lwn.git/drivers/ata/pdc_adma.c, branch v2.6.27.3

libata: rename SFF functions

2008-04-17T19:44:21+00:00

SFF functions have confusing names. Some have sff prefix, some have bmdma, some std, some pci and some none. Unify the naming by... * SFF functions which are common to both BMDMA and non-BMDMA are prefixed with ata_sff_. * SFF functions which are specific to BMDMA are prefixed with ata_bmdma_. * SFF functions which are specific to PCI but apply to both BMDMA and non-BMDMA are prefixed with ata_pci_sff_. * SFF functions which are specific to PCI and BMDMA are prefixed with ata_pci_bmdma_. * Drop generic prefixes from LLD specific routines. For example, bfin_std_dev_select -> bfin_dev_select. The following renames are noteworthy. ata_qc_issue_prot() -> ata_sff_qc_issue() ata_pci_default_filter() -> ata_bmdma_mode_filter() ata_dev_try_classify() -> ata_sff_dev_classify() This rename is in preparation of separating SFF support out of libata core layer. This patch strictly renames functions and doesn't introduce any behavior difference. Signed-off-by: Tejun Heo

pdc_adma: kill adma_host_stop()

2008-04-17T19:44:21+00:00

adma_host_stop() does the same thing that adma_port_stop() does. Kill it. Signed-off-by: Tejun Heo Cc: Mark Lord Signed-off-by: Jeff Garzik

pdc_adma: inherit ata_sff_port_ops

2008-04-17T19:44:20+00:00

With the previous ops standardization, pdc_adma now can inherit ata_sff_port_ops instead of ata_base_port_ops. Make the change. Signed-off-by: Tejun Heo Cc: Mark Lord Signed-off-by: Jeff Garzik

libata/pdc_adma: make SFF EH handle non-bmdma SFF drivers and standardize pdc_adma ops

2008-04-17T19:44:20+00:00

pdc_adma has interface similar to SFF but has its own DMA interface. It currently implements noop bmdma ops to avoid crashing ata_bmdma_error_handler() which BTW actually is EH for SFF drivers. This patch makes ata_bmdma_error_handler() dereference bmdma ops iff bmdma_addr is initialized as done in ata_bmdma_post_internal_cmd. This change allows pdc_adma to standardize ops and use SFF error_handler and post_internal_cmd. Signed-off-by: Tejun Heo Cc: Mark Lord Signed-off-by: Jeff Garzik

libata: make reset related methods proper port operations

2008-04-17T19:44:18+00:00

Currently reset methods are not specified directly in the ata_port_operations table. If a LLD wants to use custom reset methods, it should construct and use a error_handler which uses those reset methods. It's done this way for two reasons. First, the ops table already contained too many methods and adding four more of them would noticeably increase the amount of necessary boilerplate code all over low level drivers. Second, as ->error_handler uses those reset methods, it can get confusing. ie. By overriding ->error_handler, those reset ops can be made useless making layering a bit hazy. Now that ops table uses inheritance, the first problem doesn't exist anymore. The second isn't completely solved but is relieved by providing default values - most drivers can just override what it has implemented and don't have to concern itself about higher level callbacks. In fact, there currently is no driver which actually modifies error handling behavior. Drivers which override ->error_handler just wraps the standard error handler only to prepare the controller for EH. I don't think making ops layering strict has any noticeable benefit. This patch makes ->prereset, ->softreset, ->hardreset, ->postreset and their PMP counterparts propoer ops. Default ops are provided in the base ops tables and drivers are converted to override individual reset methods instead of creating custom error_handler. * ata_std_error_handler() doesn't use sata_std_hardreset() if SCRs aren't accessible. sata_promise doesn't need to use separate error_handlers for PATA and SATA anymore. * softreset is broken for sata_inic162x and sata_sx4. As libata now always prefers hardreset, this doesn't really matter but the ops are forced to NULL using ATA_OP_NULL for documentation purpose. * pata_hpt374 needs to use different prereset for the first and second PCI functions. This used to be done by branching from hpt374_error_handler(). The proper way to do this is to use separate ops and port_info tables for each function. Converted. Signed-off-by: Tejun Heo

libata: implement and use ops inheritance

2008-04-17T19:44:17+00:00

libata lets low level drivers build ata_port_operations table and register it with libata core layer. This allows low level drivers high level of flexibility but also burdens them with lots of boilerplate entries. This becomes worse for drivers which support related similar controllers which differ slightly. They share most of the operations except for a few. However, the driver still needs to list all operations for each variant. This results in large number of duplicate entries, which is not only inefficient but also error-prone as it becomes very difficult to tell what the actual differences are. This duplicate boilerplates all over the low level drivers also make updating the core layer exteremely difficult and error-prone. When compounded with multi-branched development model, it ends up accumulating inconsistencies over time. Some of those inconsistencies cause immediate problems and fixed. Others just remain there dormant making maintenance increasingly difficult. To rectify the problem, this patch implements ata_port_operations inheritance. To allow LLDs to easily re-use their own ops tables overriding only specific methods, this patch implements poor man's class inheritance. An ops table has ->inherits field which can be set to any ops table as long as it doesn't create a loop. When the host is started, the inheritance chain is followed and any operation which isn't specified is taken from the nearest ancestor which has it specified. This operation is called finalization and done only once per an ops table and the LLD doesn't have to do anything special about it other than making the ops table non-const such that libata can update it. libata provides four base ops tables lower drivers can inherit from - base, sata, pmp, sff and bmdma. To avoid overriding these ops accidentaly, these ops are declared const and LLDs should always inherit these instead of using them directly. After finalization, all the ops table are identical before and after the patch except for setting .irq_handler to ata_interrupt in drivers which didn't use to. The .irq_handler doesn't have any actual effect and the field will soon be removed by later patch. * sata_sx4 is still using old style EH and currently doesn't take advantage of ops inheritance. Signed-off-by: Tejun Heo

libata: implement and use SHT initializers

2008-04-17T19:44:17+00:00

libata lets low level drivers build scsi_host_template and register it to the SCSI layer. This allows low level drivers high level of flexibility but also burdens them with lots of boilerplate entries. This patch implements SHT initializers which can be used to initialize all the boilerplate entries in a sht. Three variants of them are implemented - BASE, BMDMA and NCQ - for different types of drivers. Note that entries can be overriden by putting individual initializers after the helper macro. All sht tables are identical before and after this patch. Signed-off-by: Tejun Heo

libata: implement and use ata_noop_irq_clear()

2008-04-17T19:44:16+00:00

->irq_clear() is used to clear IRQ bit of a SFF controller and isn't useful for drivers which don't use libata SFF HSM implementation. However, it's a required callback and many drivers implement their own noop version as placeholder. This patch implements ata_noop_irq_clear and use it to replace those custom placeholders. Also, SFF drivers which don't support BMDMA don't need to use ata_bmdma_irq_clear(). It becomes noop if BMDMA address isn't initialized. Convert them to use ata_noop_irq_clear(). Signed-off-by: Tejun Heo

libata: convert to chained sg

2008-01-23T10:24:14+00:00

libata used private sg iterator to handle padding sg. Now that sg can be chained, padding can be handled using standard sg ops. Convert to chained sg. * s/qc->__sg/qc->sg/ * s/qc->pad_sgent/qc->extra_sg[]/. Because chaining consumes one sg entry. There need to be two extra sg entries. The renaming is also for future addition of other extra sg entries. * Padding setup is moved into ata_sg_setup_extra() which is organized in a way that future addition of other extra sg entries is easy. * qc->orig_n_elem is unused and removed. * qc->n_elem now contains the number of sg entries that LLDs should map. qc->mapped_n_elem is added to carry the original number of mapped sgs for unmapping. * The last sg of the original sg list is used to chain to extra sg list. The original last sg is pointed to by qc->last_sg and the content is stored in qc->saved_last_sg. It's restored during ata_sg_clean(). * All sg walking code has been updated. Unnecessary assertions and checks for conditions the core layer already guarantees are removed. Signed-off-by: Tejun Heo Cc: Jens Axboe Signed-off-by: Jeff Garzik

libata: rename ATA_PROT_ATAPI_* to ATAPI_PROT_*

2008-01-23T10:24:14+00:00

ATA_PROT_ATAPI_* are ugly and naming schemes between ATA_PROT_* and ATA_PROT_ATAPI_* are inconsistent causing confusion. Rename them to ATAPI_PROT_* and make them consistent with ATA counterpart. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik