user/sven/linux.git/drivers/ata/libata.h, branch v3.3.5

ata: add ata port system PM callbacks

2012-01-09T00:14:58Z

Change ata_host_request_pm to ata_port_request_pm which performs port suspend/resume. Add ata port type driver which implements port PM callbacks. Signed-off-by: Lin Ming Signed-off-by: Jeff Garzik

libata: plumb sas port scan into standard libata paths

2011-03-02T07:36:45Z

The function ata_sas_port_init() has always really done its own thing. However, as a precursor to moving to the libata new eh, it has to be properly using the standard libata scan paths. This means separating the current libata scan paths into pieces which can be shared with libsas and pieces which cant (really just the async call and the host scan). Signed-off-by: James Bottomley Signed-off-by: Jeff Garzik

libata: implement cross-port EH exclusion

2010-10-22T00:21:05Z

In libata, the non-EH code paths should always take and release ap->lock explicitly when accessing hardware or shared data structures. However, once EH is active, it's assumed that the port is owned by EH and EH methods don't explicitly take ap->lock unless race from irq handler or other code paths are expected. However, libata EH didn't guarantee exclusion among EHs for ports of the same host. IOW, multiple EHs may execute in parallel on multiple ports of the same controller. In many cases, especially in SATA, the ports are completely independent of each other and this doesn't cause problems; however, there are cases where different ports share the same resource, which lead to obscure timing related bugs such as the one fixed by commit 213373cf (ata_piix: fix locking around SIDPR access). This patch implements exclusion among EHs of the same host. When EH begins, it acquires per-host EH ownership by calling ata_eh_acquire(). When EH finishes, the ownership is released by calling ata_eh_release(). EH ownership is also released whenever the EH thread goes to sleep from ata_msleep() or explicitly and reacquired after waking up. This ensures that while EH is actively accessing the hardware, it has exclusive access to it while allowing EHs to interleave and progress in parallel as they hit waiting stages, which dominate the time spent in EH. This achieves cross-port EH exclusion without pervasive and fragile changes while still allowing parallel EH for the most part. This was first reported by yuanding02@gmail.com more than three years ago in the following bugzilla. :-) https://bugzilla.kernel.org/show_bug.cgi?id=8223 Signed-off-by: Tejun Heo Cc: Alan Cox Reported-by: yuanding02@gmail.com Signed-off-by: Jeff Garzik

libata: implement LPM support for port multipliers

2010-10-22T00:21:04Z

Port multipliers can do DIPM on fan-out links fine. Implement support for it. Tested w/ SIMG 57xx and marvell PMPs. Both the host and fan-out links enter power save modes nicely. SIMG 37xx and 47xx report link offline on SStatus causing EH to detach the devices. Blacklisted. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik

libata: reimplement link power management

2010-10-22T00:21:04Z

The current LPM implementation has the following issues. * Operation order isn't well thought-out. e.g. HIPM should be configured after IPM in SControl is properly configured. Not the other way around. * Suspend/resume paths call ata_lpm_enable/disable() which must only be called from EH context directly. Also, ata_lpm_enable/disable() were called whether LPM was in use or not. * Implementation is per-port when it should be per-link. As a result, it can't be used for controllers with slave links or PMP. * LPM state isn't managed consistently. After a link reset for whatever reason including suspend/resume the actual LPM state would be reset leaving ap->lpm_policy inconsistent. * Generic/driver-specific logic boundary isn't clear. Currently, libahci has to mangle stuff which libata EH proper should be handling. This makes the implementation unnecessarily complex and fragile. * Tied to ALPM. Doesn't consider DIPM only cases and doesn't check whether the device allows HIPM. * Error handling isn't implemented. Given the extent of mismatch with the rest of libata, I don't think trying to fix it piecewise makes much sense. This patch reimplements LPM support. * The new implementation is per-link. The target policy is still port-wide (ap->target_lpm_policy) but all the mechanisms and states are per-link and integrate well with the rest of link abstraction and can work with slave and PMP links. * Core EH has proper control of LPM state. LPM state is reconfigured when and only when reconfiguration is necessary. It makes sure that LPM state is reset when probing for new device on the link. Controller agnostic logic is now implemented in libata EH proper and driver implementation only has to deal with controller specifics. * Proper error handling. LPM config failure is attributed to the device on the link and LPM is disabled for the link if it fails repeatedly. * ops->enable/disable_pm() are replaced with single ops->set_lpm() which takes @policy and @hints. This simplifies driver specific implementation. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik

libata: implement sata_link_scr_lpm() and make ata_dev_set_feature() global

2010-10-22T00:21:04Z

Link power management is about to be reimplemented. Prepare for it. * Implement sata_link_scr_lpm(). * Drop static from ata_dev_set_feature() and make it available to other libata files. * Trivial whitespace adjustments. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik

libata: clean up lpm related symbols and sysfs show/store functions

2010-10-22T00:21:04Z

Link power management related symbols are in confusing state w/ mixed usages of lpm, ipm and pm. This patch cleans up lpm related symbols and sysfs show/store functions as follows. * lpm states - NOT_AVAILABLE, MIN_POWER, MAX_PERFORMANCE and MEDIUM_POWER are renamed to ATA_LPM_UNKNOWN and ATA_LPM_{MIN|MAX|MED}_POWER. * Pre/postfixes are unified to lpm. * sysfs show/store functions for link_power_management_policy were curiously named get/put and unnecessarily complex. Renamed to show/store and simplified. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik

[libata] Add ATA transport class

2010-10-22T00:21:03Z

This is a scheleton for libata transport class. All information is read only, exporting information from libata: - ata_port class: one per ATA port - ata_link class: one per ATA port or 15 for SATA Port Multiplier - ata_device class: up to 2 for PATA link, usually one for SATA. Signed-off-by: Gwendal Grignou Reviewed-by: Grant Grundler Signed-off-by: Jeff Garzik

libata: take advantage of cmwq and remove concurrency limitations

2010-07-02T08:59:24Z

libata has two concurrency related limitations. a. ata_wq which is used for polling PIO has single thread per CPU. If there are multiple devices doing polling PIO on the same CPU, they can't be executed simultaneously. b. ata_aux_wq which is used for SCSI probing has single thread. In cases where SCSI probing is stalled for extended period of time which is possible for ATAPI devices, this will stall all probing. #a is solved by increasing maximum concurrency of ata_wq. Please note that polling PIO might be used under allocation path and thus needs to be served by a separate wq with a rescuer. #b is solved by using the default wq instead and achieving exclusion via per-port mutex. Signed-off-by: Tejun Heo Acked-by: Jeff Garzik

libata-sff: separate out BMDMA EH

2010-05-19T17:36:46Z

Some of error handling logic in ata_sff_error_handler() and all of ata_sff_post_internal_cmd() are for BMDMA. Create ata_bmdma_error_handler() and ata_bmdma_post_internal_cmd() and move BMDMA part into those. While at it, change DMA protocol check to ata_is_dma(), fix post_internal_cmd to call ap->ops->bmdma_stop instead of directly calling ata_bmdma_stop() and open code hardreset selection so that ata_std_error_handler() doesn't have to know about sff hardreset. As these two functions are BMDMA specific, there's no reason to check for bmdma_addr before calling bmdma methods if the protocol of the failed command is DMA. sata_mv and pata_mpc52xx now don't need to set .post_internal_cmd to ATA_OP_NULL and pata_icside and sata_qstor don't need to set it to their bmdma_stop routines. ata_sff_post_internal_cmd() becomes noop and is removed. This fixes p3 described in clean-up-BMDMA-initialization patch. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik