diff options
Diffstat (limited to 'Documentation/arch/ia64')
| -rw-r--r-- | Documentation/arch/ia64/aliasing.rst | 246 | ||||
| -rw-r--r-- | Documentation/arch/ia64/efirtc.rst | 144 | ||||
| -rw-r--r-- | Documentation/arch/ia64/err_inject.rst | 1067 | ||||
| -rw-r--r-- | Documentation/arch/ia64/features.rst | 3 | ||||
| -rw-r--r-- | Documentation/arch/ia64/fsys.rst | 303 | ||||
| -rw-r--r-- | Documentation/arch/ia64/ia64.rst | 49 | ||||
| -rw-r--r-- | Documentation/arch/ia64/index.rst | 19 | ||||
| -rw-r--r-- | Documentation/arch/ia64/irq-redir.rst | 80 | ||||
| -rw-r--r-- | Documentation/arch/ia64/mca.rst | 198 | ||||
| -rw-r--r-- | Documentation/arch/ia64/serial.rst | 165 |
10 files changed, 0 insertions, 2274 deletions
diff --git a/Documentation/arch/ia64/aliasing.rst b/Documentation/arch/ia64/aliasing.rst deleted file mode 100644 index 36a1e1d484..0000000000 --- a/Documentation/arch/ia64/aliasing.rst +++ /dev/null @@ -1,246 +0,0 @@ -================================== -Memory Attribute Aliasing on IA-64 -================================== - -Bjorn Helgaas <bjorn.helgaas@hp.com> - -May 4, 2006 - - -Memory Attributes -================= - - Itanium supports several attributes for virtual memory references. - The attribute is part of the virtual translation, i.e., it is - contained in the TLB entry. The ones of most interest to the Linux - kernel are: - - == ====================== - WB Write-back (cacheable) - UC Uncacheable - WC Write-coalescing - == ====================== - - System memory typically uses the WB attribute. The UC attribute is - used for memory-mapped I/O devices. The WC attribute is uncacheable - like UC is, but writes may be delayed and combined to increase - performance for things like frame buffers. - - The Itanium architecture requires that we avoid accessing the same - page with both a cacheable mapping and an uncacheable mapping[1]. - - The design of the chipset determines which attributes are supported - on which regions of the address space. For example, some chipsets - support either WB or UC access to main memory, while others support - only WB access. - -Memory Map -========== - - Platform firmware describes the physical memory map and the - supported attributes for each region. At boot-time, the kernel uses - the EFI GetMemoryMap() interface. ACPI can also describe memory - devices and the attributes they support, but Linux/ia64 currently - doesn't use this information. - - The kernel uses the efi_memmap table returned from GetMemoryMap() to - learn the attributes supported by each region of physical address - space. Unfortunately, this table does not completely describe the - address space because some machines omit some or all of the MMIO - regions from the map. - - The kernel maintains another table, kern_memmap, which describes the - memory Linux is actually using and the attribute for each region. - This contains only system memory; it does not contain MMIO space. - - The kern_memmap table typically contains only a subset of the system - memory described by the efi_memmap. Linux/ia64 can't use all memory - in the system because of constraints imposed by the identity mapping - scheme. - - The efi_memmap table is preserved unmodified because the original - boot-time information is required for kexec. - -Kernel Identity Mappings -======================== - - Linux/ia64 identity mappings are done with large pages, currently - either 16MB or 64MB, referred to as "granules." Cacheable mappings - are speculative[2], so the processor can read any location in the - page at any time, independent of the programmer's intentions. This - means that to avoid attribute aliasing, Linux can create a cacheable - identity mapping only when the entire granule supports cacheable - access. - - Therefore, kern_memmap contains only full granule-sized regions that - can referenced safely by an identity mapping. - - Uncacheable mappings are not speculative, so the processor will - generate UC accesses only to locations explicitly referenced by - software. This allows UC identity mappings to cover granules that - are only partially populated, or populated with a combination of UC - and WB regions. - -User Mappings -============= - - User mappings are typically done with 16K or 64K pages. The smaller - page size allows more flexibility because only 16K or 64K has to be - homogeneous with respect to memory attributes. - -Potential Attribute Aliasing Cases -================================== - - There are several ways the kernel creates new mappings: - -mmap of /dev/mem ----------------- - - This uses remap_pfn_range(), which creates user mappings. These - mappings may be either WB or UC. If the region being mapped - happens to be in kern_memmap, meaning that it may also be mapped - by a kernel identity mapping, the user mapping must use the same - attribute as the kernel mapping. - - If the region is not in kern_memmap, the user mapping should use - an attribute reported as being supported in the EFI memory map. - - Since the EFI memory map does not describe MMIO on some - machines, this should use an uncacheable mapping as a fallback. - -mmap of /sys/class/pci_bus/.../legacy_mem ------------------------------------------ - - This is very similar to mmap of /dev/mem, except that legacy_mem - only allows mmap of the one megabyte "legacy MMIO" area for a - specific PCI bus. Typically this is the first megabyte of - physical address space, but it may be different on machines with - several VGA devices. - - "X" uses this to access VGA frame buffers. Using legacy_mem - rather than /dev/mem allows multiple instances of X to talk to - different VGA cards. - - The /dev/mem mmap constraints apply. - -mmap of /proc/bus/pci/.../??.? ------------------------------- - - This is an MMIO mmap of PCI functions, which additionally may or - may not be requested as using the WC attribute. - - If WC is requested, and the region in kern_memmap is either WC - or UC, and the EFI memory map designates the region as WC, then - the WC mapping is allowed. - - Otherwise, the user mapping must use the same attribute as the - kernel mapping. - -read/write of /dev/mem ----------------------- - - This uses copy_from_user(), which implicitly uses a kernel - identity mapping. This is obviously safe for things in - kern_memmap. - - There may be corner cases of things that are not in kern_memmap, - but could be accessed this way. For example, registers in MMIO - space are not in kern_memmap, but could be accessed with a UC - mapping. This would not cause attribute aliasing. But - registers typically can be accessed only with four-byte or - eight-byte accesses, and the copy_from_user() path doesn't allow - any control over the access size, so this would be dangerous. - -ioremap() ---------- - - This returns a mapping for use inside the kernel. - - If the region is in kern_memmap, we should use the attribute - specified there. - - If the EFI memory map reports that the entire granule supports - WB, we should use that (granules that are partially reserved - or occupied by firmware do not appear in kern_memmap). - - If the granule contains non-WB memory, but we can cover the - region safely with kernel page table mappings, we can use - ioremap_page_range() as most other architectures do. - - Failing all of the above, we have to fall back to a UC mapping. - -Past Problem Cases -================== - -mmap of various MMIO regions from /dev/mem by "X" on Intel platforms --------------------------------------------------------------------- - - The EFI memory map may not report these MMIO regions. - - These must be allowed so that X will work. This means that - when the EFI memory map is incomplete, every /dev/mem mmap must - succeed. It may create either WB or UC user mappings, depending - on whether the region is in kern_memmap or the EFI memory map. - -mmap of 0x0-0x9FFFF /dev/mem by "hwinfo" on HP sx1000 with VGA enabled ----------------------------------------------------------------------- - - The EFI memory map reports the following attributes: - - =============== ======= ================== - 0x00000-0x9FFFF WB only - 0xA0000-0xBFFFF UC only (VGA frame buffer) - 0xC0000-0xFFFFF WB only - =============== ======= ================== - - This mmap is done with user pages, not kernel identity mappings, - so it is safe to use WB mappings. - - The kernel VGA driver may ioremap the VGA frame buffer at 0xA0000, - which uses a granule-sized UC mapping. This granule will cover some - WB-only memory, but since UC is non-speculative, the processor will - never generate an uncacheable reference to the WB-only areas unless - the driver explicitly touches them. - -mmap of 0x0-0xFFFFF legacy_mem by "X" -------------------------------------- - - If the EFI memory map reports that the entire range supports the - same attributes, we can allow the mmap (and we will prefer WB if - supported, as is the case with HP sx[12]000 machines with VGA - disabled). - - If EFI reports the range as partly WB and partly UC (as on sx[12]000 - machines with VGA enabled), we must fail the mmap because there's no - safe attribute to use. - - If EFI reports some of the range but not all (as on Intel firmware - that doesn't report the VGA frame buffer at all), we should fail the - mmap and force the user to map just the specific region of interest. - -mmap of 0xA0000-0xBFFFF legacy_mem by "X" on HP sx1000 with VGA disabled ------------------------------------------------------------------------- - - The EFI memory map reports the following attributes:: - - 0x00000-0xFFFFF WB only (no VGA MMIO hole) - - This is a special case of the previous case, and the mmap should - fail for the same reason as above. - -read of /sys/devices/.../rom ----------------------------- - - For VGA devices, this may cause an ioremap() of 0xC0000. This - used to be done with a UC mapping, because the VGA frame buffer - at 0xA0000 prevents use of a WB granule. The UC mapping causes - an MCA on HP sx[12]000 chipsets. - - We should use WB page table mappings to avoid covering the VGA - frame buffer. - -Notes -===== - - [1] SDM rev 2.2, vol 2, sec 4.4.1. - [2] SDM rev 2.2, vol 2, sec 4.4.6. diff --git a/Documentation/arch/ia64/efirtc.rst b/Documentation/arch/ia64/efirtc.rst deleted file mode 100644 index fd83284083..0000000000 --- a/Documentation/arch/ia64/efirtc.rst +++ /dev/null @@ -1,144 +0,0 @@ -========================== -EFI Real Time Clock driver -========================== - -S. Eranian <eranian@hpl.hp.com> - -March 2000 - -1. Introduction -=============== - -This document describes the efirtc.c driver has provided for -the IA-64 platform. - -The purpose of this driver is to supply an API for kernel and user applications -to get access to the Time Service offered by EFI version 0.92. - -EFI provides 4 calls one can make once the OS is booted: GetTime(), -SetTime(), GetWakeupTime(), SetWakeupTime() which are all supported by this -driver. We describe those calls as well the design of the driver in the -following sections. - -2. Design Decisions -=================== - -The original ideas was to provide a very simple driver to get access to, -at first, the time of day service. This is required in order to access, in a -portable way, the CMOS clock. A program like /sbin/hwclock uses such a clock -to initialize the system view of the time during boot. - -Because we wanted to minimize the impact on existing user-level apps using -the CMOS clock, we decided to expose an API that was very similar to the one -used today with the legacy RTC driver (driver/char/rtc.c). However, because -EFI provides a simpler services, not all ioctl() are available. Also -new ioctl()s have been introduced for things that EFI provides but not the -legacy. - -EFI uses a slightly different way of representing the time, noticeably -the reference date is different. Year is the using the full 4-digit format. -The Epoch is January 1st 1998. For backward compatibility reasons we don't -expose this new way of representing time. Instead we use something very -similar to the struct tm, i.e. struct rtc_time, as used by hwclock. -One of the reasons for doing it this way is to allow for EFI to still evolve -without necessarily impacting any of the user applications. The decoupling -enables flexibility and permits writing wrapper code is ncase things change. - -The driver exposes two interfaces, one via the device file and a set of -ioctl()s. The other is read-only via the /proc filesystem. - -As of today we don't offer a /proc/sys interface. - -To allow for a uniform interface between the legacy RTC and EFI time service, -we have created the include/linux/rtc.h header file to contain only the -"public" API of the two drivers. The specifics of the legacy RTC are still -in include/linux/mc146818rtc.h. - - -3. Time of day service -====================== - -The part of the driver gives access to the time of day service of EFI. -Two ioctl()s, compatible with the legacy RTC calls: - - Read the CMOS clock:: - - ioctl(d, RTC_RD_TIME, &rtc); - - Write the CMOS clock:: - - ioctl(d, RTC_SET_TIME, &rtc); - -The rtc is a pointer to a data structure defined in rtc.h which is close -to a struct tm:: - - struct rtc_time { - int tm_sec; - int tm_min; - int tm_hour; - int tm_mday; - int tm_mon; - int tm_year; - int tm_wday; - int tm_yday; - int tm_isdst; - }; - -The driver takes care of converting back an forth between the EFI time and -this format. - -Those two ioctl()s can be exercised with the hwclock command: - -For reading:: - - # /sbin/hwclock --show - Mon Mar 6 15:32:32 2000 -0.910248 seconds - -For setting:: - - # /sbin/hwclock --systohc - -Root privileges are required to be able to set the time of day. - -4. Wakeup Alarm service -======================= - -EFI provides an API by which one can program when a machine should wakeup, -i.e. reboot. This is very different from the alarm provided by the legacy -RTC which is some kind of interval timer alarm. For this reason we don't use -the same ioctl()s to get access to the service. Instead we have -introduced 2 news ioctl()s to the interface of an RTC. - -We have added 2 new ioctl()s that are specific to the EFI driver: - - Read the current state of the alarm:: - - ioctl(d, RTC_WKALM_RD, &wkt) - - Set the alarm or change its status:: - - ioctl(d, RTC_WKALM_SET, &wkt) - -The wkt structure encapsulates a struct rtc_time + 2 extra fields to get -status information:: - - struct rtc_wkalrm { - - unsigned char enabled; /* =1 if alarm is enabled */ - unsigned char pending; /* =1 if alarm is pending */ - - struct rtc_time time; - } - -As of today, none of the existing user-level apps supports this feature. -However writing such a program should be hard by simply using those two -ioctl(). - -Root privileges are required to be able to set the alarm. - -5. References -============= - -Checkout the following Web site for more information on EFI: - -http://developer.intel.com/technology/efi/ diff --git a/Documentation/arch/ia64/err_inject.rst b/Documentation/arch/ia64/err_inject.rst deleted file mode 100644 index 900f71e93a..0000000000 --- a/Documentation/arch/ia64/err_inject.rst +++ /dev/null @@ -1,1067 +0,0 @@ -======================================== -IPF Machine Check (MC) error inject tool -======================================== - -IPF Machine Check (MC) error inject tool is used to inject MC -errors from Linux. The tool is a test bed for IPF MC work flow including -hardware correctable error handling, OS recoverable error handling, MC -event logging, etc. - -The tool includes two parts: a kernel driver and a user application -sample. The driver provides interface to PAL to inject error -and query error injection capabilities. The driver code is in -arch/ia64/kernel/err_inject.c. The application sample (shown below) -provides a combination of various errors and calls the driver's interface -(sysfs interface) to inject errors or query error injection capabilities. - -The tool can be used to test Intel IPF machine MC handling capabilities. -It's especially useful for people who can not access hardware MC injection -tool to inject error. It's also very useful to integrate with other -software test suits to do stressful testing on IPF. - -Below is a sample application as part of the whole tool. The sample -can be used as a working test tool. Or it can be expanded to include -more features. It also can be a integrated into a library or other user -application to have more thorough test. - -The sample application takes err.conf as error configuration input. GCC -compiles the code. After you install err_inject driver, you can run -this sample application to inject errors. - -Errata: Itanium 2 Processors Specification Update lists some errata against -the pal_mc_error_inject PAL procedure. The following err.conf has been tested -on latest Montecito PAL. - -err.conf:: - - #This is configuration file for err_inject_tool. - #The format of the each line is: - #cpu, loop, interval, err_type_info, err_struct_info, err_data_buffer - #where - # cpu: logical cpu number the error will be inject in. - # loop: times the error will be injected. - # interval: In second. every so often one error is injected. - # err_type_info, err_struct_info: PAL parameters. - # - #Note: All values are hex w/o or w/ 0x prefix. - - - #On cpu2, inject only total 0x10 errors, interval 5 seconds - #corrected, data cache, hier-2, physical addr(assigned by tool code). - #working on Montecito latest PAL. - 2, 10, 5, 4101, 95 - - #On cpu4, inject and consume total 0x10 errors, interval 5 seconds - #corrected, data cache, hier-2, physical addr(assigned by tool code). - #working on Montecito latest PAL. - 4, 10, 5, 4109, 95 - - #On cpu15, inject and consume total 0x10 errors, interval 5 seconds - #recoverable, DTR0, hier-2. - #working on Montecito latest PAL. - 0xf, 0x10, 5, 4249, 15 - -The sample application source code: - -err_injection_tool.c:: - - /* - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or - * NON INFRINGEMENT. See the GNU General Public License for more - * details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - * - * Copyright (C) 2006 Intel Co - * Fenghua Yu <fenghua.yu@intel.com> - * - */ - #include <sys/types.h> - #include <sys/stat.h> - #include <fcntl.h> - #include <stdio.h> - #include <sched.h> - #include <unistd.h> - #include <stdlib.h> - #include <stdarg.h> - #include <string.h> - #include <errno.h> - #include <time.h> - #include <sys/ipc.h> - #include <sys/sem.h> - #include <sys/wait.h> - #include <sys/mman.h> - #include <sys/shm.h> - - #define MAX_FN_SIZE 256 - #define MAX_BUF_SIZE 256 - #define DATA_BUF_SIZE 256 - #define NR_CPUS 512 - #define MAX_TASK_NUM 2048 - #define MIN_INTERVAL 5 // seconds - #define ERR_DATA_BUFFER_SIZE 3 // Three 8-byte. - #define PARA_FIELD_NUM 5 - #define MASK_SIZE (NR_CPUS/64) - #define PATH_FORMAT "/sys/devices/system/cpu/cpu%d/err_inject/" - - int sched_setaffinity(pid_t pid, unsigned int len, unsigned long *mask); - - int verbose; - #define vbprintf if (verbose) printf - - int log_info(int cpu, const char *fmt, ...) - { - FILE *log; - char fn[MAX_FN_SIZE]; - char buf[MAX_BUF_SIZE]; - va_list args; - - sprintf(fn, "%d.log", cpu); - log=fopen(fn, "a+"); - if (log==NULL) { - perror("Error open:"); - return -1; - } - - va_start(args, fmt); - vprintf(fmt, args); - memset(buf, 0, MAX_BUF_SIZE); - vsprintf(buf, fmt, args); - va_end(args); - - fwrite(buf, sizeof(buf), 1, log); - fclose(log); - - return 0; - } - - typedef unsigned long u64; - typedef unsigned int u32; - - typedef union err_type_info_u { - struct { - u64 mode : 3, /* 0-2 */ - err_inj : 3, /* 3-5 */ - err_sev : 2, /* 6-7 */ - err_struct : 5, /* 8-12 */ - struct_hier : 3, /* 13-15 */ - reserved : 48; /* 16-63 */ - } err_type_info_u; - u64 err_type_info; - } err_type_info_t; - - typedef union err_struct_info_u { - struct { - u64 siv : 1, /* 0 */ - c_t : 2, /* 1-2 */ - cl_p : 3, /* 3-5 */ - cl_id : 3, /* 6-8 */ - cl_dp : 1, /* 9 */ - reserved1 : 22, /* 10-31 */ - tiv : 1, /* 32 */ - trigger : 4, /* 33-36 */ - trigger_pl : 3, /* 37-39 */ - reserved2 : 24; /* 40-63 */ - } err_struct_info_cache; - struct { - u64 siv : 1, /* 0 */ - tt : 2, /* 1-2 */ - tc_tr : 2, /* 3-4 */ - tr_slot : 8, /* 5-12 */ - reserved1 : 19, /* 13-31 */ - tiv : 1, /* 32 */ - trigger : 4, /* 33-36 */ - trigger_pl : 3, /* 37-39 */ - reserved2 : 24; /* 40-63 */ - } err_struct_info_tlb; - struct { - u64 siv : 1, /* 0 */ - regfile_id : 4, /* 1-4 */ - reg_num : 7, /* 5-11 */ - reserved1 : 20, /* 12-31 */ - tiv : 1, /* 32 */ - trigger : 4, /* 33-36 */ - trigger_pl : 3, /* 37-39 */ - reserved2 : 24; /* 40-63 */ - } err_struct_info_register; - struct { - u64 reserved; - } err_struct_info_bus_processor_interconnect; - u64 err_struct_info; - } err_struct_info_t; - - typedef union err_data_buffer_u { - struct { - u64 trigger_addr; /* 0-63 */ - u64 inj_addr; /* 64-127 */ - u64 way : 5, /* 128-132 */ - index : 20, /* 133-152 */ - : 39; /* 153-191 */ - } err_data_buffer_cache; - struct { - u64 trigger_addr; /* 0-63 */ - u64 inj_addr; /* 64-127 */ - u64 way : 5, /* 128-132 */ - index : 20, /* 133-152 */ - reserved : 39; /* 153-191 */ - } err_data_buffer_tlb; - struct { - u64 trigger_addr; /* 0-63 */ - } err_data_buffer_register; - struct { - u64 reserved; /* 0-63 */ - } err_data_buffer_bus_processor_interconnect; - u64 err_data_buffer[ERR_DATA_BUFFER_SIZE]; - } err_data_buffer_t; - - typedef union capabilities_u { - struct { - u64 i : 1, - d : 1, - rv : 1, - tag : 1, - data : 1, - mesi : 1, - dp : 1, - reserved1 : 3, - pa : 1, - va : 1, - wi : 1, - reserved2 : 20, - trigger : 1, - trigger_pl : 1, - reserved3 : 30; - } capabilities_cache; - struct { - u64 d : 1, - i : 1, - rv : 1, - tc : 1, - tr : 1, - reserved1 : 27, - trigger : 1, - trigger_pl : 1, - reserved2 : 30; - } capabilities_tlb; - struct { - u64 gr_b0 : 1, - gr_b1 : 1, - fr : 1, - br : 1, - pr : 1, - ar : 1, - cr : 1, - rr : 1, - pkr : 1, - dbr : 1, - ibr : 1, - pmc : 1, - pmd : 1, - reserved1 : 3, - regnum : 1, - reserved2 : 15, - trigger : 1, - trigger_pl : 1, - reserved3 : 30; - } capabilities_register; - struct { - u64 reserved; - } capabilities_bus_processor_interconnect; - } capabilities_t; - - typedef struct resources_s { - u64 ibr0 : 1, - ibr2 : 1, - ibr4 : 1, - ibr6 : 1, - dbr0 : 1, - dbr2 : 1, - dbr4 : 1, - dbr6 : 1, - reserved : 48; - } resources_t; - - - long get_page_size(void) - { - long page_size=sysconf(_SC_PAGESIZE); - return page_size; - } - - #define PAGE_SIZE (get_page_size()==-1?0x4000:get_page_size()) - #define SHM_SIZE (2*PAGE_SIZE*NR_CPUS) - #define SHM_VA 0x2000000100000000 - - int shmid; - void *shmaddr; - - int create_shm(void) - { - key_t key; - char fn[MAX_FN_SIZE]; - - /* cpu0 is always existing */ - sprintf(fn, PATH_FORMAT, 0); - if ((key = ftok(fn, 's')) == -1) { - perror("ftok"); - return -1; - } - - shmid = shmget(key, SHM_SIZE, 0644 | IPC_CREAT); - if (shmid == -1) { - if (errno==EEXIST) { - shmid = shmget(key, SHM_SIZE, 0); - if (shmid == -1) { - perror("shmget"); - return -1; - } - } - else { - perror("shmget"); - return -1; - } - } - vbprintf("shmid=%d", shmid); - - /* connect to the segment: */ - shmaddr = shmat(shmid, (void *)SHM_VA, 0); - if (shmaddr == (void*)-1) { - perror("shmat"); - return -1; - } - - memset(shmaddr, 0, SHM_SIZE); - mlock(shmaddr, SHM_SIZE); - - return 0; - } - - int free_shm() - { - munlock(shmaddr, SHM_SIZE); - shmdt(shmaddr); - semctl(shmid, 0, IPC_RMID); - - return 0; - } - - #ifdef _SEM_SEMUN_UNDEFINED - union semun - { - int val; - struct semid_ds *buf; - unsigned short int *array; - struct seminfo *__buf; - }; - #endif - - u32 mode=1; /* 1: physical mode; 2: virtual mode. */ - int one_lock=1; - key_t key[NR_CPUS]; - int semid[NR_CPUS]; - - int create_sem(int cpu) - { - union semun arg; - char fn[MAX_FN_SIZE]; - int sid; - - sprintf(fn, PATH_FORMAT, cpu); - sprintf(fn, "%s/%s", fn, "err_type_info"); - if ((key[cpu] = ftok(fn, 'e')) == -1) { - perror("ftok"); - return -1; - } - - if (semid[cpu]!=0) - return 0; - - /* clear old semaphore */ - if ((sid = semget(key[cpu], 1, 0)) != -1) - semctl(sid, 0, IPC_RMID); - - /* get one semaphore */ - if ((semid[cpu] = semget(key[cpu], 1, IPC_CREAT | IPC_EXCL)) == -1) { - perror("semget"); - printf("Please remove semaphore with key=0x%lx, then run the tool.\n", - (u64)key[cpu]); - return -1; - } - - vbprintf("semid[%d]=0x%lx, key[%d]=%lx\n",cpu,(u64)semid[cpu],cpu, - (u64)key[cpu]); - /* initialize the semaphore to 1: */ - arg.val = 1; - if (semctl(semid[cpu], 0, SETVAL, arg) == -1) { - perror("semctl"); - return -1; - } - - return 0; - } - - static int lock(int cpu) - { - struct sembuf lock; - - lock.sem_num = cpu; - lock.sem_op = 1; - semop(semid[cpu], &lock, 1); - - return 0; - } - - static int unlock(int cpu) - { - struct sembuf unlock; - - unlock.sem_num = cpu; - unlock.sem_op = -1; - semop(semid[cpu], &unlock, 1); - - return 0; - } - - void free_sem(int cpu) - { - semctl(semid[cpu], 0, IPC_RMID); - } - - int wr_multi(char *fn, unsigned long *data, int size) - { - int fd; - char buf[MAX_BUF_SIZE]; - int ret; - - if (size==1) - sprintf(buf, "%lx", *data); - else if (size==3) - sprintf(buf, "%lx,%lx,%lx", data[0], data[1], data[2]); - else { - fprintf(stderr,"write to file with wrong size!\n"); - return -1; - } - - fd=open(fn, O_RDWR); - if (!fd) { - perror("Error:"); - return -1; - } - ret=write(fd, buf, sizeof(buf)); - close(fd); - return ret; - } - - int wr(char *fn, unsigned long data) - { - return wr_multi(fn, &data, 1); - } - - int rd(char *fn, unsigned long *data) - { - int fd; - char buf[MAX_BUF_SIZE]; - - fd=open(fn, O_RDONLY); - if (fd<0) { - perror("Error:"); - return -1; - } - read(fd, buf, MAX_BUF_SIZE); - *data=strtoul(buf, NULL, 16); - close(fd); - return 0; - } - - int rd_status(char *path, int *status) - { - char fn[MAX_FN_SIZE]; - sprintf(fn, "%s/status", path); - if (rd(fn, (u64*)status)<0) { - perror("status reading error.\n"); - return -1; - } - - return 0; - } - - int rd_capabilities(char *path, u64 *capabilities) - { - char fn[MAX_FN_SIZE]; - sprintf(fn, "%s/capabilities", path); - if (rd(fn, capabilities)<0) { - perror("capabilities reading error.\n"); - return -1; - } - - return 0; - } - - int rd_all(char *path) - { - unsigned long err_type_info, err_struct_info, err_data_buffer; - int status; - unsigned long capabilities, resources; - char fn[MAX_FN_SIZE]; - - sprintf(fn, "%s/err_type_info", path); - if (rd(fn, &err_type_info)<0) { - perror("err_type_info reading error.\n"); - return -1; - } - printf("err_type_info=%lx\n", err_type_info); - - sprintf(fn, "%s/err_struct_info", path); - if (rd(fn, &err_struct_info)<0) { - perror("err_struct_info reading error.\n"); - return -1; - } - printf("err_struct_info=%lx\n", err_struct_info); - - sprintf(fn, "%s/err_data_buffer", path); - if (rd(fn, &err_data_buffer)<0) { - perror("err_data_buffer reading error.\n"); - return -1; - } - printf("err_data_buffer=%lx\n", err_data_buffer); - - sprintf(fn, "%s/status", path); - if (rd("status", (u64*)&status)<0) { - perror("status reading error.\n"); - return -1; - } - printf("status=%d\n", status); - - sprintf(fn, "%s/capabilities", path); - if (rd(fn,&capabilities)<0) { - perror("capabilities reading error.\n"); - return -1; - } - printf("capabilities=%lx\n", capabilities); - - sprintf(fn, "%s/resources", path); - if (rd(fn, &resources)<0) { - perror("resources reading error.\n"); - return -1; - } - printf("resources=%lx\n", resources); - - return 0; - } - - int query_capabilities(char *path, err_type_info_t err_type_info, - u64 *capabilities) - { - char fn[MAX_FN_SIZE]; - err_struct_info_t err_struct_info; - err_data_buffer_t err_data_buffer; - - err_struct_info.err_struct_info=0; - memset(err_data_buffer.err_data_buffer, -1, ERR_DATA_BUFFER_SIZE*8); - - sprintf(fn, "%s/err_type_info", path); - wr(fn, err_type_info.err_type_info); - sprintf(fn, "%s/err_struct_info", path); - wr(fn, 0x0); - sprintf(fn, "%s/err_data_buffer", path); - wr_multi(fn, err_data_buffer.err_data_buffer, ERR_DATA_BUFFER_SIZE); - - // Fire pal_mc_error_inject procedure. - sprintf(fn, "%s/call_start", path); - wr(fn, mode); - - if (rd_capabilities(path, capabilities)<0) - return -1; - - return 0; - } - - int query_all_capabilities() - { - int status; - err_type_info_t err_type_info; - int err_sev, err_struct, struct_hier; - int cap=0; - u64 capabilities; - char path[MAX_FN_SIZE]; - - err_type_info.err_type_info=0; // Initial - err_type_info.err_type_info_u.mode=0; // Query mode; - err_type_info.err_type_info_u.err_inj=0; - - printf("All capabilities implemented in pal_mc_error_inject:\n"); - sprintf(path, PATH_FORMAT ,0); - for (err_sev=0;err_sev<3;err_sev++) - for (err_struct=0;err_struct<5;err_struct++) - for (struct_hier=0;struct_hier<5;struct_hier++) - { - status=-1; - capabilities=0; - err_type_info.err_type_info_u.err_sev=err_sev; - err_type_info.err_type_info_u.err_struct=err_struct; - err_type_info.err_type_info_u.struct_hier=struct_hier; - - if (query_capabilities(path, err_type_info, &capabilities)<0) - continue; - - if (rd_status(path, &status)<0) - continue; - - if (status==0) { - cap=1; - printf("For err_sev=%d, err_struct=%d, struct_hier=%d: ", - err_sev, err_struct, struct_hier); - printf("capabilities 0x%lx\n", capabilities); - } - } - if (!cap) { - printf("No capabilities supported.\n"); - return 0; - } - - return 0; - } - - int err_inject(int cpu, char *path, err_type_info_t err_type_info, - err_struct_info_t err_struct_info, - err_data_buffer_t err_data_buffer) - { - int status; - char fn[MAX_FN_SIZE]; - - log_info(cpu, "err_type_info=%lx, err_struct_info=%lx, ", - err_type_info.err_type_info, - err_struct_info.err_struct_info); - log_info(cpu,"err_data_buffer=[%lx,%lx,%lx]\n", - err_data_buffer.err_data_buffer[0], - err_data_buffer.err_data_buffer[1], - err_data_buffer.err_data_buffer[2]); - sprintf(fn, "%s/err_type_info", path); - wr(fn, err_type_info.err_type_info); - sprintf(fn, "%s/err_struct_info", path); - wr(fn, err_struct_info.err_struct_info); - sprintf(fn, "%s/err_data_buffer", path); - wr_multi(fn, err_data_buffer.err_data_buffer, ERR_DATA_BUFFER_SIZE); - - // Fire pal_mc_error_inject procedure. - sprintf(fn, "%s/call_start", path); - wr(fn,mode); - - if (rd_status(path, &status)<0) { - vbprintf("fail: read status\n"); - return -100; - } - - if (status!=0) { - log_info(cpu, "fail: status=%d\n", status); - return status; - } - - return status; - } - - static int construct_data_buf(char *path, err_type_info_t err_type_info, - err_struct_info_t err_struct_info, - err_data_buffer_t *err_data_buffer, - void *va1) - { - char fn[MAX_FN_SIZE]; - u64 virt_addr=0, phys_addr=0; - - vbprintf("va1=%lx\n", (u64)va1); - memset(&err_data_buffer->err_data_buffer_cache, 0, ERR_DATA_BUFFER_SIZE*8); - - switch (err_type_info.err_type_info_u.err_struct) { - case 1: // Cache - switch (err_struct_info.err_struct_info_cache.cl_id) { - case 1: //Virtual addr - err_data_buffer->err_data_buffer_cache.inj_addr=(u64)va1; - break; - case 2: //Phys addr - sprintf(fn, "%s/virtual_to_phys", path); - virt_addr=(u64)va1; - if (wr(fn,virt_addr)<0) - return -1; - rd(fn, &phys_addr); - err_data_buffer->err_data_buffer_cache.inj_addr=phys_addr; - break; - default: - printf("Not supported cl_id\n"); - break; - } - break; - case 2: // TLB - break; - case 3: // Register file - break; - case 4: // Bus/system interconnect - default: - printf("Not supported err_struct\n"); - break; - } - - return 0; - } - - typedef struct { - u64 cpu; - u64 loop; - u64 interval; - u64 err_type_info; - u64 err_struct_info; - u64 err_data_buffer[ERR_DATA_BUFFER_SIZE]; - } parameters_t; - - parameters_t line_para; - int para; - - static int empty_data_buffer(u64 *err_data_buffer) - { - int empty=1; - int i; - - for (i=0;i<ERR_DATA_BUFFER_SIZE; i++) - if (err_data_buffer[i]!=-1) - empty=0; - - return empty; - } - - int err_inj() - { - err_type_info_t err_type_info; - err_struct_info_t err_struct_info; - err_data_buffer_t err_data_buffer; - int count; - FILE *fp; - unsigned long cpu, loop, interval, err_type_info_conf, err_struct_info_conf; - u64 err_data_buffer_conf[ERR_DATA_BUFFER_SIZE]; - int num; - int i; - char path[MAX_FN_SIZE]; - parameters_t parameters[MAX_TASK_NUM]={}; - pid_t child_pid[MAX_TASK_NUM]; - time_t current_time; - int status; - - if (!para) { - fp=fopen("err.conf", "r"); - if (fp==NULL) { - perror("Error open err.conf"); - return -1; - } - - num=0; - while (!feof(fp)) { - char buf[256]; - memset(buf,0,256); - fgets(buf, 256, fp); - count=sscanf(buf, "%lx, %lx, %lx, %lx, %lx, %lx, %lx, %lx\n", - &cpu, &loop, &interval,&err_type_info_conf, - &err_struct_info_conf, - &err_data_buffer_conf[0], - &err_data_buffer_conf[1], - &err_data_buffer_conf[2]); - if (count!=PARA_FIELD_NUM+3) { - err_data_buffer_conf[0]=-1; - err_data_buffer_conf[1]=-1; - err_data_buffer_conf[2]=-1; - count=sscanf(buf, "%lx, %lx, %lx, %lx, %lx\n", - &cpu, &loop, &interval,&err_type_info_conf, - &err_struct_info_conf); - if (count!=PARA_FIELD_NUM) - continue; - } - - parameters[num].cpu=cpu; - parameters[num].loop=loop; - parameters[num].interval= interval>MIN_INTERVAL - ?interval:MIN_INTERVAL; - parameters[num].err_type_info=err_type_info_conf; - parameters[num].err_struct_info=err_struct_info_conf; - memcpy(parameters[num++].err_data_buffer, - err_data_buffer_conf,ERR_DATA_BUFFER_SIZE*8) ; - - if (num>=MAX_TASK_NUM) - break; - } - } - else { - parameters[0].cpu=line_para.cpu; - parameters[0].loop=line_para.loop; - parameters[0].interval= line_para.interval>MIN_INTERVAL - ?line_para.interval:MIN_INTERVAL; - parameters[0].err_type_info=line_para.err_type_info; - parameters[0].err_struct_info=line_para.err_struct_info; - memcpy(parameters[0].err_data_buffer, - line_para.err_data_buffer,ERR_DATA_BUFFER_SIZE*8) ; - - num=1; - } - - /* Create semaphore: If one_lock, one semaphore for all processors. - Otherwise, one semaphore for each processor. */ - if (one_lock) { - if (create_sem(0)) { - printf("Can not create semaphore...exit\n"); - free_sem(0); - return -1; - } - } - else { - for (i=0;i<num;i++) { - if (create_sem(parameters[i].cpu)) { - printf("Can not create semaphore for cpu%d...exit\n",i); - free_sem(parameters[num].cpu); - return -1; - } - } - } - - /* Create a shm segment which will be used to inject/consume errors on.*/ - if (create_shm()==-1) { - printf("Error to create shm...exit\n"); - return -1; - } - - for (i=0;i<num;i++) { - pid_t pid; - - current_time=time(NULL); - log_info(parameters[i].cpu, "\nBegine at %s", ctime(¤t_time)); - log_info(parameters[i].cpu, "Configurations:\n"); - log_info(parameters[i].cpu,"On cpu%ld: loop=%lx, interval=%lx(s)", - parameters[i].cpu, - parameters[i].loop, - parameters[i].interval); - log_info(parameters[i].cpu," err_type_info=%lx,err_struct_info=%lx\n", - parameters[i].err_type_info, - parameters[i].err_struct_info); - - sprintf(path, PATH_FORMAT, (int)parameters[i].cpu); - err_type_info.err_type_info=parameters[i].err_type_info; - err_struct_info.err_struct_info=parameters[i].err_struct_info; - memcpy(err_data_buffer.err_data_buffer, - parameters[i].err_data_buffer, - ERR_DATA_BUFFER_SIZE*8); - - pid=fork(); - if (pid==0) { - unsigned long mask[MASK_SIZE]; - int j, k; - - void *va1, *va2; - - /* Allocate two memory areas va1 and va2 in shm */ - va1=shmaddr+parameters[i].cpu*PAGE_SIZE; - va2=shmaddr+parameters[i].cpu*PAGE_SIZE+PAGE_SIZE; - - vbprintf("va1=%lx, va2=%lx\n", (u64)va1, (u64)va2); - memset(va1, 0x1, PAGE_SIZE); - memset(va2, 0x2, PAGE_SIZE); - - if (empty_data_buffer(err_data_buffer.err_data_buffer)) - /* If not specified yet, construct data buffer - * with va1 - */ - construct_data_buf(path, err_type_info, - err_struct_info, &err_data_buffer,va1); - - for (j=0;j<MASK_SIZE;j++) - mask[j]=0; - - cpu=parameters[i].cpu; - k = cpu%64; - j = cpu/64; - mask[j] = 1UL << k; - - if (sched_setaffinity(0, MASK_SIZE*8, mask)==-1) { - perror("Error sched_setaffinity:"); - return -1; - } - - for (j=0; j<parameters[i].loop; j++) { - log_info(parameters[i].cpu,"Injection "); - log_info(parameters[i].cpu,"on cpu%ld: #%d/%ld ", - - parameters[i].cpu,j+1, parameters[i].loop); - - /* Hold the lock */ - if (one_lock) - lock(0); - else - /* Hold lock on this cpu */ - lock(parameters[i].cpu); - - if ((status=err_inject(parameters[i].cpu, - path, err_type_info, - err_struct_info, err_data_buffer)) - ==0) { - /* consume the error for "inject only"*/ - memcpy(va2, va1, PAGE_SIZE); - memcpy(va1, va2, PAGE_SIZE); - log_info(parameters[i].cpu, - "successful\n"); - } - else { - log_info(parameters[i].cpu,"fail:"); - log_info(parameters[i].cpu, - "status=%d\n", status); - unlock(parameters[i].cpu); - break; - } - if (one_lock) - /* Release the lock */ - unlock(0); - /* Release lock on this cpu */ - else - unlock(parameters[i].cpu); - - if (j < parameters[i].loop-1) - sleep(parameters[i].interval); - } - current_time=time(NULL); - log_info(parameters[i].cpu, "Done at %s", ctime(¤t_time)); - return 0; - } - else if (pid<0) { - perror("Error fork:"); - continue; - } - child_pid[i]=pid; - } - for (i=0;i<num;i++) - waitpid(child_pid[i], NULL, 0); - - if (one_lock) - free_sem(0); - else - for (i=0;i<num;i++) - free_sem(parameters[i].cpu); - - printf("All done.\n"); - - return 0; - } - - void help() - { - printf("err_inject_tool:\n"); - printf("\t-q: query all capabilities. default: off\n"); - printf("\t-m: procedure mode. 1: physical 2: virtual. default: 1\n"); - printf("\t-i: inject errors. default: off\n"); - printf("\t-l: one lock per cpu. default: one lock for all\n"); - printf("\t-e: error parameters:\n"); - printf("\t\tcpu,loop,interval,err_type_info,err_struct_info[,err_data_buffer[0],err_data_buffer[1],err_data_buffer[2]]\n"); - printf("\t\t cpu: logical cpu number the error will be inject in.\n"); - printf("\t\t loop: times the error will be injected.\n"); - printf("\t\t interval: In second. every so often one error is injected.\n"); - printf("\t\t err_type_info, err_struct_info: PAL parameters.\n"); - printf("\t\t err_data_buffer: PAL parameter. Optional. If not present,\n"); - printf("\t\t it's constructed by tool automatically. Be\n"); - printf("\t\t careful to provide err_data_buffer and make\n"); - printf("\t\t sure it's working with the environment.\n"); - printf("\t Note:no space between error parameters.\n"); - printf("\t default: Take error parameters from err.conf instead of command line.\n"); - printf("\t-v: verbose. default: off\n"); - printf("\t-h: help\n\n"); - printf("The tool will take err.conf file as "); - printf("input to inject single or multiple errors "); - printf("on one or multiple cpus in parallel.\n"); - } - - int main(int argc, char **argv) - { - char c; - int do_err_inj=0; - int do_query_all=0; - int count; - u32 m; - - /* Default one lock for all cpu's */ - one_lock=1; - while ((c = getopt(argc, argv, "m:iqvhle:")) != EOF) - switch (c) { - case 'm': /* Procedure mode. 1: phys 2: virt */ - count=sscanf(optarg, "%x", &m); - if (count!=1 || (m!=1 && m!=2)) { - printf("Wrong mode number.\n"); - help(); - return -1; - } - mode=m; - break; - case 'i': /* Inject errors */ - do_err_inj=1; - break; - case 'q': /* Query */ - do_query_all=1; - break; - case 'v': /* Verbose */ - verbose=1; - break; - case 'l': /* One lock per cpu */ - one_lock=0; - break; - case 'e': /* error arguments */ - /* Take parameters: - * #cpu, loop, interval, err_type_info, err_struct_info[, err_data_buffer] - * err_data_buffer is optional. Recommend not to specify - * err_data_buffer. Better to use tool to generate it. - */ - count=sscanf(optarg, - "%lx, %lx, %lx, %lx, %lx, %lx, %lx, %lx\n", - &line_para.cpu, - &line_para.loop, - &line_para.interval, - &line_para.err_type_info, - &line_para.err_struct_info, - &line_para.err_data_buffer[0], - &line_para.err_data_buffer[1], - &line_para.err_data_buffer[2]); - if (count!=PARA_FIELD_NUM+3) { - line_para.err_data_buffer[0]=-1, - line_para.err_data_buffer[1]=-1, - line_para.err_data_buffer[2]=-1; - count=sscanf(optarg, "%lx, %lx, %lx, %lx, %lx\n", - &line_para.cpu, - &line_para.loop, - &line_para.interval, - &line_para.err_type_info, - &line_para.err_struct_info); - if (count!=PARA_FIELD_NUM) { - printf("Wrong error arguments.\n"); - help(); - return -1; - } - } - para=1; - break; - continue; - break; - case 'h': - help(); - return 0; - default: - break; - } - - if (do_query_all) - query_all_capabilities(); - if (do_err_inj) - err_inj(); - - if (!do_query_all && !do_err_inj) - help(); - - return 0; - } diff --git a/Documentation/arch/ia64/features.rst b/Documentation/arch/ia64/features.rst deleted file mode 100644 index d7226fdcf5..0000000000 --- a/Documentation/arch/ia64/features.rst +++ /dev/null @@ -1,3 +0,0 @@ -.. SPDX-License-Identifier: GPL-2.0 - -.. kernel-feat:: $srctree/Documentation/features ia64 diff --git a/Documentation/arch/ia64/fsys.rst b/Documentation/arch/ia64/fsys.rst deleted file mode 100644 index a702d2cc94..0000000000 --- a/Documentation/arch/ia64/fsys.rst +++ /dev/null @@ -1,303 +0,0 @@ -=================================== -Light-weight System Calls for IA-64 -=================================== - - Started: 13-Jan-2003 - - Last update: 27-Sep-2003 - - David Mosberger-Tang - <davidm@hpl.hp.com> - -Using the "epc" instruction effectively introduces a new mode of -execution to the ia64 linux kernel. We call this mode the -"fsys-mode". To recap, the normal states of execution are: - - - kernel mode: - Both the register stack and the memory stack have been - switched over to kernel memory. The user-level state is saved - in a pt-regs structure at the top of the kernel memory stack. - - - user mode: - Both the register stack and the kernel stack are in - user memory. The user-level state is contained in the - CPU registers. - - - bank 0 interruption-handling mode: - This is the non-interruptible state which all - interruption-handlers start execution in. The user-level - state remains in the CPU registers and some kernel state may - be stored in bank 0 of registers r16-r31. - -In contrast, fsys-mode has the following special properties: - - - execution is at privilege level 0 (most-privileged) - - - CPU registers may contain a mixture of user-level and kernel-level - state (it is the responsibility of the kernel to ensure that no - security-sensitive kernel-level state is leaked back to - user-level) - - - execution is interruptible and preemptible (an fsys-mode handler - can disable interrupts and avoid all other interruption-sources - to avoid preemption) - - - neither the memory-stack nor the register-stack can be trusted while - in fsys-mode (they point to the user-level stacks, which may - be invalid, or completely bogus addresses) - -In summary, fsys-mode is much more similar to running in user-mode -than it is to running in kernel-mode. Of course, given that the -privilege level is at level 0, this means that fsys-mode requires some -care (see below). - - -How to tell fsys-mode -===================== - -Linux operates in fsys-mode when (a) the privilege level is 0 (most -privileged) and (b) the stacks have NOT been switched to kernel memory -yet. For convenience, the header file <asm-ia64/ptrace.h> provides -three macros:: - - user_mode(regs) - user_stack(task,regs) - fsys_mode(task,regs) - -The "regs" argument is a pointer to a pt_regs structure. The "task" -argument is a pointer to the task structure to which the "regs" -pointer belongs to. user_mode() returns TRUE if the CPU state pointed -to by "regs" was executing in user mode (privilege level 3). -user_stack() returns TRUE if the state pointed to by "regs" was -executing on the user-level stack(s). Finally, fsys_mode() returns -TRUE if the CPU state pointed to by "regs" was executing in fsys-mode. -The fsys_mode() macro is equivalent to the expression:: - - !user_mode(regs) && user_stack(task,regs) - -How to write an fsyscall handler -================================ - -The file arch/ia64/kernel/fsys.S contains a table of fsyscall-handlers -(fsyscall_table). This table contains one entry for each system call. -By default, a system call is handled by fsys_fallback_syscall(). This -routine takes care of entering (full) kernel mode and calling the -normal Linux system call handler. For performance-critical system -calls, it is possible to write a hand-tuned fsyscall_handler. For -example, fsys.S contains fsys_getpid(), which is a hand-tuned version -of the getpid() system call. - -The entry and exit-state of an fsyscall handler is as follows: - -Machine state on entry to fsyscall handler ------------------------------------------- - - ========= =============================================================== - r10 0 - r11 saved ar.pfs (a user-level value) - r15 system call number - r16 "current" task pointer (in normal kernel-mode, this is in r13) - r32-r39 system call arguments - b6 return address (a user-level value) - ar.pfs previous frame-state (a user-level value) - PSR.be cleared to zero (i.e., little-endian byte order is in effect) - - all other registers may contain values passed in from user-mode - ========= =============================================================== - -Required machine state on exit to fsyscall handler --------------------------------------------------- - - ========= =========================================================== - r11 saved ar.pfs (as passed into the fsyscall handler) - r15 system call number (as passed into the fsyscall handler) - r32-r39 system call arguments (as passed into the fsyscall handler) - b6 return address (as passed into the fsyscall handler) - ar.pfs previous frame-state (as passed into the fsyscall handler) - ========= =========================================================== - -Fsyscall handlers can execute with very little overhead, but with that -speed comes a set of restrictions: - - * Fsyscall-handlers MUST check for any pending work in the flags - member of the thread-info structure and if any of the - TIF_ALLWORK_MASK flags are set, the handler needs to fall back on - doing a full system call (by calling fsys_fallback_syscall). - - * Fsyscall-handlers MUST preserve incoming arguments (r32-r39, r11, - r15, b6, and ar.pfs) because they will be needed in case of a - system call restart. Of course, all "preserved" registers also - must be preserved, in accordance to the normal calling conventions. - - * Fsyscall-handlers MUST check argument registers for containing a - NaT value before using them in any way that could trigger a - NaT-consumption fault. If a system call argument is found to - contain a NaT value, an fsyscall-handler may return immediately - with r8=EINVAL, r10=-1. - - * Fsyscall-handlers MUST NOT use the "alloc" instruction or perform - any other operation that would trigger mandatory RSE - (register-stack engine) traffic. - - * Fsyscall-handlers MUST NOT write to any stacked registers because - it is not safe to assume that user-level called a handler with the - proper number of arguments. - - * Fsyscall-handlers need to be careful when accessing per-CPU variables: - unless proper safe-guards are taken (e.g., interruptions are avoided), - execution may be pre-empted and resumed on another CPU at any given - time. - - * Fsyscall-handlers must be careful not to leak sensitive kernel' - information back to user-level. In particular, before returning to - user-level, care needs to be taken to clear any scratch registers - that could contain sensitive information (note that the current - task pointer is not considered sensitive: it's already exposed - through ar.k6). - - * Fsyscall-handlers MUST NOT access user-memory without first - validating access-permission (this can be done typically via - probe.r.fault and/or probe.w.fault) and without guarding against - memory access exceptions (this can be done with the EX() macros - defined by asmmacro.h). - -The above restrictions may seem draconian, but remember that it's -possible to trade off some of the restrictions by paying a slightly -higher overhead. For example, if an fsyscall-handler could benefit -from the shadow register bank, it could temporarily disable PSR.i and -PSR.ic, switch to bank 0 (bsw.0) and then use the shadow registers as -needed. In other words, following the above rules yields extremely -fast system call execution (while fully preserving system call -semantics), but there is also a lot of flexibility in handling more -complicated cases. - -Signal handling -=============== - -The delivery of (asynchronous) signals must be delayed until fsys-mode -is exited. This is accomplished with the help of the lower-privilege -transfer trap: arch/ia64/kernel/process.c:do_notify_resume_user() -checks whether the interrupted task was in fsys-mode and, if so, sets -PSR.lp and returns immediately. When fsys-mode is exited via the -"br.ret" instruction that lowers the privilege level, a trap will -occur. The trap handler clears PSR.lp again and returns immediately. -The kernel exit path then checks for and delivers any pending signals. - -PSR Handling -============ - -The "epc" instruction doesn't change the contents of PSR at all. This -is in contrast to a regular interruption, which clears almost all -bits. Because of that, some care needs to be taken to ensure things -work as expected. The following discussion describes how each PSR bit -is handled. - -======= ======================================================================= -PSR.be Cleared when entering fsys-mode. A srlz.d instruction is used - to ensure the CPU is in little-endian mode before the first - load/store instruction is executed. PSR.be is normally NOT - restored upon return from an fsys-mode handler. In other - words, user-level code must not rely on PSR.be being preserved - across a system call. -PSR.up Unchanged. -PSR.ac Unchanged. -PSR.mfl Unchanged. Note: fsys-mode handlers must not write-registers! -PSR.mfh Unchanged. Note: fsys-mode handlers must not write-registers! -PSR.ic Unchanged. Note: fsys-mode handlers can clear the bit, if needed. -PSR.i Unchanged. Note: fsys-mode handlers can clear the bit, if needed. -PSR.pk Unchanged. -PSR.dt Unchanged. -PSR.dfl Unchanged. Note: fsys-mode handlers must not write-registers! -PSR.dfh Unchanged. Note: fsys-mode handlers must not write-registers! -PSR.sp Unchanged. -PSR.pp Unchanged. -PSR.di Unchanged. -PSR.si Unchanged. -PSR.db Unchanged. The kernel prevents user-level from setting a hardware - breakpoint that triggers at any privilege level other than - 3 (user-mode). -PSR.lp Unchanged. -PSR.tb Lazy redirect. If a taken-branch trap occurs while in - fsys-mode, the trap-handler modifies the saved machine state - such that execution resumes in the gate page at - syscall_via_break(), with privilege level 3. Note: the - taken branch would occur on the branch invoking the - fsyscall-handler, at which point, by definition, a syscall - restart is still safe. If the system call number is invalid, - the fsys-mode handler will return directly to user-level. This - return will trigger a taken-branch trap, but since the trap is - taken _after_ restoring the privilege level, the CPU has already - left fsys-mode, so no special treatment is needed. -PSR.rt Unchanged. -PSR.cpl Cleared to 0. -PSR.is Unchanged (guaranteed to be 0 on entry to the gate page). -PSR.mc Unchanged. -PSR.it Unchanged (guaranteed to be 1). -PSR.id Unchanged. Note: the ia64 linux kernel never sets this bit. -PSR.da Unchanged. Note: the ia64 linux kernel never sets this bit. -PSR.dd Unchanged. Note: the ia64 linux kernel never sets this bit. -PSR.ss Lazy redirect. If set, "epc" will cause a Single Step Trap to - be taken. The trap handler then modifies the saved machine - state such that execution resumes in the gate page at - syscall_via_break(), with privilege level 3. -PSR.ri Unchanged. -PSR.ed Unchanged. Note: This bit could only have an effect if an fsys-mode - handler performed a speculative load that gets NaTted. If so, this - would be the normal & expected behavior, so no special treatment is - needed. -PSR.bn Unchanged. Note: fsys-mode handlers may clear the bit, if needed. - Doing so requires clearing PSR.i and PSR.ic as well. -PSR.ia Unchanged. Note: the ia64 linux kernel never sets this bit. -======= ======================================================================= - -Using fast system calls -======================= - -To use fast system calls, userspace applications need simply call -__kernel_syscall_via_epc(). For example - --- example fgettimeofday() call -- - --- fgettimeofday.S -- - -:: - - #include <asm/asmmacro.h> - - GLOBAL_ENTRY(fgettimeofday) - .prologue - .save ar.pfs, r11 - mov r11 = ar.pfs - .body - - mov r2 = 0xa000000000020660;; // gate address - // found by inspection of System.map for the - // __kernel_syscall_via_epc() function. See - // below for how to do this for real. - - mov b7 = r2 - mov r15 = 1087 // gettimeofday syscall - ;; - br.call.sptk.many b6 = b7 - ;; - - .restore sp - - mov ar.pfs = r11 - br.ret.sptk.many rp;; // return to caller - END(fgettimeofday) - --- end fgettimeofday.S -- - -In reality, getting the gate address is accomplished by two extra -values passed via the ELF auxiliary vector (include/asm-ia64/elf.h) - - * AT_SYSINFO : is the address of __kernel_syscall_via_epc() - * AT_SYSINFO_EHDR : is the address of the kernel gate ELF DSO - -The ELF DSO is a pre-linked library that is mapped in by the kernel at -the gate page. It is a proper ELF shared object so, with a dynamic -loader that recognises the library, you should be able to make calls to -the exported functions within it as with any other shared library. -AT_SYSINFO points into the kernel DSO at the -__kernel_syscall_via_epc() function for historical reasons (it was -used before the kernel DSO) and as a convenience. diff --git a/Documentation/arch/ia64/ia64.rst b/Documentation/arch/ia64/ia64.rst deleted file mode 100644 index b725019a94..0000000000 --- a/Documentation/arch/ia64/ia64.rst +++ /dev/null @@ -1,49 +0,0 @@ -=========================================== -Linux kernel release for the IA-64 Platform -=========================================== - - These are the release notes for Linux since version 2.4 for IA-64 - platform. This document provides information specific to IA-64 - ONLY, to get additional information about the Linux kernel also - read the original Linux README provided with the kernel. - -Installing the Kernel -===================== - - - IA-64 kernel installation is the same as the other platforms, see - original README for details. - - -Software Requirements -===================== - - Compiling and running this kernel requires an IA-64 compliant GCC - compiler. And various software packages also compiled with an - IA-64 compliant GCC compiler. - - -Configuring the Kernel -====================== - - Configuration is the same, see original README for details. - - -Compiling the Kernel: - - - Compiling this kernel doesn't differ from other platform so read - the original README for details BUT make sure you have an IA-64 - compliant GCC compiler. - -IA-64 Specifics -=============== - - - General issues: - - * Hardly any performance tuning has been done. Obvious targets - include the library routines (IP checksum, etc.). Less - obvious targets include making sure we don't flush the TLB - needlessly, etc. - - * SMP locks cleanup/optimization - - * IA32 support. Currently experimental. It mostly works. diff --git a/Documentation/arch/ia64/index.rst b/Documentation/arch/ia64/index.rst deleted file mode 100644 index 761f2154df..0000000000 --- a/Documentation/arch/ia64/index.rst +++ /dev/null @@ -1,19 +0,0 @@ -.. SPDX-License-Identifier: GPL-2.0 - -================== -IA-64 Architecture -================== - -.. toctree:: - :maxdepth: 1 - - ia64 - aliasing - efirtc - err_inject - fsys - irq-redir - mca - serial - - features diff --git a/Documentation/arch/ia64/irq-redir.rst b/Documentation/arch/ia64/irq-redir.rst deleted file mode 100644 index 6bbbbe4f73..0000000000 --- a/Documentation/arch/ia64/irq-redir.rst +++ /dev/null @@ -1,80 +0,0 @@ -============================== -IRQ affinity on IA64 platforms -============================== - -07.01.2002, Erich Focht <efocht@ess.nec.de> - - -By writing to /proc/irq/IRQ#/smp_affinity the interrupt routing can be -controlled. The behavior on IA64 platforms is slightly different from -that described in Documentation/core-api/irq/irq-affinity.rst for i386 systems. - -Because of the usage of SAPIC mode and physical destination mode the -IRQ target is one particular CPU and cannot be a mask of several -CPUs. Only the first non-zero bit is taken into account. - - -Usage examples -============== - -The target CPU has to be specified as a hexadecimal CPU mask. The -first non-zero bit is the selected CPU. This format has been kept for -compatibility reasons with i386. - -Set the delivery mode of interrupt 41 to fixed and route the -interrupts to CPU #3 (logical CPU number) (2^3=0x08):: - - echo "8" >/proc/irq/41/smp_affinity - -Set the default route for IRQ number 41 to CPU 6 in lowest priority -delivery mode (redirectable):: - - echo "r 40" >/proc/irq/41/smp_affinity - -The output of the command:: - - cat /proc/irq/IRQ#/smp_affinity - -gives the target CPU mask for the specified interrupt vector. If the CPU -mask is preceded by the character "r", the interrupt is redirectable -(i.e. lowest priority mode routing is used), otherwise its route is -fixed. - - - -Initialization and default behavior -=================================== - -If the platform features IRQ redirection (info provided by SAL) all -IO-SAPIC interrupts are initialized with CPU#0 as their default target -and the routing is the so called "lowest priority mode" (actually -fixed SAPIC mode with hint). The XTP chipset registers are used as hints -for the IRQ routing. Currently in Linux XTP registers can have three -values: - - - minimal for an idle task, - - normal if any other task runs, - - maximal if the CPU is going to be switched off. - -The IRQ is routed to the CPU with lowest XTP register value, the -search begins at the default CPU. Therefore most of the interrupts -will be handled by CPU #0. - -If the platform doesn't feature interrupt redirection IOSAPIC fixed -routing is used. The target CPUs are distributed in a round robin -manner. IRQs will be routed only to the selected target CPUs. Check -with:: - - cat /proc/interrupts - - - -Comments -======== - -On large (multi-node) systems it is recommended to route the IRQs to -the node to which the corresponding device is connected. -For systems like the NEC AzusA we get IRQ node-affinity for free. This -is because usually the chipsets on each node redirect the interrupts -only to their own CPUs (as they cannot see the XTP registers on the -other nodes). diff --git a/Documentation/arch/ia64/mca.rst b/Documentation/arch/ia64/mca.rst deleted file mode 100644 index 08270bba44..0000000000 --- a/Documentation/arch/ia64/mca.rst +++ /dev/null @@ -1,198 +0,0 @@ -============================================================= -An ad-hoc collection of notes on IA64 MCA and INIT processing -============================================================= - -Feel free to update it with notes about any area that is not clear. - ---- - -MCA/INIT are completely asynchronous. They can occur at any time, when -the OS is in any state. Including when one of the cpus is already -holding a spinlock. Trying to get any lock from MCA/INIT state is -asking for deadlock. Also the state of structures that are protected -by locks is indeterminate, including linked lists. - ---- - -The complicated ia64 MCA process. All of this is mandated by Intel's -specification for ia64 SAL, error recovery and unwind, it is not as -if we have a choice here. - -* MCA occurs on one cpu, usually due to a double bit memory error. - This is the monarch cpu. - -* SAL sends an MCA rendezvous interrupt (which is a normal interrupt) - to all the other cpus, the slaves. - -* Slave cpus that receive the MCA interrupt call down into SAL, they - end up spinning disabled while the MCA is being serviced. - -* If any slave cpu was already spinning disabled when the MCA occurred - then it cannot service the MCA interrupt. SAL waits ~20 seconds then - sends an unmaskable INIT event to the slave cpus that have not - already rendezvoused. - -* Because MCA/INIT can be delivered at any time, including when the cpu - is down in PAL in physical mode, the registers at the time of the - event are _completely_ undefined. In particular the MCA/INIT - handlers cannot rely on the thread pointer, PAL physical mode can - (and does) modify TP. It is allowed to do that as long as it resets - TP on return. However MCA/INIT events expose us to these PAL - internal TP changes. Hence curr_task(). - -* If an MCA/INIT event occurs while the kernel was running (not user - space) and the kernel has called PAL then the MCA/INIT handler cannot - assume that the kernel stack is in a fit state to be used. Mainly - because PAL may or may not maintain the stack pointer internally. - Because the MCA/INIT handlers cannot trust the kernel stack, they - have to use their own, per-cpu stacks. The MCA/INIT stacks are - preformatted with just enough task state to let the relevant handlers - do their job. - -* Unlike most other architectures, the ia64 struct task is embedded in - the kernel stack[1]. So switching to a new kernel stack means that - we switch to a new task as well. Because various bits of the kernel - assume that current points into the struct task, switching to a new - stack also means a new value for current. - -* Once all slaves have rendezvoused and are spinning disabled, the - monarch is entered. The monarch now tries to diagnose the problem - and decide if it can recover or not. - -* Part of the monarch's job is to look at the state of all the other - tasks. The only way to do that on ia64 is to call the unwinder, - as mandated by Intel. - -* The starting point for the unwind depends on whether a task is - running or not. That is, whether it is on a cpu or is blocked. The - monarch has to determine whether or not a task is on a cpu before it - knows how to start unwinding it. The tasks that received an MCA or - INIT event are no longer running, they have been converted to blocked - tasks. But (and its a big but), the cpus that received the MCA - rendezvous interrupt are still running on their normal kernel stacks! - -* To distinguish between these two cases, the monarch must know which - tasks are on a cpu and which are not. Hence each slave cpu that - switches to an MCA/INIT stack, registers its new stack using - set_curr_task(), so the monarch can tell that the _original_ task is - no longer running on that cpu. That gives us a decent chance of - getting a valid backtrace of the _original_ task. - -* MCA/INIT can be nested, to a depth of 2 on any cpu. In the case of a - nested error, we want diagnostics on the MCA/INIT handler that - failed, not on the task that was originally running. Again this - requires set_curr_task() so the MCA/INIT handlers can register their - own stack as running on that cpu. Then a recursive error gets a - trace of the failing handler's "task". - -[1] - My (Keith Owens) original design called for ia64 to separate its - struct task and the kernel stacks. Then the MCA/INIT data would be - chained stacks like i386 interrupt stacks. But that required - radical surgery on the rest of ia64, plus extra hard wired TLB - entries with its associated performance degradation. David - Mosberger vetoed that approach. Which meant that separate kernel - stacks meant separate "tasks" for the MCA/INIT handlers. - ---- - -INIT is less complicated than MCA. Pressing the nmi button or using -the equivalent command on the management console sends INIT to all -cpus. SAL picks one of the cpus as the monarch and the rest are -slaves. All the OS INIT handlers are entered at approximately the same -time. The OS monarch prints the state of all tasks and returns, after -which the slaves return and the system resumes. - -At least that is what is supposed to happen. Alas there are broken -versions of SAL out there. Some drive all the cpus as monarchs. Some -drive them all as slaves. Some drive one cpu as monarch, wait for that -cpu to return from the OS then drive the rest as slaves. Some versions -of SAL cannot even cope with returning from the OS, they spin inside -SAL on resume. The OS INIT code has workarounds for some of these -broken SAL symptoms, but some simply cannot be fixed from the OS side. - ---- - -The scheduler hooks used by ia64 (curr_task, set_curr_task) are layer -violations. Unfortunately MCA/INIT start off as massive layer -violations (can occur at _any_ time) and they build from there. - -At least ia64 makes an attempt at recovering from hardware errors, but -it is a difficult problem because of the asynchronous nature of these -errors. When processing an unmaskable interrupt we sometimes need -special code to cope with our inability to take any locks. - ---- - -How is ia64 MCA/INIT different from x86 NMI? - -* x86 NMI typically gets delivered to one cpu. MCA/INIT gets sent to - all cpus. - -* x86 NMI cannot be nested. MCA/INIT can be nested, to a depth of 2 - per cpu. - -* x86 has a separate struct task which points to one of multiple kernel - stacks. ia64 has the struct task embedded in the single kernel - stack, so switching stack means switching task. - -* x86 does not call the BIOS so the NMI handler does not have to worry - about any registers having changed. MCA/INIT can occur while the cpu - is in PAL in physical mode, with undefined registers and an undefined - kernel stack. - -* i386 backtrace is not very sensitive to whether a process is running - or not. ia64 unwind is very, very sensitive to whether a process is - running or not. - ---- - -What happens when MCA/INIT is delivered what a cpu is running user -space code? - -The user mode registers are stored in the RSE area of the MCA/INIT on -entry to the OS and are restored from there on return to SAL, so user -mode registers are preserved across a recoverable MCA/INIT. Since the -OS has no idea what unwind data is available for the user space stack, -MCA/INIT never tries to backtrace user space. Which means that the OS -does not bother making the user space process look like a blocked task, -i.e. the OS does not copy pt_regs and switch_stack to the user space -stack. Also the OS has no idea how big the user space RSE and memory -stacks are, which makes it too risky to copy the saved state to a user -mode stack. - ---- - -How do we get a backtrace on the tasks that were running when MCA/INIT -was delivered? - -mca.c:::ia64_mca_modify_original_stack(). That identifies and -verifies the original kernel stack, copies the dirty registers from -the MCA/INIT stack's RSE to the original stack's RSE, copies the -skeleton struct pt_regs and switch_stack to the original stack, fills -in the skeleton structures from the PAL minstate area and updates the -original stack's thread.ksp. That makes the original stack look -exactly like any other blocked task, i.e. it now appears to be -sleeping. To get a backtrace, just start with thread.ksp for the -original task and unwind like any other sleeping task. - ---- - -How do we identify the tasks that were running when MCA/INIT was -delivered? - -If the previous task has been verified and converted to a blocked -state, then sos->prev_task on the MCA/INIT stack is updated to point to -the previous task. You can look at that field in dumps or debuggers. -To help distinguish between the handler and the original tasks, -handlers have _TIF_MCA_INIT set in thread_info.flags. - -The sos data is always in the MCA/INIT handler stack, at offset -MCA_SOS_OFFSET. You can get that value from mca_asm.h or calculate it -as KERNEL_STACK_SIZE - sizeof(struct pt_regs) - sizeof(struct -ia64_sal_os_state), with 16 byte alignment for all structures. - -Also the comm field of the MCA/INIT task is modified to include the pid -of the original task, for humans to use. For example, a comm field of -'MCA 12159' means that pid 12159 was running when the MCA was -delivered. diff --git a/Documentation/arch/ia64/serial.rst b/Documentation/arch/ia64/serial.rst deleted file mode 100644 index 1de70c305a..0000000000 --- a/Documentation/arch/ia64/serial.rst +++ /dev/null @@ -1,165 +0,0 @@ -============== -Serial Devices -============== - -Serial Device Naming -==================== - - As of 2.6.10, serial devices on ia64 are named based on the - order of ACPI and PCI enumeration. The first device in the - ACPI namespace (if any) becomes /dev/ttyS0, the second becomes - /dev/ttyS1, etc., and PCI devices are named sequentially - starting after the ACPI devices. - - Prior to 2.6.10, there were confusing exceptions to this: - - - Firmware on some machines (mostly from HP) provides an HCDP - table[1] that tells the kernel about devices that can be used - as a serial console. If the user specified "console=ttyS0" - or the EFI ConOut path contained only UART devices, the - kernel registered the device described by the HCDP as - /dev/ttyS0. - - - If there was no HCDP, we assumed there were UARTs at the - legacy COM port addresses (I/O ports 0x3f8 and 0x2f8), so - the kernel registered those as /dev/ttyS0 and /dev/ttyS1. - - Any additional ACPI or PCI devices were registered sequentially - after /dev/ttyS0 as they were discovered. - - With an HCDP, device names changed depending on EFI configuration - and "console=" arguments. Without an HCDP, device names didn't - change, but we registered devices that might not really exist. - - For example, an HP rx1600 with a single built-in serial port - (described in the ACPI namespace) plus an MP[2] (a PCI device) has - these ports: - - ========== ========== ============ ============ ======= - Type MMIO pre-2.6.10 pre-2.6.10 2.6.10+ - address - (EFI console (EFI console - on builtin) on MP port) - ========== ========== ============ ============ ======= - builtin 0xff5e0000 ttyS0 ttyS1 ttyS0 - MP UPS 0xf8031000 ttyS1 ttyS2 ttyS1 - MP Console 0xf8030000 ttyS2 ttyS0 ttyS2 - MP 2 0xf8030010 ttyS3 ttyS3 ttyS3 - MP 3 0xf8030038 ttyS4 ttyS4 ttyS4 - ========== ========== ============ ============ ======= - -Console Selection -================= - - EFI knows what your console devices are, but it doesn't tell the - kernel quite enough to actually locate them. The DIG64 HCDP - table[1] does tell the kernel where potential serial console - devices are, but not all firmware supplies it. Also, EFI supports - multiple simultaneous consoles and doesn't tell the kernel which - should be the "primary" one. - - So how do you tell Linux which console device to use? - - - If your firmware supplies the HCDP, it is simplest to - configure EFI with a single device (either a UART or a VGA - card) as the console. Then you don't need to tell Linux - anything; the kernel will automatically use the EFI console. - - (This works only in 2.6.6 or later; prior to that you had - to specify "console=ttyS0" to get a serial console.) - - - Without an HCDP, Linux defaults to a VGA console unless you - specify a "console=" argument. - - NOTE: Don't assume that a serial console device will be /dev/ttyS0. - It might be ttyS1, ttyS2, etc. Make sure you have the appropriate - entries in /etc/inittab (for getty) and /etc/securetty (to allow - root login). - -Early Serial Console -==================== - - The kernel can't start using a serial console until it knows where - the device lives. Normally this happens when the driver enumerates - all the serial devices, which can happen a minute or more after the - kernel starts booting. - - 2.6.10 and later kernels have an "early uart" driver that works - very early in the boot process. The kernel will automatically use - this if the user supplies an argument like "console=uart,io,0x3f8", - or if the EFI console path contains only a UART device and the - firmware supplies an HCDP. - -Troubleshooting Serial Console Problems -======================================= - - No kernel output after elilo prints "Uncompressing Linux... done": - - - You specified "console=ttyS0" but Linux changed the device - to which ttyS0 refers. Configure exactly one EFI console - device[3] and remove the "console=" option. - - - The EFI console path contains both a VGA device and a UART. - EFI and elilo use both, but Linux defaults to VGA. Remove - the VGA device from the EFI console path[3]. - - - Multiple UARTs selected as EFI console devices. EFI and - elilo use all selected devices, but Linux uses only one. - Make sure only one UART is selected in the EFI console - path[3]. - - - You're connected to an HP MP port[2] but have a non-MP UART - selected as EFI console device. EFI uses the MP as a - console device even when it isn't explicitly selected. - Either move the console cable to the non-MP UART, or change - the EFI console path[3] to the MP UART. - - Long pause (60+ seconds) between "Uncompressing Linux... done" and - start of kernel output: - - - No early console because you used "console=ttyS<n>". Remove - the "console=" option if your firmware supplies an HCDP. - - - If you don't have an HCDP, the kernel doesn't know where - your console lives until the driver discovers serial - devices. Use "console=uart,io,0x3f8" (or appropriate - address for your machine). - - Kernel and init script output works fine, but no "login:" prompt: - - - Add getty entry to /etc/inittab for console tty. Look for - the "Adding console on ttyS<n>" message that tells you which - device is the console. - - "login:" prompt, but can't login as root: - - - Add entry to /etc/securetty for console tty. - - No ACPI serial devices found in 2.6.17 or later: - - - Turn on CONFIG_PNP and CONFIG_PNPACPI. Prior to 2.6.17, ACPI - serial devices were discovered by 8250_acpi. In 2.6.17, - 8250_acpi was replaced by the combination of 8250_pnp and - CONFIG_PNPACPI. - - - -[1] - http://www.dig64.org/specifications/agreement - The table was originally defined as the "HCDP" for "Headless - Console/Debug Port." The current version is the "PCDP" for - "Primary Console and Debug Port Devices." - -[2] - The HP MP (management processor) is a PCI device that provides - several UARTs. One of the UARTs is often used as a console; the - EFI Boot Manager identifies it as "Acpi(HWP0002,700)/Pci(...)/Uart". - The external connection is usually a 25-pin connector, and a - special dongle converts that to three 9-pin connectors, one of - which is labelled "Console." - -[3] - EFI console devices are configured using the EFI Boot Manager - "Boot option maintenance" menu. You may have to interrupt the - boot sequence to use this menu, and you will have to reset the - box after changing console configuration. |