diff options
Diffstat (limited to 'drivers/firmware/google/gsmi.c')
| -rw-r--r-- | drivers/firmware/google/gsmi.c | 236 |
1 files changed, 193 insertions, 43 deletions
diff --git a/drivers/firmware/google/gsmi.c b/drivers/firmware/google/gsmi.c index acba0b9f4406..0ceccde5a302 100644 --- a/drivers/firmware/google/gsmi.c +++ b/drivers/firmware/google/gsmi.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2010 Google Inc. All Rights Reserved. * Author: dlaurie@google.com (Duncan Laurie) @@ -16,9 +17,9 @@ #include <linux/string.h> #include <linux/spinlock.h> #include <linux/dma-mapping.h> -#include <linux/dmapool.h> #include <linux/fs.h> #include <linux/slab.h> +#include <linux/panic_notifier.h> #include <linux/ioctl.h> #include <linux/acpi.h> #include <linux/io.h> @@ -29,6 +30,7 @@ #include <linux/efi.h> #include <linux/module.h> #include <linux/ucs2_string.h> +#include <linux/suspend.h> #define GSMI_SHUTDOWN_CLEAN 0 /* Clean Shutdown */ /* TODO(mikew@google.com): Tie in HARDLOCKUP_DETECTOR with NMIWDT */ @@ -70,8 +72,11 @@ #define GSMI_CMD_SET_NVRAM_VAR 0x03 #define GSMI_CMD_SET_EVENT_LOG 0x08 #define GSMI_CMD_CLEAR_EVENT_LOG 0x09 +#define GSMI_CMD_LOG_S0IX_SUSPEND 0x0a +#define GSMI_CMD_LOG_S0IX_RESUME 0x0b #define GSMI_CMD_CLEAR_CONFIG 0x20 #define GSMI_CMD_HANDSHAKE_TYPE 0xC1 +#define GSMI_CMD_RESERVED 0xff /* Magic entry type for kernel events */ #define GSMI_LOG_ENTRY_TYPE_KERNEL 0xDEAD @@ -80,11 +85,10 @@ struct gsmi_buf { u8 *start; /* start of buffer */ size_t length; /* length of buffer */ - dma_addr_t handle; /* dma allocation handle */ u32 address; /* physical address of buffer */ }; -struct gsmi_device { +static struct gsmi_device { struct platform_device *pdev; /* platform device */ struct gsmi_buf *name_buf; /* variable name buffer */ struct gsmi_buf *data_buf; /* generic data buffer */ @@ -92,7 +96,7 @@ struct gsmi_device { spinlock_t lock; /* serialize access to SMIs */ u16 smi_cmd; /* SMI command port */ int handshake_type; /* firmware handler interlock type */ - struct dma_pool *dma_pool; /* DMA buffer pool */ + struct kmem_cache *mem_pool; /* kmem cache for gsmi_buf allocations */ } gsmi_dev; /* Packed structures for communicating with the firmware */ @@ -122,7 +126,6 @@ struct gsmi_log_entry_type_1 { u32 instance; } __packed; - /* * Some platforms don't have explicit SMI handshake * and need to wait for SMI to complete. @@ -133,6 +136,19 @@ module_param(spincount, uint, 0600); MODULE_PARM_DESC(spincount, "The number of loop iterations to use when using the spin handshake."); +/* + * Some older platforms with Apollo Lake chipsets do not support S0ix logging + * in their GSMI handlers, and behaved poorly when resuming via power button + * press if the logging was attempted. Updated firmware with proper behavior + * has long since shipped, removing the need for this opt-in parameter. It + * now exists as an opt-out parameter for folks defiantly running old + * firmware, or unforeseen circumstances. After the change from opt-in to + * opt-out has baked sufficiently, this parameter should probably be removed + * entirely. + */ +static bool s0ix_logging_enable = true; +module_param(s0ix_logging_enable, bool, 0600); + static struct gsmi_buf *gsmi_buf_alloc(void) { struct gsmi_buf *smibuf; @@ -144,8 +160,7 @@ static struct gsmi_buf *gsmi_buf_alloc(void) } /* allocate buffer in 32bit address space */ - smibuf->start = dma_pool_alloc(gsmi_dev.dma_pool, GFP_KERNEL, - &smibuf->handle); + smibuf->start = kmem_cache_alloc(gsmi_dev.mem_pool, GFP_KERNEL); if (!smibuf->start) { printk(KERN_ERR "gsmi: failed to allocate name buffer\n"); kfree(smibuf); @@ -163,8 +178,7 @@ static void gsmi_buf_free(struct gsmi_buf *smibuf) { if (smibuf) { if (smibuf->start) - dma_pool_free(gsmi_dev.dma_pool, smibuf->start, - smibuf->handle); + kmem_cache_free(gsmi_dev.mem_pool, smibuf->start); kfree(smibuf); } } @@ -289,6 +303,10 @@ static int gsmi_exec(u8 func, u8 sub) return rc; } +#ifdef CONFIG_EFI + +static struct efivars efivars; + static efi_status_t gsmi_get_variable(efi_char16_t *name, efi_guid_t *vendor, u32 *attr, unsigned long *data_size, @@ -343,9 +361,10 @@ static efi_status_t gsmi_get_variable(efi_char16_t *name, memcpy(data, gsmi_dev.data_buf->start, *data_size); /* All variables are have the following attributes */ - *attr = EFI_VARIABLE_NON_VOLATILE | - EFI_VARIABLE_BOOTSERVICE_ACCESS | - EFI_VARIABLE_RUNTIME_ACCESS; + if (attr) + *attr = EFI_VARIABLE_NON_VOLATILE | + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS; } spin_unlock_irqrestore(&gsmi_dev.lock, flags); @@ -466,8 +485,10 @@ static const struct efivar_operations efivar_ops = { .get_next_variable = gsmi_get_next_variable, }; +#endif /* CONFIG_EFI */ + static ssize_t eventlog_write(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, + const struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t count) { struct gsmi_set_eventlog_param param = { @@ -480,11 +501,10 @@ static ssize_t eventlog_write(struct file *filp, struct kobject *kobj, 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) + if ((count - sizeof(u32)) > gsmi_dev.data_buf->length) return -EINVAL; param.data_len = count - sizeof(u32); @@ -504,11 +524,11 @@ static ssize_t eventlog_write(struct file *filp, struct kobject *kobj, spin_unlock_irqrestore(&gsmi_dev.lock, flags); - return rc; + return (rc == 0) ? count : rc; } -static struct bin_attribute eventlog_bin_attr = { +static const struct bin_attribute eventlog_bin_attr = { .attr = {.name = "append_to_eventlog", .mode = 0200}, .write = eventlog_write, }; @@ -525,7 +545,7 @@ static ssize_t gsmi_clear_eventlog_store(struct kobject *kobj, u32 data_type; } param; - rc = strict_strtoul(buf, 0, &val); + rc = kstrtoul(buf, 0, &val); if (rc) return rc; @@ -662,6 +682,15 @@ static struct notifier_block gsmi_die_notifier = { static int gsmi_panic_callback(struct notifier_block *nb, unsigned long reason, void *arg) { + + /* + * Panic callbacks are executed with all other CPUs stopped, + * so we must not attempt to spin waiting for gsmi_dev.lock + * to be released. + */ + if (spin_is_locked(&gsmi_dev.lock)) + return NOTIFY_DONE; + gsmi_shutdown_reason(GSMI_SHUTDOWN_PANIC); return NOTIFY_DONE; } @@ -709,13 +738,19 @@ static u32 __init hash_oem_table_id(char s[8]) return local_hash_64(input, 32); } -static struct dmi_system_id gsmi_dmi_table[] __initdata = { +static const struct dmi_system_id gsmi_dmi_table[] __initconst = { { .ident = "Google Board", .matches = { DMI_MATCH(DMI_BOARD_VENDOR, "Google, Inc."), }, }, + { + .ident = "Coreboot Firmware", + .matches = { + DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"), + }, + }, {} }; MODULE_DEVICE_TABLE(dmi, gsmi_dmi_table); @@ -723,6 +758,7 @@ MODULE_DEVICE_TABLE(dmi, gsmi_dmi_table); static __init int gsmi_system_valid(void) { u32 hash; + u16 cmd, result; if (!dmi_check_system(gsmi_dmi_table)) return -ENODEV; @@ -757,12 +793,107 @@ static __init int gsmi_system_valid(void) return -ENODEV; } + /* Test the smihandler with a bogus command. If it leaves the + * calling argument in %ax untouched, there is no handler for + * GSMI commands. + */ + cmd = GSMI_CALLBACK | GSMI_CMD_RESERVED << 8; + asm volatile ( + "outb %%al, %%dx\n\t" + : "=a" (result) + : "0" (cmd), + "d" (acpi_gbl_FADT.smi_command) + : "memory", "cc" + ); + if (cmd == result) { + pr_info("gsmi: no gsmi handler in firmware\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), +}; + +#ifdef CONFIG_PM +static void gsmi_log_s0ix_info(u8 cmd) +{ + unsigned long flags; + + /* + * If platform has not enabled S0ix logging, then no action is + * necessary. + */ + if (!s0ix_logging_enable) + return; + + spin_lock_irqsave(&gsmi_dev.lock, flags); + + memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); + + gsmi_exec(GSMI_CALLBACK, cmd); + + spin_unlock_irqrestore(&gsmi_dev.lock, flags); +} + +static int gsmi_log_s0ix_suspend(struct device *dev) +{ + /* + * If system is not suspending via firmware using the standard ACPI Sx + * types, then make a GSMI call to log the suspend info. + */ + if (!pm_suspend_via_firmware()) + gsmi_log_s0ix_info(GSMI_CMD_LOG_S0IX_SUSPEND); + + /* + * Always return success, since we do not want suspend + * to fail just because of logging failure. + */ + return 0; +} + +static int gsmi_log_s0ix_resume(struct device *dev) +{ + /* + * If system did not resume via firmware, then make a GSMI call to log + * the resume info and wake source. + */ + if (!pm_resume_via_firmware()) + gsmi_log_s0ix_info(GSMI_CMD_LOG_S0IX_RESUME); + + /* + * Always return success, since we do not want resume + * to fail just because of logging failure. + */ + return 0; +} + +static const struct dev_pm_ops gsmi_pm_ops = { + .suspend_noirq = gsmi_log_s0ix_suspend, + .resume_noirq = gsmi_log_s0ix_resume, +}; + +static int gsmi_platform_driver_probe(struct platform_device *dev) +{ + return 0; +} + +static struct platform_driver gsmi_driver_info = { + .driver = { + .name = "gsmi", + .pm = &gsmi_pm_ops, + }, + .probe = gsmi_platform_driver_probe, +}; +#endif static __init int gsmi_init(void) { @@ -775,24 +906,40 @@ static __init int gsmi_init(void) gsmi_dev.smi_cmd = acpi_gbl_FADT.smi_command; +#ifdef CONFIG_PM + ret = platform_driver_register(&gsmi_driver_info); + if (unlikely(ret)) { + printk(KERN_ERR "gsmi: unable to register platform driver\n"); + return ret; + } +#endif + /* register device */ - gsmi_dev.pdev = platform_device_register_simple("gsmi", -1, NULL, 0); + 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); + ret = PTR_ERR(gsmi_dev.pdev); + goto out_unregister; } /* SMI access needs to be serialized */ spin_lock_init(&gsmi_dev.lock); - /* SMI callbacks require 32bit addresses */ - gsmi_dev.pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32); - gsmi_dev.pdev->dev.dma_mask = - &gsmi_dev.pdev->dev.coherent_dma_mask; 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) + + /* + * SLAB cache is created using SLAB_CACHE_DMA32 to ensure that the + * allocations for gsmi_buf come from the DMA32 memory zone. These + * buffers have nothing to do with DMA. They are required for + * communication with firmware executing in SMI mode which can only + * access the bottom 4GiB of physical memory. Since DMA32 memory zone + * guarantees allocation under the 4GiB boundary, this driver creates + * a SLAB cache with SLAB_CACHE_DMA32 flag. + */ + gsmi_dev.mem_pool = kmem_cache_create("gsmi", GSMI_BUF_SIZE, + GSMI_BUF_ALIGN, + SLAB_CACHE_DMA32, NULL); + if (!gsmi_dev.mem_pool) goto out_err; /* @@ -883,18 +1030,14 @@ static __init int gsmi_init(void) goto out_remove_bin_file; } - ret = efivars_register(&efivars, &efivar_ops, gsmi_kobj); +#ifdef CONFIG_EFI + ret = efivars_register(&efivars, &efivar_ops); if (ret) { printk(KERN_INFO "gsmi: Failed to register efivars\n"); - goto out_remove_sysfs_files; - } - - ret = efivars_sysfs_init(); - if (ret) { - printk(KERN_INFO "gsmi: Failed to create efivars files\n"); - efivars_unregister(&efivars); - goto out_remove_sysfs_files; + sysfs_remove_files(gsmi_kobj, gsmi_attrs); + goto out_remove_bin_file; } +#endif register_reboot_notifier(&gsmi_reboot_notifier); register_die_notifier(&gsmi_die_notifier); @@ -905,8 +1048,6 @@ static __init int gsmi_init(void) 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: @@ -914,9 +1055,12 @@ out_err: gsmi_buf_free(gsmi_dev.param_buf); gsmi_buf_free(gsmi_dev.data_buf); gsmi_buf_free(gsmi_dev.name_buf); - if (gsmi_dev.dma_pool) - dma_pool_destroy(gsmi_dev.dma_pool); + kmem_cache_destroy(gsmi_dev.mem_pool); platform_device_unregister(gsmi_dev.pdev); +out_unregister: +#ifdef CONFIG_PM + platform_driver_unregister(&gsmi_driver_info); +#endif pr_info("gsmi: failed to load: %d\n", ret); return ret; } @@ -927,7 +1071,9 @@ static void __exit gsmi_exit(void) unregister_die_notifier(&gsmi_die_notifier); atomic_notifier_chain_unregister(&panic_notifier_list, &gsmi_panic_notifier); +#ifdef CONFIG_EFI efivars_unregister(&efivars); +#endif sysfs_remove_files(gsmi_kobj, gsmi_attrs); sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr); @@ -935,12 +1081,16 @@ static void __exit gsmi_exit(void) 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); + kmem_cache_destroy(gsmi_dev.mem_pool); platform_device_unregister(gsmi_dev.pdev); +#ifdef CONFIG_PM + platform_driver_unregister(&gsmi_driver_info); +#endif } module_init(gsmi_init); module_exit(gsmi_exit); MODULE_AUTHOR("Google, Inc."); +MODULE_DESCRIPTION("EFI SMI interface for Google platforms"); MODULE_LICENSE("GPL"); |