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path: root/drivers/acpi/acpi_ipmi.c
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2013-09-30ACPI / IPMI: Cleanup coding stylesLv Zheng
This patch only introduces indentation cleanups. No functional changes. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30ACPI / IPMI: Cleanup some inclusion codesLv Zheng
This (trivial) patch: 1. Deletes several useless header inclusions. 2. Kernel codes should always include <linux/acpi.h> instead of <acpi/acpi_bus.h> or <acpi/acpi_drivers.h> where many conditional declarations are handled. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30ACPI / IPMI: Cleanup some initialization codesLv Zheng
This (trivial) patch. 1. Changes dynamic mutex initialization to static initialization. 2. Removes one acpi_ipmi_init() variable initialization as it is not needed. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30ACPI / IPMI: Cleanup several acpi_ipmi_device membersLv Zheng
This (trivial) patch: 1. Deletes a member of the acpi_ipmi_device, smi_data, which is not actually used. 2. Updates a member of the acpi_ipmi_device, pnp_dev, which is only used by dev_warn() invocations, so changes it to a struct device. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30ACPI / IPMI: Add reference counting for ACPI IPMI transfersLv Zheng
This patch adds reference counting for ACPI IPMI transfers to tune the locking granularity of tx_msg_lock. This patch also makes the whole acpi_ipmi module's coding style consistent by using reference counting for all its objects (i.e., acpi_ipmi_device and acpi_ipmi_msg). The acpi_ipmi_msg handling is re-designed using referece counting. 1. tx_msg is always unlinked before complete(), so that it is safe to put complete() out side of tx_msg_lock. 2. tx_msg reference counters are incremented before calling ipmi_request_settime() and tx_msg_lock protection is added to ipmi_cancel_tx_msg() so that a complete() can be safely called in parellel with tx_msg unlinking in failure cases. 3. tx_msg holds a reference to acpi_ipmi_device so that it can be flushed and freed in the contexts other than acpi_ipmi_space_handler(). The lockdep_chains shows all acpi_ipmi locks are leaf locks after the tuning: 1. ipmi_lock is always leaf: irq_context: 0 [ffffffff81a943f8] smi_watchers_mutex [ffffffffa06eca60] driver_data.ipmi_lock irq_context: 0 [ffffffff82767b40] &buffer->mutex [ffffffffa00a6678] s_active#103 [ffffffffa06eca60] driver_data.ipmi_lock 2. without this patch applied, lock used by complete() is held after holding tx_msg_lock: irq_context: 0 [ffffffff82767b40] &buffer->mutex [ffffffffa00a6678] s_active#103 [ffffffffa06ecce8] &(&ipmi_device->tx_msg_lock)->rlock irq_context: 1 [ffffffffa06ecce8] &(&ipmi_device->tx_msg_lock)->rlock irq_context: 1 [ffffffffa06ecce8] &(&ipmi_device->tx_msg_lock)->rlock [ffffffffa06eccf0] &x->wait#25 irq_context: 1 [ffffffffa06ecce8] &(&ipmi_device->tx_msg_lock)->rlock [ffffffffa06eccf0] &x->wait#25 [ffffffff81e36620] &p->pi_lock irq_context: 1 [ffffffffa06ecce8] &(&ipmi_device->tx_msg_lock)->rlock [ffffffffa06eccf0] &x->wait#25 [ffffffff81e36620] &p->pi_lock [ffffffff81e5d0a8] &rq->lock 3. with this patch applied, tx_msg_lock is always leaf: irq_context: 0 [ffffffff82767b40] &buffer->mutex [ffffffffa00a66d8] s_active#107 [ffffffffa07ecdc8] &(&ipmi_device->tx_msg_lock)->rlock irq_context: 1 [ffffffffa07ecdc8] &(&ipmi_device->tx_msg_lock)->rlock Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30ACPI / IPMI: Use global IPMI operation region handlerLv Zheng
It is found on a real machine, in its ACPI namespace, the IPMI OperationRegions (in the ACPI000D - ACPI power meter) are not defined under the IPMI system interface device (the IPI0001 with KCS type returned from _IFT control method): Device (PMI0) { Name (_HID, "ACPI000D") // _HID: Hardware ID OperationRegion (SYSI, IPMI, 0x0600, 0x0100) Field (SYSI, BufferAcc, Lock, Preserve) { AccessAs (BufferAcc, 0x01), Offset (0x58), SCMD, 8, GCMD, 8 } OperationRegion (POWR, IPMI, 0x3000, 0x0100) Field (POWR, BufferAcc, Lock, Preserve) { AccessAs (BufferAcc, 0x01), Offset (0xB3), GPMM, 8 } } Device (PCI0) { Device (ISA) { Device (NIPM) { Name (_HID, EisaId ("IPI0001")) // _HID: Hardware ID Method (_IFT, 0, NotSerialized) // _IFT: IPMI Interface Type { Return (0x01) } } } } Current ACPI_IPMI code registers IPMI operation region handler on a per-device basis, so for the above namespace the IPMI operation region handler is registered only under the scope of \_SB.PCI0.ISA.NIPM. Thus when an IPMI operation region field of \PMI0 is accessed, there are errors reported on such platform: ACPI Error: No handlers for Region [IPMI] ACPI Error: Region IPMI(7) has no handler The solution is to install an IPMI operation region handler from root node so that every object that defines IPMI OperationRegion can get an address space handler registered. When an IPMI operation region field is accessed, the Network Function (0x06 for SYSI and 0x30 for POWR) and the Command (SCMD, GCMD, GPMM) are passed to the operation region handler, there is no system interface specified by the BIOS. The patch tries to select one system interface by monitoring the system interface notification. IPMI messages passed from the ACPI codes are sent to this selected global IPMI system interface. The ACPI_IPMI will always select the first registered IPMI interface with an ACPI handle (i.e., defined in the ACPI namespace). It's hard to determine the selection when there are multiple IPMI system interfaces defined in the ACPI namespace. According to the IPMI specification: A BMC device may make available multiple system interfaces, but only one management controller is allowed to be 'active' BMC that provides BMC functionality for the system (in case of a 'partitioned' system, there can be only one active BMC per partition). Only the system interface(s) for the active BMC allowed to respond to the 'Get Device Id' command. According to the ipmi_si desigin: The ipmi_si registeration notifications can only happen after a successful "Get Device ID" command. Thus it should be OK for non-partitioned systems to do such selection. However, we do not have much knowledge on 'partitioned' systems. References: https://bugzilla.kernel.org/show_bug.cgi?id=46741 Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30ACPI / IPMI: Fix race caused by the unprotected ACPI IPMI userLv Zheng
This patch uses reference counting to fix the race caused by the unprotected ACPI IPMI user. There are two rules for using the ipmi_si APIs: 1. In ipmi_si, ipmi_destroy_user() can ensure that no ipmi_recv_msg will be passed to ipmi_msg_handler(), but ipmi_request_settime() can not use an invalid ipmi_user_t. This means the ipmi_si users must ensure that there won't be any local references on ipmi_user_t before invoking ipmi_destroy_user(). 2. In ipmi_si, the smi_gone()/new_smi() callbacks are protected by smi_watchers_mutex, so their execution is serialized. But as a new smi can re-use a freed intf_num, it requires that the callback implementation must not use intf_num as an identification mean or it must ensure all references to the previous smi are all dropped before exiting smi_gone() callback. As the acpi_ipmi_device->user_interface check in acpi_ipmi_space_handler() can happen before setting user_interface to NULL and codes after the check in acpi_ipmi_space_handler() can happen after user_interface becomes NULL, the on-going acpi_ipmi_space_handler() still can pass an invalid acpi_ipmi_device->user_interface to ipmi_request_settime(). Such race conditions are not allowed by the IPMI layer's API design as a crash will happen in ipmi_request_settime() if something like that happens. This patch follows the ipmi_devintf.c design: 1. Invoke ipmi_destroy_user() after the reference count of acpi_ipmi_device drops to 0. References of acpi_ipmi_device dropping to 0 also means tx_msg related to this acpi_ipmi_device are all freed. This matches the IPMI layer's API calling rule on ipmi_destroy_user() and ipmi_request_settime(). 2. ipmi_flush_tx_msg() is performed so that no on-going tx_msg can still be running in acpi_ipmi_space_handler(). And it is invoked after invoking __ipmi_dev_kill() where acpi_ipmi_device is deleted from the list with a "dead" flag set, and the "dead" flag check is also introduced to the point where a tx_msg is going to be added to the tx_msg_list so that no new tx_msg can be created after returning from the __ipmi_dev_kill(). 3. The waiting codes in ipmi_flush_tx_msg() is deleted because it is not required since this patch ensures no acpi_ipmi reference is still held for ipmi_user_t before calling ipmi_destroy_user() and ipmi_destroy_user() can ensure no more ipmi_msg_handler() can happen after returning from ipmi_destroy_user(). 4. The flushing of tx_msg is also moved out of ipmi_lock in this patch. The forthcoming IPMI operation region handler installation changes also requires acpi_ipmi_device be handled in this style. The header comment of the file is also updated due to this design change. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30ACPI / IPMI: Fix race caused by the timed out ACPI IPMI transfersLv Zheng
This patch fixes races caused by timed out ACPI IPMI transfers. This patch uses timeout mechanism provided by ipmi_si to avoid the race that the msg_done flag is set but without any protection, its content can be invalid. Thanks for the suggestion of Corey Minyard. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30ACPI / IPMI: Fix race caused by the unprotected ACPI IPMI transfersLv Zheng
This patch fixes races caused by unprotected ACPI IPMI transfers. We can see that the following crashes may occur: 1. There is no tx_msg_lock held for iterating tx_msg_list in ipmi_flush_tx_msg() while it may be unlinked on failure in parallel in acpi_ipmi_space_handler() under tx_msg_lock. 2. There is no lock held for freeing tx_msg in acpi_ipmi_space_handler() while it may be accessed in parallel in ipmi_flush_tx_msg() and ipmi_msg_handler(). This patch enhances tx_msg_lock to protect all tx_msg accesses to solve this issue. Then tx_msg_lock is always held around complete() and tx_msg accesses. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30ACPI / IPMI: Fix potential response buffer overflowLv Zheng
This patch enhances sanity checks on message size to avoid potential buffer overflow. The kernel IPMI message size is IPMI_MAX_MSG_LENGTH(272 bytes) while the ACPI specification defined IPMI message size is 64 bytes. The difference is not handled by the original codes. This may cause crash in the response handling codes. This patch closes this gap and also combines rx_data/tx_data to use single data/len pair since they need not be seperate. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-25ACPI / IPMI: Fix atomic context requirement of ipmi_msg_handler()Lv Zheng
This patch fixes the issues indicated by the test results that ipmi_msg_handler() is invoked in atomic context. BUG: scheduling while atomic: kipmi0/18933/0x10000100 Modules linked in: ipmi_si acpi_ipmi ... CPU: 3 PID: 18933 Comm: kipmi0 Tainted: G AW 3.10.0-rc7+ #2 Hardware name: QCI QSSC-S4R/QSSC-S4R, BIOS QSSC-S4R.QCI.01.00.0027.070120100606 07/01/2010 ffff8838245eea00 ffff88103fc63c98 ffffffff814c4a1e ffff88103fc63ca8 ffffffff814bfbab ffff88103fc63d28 ffffffff814c73e0 ffff88103933cbd4 0000000000000096 ffff88103fc63ce8 ffff88102f618000 ffff881035c01fd8 Call Trace: <IRQ> [<ffffffff814c4a1e>] dump_stack+0x19/0x1b [<ffffffff814bfbab>] __schedule_bug+0x46/0x54 [<ffffffff814c73e0>] __schedule+0x83/0x59c [<ffffffff81058853>] __cond_resched+0x22/0x2d [<ffffffff814c794b>] _cond_resched+0x14/0x1d [<ffffffff814c6d82>] mutex_lock+0x11/0x32 [<ffffffff8101e1e9>] ? __default_send_IPI_dest_field.constprop.0+0x53/0x58 [<ffffffffa09e3f9c>] ipmi_msg_handler+0x23/0x166 [ipmi_si] [<ffffffff812bf6e4>] deliver_response+0x55/0x5a [<ffffffff812c0fd4>] handle_new_recv_msgs+0xb67/0xc65 [<ffffffff81007ad1>] ? read_tsc+0x9/0x19 [<ffffffff814c8620>] ? _raw_spin_lock_irq+0xa/0xc [<ffffffffa09e1128>] ipmi_thread+0x5c/0x146 [ipmi_si] ... Also Tony Camuso says: We were getting occasional "Scheduling while atomic" call traces during boot on some systems. Problem was first seen on a Cisco C210 but we were able to reproduce it on a Cisco c220m3. Setting CONFIG_LOCKDEP and LOCKDEP_SUPPORT to 'y' exposed a lockdep around tx_msg_lock in acpi_ipmi.c struct acpi_ipmi_device. ================================= [ INFO: inconsistent lock state ] 2.6.32-415.el6.x86_64-debug-splck #1 --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. ksoftirqd/3/17 [HC0[0]:SC1[1]:HE1:SE0] takes: (&ipmi_device->tx_msg_lock){+.?...}, at: [<ffffffff81337a27>] ipmi_msg_handler+0x71/0x126 {SOFTIRQ-ON-W} state was registered at: [<ffffffff810ba11c>] __lock_acquire+0x63c/0x1570 [<ffffffff810bb0f4>] lock_acquire+0xa4/0x120 [<ffffffff815581cc>] __mutex_lock_common+0x4c/0x400 [<ffffffff815586ea>] mutex_lock_nested+0x4a/0x60 [<ffffffff8133789d>] acpi_ipmi_space_handler+0x11b/0x234 [<ffffffff81321c62>] acpi_ev_address_space_dispatch+0x170/0x1be The fix implemented by this change has been tested by Tony: Tested the patch in a boot loop with lockdep debug enabled and never saw the problem in over 400 reboots. Reported-and-tested-by: Tony Camuso <tcamuso@redhat.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2010-12-14IPMI/ACPI: Add the IPMI opregion driver to enable ACPI to access BMC controllerZhao Yakui
ACPI 4.0 spec adds the ACPI IPMI opregion, which means that the ACPI AML code can also communicate with the BMC controller. This is to install the ACPI IPMI opregion and enable the ACPI to access the BMC controller through the IPMI message. It will create IPMI user interface for every IPMI device detected in ACPI namespace and install the corresponding IPMI opregion space handler. Then it can enable ACPI to access the BMC controller through the IPMI message. The following describes how to process the IPMI request in IPMI space handler: 1. format the IPMI message based on the request in AML code. IPMI system address. Now the address type is SYSTEM_INTERFACE_ADDR_TYPE IPMI net function & command IPMI message payload 2. send the IPMI message by using the function of ipmi_request_settime 3. wait for the completion of IPMI message. It can be done in different routes: One is in handled in IPMI user recv callback function. Another is handled in timeout function. 4. format the IPMI response and return it to ACPI AML code. At the same time it also addes the module dependency. The ACPI IPMI opregion will depend on the IPMI subsystem. Signed-off-by: Zhao Yakui <yakui.zhao@intel.com> cc: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Len Brown <len.brown@intel.com>