diff options
| -rw-r--r-- | Documentation/PCI/pci-error-recovery.rst | 5 | ||||
| -rw-r--r-- | Documentation/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/powerpc/bootwrapper.rst (renamed from Documentation/powerpc/bootwrapper.txt) | 28 | ||||
| -rw-r--r-- | Documentation/powerpc/cpu_families.rst (renamed from Documentation/powerpc/cpu_families.txt) | 23 | ||||
| -rw-r--r-- | Documentation/powerpc/cpu_features.rst (renamed from Documentation/powerpc/cpu_features.txt) | 6 | ||||
| -rw-r--r-- | Documentation/powerpc/cxl.rst (renamed from Documentation/powerpc/cxl.txt) | 46 | ||||
| -rw-r--r-- | Documentation/powerpc/cxlflash.rst (renamed from Documentation/powerpc/cxlflash.txt) | 10 | ||||
| -rw-r--r-- | Documentation/powerpc/dawr-power9.rst (renamed from Documentation/powerpc/DAWR-POWER9.txt) | 15 | ||||
| -rw-r--r-- | Documentation/powerpc/dscr.rst (renamed from Documentation/powerpc/dscr.txt) | 18 | ||||
| -rw-r--r-- | Documentation/powerpc/eeh-pci-error-recovery.rst (renamed from Documentation/powerpc/eeh-pci-error-recovery.txt) | 108 | ||||
| -rw-r--r-- | Documentation/powerpc/firmware-assisted-dump.rst (renamed from Documentation/powerpc/firmware-assisted-dump.txt) | 117 | ||||
| -rw-r--r-- | Documentation/powerpc/hvcs.rst (renamed from Documentation/powerpc/hvcs.txt) | 108 | ||||
| -rw-r--r-- | Documentation/powerpc/index.rst | 34 | ||||
| -rw-r--r-- | Documentation/powerpc/isa-versions.rst | 15 | ||||
| -rw-r--r-- | Documentation/powerpc/mpc52xx.rst (renamed from Documentation/powerpc/mpc52xx.txt) | 12 | ||||
| -rw-r--r-- | Documentation/powerpc/pci_iov_resource_on_powernv.rst (renamed from Documentation/powerpc/pci_iov_resource_on_powernv.txt) | 15 | ||||
| -rw-r--r-- | Documentation/powerpc/pmu-ebb.rst (renamed from Documentation/powerpc/pmu-ebb.txt) | 1 | ||||
| -rw-r--r-- | Documentation/powerpc/ptrace.rst | 156 | ||||
| -rw-r--r-- | Documentation/powerpc/ptrace.txt | 151 | ||||
| -rw-r--r-- | Documentation/powerpc/qe_firmware.rst (renamed from Documentation/powerpc/qe_firmware.txt) | 37 | ||||
| -rw-r--r-- | Documentation/powerpc/syscall64-abi.rst (renamed from Documentation/powerpc/syscall64-abi.txt) | 29 | ||||
| -rw-r--r-- | Documentation/powerpc/transactional_memory.rst (renamed from Documentation/powerpc/transactional_memory.txt) | 45 | ||||
| -rw-r--r-- | MAINTAINERS | 6 | ||||
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 2 | ||||
| -rw-r--r-- | drivers/soc/fsl/qe/qe.c | 2 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvcs.c | 2 | ||||
| -rw-r--r-- | include/soc/fsl/qe/qe.h | 2 |
27 files changed, 567 insertions, 427 deletions
diff --git a/Documentation/PCI/pci-error-recovery.rst b/Documentation/PCI/pci-error-recovery.rst index 83db42092935..e5d450df06b4 100644 --- a/Documentation/PCI/pci-error-recovery.rst +++ b/Documentation/PCI/pci-error-recovery.rst @@ -403,7 +403,7 @@ That is, the recovery API only requires that: .. note:: Implementation details for the powerpc platform are discussed in - the file Documentation/powerpc/eeh-pci-error-recovery.txt + the file Documentation/powerpc/eeh-pci-error-recovery.rst As of this writing, there is a growing list of device drivers with patches implementing error recovery. Not all of these patches are in @@ -422,3 +422,6 @@ That is, the recovery API only requires that: - drivers/net/cxgb3 - drivers/net/s2io.c - drivers/net/qlge + +The End +------- diff --git a/Documentation/index.rst b/Documentation/index.rst index 70ae148ec980..3fe6170aa41d 100644 --- a/Documentation/index.rst +++ b/Documentation/index.rst @@ -143,6 +143,7 @@ implementation. arm64/index ia64/index m68k/index + powerpc/index riscv/index s390/index sh/index diff --git a/Documentation/powerpc/bootwrapper.txt b/Documentation/powerpc/bootwrapper.rst index d60fced5e1cc..a6292afba573 100644 --- a/Documentation/powerpc/bootwrapper.txt +++ b/Documentation/powerpc/bootwrapper.rst @@ -1,5 +1,7 @@ +======================== The PowerPC boot wrapper ------------------------- +======================== + Copyright (C) Secret Lab Technologies Ltd. PowerPC image targets compresses and wraps the kernel image (vmlinux) with @@ -21,6 +23,7 @@ it uses the wrapper script (arch/powerpc/boot/wrapper) to generate target image. The details of the build system is discussed in the next section. Currently, the following image format targets exist: + ==================== ======================================================== cuImage.%: Backwards compatible uImage for older version of U-Boot (for versions that don't understand the device tree). This image embeds a device tree blob inside @@ -29,31 +32,36 @@ Currently, the following image format targets exist: with boot wrapper code that extracts data from the old bd_info structure and loads the data into the device tree before jumping into the kernel. - Because of the series of #ifdefs found in the + + Because of the series of #ifdefs found in the bd_info structure used in the old U-Boot interfaces, cuImages are platform specific. Each specific U-Boot platform has a different platform init file which populates the embedded device tree with data from the platform specific bd_info file. The platform specific cuImage platform init code can be found in - arch/powerpc/boot/cuboot.*.c. Selection of the correct + `arch/powerpc/boot/cuboot.*.c`. Selection of the correct cuImage init code for a specific board can be found in the wrapper structure. + dtbImage.%: Similar to zImage, except device tree blob is embedded inside the image instead of provided by firmware. The output image file can be either an elf file or a flat binary depending on the platform. - dtbImages are used on systems which do not have an + + dtbImages are used on systems which do not have an interface for passing a device tree directly. dtbImages are similar to simpleImages except that dtbImages have platform specific code for extracting data from the board firmware, but simpleImages do not talk to the firmware at all. - PlayStation 3 support uses dtbImage. So do Embedded + + PlayStation 3 support uses dtbImage. So do Embedded Planet boards using the PlanetCore firmware. Board specific initialization code is typically found in a file named arch/powerpc/boot/<platform>.c; but this can be overridden by the wrapper script. + simpleImage.%: Firmware independent compressed image that does not depend on any particular firmware interface and embeds a device tree blob. This image is a flat binary that @@ -61,14 +69,16 @@ Currently, the following image format targets exist: Firmware cannot pass any configuration data to the kernel with this image type and it depends entirely on the embedded device tree for all information. - The simpleImage is useful for booting systems with + + The simpleImage is useful for booting systems with an unknown firmware interface or for booting from a debugger when no firmware is present (such as on the Xilinx Virtex platform). The only assumption that simpleImage makes is that RAM is correctly initialized and that the MMU is either off or has RAM mapped to base address 0. - simpleImage also supports inserting special platform + + simpleImage also supports inserting special platform specific initialization code to the start of the bootup sequence. The virtex405 platform uses this feature to ensure that the cache is invalidated before caching @@ -81,9 +91,11 @@ Currently, the following image format targets exist: named (virtex405-<board>.dts). Search the wrapper script for 'virtex405' and see the file arch/powerpc/boot/virtex405-head.S for details. + treeImage.%; Image format for used with OpenBIOS firmware found on some ppc4xx hardware. This image embeds a device tree blob inside the image. + uImage: Native image format used by U-Boot. The uImage target does not add any boot code. It just wraps a compressed vmlinux in the uImage data structure. This image @@ -91,12 +103,14 @@ Currently, the following image format targets exist: a device tree to the kernel at boot. If using an older version of U-Boot, then you need to use a cuImage instead. + zImage.%: Image format which does not embed a device tree. Used by OpenFirmware and other firmware interfaces which are able to supply a device tree. This image expects firmware to provide the device tree at boot. Typically, if you have general purpose PowerPC hardware then you want this image format. + ==================== ======================================================== Image types which embed a device tree blob (simpleImage, dtbImage, treeImage, and cuImage) all generate the device tree blob from a file in the diff --git a/Documentation/powerpc/cpu_families.txt b/Documentation/powerpc/cpu_families.rst index fc08e22feb1a..1e063c5440c3 100644 --- a/Documentation/powerpc/cpu_families.txt +++ b/Documentation/powerpc/cpu_families.rst @@ -1,3 +1,4 @@ +============ CPU Families ============ @@ -8,8 +9,8 @@ and are supported by arch/powerpc. Book3S (aka sPAPR) ------------------ - - Hash MMU - - Mix of 32 & 64 bit +- Hash MMU +- Mix of 32 & 64 bit:: +--------------+ +----------------+ | Old POWER | --------------> | RS64 (threads) | @@ -108,8 +109,8 @@ Book3S (aka sPAPR) IBM BookE --------- - - Software loaded TLB. - - All 32 bit +- Software loaded TLB. +- All 32 bit:: +--------------+ | 401 | @@ -155,8 +156,8 @@ IBM BookE Motorola/Freescale 8xx ---------------------- - - Software loaded with hardware assist. - - All 32 bit +- Software loaded with hardware assist. +- All 32 bit:: +-------------+ | MPC8xx Core | @@ -166,9 +167,9 @@ Motorola/Freescale 8xx Freescale BookE --------------- - - Software loaded TLB. - - e6500 adds HW loaded indirect TLB entries. - - Mix of 32 & 64 bit +- Software loaded TLB. +- e6500 adds HW loaded indirect TLB entries. +- Mix of 32 & 64 bit:: +--------------+ | e200 | @@ -207,8 +208,8 @@ Freescale BookE IBM A2 core ----------- - - Book3E, software loaded TLB + HW loaded indirect TLB entries. - - 64 bit +- Book3E, software loaded TLB + HW loaded indirect TLB entries. +- 64 bit:: +--------------+ +----------------+ | A2 core | --> | WSP | diff --git a/Documentation/powerpc/cpu_features.txt b/Documentation/powerpc/cpu_features.rst index ae09df8722c8..b7bcdd2f41bb 100644 --- a/Documentation/powerpc/cpu_features.txt +++ b/Documentation/powerpc/cpu_features.rst @@ -1,3 +1,7 @@ +============ +CPU Features +============ + Hollis Blanchard <hollis@austin.ibm.com> 5 Jun 2002 @@ -32,7 +36,7 @@ anyways). After detecting the processor type, the kernel patches out sections of code that shouldn't be used by writing nop's over it. Using cpufeatures requires just 2 macros (found in arch/powerpc/include/asm/cputable.h), as seen in head.S -transfer_to_handler: +transfer_to_handler:: #ifdef CONFIG_ALTIVEC BEGIN_FTR_SECTION diff --git a/Documentation/powerpc/cxl.txt b/Documentation/powerpc/cxl.rst index c5e8d5098ed3..920546d81326 100644 --- a/Documentation/powerpc/cxl.txt +++ b/Documentation/powerpc/cxl.rst @@ -1,3 +1,4 @@ +==================================== Coherent Accelerator Interface (CXL) ==================================== @@ -21,6 +22,8 @@ Introduction Hardware overview ================= + :: + POWER8/9 FPGA +----------+ +---------+ | | | | @@ -59,14 +62,16 @@ Hardware overview the fault. The context to which this fault is serviced is based on who owns that acceleration function. - POWER8 <-----> PSL Version 8 is compliant to the CAIA Version 1.0. - POWER9 <-----> PSL Version 9 is compliant to the CAIA Version 2.0. + - POWER8 and PSL Version 8 are compliant to the CAIA Version 1.0. + - POWER9 and PSL Version 9 are compliant to the CAIA Version 2.0. + This PSL Version 9 provides new features such as: + * Interaction with the nest MMU on the P9 chip. * Native DMA support. * Supports sending ASB_Notify messages for host thread wakeup. * Supports Atomic operations. - * .... + * etc. Cards with a PSL9 won't work on a POWER8 system and cards with a PSL8 won't work on a POWER9 system. @@ -147,7 +152,9 @@ User API master devices. A userspace library libcxl is available here: + https://github.com/ibm-capi/libcxl + This provides a C interface to this kernel API. open @@ -165,7 +172,8 @@ open When all available contexts are allocated the open call will fail and return -ENOSPC. - Note: IRQs need to be allocated for each context, which may limit + Note: + IRQs need to be allocated for each context, which may limit the number of contexts that can be created, and therefore how many times the device can be opened. The POWER8 CAPP supports 2040 IRQs and 3 are used by the kernel, so 2037 are @@ -186,7 +194,9 @@ ioctl updated as userspace allocates and frees memory. This ioctl returns once the AFU context is started. - Takes a pointer to a struct cxl_ioctl_start_work: + Takes a pointer to a struct cxl_ioctl_start_work + + :: struct cxl_ioctl_start_work { __u64 flags; @@ -269,7 +279,7 @@ read The buffer passed to read() must be at least 4K bytes. The result of the read will be a buffer of one or more events, - each event is of type struct cxl_event, of varying size. + each event is of type struct cxl_event, of varying size:: struct cxl_event { struct cxl_event_header header; @@ -280,7 +290,9 @@ read }; }; - The struct cxl_event_header is defined as: + The struct cxl_event_header is defined as + + :: struct cxl_event_header { __u16 type; @@ -307,7 +319,9 @@ read For future extensions and padding. If the event type is CXL_EVENT_AFU_INTERRUPT then the event - structure is defined as: + structure is defined as + + :: struct cxl_event_afu_interrupt { __u16 flags; @@ -326,7 +340,9 @@ read For future extensions and padding. If the event type is CXL_EVENT_DATA_STORAGE then the event - structure is defined as: + structure is defined as + + :: struct cxl_event_data_storage { __u16 flags; @@ -356,7 +372,9 @@ read For future extensions If the event type is CXL_EVENT_AFU_ERROR then the event structure - is defined as: + is defined as + + :: struct cxl_event_afu_error { __u16 flags; @@ -393,15 +411,15 @@ open ioctl ----- -CXL_IOCTL_DOWNLOAD_IMAGE: -CXL_IOCTL_VALIDATE_IMAGE: +CXL_IOCTL_DOWNLOAD_IMAGE / CXL_IOCTL_VALIDATE_IMAGE: Starts and controls flashing a new FPGA image. Partial reconfiguration is not supported (yet), so the image must contain a copy of the PSL and AFU(s). Since an image can be quite large, the caller may have to iterate, splitting the image in smaller chunks. - Takes a pointer to a struct cxl_adapter_image: + Takes a pointer to a struct cxl_adapter_image:: + struct cxl_adapter_image { __u64 flags; __u64 data; @@ -442,7 +460,7 @@ Udev rules The following udev rules could be used to create a symlink to the most logical chardev to use in any programming mode (afuX.Yd for dedicated, afuX.Ys for afu directed), since the API is virtually - identical for each: + identical for each:: SUBSYSTEM=="cxl", ATTRS{mode}=="dedicated_process", SYMLINK="cxl/%b" SUBSYSTEM=="cxl", ATTRS{mode}=="afu_directed", \ diff --git a/Documentation/powerpc/cxlflash.txt b/Documentation/powerpc/cxlflash.rst index a64bdaa0a1cf..cea67931b3b9 100644 --- a/Documentation/powerpc/cxlflash.txt +++ b/Documentation/powerpc/cxlflash.rst @@ -1,3 +1,7 @@ +================================ +Coherent Accelerator (CXL) Flash +================================ + Introduction ============ @@ -28,7 +32,7 @@ Introduction responsible for the initialization of the adapter, setting up the special path for user space access, and performing error recovery. It communicates directly the Flash Accelerator Functional Unit (AFU) - as described in Documentation/powerpc/cxl.txt. + as described in Documentation/powerpc/cxl.rst. The cxlflash driver supports two, mutually exclusive, modes of operation at the device (LUN) level: @@ -58,7 +62,7 @@ Overview The CXL Flash Adapter Driver establishes a master context with the AFU. It uses memory mapped I/O (MMIO) for this control and setup. The - Adapter Problem Space Memory Map looks like this: + Adapter Problem Space Memory Map looks like this:: +-------------------------------+ | 512 * 64 KB User MMIO | @@ -375,7 +379,7 @@ CXL Flash Driver Host IOCTLs Each host adapter instance that is supported by the cxlflash driver has a special character device associated with it to enable a set of host management function. These character devices are hosted in a - class dedicated for cxlflash and can be accessed via /dev/cxlflash/*. + class dedicated for cxlflash and can be accessed via `/dev/cxlflash/*`. Applications can be written to perform various functions using the host ioctl APIs below. diff --git a/Documentation/powerpc/DAWR-POWER9.txt b/Documentation/powerpc/dawr-power9.rst index ecdbb076438c..c96ab6befd9c 100644 --- a/Documentation/powerpc/DAWR-POWER9.txt +++ b/Documentation/powerpc/dawr-power9.rst @@ -1,10 +1,11 @@ +===================== DAWR issues on POWER9 -============================ +===================== On POWER9 the Data Address Watchpoint Register (DAWR) can cause a checkstop if it points to cache inhibited (CI) memory. Currently Linux has no way to disinguish CI memory when configuring the DAWR, so (for now) the DAWR is -disabled by this commit: +disabled by this commit:: commit 9654153158d3e0684a1bdb76dbababdb7111d5a0 Author: Michael Neuling <mikey@neuling.org> @@ -12,7 +13,7 @@ disabled by this commit: powerpc: Disable DAWR in the base POWER9 CPU features Technical Details: -============================ +================== DAWR has 6 different ways of being set. 1) ptrace @@ -37,7 +38,7 @@ DAWR on the migration. For xmon, the 'bd' command will return an error on P9. Consequences for users -============================ +====================== For GDB watchpoints (ie 'watch' command) on POWER9 bare metal , GDB will accept the command. Unfortunately since there is no hardware @@ -57,8 +58,8 @@ trapped in GDB. The watchpoint is remembered, so if the guest is migrated back to the POWER8 host, it will start working again. Force enabling the DAWR -============================= -Kernels (since ~v5.2) have an option to force enable the DAWR via: +======================= +Kernels (since ~v5.2) have an option to force enable the DAWR via:: echo Y > /sys/kernel/debug/powerpc/dawr_enable_dangerous @@ -86,5 +87,7 @@ dawr_enable_dangerous file will fail if the hypervisor doesn't support writing the DAWR. To double check the DAWR is working, run this kernel selftest: + tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c + Any errors/failures/skips mean something is wrong. diff --git a/Documentation/powerpc/dscr.txt b/Documentation/powerpc/dscr.rst index ece300c64f76..2ab99006014c 100644 --- a/Documentation/powerpc/dscr.txt +++ b/Documentation/powerpc/dscr.rst @@ -1,5 +1,6 @@ - DSCR (Data Stream Control Register) - ================================================ +=================================== +DSCR (Data Stream Control Register) +=================================== DSCR register in powerpc allows user to have some control of prefetch of data stream in the processor. Please refer to the ISA documents or related manual @@ -10,14 +11,17 @@ user interface. (A) Data Structures: - (1) thread_struct: + (1) thread_struct:: + dscr /* Thread DSCR value */ dscr_inherit /* Thread has changed default DSCR */ - (2) PACA: + (2) PACA:: + dscr_default /* per-CPU DSCR default value */ - (3) sysfs.c: + (3) sysfs.c:: + dscr_default /* System DSCR default value */ (B) Scheduler Changes: @@ -35,8 +39,8 @@ user interface. (C) SYSFS Interface: - Global DSCR default: /sys/devices/system/cpu/dscr_default - CPU specific DSCR default: /sys/devices/system/cpu/cpuN/dscr + - Global DSCR default: /sys/devices/system/cpu/dscr_default + - CPU specific DSCR default: /sys/devices/system/cpu/cpuN/dscr Changing the global DSCR default in the sysfs will change all the CPU specific DSCR defaults immediately in their PACA structures. Again if diff --git a/Documentation/powerpc/eeh-pci-error-recovery.txt b/Documentation/powerpc/eeh-pci-error-recovery.rst index 678189280bb4..438a87ebc095 100644 --- a/Documentation/powerpc/eeh-pci-error-recovery.txt +++ b/Documentation/powerpc/eeh-pci-error-recovery.rst @@ -1,10 +1,10 @@ +========================== +PCI Bus EEH Error Recovery +========================== +Linas Vepstas <linas@austin.ibm.com> - PCI Bus EEH Error Recovery - -------------------------- - Linas Vepstas - <linas@austin.ibm.com> - 12 January 2005 +12 January 2005 Overview: @@ -143,17 +143,17 @@ seen in /proc/ppc64/eeh (subject to change). Normally, almost all of these occur during boot, when the PCI bus is scanned, where a large number of 0xff reads are part of the bus scan procedure. -If a frozen slot is detected, code in -arch/powerpc/platforms/pseries/eeh.c will print a stack trace to -syslog (/var/log/messages). This stack trace has proven to be very -useful to device-driver authors for finding out at what point the EEH -error was detected, as the error itself usually occurs slightly +If a frozen slot is detected, code in +arch/powerpc/platforms/pseries/eeh.c will print a stack trace to +syslog (/var/log/messages). This stack trace has proven to be very +useful to device-driver authors for finding out at what point the EEH +error was detected, as the error itself usually occurs slightly beforehand. Next, it uses the Linux kernel notifier chain/work queue mechanism to allow any interested parties to find out about the failure. Device drivers, or other parts of the kernel, can use -eeh_register_notifier(struct notifier_block *) to find out about EEH +`eeh_register_notifier(struct notifier_block *)` to find out about EEH events. The event will include a pointer to the pci device, the device node and some state info. Receivers of the event can "do as they wish"; the default handler will be described further in this @@ -162,10 +162,13 @@ section. To assist in the recovery of the device, eeh.c exports the following functions: -rtas_set_slot_reset() -- assert the PCI #RST line for 1/8th of a second -rtas_configure_bridge() -- ask firmware to configure any PCI bridges +rtas_set_slot_reset() + assert the PCI #RST line for 1/8th of a second +rtas_configure_bridge() + ask firmware to configure any PCI bridges located topologically under the pci slot. -eeh_save_bars() and eeh_restore_bars(): save and restore the PCI +eeh_save_bars() and eeh_restore_bars(): + save and restore the PCI config-space info for a device and any devices under it. @@ -191,7 +194,7 @@ events get delivered to user-space scripts. Following is an example sequence of events that cause a device driver close function to be called during the first phase of an EEH reset. -The following sequence is an example of the pcnet32 device driver. +The following sequence is an example of the pcnet32 device driver:: rpa_php_unconfig_pci_adapter (struct slot *) // in rpaphp_pci.c { @@ -241,53 +244,54 @@ The following sequence is an example of the pcnet32 device driver. }}}}}} - in drivers/pci/pci_driver.c, - struct device_driver->remove() is just pci_device_remove() - which calls struct pci_driver->remove() which is pcnet32_remove_one() - which calls unregister_netdev() (in net/core/dev.c) - which calls dev_close() (in net/core/dev.c) - which calls dev->stop() which is pcnet32_close() - which then does the appropriate shutdown. +in drivers/pci/pci_driver.c, +struct device_driver->remove() is just pci_device_remove() +which calls struct pci_driver->remove() which is pcnet32_remove_one() +which calls unregister_netdev() (in net/core/dev.c) +which calls dev_close() (in net/core/dev.c) +which calls dev->stop() which is pcnet32_close() +which then does the appropriate shutdown. --- + Following is the analogous stack trace for events sent to user-space -when the pci device is unconfigured. +when the pci device is unconfigured:: -rpa_php_unconfig_pci_adapter() { // in rpaphp_pci.c - calls - pci_remove_bus_device (struct pci_dev *) { // in /drivers/pci/remove.c + rpa_php_unconfig_pci_adapter() { // in rpaphp_pci.c calls - pci_destroy_dev (struct pci_dev *) { + pci_remove_bus_device (struct pci_dev *) { // in /drivers/pci/remove.c calls - device_unregister (&dev->dev) { // in /drivers/base/core.c + pci_destroy_dev (struct pci_dev *) { calls - device_del(struct device * dev) { // in /drivers/base/core.c + device_unregister (&dev->dev) { // in /drivers/base/core.c calls - kobject_del() { //in /libs/kobject.c + device_del(struct device * dev) { // in /drivers/base/core.c calls - kobject_uevent() { // in /libs/kobject.c + kobject_del() { //in /libs/kobject.c calls - kset_uevent() { // in /lib/kobject.c + kobject_uevent() { // in /libs/kobject.c calls - kset->uevent_ops->uevent() // which is really just - a call to - dev_uevent() { // in /drivers/base/core.c + kset_uevent() { // in /lib/kobject.c calls - dev->bus->uevent() which is really just a call to - pci_uevent () { // in drivers/pci/hotplug.c - which prints device name, etc.... + kset->uevent_ops->uevent() // which is really just + a call to + dev_uevent() { // in /drivers/base/core.c + calls + dev->bus->uevent() which is really just a call to + pci_uevent () { // in drivers/pci/hotplug.c + which prints device name, etc.... + } } - } - then kobject_uevent() sends a netlink uevent to userspace - --> userspace uevent - (during early boot, nobody listens to netlink events and - kobject_uevent() executes uevent_helper[], which runs the - event process /sbin/hotplug) + then kobject_uevent() sends a netlink uevent to userspace + --> userspace uevent + (during early boot, nobody listens to netlink events and + kobject_uevent() executes uevent_helper[], which runs the + event process /sbin/hotplug) + } } - } - kobject_del() then calls sysfs_remove_dir(), which would - trigger any user-space daemon that was watching /sysfs, - and notice the delete event. + kobject_del() then calls sysfs_remove_dir(), which would + trigger any user-space daemon that was watching /sysfs, + and notice the delete event. Pro's and Con's of the Current Design @@ -299,12 +303,12 @@ individual device drivers, so that the current design throws a wide net. The biggest negative of the design is that it potentially disturbs network daemons and file systems that didn't need to be disturbed. --- A minor complaint is that resetting the network card causes +- A minor complaint is that resetting the network card causes user-space back-to-back ifdown/ifup burps that potentially disturb network daemons, that didn't need to even know that the pci card was being rebooted. --- A more serious concern is that the same reset, for SCSI devices, +- A more serious concern is that the same reset, for SCSI devices, causes havoc to mounted file systems. Scripts cannot post-facto unmount a file system without flushing pending buffers, but this is impossible, because I/O has already been stopped. Thus, @@ -322,7 +326,7 @@ network daemons and file systems that didn't need to be disturbed. from the block layer. It would be very natural to add an EEH reset into this chain of events. --- If a SCSI error occurs for the root device, all is lost unless +- If a SCSI error occurs for the root device, all is lost unless the sysadmin had the foresight to run /bin, /sbin, /etc, /var and so on, out of ramdisk/tmpfs. @@ -330,5 +334,3 @@ network daemons and file systems that didn't need to be disturbed. Conclusions ----------- There's forward progress ... - - diff --git a/Documentation/powerpc/firmware-assisted-dump.txt b/Documentation/powerpc/firmware-assisted-dump.rst index 10e7f4d16c14..9ca12830a48e 100644 --- a/Documentation/powerpc/firmware-assisted-dump.txt +++ b/Documentation/powerpc/firmware-assisted-dump.rst @@ -1,7 +1,8 @@ +====================== +Firmware-Assisted Dump +====================== - Firmware-Assisted Dump - ------------------------ - July 2011 +July 2011 The goal of firmware-assisted dump is to enable the dump of a crashed system, and to do so from a fully-reset system, and @@ -27,11 +28,11 @@ in production use. Comparing with kdump or other strategies, firmware-assisted dump offers several strong, practical advantages: --- Unlike kdump, the system has been reset, and loaded +- Unlike kdump, the system has been reset, and loaded with a fresh copy of the kernel. In particular, PCI and I/O devices have been reinitialized and are in a clean, consistent state. --- Once the dump is copied out, the memory that held the dump +- Once the dump is copied out, the memory that held the dump is immediately available to the running kernel. And therefore, unlike kdump, fadump doesn't need a 2nd reboot to get back the system to the production configuration. @@ -40,17 +41,18 @@ The above can only be accomplished by coordination with, and assistance from the Power firmware. The procedure is as follows: --- The first kernel registers the sections of memory with the +- The first kernel registers the sections of memory with the Power firmware for dump preservation during OS initialization. These registered sections of memory are reserved by the first kernel during early boot. --- When a system crashes, the Power firmware wi |