KERN_ERR "gsmi: exec 0x%04x: Not ready\n", cmd);
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rc = -EBUSY;
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break;
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case GSMI_DEVICE_ERROR:
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printk(KERN_ERR "gsmi: exec 0x%04x: Device error\n", cmd);
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rc = -EFAULT;
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break;
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case GSMI_NOT_FOUND:
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printk(KERN_ERR "gsmi: exec 0x%04x: Data not found\n", cmd);
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rc = -ENOENT;
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break;
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case GSMI_LOG_FULL:
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printk(KERN_ERR "gsmi: exec 0x%04x: Log full\n", cmd);
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rc = -ENOSPC;
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break;
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case GSMI_HANDSHAKE_CF:
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case GSMI_HANDSHAKE_SPIN:
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case GSMI_HANDSHAKE_NONE:
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rc = result;
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break;
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default:
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printk(KERN_ERR "gsmi: exec 0x%04x: Unknown error 0x%04x\n",
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cmd, result);
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rc = -ENXIO;
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}
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return rc;
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}
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static efi_status_t gsmi_get_variable(efi_char16_t *name,
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efi_guid_t *vendor, u32 *attr,
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unsigned long *data_size,
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void *data)
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{
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struct gsmi_nvram_var_param param = {
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.name_ptr = gsmi_dev.name_buf->address,
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.data_ptr = gsmi_dev.data_buf->address,
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.data_len = (u32)*data_size,
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};
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efi_status_t ret = EFI_SUCCESS;
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unsigned long flags;
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size_t name_len = ucs2_strnlen(name, GSMI_BUF_SIZE / 2);
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int rc;
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if (name_len >= GSMI_BUF_SIZE / 2)
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return EFI_BAD_BUFFER_SIZE;
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spin_lock_irqsave(&gsmi_dev.lock, flags);
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/* Vendor guid */
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memcpy(¶m.guid, vendor, sizeof(param.guid));
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/* variable name, already in UTF-16 */
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memset(gsmi_dev.name_buf->start, 0, gsmi_dev.name_buf->length);
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memcpy(gsmi_dev.name_buf->start, name, name_len * 2);
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/* data pointer */
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memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
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/* parameter buffer */
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memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
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memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
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rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_GET_NVRAM_VAR);
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if (rc < 0) {
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printk(KERN_ERR "gsmi: Get Variable failed\n");
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ret = EFI_LOAD_ERROR;
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} else if (rc == 1) {
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/* variable was not found */
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ret = EFI_NOT_FOUND;
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} else {
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/* Get the arguments back */
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memcpy(¶m, gsmi_dev.param_buf->start, sizeof(param));
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/* The size reported is the min of all of our buffers */
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*data_size = min_t(unsigned long, *data_size,
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gsmi_dev.data_buf->length);
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*data_size = min_t(unsigned long, *data_size, param.data_len);
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/* Copy data back to return buffer. */
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memcpy(data, gsmi_dev.data_buf->start, *data_size);
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/* All variables are have the following attributes */
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*attr = EFI_VARIABLE_NON_VOLATILE |
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EFI_VARIABLE_BOOTSERVICE_ACCESS |
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EFI_VARIABLE_RUNTIME_ACCESS;
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}
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spin_unlock_irqrestore(&gsmi_dev.lock, flags);
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return ret;
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}
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static efi_status_t gsmi_get_next_variable(unsigned long *name_size,
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efi_char16_t *name,
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efi_guid_t *vendor)
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{
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struct gsmi_get_next_var_param param = {
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.name_ptr = gsmi_dev.name_buf->address,
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.name_len = gsmi_dev.name_buf->length,
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};
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efi_status_t ret = EFI_SUCCESS;
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int rc;
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unsigned long flags;
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/* For the moment, only support buffers that exactly match in size */
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if (*name_size != GSMI_BUF_SIZE)
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return EFI_BAD_BUFFER_SIZE;
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/* Let's make sure the thing is at least null-terminated */
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if (ucs2_strnlen(name, GSMI_BUF_SIZE / 2) == GSMI_BUF_SIZE / 2)
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return EFI_INVALID_PARAMETER;
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spin_lock_irqsave(&gsmi_dev.lock, flags);
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/* guid */
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memcpy(¶m.guid, vendor, sizeof(param.guid));
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/* variable name, already in UTF-16 */
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memcpy(gsmi_dev.name_buf->start, name, *name_size);
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/* parameter buffer */
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memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
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memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
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rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_GET_NEXT_VAR);
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if (rc < 0) {
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printk(KERN_ERR "gsmi: Get Next Variable Name failed\n");
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ret = EFI_LOAD_ERROR;
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} else if (rc == 1) {
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/* variable not found -- end of list */
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ret = EFI_NOT_FOUND;
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} else {
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/* copy variable data back to return buffer */
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memcpy(¶m, gsmi_dev.param_buf->start, sizeof(param));
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/* Copy the name back */
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memcpy(name, gsmi_dev.name_buf->start, GSMI_BUF_SIZE);
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*name_size = ucs2_strnlen(name, GSMI_BUF_SIZE / 2) * 2;
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/* copy guid to return buffer */
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memcpy(vendor, ¶m.guid, sizeof(param.guid));
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ret = EFI_SUCCESS;
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}
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spin_unlock_irqrestore(&gsmi_dev.lock, flags);
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return ret;
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}
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static efi_status_t gsmi_set_variable(efi_char16_t *name,
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efi_guid_t *vendor,
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u32 attr,
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unsigned long data_size,
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void *data)
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{
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struct gsmi_nvram_var_param param = {
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.name_ptr = gsmi_dev.name_buf->address,
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.data_ptr = gsmi_dev.data_buf->address,
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.data_len = (u32)data_size,
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.attributes = EFI_VARIABLE_NON_VOLATILE |
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EFI_VARIABLE_BOOTSERVICE_ACCESS |
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EFI_VARIABLE_RUNTIME_ACCESS,
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};
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size_t name_len = ucs2_strnlen(name, GSMI_BUF_SIZE / 2);
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efi_status_t ret = EFI_SUCCESS;
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int rc;
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unsigned long flags;
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if (name_len >= GSMI_BUF_SIZE / 2)
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return EFI_BAD_BUFFER_SIZE;
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spin_lock_irqsave(&gsmi_dev.lock, flags);
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/* guid */
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memcpy(¶m.guid, vendor, sizeof(param.guid));
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/* variable name, already in UTF-16 */
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memset(gsmi_dev.name_buf->start, 0, gsmi_dev.name_buf->length);
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memcpy(gsmi_dev.name_buf->start, name, name_len * 2);
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/* data pointer */
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memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
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memcpy(gsmi_dev.data_buf->start, data, data_size);
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/* parameter buffer */
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memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
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memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
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rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_NVRAM_VAR);
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if (rc < 0) {
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printk(KERN_ERR "gsmi: Set Variable failed\n");
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ret = EFI_INVALID_PARAMETER;
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}
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spin_unlock_irqrestore(&gsmi_dev.lock, flags);
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return ret;
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}
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static const struct efivar_operations efivar_ops = {
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.get_variable = gsmi_get_variable,
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.set_variable = gsmi_set_variable,
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.get_next_variable = gsmi_get_next_variable,
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};
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static ssize_t eventlog_write(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t pos, size_t count)
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{
|
|
struct gsmi_set_eventlog_param param = {
|
|
.data_ptr = gsmi_dev.data_buf->address,
|
|
};
|
|
int rc = 0;
|
|
unsigned long flags;
|
|
|
|
/* Pull the type out */
|
|
if (count < sizeof(u32))
|
|
return -EINVAL;
|
|
param.type = *(u32 *)buf;
|
|
count -= sizeof(u32);
|
|
buf += sizeof(u32);
|
|
|
|
/* The remaining buffer is the data payload */
|
|
if (count > gsmi_dev.data_buf->length)
|
|
return -EINVAL;
|
|
param.data_len = count - sizeof(u32);
|
|
|
|
spin_lock_irqsave(&gsmi_dev.lock, flags);
|
|
|
|
/* data pointer */
|
|
memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
|
|
memcpy(gsmi_dev.data_buf->start, buf, param.data_len);
|
|
|
|
/* parameter buffer */
|
|
memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
|
|
memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
|
|
|
|
rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_EVENT_LOG);
|
|
if (rc < 0)
|
|
printk(KERN_ERR "gsmi: Set Event Log failed\n");
|
|
|
|
spin_unlock_irqrestore(&gsmi_dev.lock, flags);
|
|
|
|
return rc;
|
|
|
|
}
|
|
|
|
static struct bin_attribute eventlog_bin_attr = {
|
|
.attr = {.name = "append_to_eventlog", .mode = 0200},
|
|
.write = eventlog_write,
|
|
};
|
|
|
|
static ssize_t gsmi_clear_eventlog_store(struct kobject *kobj,
|
|
struct kobj_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
int rc;
|
|
unsigned long flags;
|
|
unsigned long val;
|
|
struct {
|
|
u32 percentage;
|
|
u32 data_type;
|
|
} param;
|
|
|
|
rc = kstrtoul(buf, 0, &val);
|
|
if (rc)
|
|
return rc;
|
|
|
|
/*
|
|
* Value entered is a percentage, 0 through 100, anything else
|
|
* is invalid.
|
|
*/
|
|
if (val > 100)
|
|
return -EINVAL;
|
|
|
|
/* data_type here selects the smbios event log. */
|
|
param.percentage = val;
|
|
param.data_type = 0;
|
|
|
|
spin_lock_irqsave(&gsmi_dev.lock, flags);
|
|
|
|
/* parameter buffer */
|
|
memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
|
|
memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
|
|
|
|
rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_CLEAR_EVENT_LOG);
|
|
|
|
spin_unlock_irqrestore(&gsmi_dev.lock, flags);
|
|
|
|
if (rc)
|
|
return rc;
|
|
return count;
|
|
}
|
|
|
|
static struct kobj_attribute gsmi_clear_eventlog_attr = {
|
|
.attr = {.name = "clear_eventlog", .mode = 0200},
|
|
.store = gsmi_clear_eventlog_store,
|
|
};
|
|
|
|
static ssize_t gsmi_clear_config_store(struct kobject *kobj,
|
|
struct kobj_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
int rc;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&gsmi_dev.lock, flags);
|
|
|
|
/* clear parameter buffer */
|
|
memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
|
|
|
|
rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_CLEAR_CONFIG);
|
|
|
|
spin_unlock_irqrestore(&gsmi_dev.lock, flags);
|
|
|
|
if (rc)
|
|
return rc;
|
|
return count;
|
|
}
|
|
|
|
static struct kobj_attribute gsmi_clear_config_attr = {
|
|
.attr = {.name = "clear_config", .mode = 0200},
|
|
.store = gsmi_clear_config_store,
|
|
};
|
|
|
|
static const struct attribute *gsmi_attrs[] = {
|
|
&gsmi_clear_config_attr.attr,
|
|
&gsmi_clear_eventlog_attr.attr,
|
|
NULL,
|
|
};
|
|
|
|
static int gsmi_shutdown_reason(int reason)
|
|
{
|
|
struct gsmi_log_entry_type_1 entry = {
|
|
.type = GSMI_LOG_ENTRY_TYPE_KERNEL,
|
|
.instance = reason,
|
|
};
|
|
struct gsmi_set_eventlog_param param = {
|
|
.data_len = sizeof(entry),
|
|
.type = 1,
|
|
};
|
|
static int saved_reason;
|
|
int rc = 0;
|
|
unsigned long flags;
|
|
|
|
/* avoid duplicate entries in the log */
|
|
if (saved_reason & (1 << reason))
|
|
return 0;
|
|
|
|
spin_lock_irqsave(&gsmi_dev.lock, flags);
|
|
|
|
saved_reason |= (1 << reason);
|
|
|
|
/* data pointer */
|
|
memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
|
|
memcpy(gsmi_dev.data_buf->start, &entry, sizeof(entry));
|
|
|
|
/* parameter buffer */
|
|
param.data_ptr = gsmi_dev.data_buf->address;
|
|
memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
|
|
memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
|
|
|
|
rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_EVENT_LOG);
|
|
|
|
spin_unlock_irqrestore(&gsmi_dev.lock, flags);
|
|
|
|
if (rc < 0)
|
|
printk(KERN_ERR "gsmi: Log Shutdown Reason failed\n");
|
|
else
|
|
printk(KERN_EMERG "gsmi: Log Shutdown Reason 0x%02x\n",
|
|
reason);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int gsmi_reboot_callback(struct notifier_block *nb,
|
|
unsigned long reason, void *arg)
|
|
{
|
|
gsmi_shutdown_reason(GSMI_SHUTDOWN_CLEAN);
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct notifier_block gsmi_reboot_notifier = {
|
|
.notifier_call = gsmi_reboot_callback
|
|
};
|
|
|
|
static int gsmi_die_callback(struct notifier_block *nb,
|
|
unsigned long reason, void *arg)
|
|
{
|
|
if (reason == DIE_OOPS)
|
|
gsmi_shutdown_reason(GSMI_SHUTDOWN_OOPS);
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct notifier_block gsmi_die_notifier = {
|
|
.notifier_call = gsmi_die_callback
|
|
};
|
|
|
|
static int gsmi_panic_callback(struct notifier_block *nb,
|
|
unsigned long reason, void *arg)
|
|
{
|
|
gsmi_shutdown_reason(GSMI_SHUTDOWN_PANIC);
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct notifier_block gsmi_panic_notifier = {
|
|
.notifier_call = gsmi_panic_callback,
|
|
};
|
|
|
|
/*
|
|
* This hash function was blatantly copied from include/linux/hash.h.
|
|
* It is used by this driver to obfuscate a board name that requires a
|
|
* quirk within this driver.
|
|
*
|
|
* Please do not remove this copy of the function as any changes to the
|
|
* global utility hash_64() function would break this driver's ability
|
|
* to identify a board and provide the appropriate quirk -- mikew@google.com
|
|
*/
|
|
static u64 __init local_hash_64(u64 val, unsigned bits)
|
|
{
|
|
u64 hash = val;
|
|
|
|
/* Sigh, gcc can't optimise this alone like it does for 32 bits. */
|
|
u64 n = hash;
|
|
n <<= 18;
|
|
hash -= n;
|
|
n <<= 33;
|
|
hash -= n;
|
|
n <<= 3;
|
|
hash += n;
|
|
n <<= 3;
|
|
hash -= n;
|
|
n <<= 4;
|
|
hash += n;
|
|
n <<= 2;
|
|
hash += n;
|
|
|
|
/* High bits are more random, so use them. */
|
|
return hash >> (64 - bits);
|
|
}
|
|
|
|
static u32 __init hash_oem_table_id(char s[8])
|
|
{
|
|
u64 input;
|
|
memcpy(&input, s, 8);
|
|
return local_hash_64(input, 32);
|
|
}
|
|
|
|
static const struct dmi_system_id gsmi_dmi_table[] __initconst = {
|
|
{
|
|
.ident = "Google Board",
|
|
.matches = {
|
|
DMI_MATCH(DMI_BOARD_VENDOR, "Google, Inc."),
|
|
},
|
|
},
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(dmi, gsmi_dmi_table);
|
|
|
|
static __init int gsmi_system_valid(void)
|
|
{
|
|
u32 hash;
|
|
|
|
if (!dmi_check_system(gsmi_dmi_table))
|
|
return -ENODEV;
|
|
|
|
/*
|
|
* Only newer firmware supports the gsmi interface. All older
|
|
* firmware that didn't support this interface used to plug the
|
|
* table name in the first four bytes of the oem_table_id field.
|
|
* Newer firmware doesn't do that though, so use that as the
|
|
* discriminant factor. We have to do this in order to
|
|
* whitewash our board names out of the public driver.
|
|
*/
|
|
if (!strncmp(acpi_gbl_FADT.header.oem_table_id, "FACP", 4)) {
|
|
printk(KERN_INFO "gsmi: Board is too old\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
/* Disable on board with 1.0 BIOS due to Google bug 2602657 */
|
|
hash = hash_oem_table_id(acpi_gbl_FADT.header.oem_table_id);
|
|
if (hash == QUIRKY_BOARD_HASH) {
|
|
const char *bios_ver = dmi_get_system_info(DMI_BIOS_VERSION);
|
|
if (strncmp(bios_ver, "1.0", 3) == 0) {
|
|
pr_info("gsmi: disabled on this board's BIOS %s\n",
|
|
bios_ver);
|
|
return -ENODEV;
|
|
}
|
|
}
|
|
|
|
/* check for valid SMI command port in ACPI FADT */
|
|
if (acpi_gbl_FADT.smi_command == 0) {
|
|
pr_info("gsmi: missing smi_command\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
/* Found */
|
|
return 0;
|
|
}
|
|
|
|
static struct kobject *gsmi_kobj;
|
|
static struct efivars efivars;
|
|
|
|
static const struct platform_device_info gsmi_dev_info = {
|
|
.name = "gsmi",
|
|
.id = -1,
|
|
/* SMI callbacks require 32bit addresses */
|
|
.dma_mask = DMA_BIT_MASK(32),
|
|
};
|
|
|
|
static __init int gsmi_init(void)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
ret = gsmi_system_valid();
|
|
if (ret)
|
|
return ret;
|
|
|
|
gsmi_dev.smi_cmd = acpi_gbl_FADT.smi_command;
|
|
|
|
/* register device */
|
|
gsmi_dev.pdev = platform_device_register_full(&gsmi_dev_info);
|
|
if (IS_ERR(gsmi_dev.pdev)) {
|
|
printk(KERN_ERR "gsmi: unable to register platform device\n");
|
|
return PTR_ERR(gsmi_dev.pdev);
|
|
}
|
|
|
|
/* SMI access needs to be serialized */
|
|
spin_lock_init(&gsmi_dev.lock);
|
|
|
|
ret = -ENOMEM;
|
|
gsmi_dev.dma_pool = dma_pool_create("gsmi", &gsmi_dev.pdev->dev,
|
|
GSMI_BUF_SIZE, GSMI_BUF_ALIGN, 0);
|
|
if (!gsmi_dev.dma_pool)
|
|
goto out_err;
|
|
|
|
/*
|
|
* pre-allocate buffers because sometimes we are called when
|
|
* this is not feasible: oops, panic, die, mce, etc
|
|
*/
|
|
gsmi_dev.name_buf = gsmi_buf_alloc();
|
|
if (!gsmi_dev.name_buf) {
|
|
printk(KERN_ERR "gsmi: failed to allocate name buffer\n");
|
|
goto out_err;
|
|
}
|
|
|
|
gsmi_dev.data_buf = gsmi_buf_alloc();
|
|
if (!gsmi_dev.data_buf) {
|
|
printk(KERN_ERR "gsmi: failed to allocate data buffer\n");
|
|
goto out_err;
|
|
}
|
|
|
|
gsmi_dev.param_buf = gsmi_buf_alloc();
|
|
if (!gsmi_dev.param_buf) {
|
|
printk(KERN_ERR "gsmi: failed to allocate param buffer\n");
|
|
goto out_err;
|
|
}
|
|
|
|
/*
|
|
* Determine type of handshake used to serialize the SMI
|
|
* entry. See also gsmi_exec().
|
|
*
|
|
* There's a "behavior" present on some chipsets where writing the
|
|
* SMI trigger register in the southbridge doesn't result in an
|
|
* immediate SMI. Rather, the processor can execute "a few" more
|
|
* instructions before the SMI takes effect. To ensure synchronous
|
|
* behavior, implement a handshake between the kernel driver and the
|
|
* firmware handler to spin until released. This ioctl determines
|
|
* the type of handshake.
|
|
*
|
|
* NONE: The firmware handler does not implement any
|
|
* handshake. Either it doesn't need to, or it's legacy firmware
|
|
* that doesn't know it needs to and never will.
|
|
*
|
|
* CF: The firmware handler will clear the CF in the saved
|
|
* state before returning. The driver may set the CF and test for
|
|
* it to clear before proceeding.
|
|
*
|
|
* SPIN: The firmware handler does not implement any handshake
|
|
* but the driver should spin for a hundred or so microseconds
|
|
* to ensure the SMI has triggered.
|
|
*
|
|
* Finally, the handler will return -ENOSYS if
|
|
* GSMI_CMD_HANDSHAKE_TYPE is unimplemented, which implies
|
|
* HANDSHAKE_NONE.
|
|
*/
|
|
spin_lock_irqsave(&gsmi_dev.lock, flags);
|
|
gsmi_dev.handshake_type = GSMI_HANDSHAKE_SPIN;
|
|
gsmi_dev.handshake_type =
|
|
gsmi_exec(GSMI_CALLBACK, GSMI_CMD_HANDSHAKE_TYPE);
|
|
if (gsmi_dev.handshake_type == -ENOSYS)
|
|
gsmi_dev.handshake_type = GSMI_HANDSHAKE_NONE;
|
|
spin_unlock_irqrestore(&gsmi_dev.lock, flags);
|
|
|
|
/* Remove and clean up gsmi if the handshake could not complete. */
|
|
if (gsmi_dev.handshake_type == -ENXIO) {
|
|
printk(KERN_INFO "gsmi version " DRIVER_VERSION
|
|
" failed to load\n");
|
|
ret = -ENODEV;
|
|
goto out_err;
|
|
}
|
|
|
|
/* Register in the firmware directory */
|
|
ret = -ENOMEM;
|
|
gsmi_kobj = kobject_create_and_add("gsmi", firmware_kobj);
|
|
if (!gsmi_kobj) {
|
|
printk(KERN_INFO "gsmi: Failed to create firmware kobj\n");
|
|
goto out_err;
|
|
}
|
|
|
|
/* Setup eventlog access */
|
|
ret = sysfs_create_bin_file(gsmi_kobj, &eventlog_bin_attr);
|
|
if (ret) {
|
|
printk(KERN_INFO "gsmi: Failed to setup eventlog");
|
|
goto out_err;
|
|
}
|
|
|
|
/* Other attributes */
|
|
ret = sysfs_create_files(gsmi_kobj, gsmi_attrs);
|
|
if (ret) {
|
|
printk(KERN_INFO "gsmi: Failed to add attrs");
|
|
goto out_remove_bin_file;
|
|
}
|
|
|
|
ret = efivars_register(&efivars, &efivar_ops, gsmi_kobj);
|
|
if (ret) {
|
|
printk(KERN_INFO "gsmi: Failed to register efivars\n");
|
|
goto out_remove_sysfs_files;
|
|
}
|
|
|
|
register_reboot_notifier(&gsmi_reboot_notifier);
|
|
register_die_notifier(&gsmi_die_notifier);
|
|
atomic_notifier_chain_register(&panic_notifier_list,
|
|
&gsmi_panic_notifier);
|
|
|
|
printk(KERN_INFO "gsmi version " DRIVER_VERSION " loaded\n");
|
|
|
|
return 0;
|
|
|
|
out_remove_sysfs_files:
|
|
sysfs_remove_files(gsmi_kobj, gsmi_attrs);
|
|
out_remove_bin_file:
|
|
sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr);
|
|
out_err:
|
|
kobject_put(gsmi_kobj);
|
|
gsmi_buf_free(gsmi_dev.param_buf);
|
|
gsmi_buf_free(gsmi_dev.data_buf);
|
|
gsmi_buf_free(gsmi_dev.name_buf);
|
|
dma_pool_destroy(gsmi_dev.dma_pool);
|
|
platform_device_unregister(gsmi_dev.pdev);
|
|
pr_info("gsmi: failed to load: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
static void __exit gsmi_exit(void)
|
|
{
|
|
unregister_reboot_notifier(&gsmi_reboot_notifier);
|
|
unregister_die_notifier(&gsmi_die_notifier);
|
|
atomic_notifier_chain_unregister(&panic_notifier_list,
|
|
&gsmi_panic_notifier);
|
|
efivars_unregister(&efivars);
|
|
|
|
sysfs_remove_files(gsmi_kobj, gsmi_attrs);
|
|
sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr);
|
|
kobject_put(gsmi_kobj);
|
|
gsmi_buf_free(gsmi_dev.param_buf);
|
|
gsmi_buf_free(gsmi_dev.data_buf);
|
|
gsmi_buf_free(gsmi_dev.name_buf);
|
|
dma_pool_destroy(gsmi_dev.dma_pool);
|
|
platform_device_unregister(gsmi_dev.pdev);
|
|
}
|
|
|
|
module_init(gsmi_init);
|
|
module_exit(gsmi_exit);
|
|
|
|
MODULE_AUTHOR("Google, Inc.");
|
|
MODULE_LICENSE("GPL");
|