linux-stable/drivers/s390/scsi/zfcp_qdio.h

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 14:07:57 +00:00
/* SPDX-License-Identifier: GPL-2.0 */
/*
* zfcp device driver
*
* Header file for zfcp qdio interface
*
* Copyright IBM Corp. 2010
*/
#ifndef ZFCP_QDIO_H
#define ZFCP_QDIO_H
scsi: zfcp: Lift Input Queue tasklet from qdio Shift the IRQ tasklet processing from the qdio layer into zfcp. This will allow for a good amount of cleanups in qdio, and provides future opportunity to improve the IRQ processing inside zfcp. We continue to use the qdio layer's internal tasklet/timer mechanism (ie. scan_threshold etc) to check for Request Queue completions. Initially we planned to check for such completions after inspecting the Response Queue - this should typically work, but there's a theoretical race where the device only presents the Request Queue completions _after_ all Response Queue processing has finished. If the Request Queue is then also _completely_ full, we could send no further IOs and thus get no interrupt that would trigger an inspection of the Request Queue. So for now stick to the old model, where we can trust that such a race would be recovered by qdio's internal timer. Code-flow wise, this establishes two levels of control: 1. The qdio layer will only deliver IRQs to the device driver if the QDIO_IRQ_DISABLED flag is cleared. zfcp manages this through qdio_start_irq() / qdio_stop_irq(). The initial state is DISABLED, and zfcp_qdio_open() schedules zfcp's IRQ tasklet once during startup to explicitly enable IRQ delivery. 2. The zfcp tasklet is initialized with tasklet_disable(), and only gets enabled once we open the qdio device. When closing the qdio device, we must disable the tasklet _before_ disabling IRQ delivery (otherwise a concurrently running tasklet could re-enable IRQ delivery after we disabled it). A final tasklet_kill() during teardown ensures that no lingering tasklet_schedule() is still accessing the tasklet structure. Link: https://lore.kernel.org/r/94a765211c48b74a7b91c5e60b158de01db98d43.1603908167.git.bblock@linux.ibm.com Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-10-28 18:30:48 +00:00
#include <linux/interrupt.h>
#include <asm/qdio.h>
#define ZFCP_QDIO_SBALE_LEN PAGE_SIZE
/* Max SBALS for chaining */
#define ZFCP_QDIO_MAX_SBALS_PER_REQ 36
/**
* struct zfcp_qdio - basic qdio data structure
* @res_q: response queue
* @req_q: request queue
* @req_q_idx: index of next free buffer
* @req_q_free: number of free buffers in queue
* @stat_lock: lock to protect req_q_util and req_q_time
* @req_q_lock: lock to serialize access to request queue
* @req_q_time: time of last fill level change
* @req_q_util: used for accounting
* @req_q_full: queue full incidents
* @req_q_wq: used to wait for SBAL availability
scsi: zfcp: Lift Request Queue tasklet & timer from qdio The qdio layer currently provides its own infrastructure to scan for Request Queue completions & to report them to the device driver. This comes with several drawbacks - having an async tasklet & timer construct in qdio introduces additional lifetime complexity, and makes it harder to integrate them with the rest of the device driver. The timeouts are also currently hard-coded, and can't be tweaked without affecting other qdio drivers (ie. qeth). But due to recent enhancements to the qdio layer, zfcp can actually take full control of the Request Queue completion processing. It merely needs to opt-out from the qdio layer mechanisms by setting the scan_threshold to 0, and then use qdio_inspect_queue() to scan for completions. So re-implement the tasklet & timer mechanism in zfcp, while initially copying the scan conditions from qdio's handle_outbound() and qdio_outbound_tasklet(). One minor behavioural change is that zfcp_qdio_send() will unconditionally reduce the timeout to 1 HZ, rather than leaving it at 10 Hz if it was last armed by the tasklet. This just makes things more consistent. Also note that we can drop a lot of the accumulated cruft in qdio_outbound_tasklet(), as zfcp doesn't even use PCI interrupt requests any longer. This also slightly touches the Response Queue processing, as qdio_get_next_buffers() will no longer implicitly scan for Request Queue completions. So complete the migration to qdio_inspect_queue() here as well and make the tasklet_schedule() visible. Link: https://lore.kernel.org/r/018d3ddd029f8d6ac00cf4184880288c637c4fd1.1618417667.git.bblock@linux.ibm.com Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-14 17:08:04 +00:00
* @irq_tasklet: used for QDIO interrupt processing
* @request_tasklet: used for Request Queue completion processing
* @request_timer: used to trigger the Request Queue completion processing
* @adapter: adapter used in conjunction with this qdio structure
* @max_sbale_per_sbal: qdio limit per sbal
* @max_sbale_per_req: qdio limit per request
*/
struct zfcp_qdio {
struct qdio_buffer *res_q[QDIO_MAX_BUFFERS_PER_Q];
struct qdio_buffer *req_q[QDIO_MAX_BUFFERS_PER_Q];
u8 req_q_idx;
atomic_t req_q_free;
spinlock_t stat_lock;
spinlock_t req_q_lock;
unsigned long long req_q_time;
u64 req_q_util;
atomic_t req_q_full;
wait_queue_head_t req_q_wq;
scsi: zfcp: Lift Input Queue tasklet from qdio Shift the IRQ tasklet processing from the qdio layer into zfcp. This will allow for a good amount of cleanups in qdio, and provides future opportunity to improve the IRQ processing inside zfcp. We continue to use the qdio layer's internal tasklet/timer mechanism (ie. scan_threshold etc) to check for Request Queue completions. Initially we planned to check for such completions after inspecting the Response Queue - this should typically work, but there's a theoretical race where the device only presents the Request Queue completions _after_ all Response Queue processing has finished. If the Request Queue is then also _completely_ full, we could send no further IOs and thus get no interrupt that would trigger an inspection of the Request Queue. So for now stick to the old model, where we can trust that such a race would be recovered by qdio's internal timer. Code-flow wise, this establishes two levels of control: 1. The qdio layer will only deliver IRQs to the device driver if the QDIO_IRQ_DISABLED flag is cleared. zfcp manages this through qdio_start_irq() / qdio_stop_irq(). The initial state is DISABLED, and zfcp_qdio_open() schedules zfcp's IRQ tasklet once during startup to explicitly enable IRQ delivery. 2. The zfcp tasklet is initialized with tasklet_disable(), and only gets enabled once we open the qdio device. When closing the qdio device, we must disable the tasklet _before_ disabling IRQ delivery (otherwise a concurrently running tasklet could re-enable IRQ delivery after we disabled it). A final tasklet_kill() during teardown ensures that no lingering tasklet_schedule() is still accessing the tasklet structure. Link: https://lore.kernel.org/r/94a765211c48b74a7b91c5e60b158de01db98d43.1603908167.git.bblock@linux.ibm.com Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-10-28 18:30:48 +00:00
struct tasklet_struct irq_tasklet;
scsi: zfcp: Lift Request Queue tasklet & timer from qdio The qdio layer currently provides its own infrastructure to scan for Request Queue completions & to report them to the device driver. This comes with several drawbacks - having an async tasklet & timer construct in qdio introduces additional lifetime complexity, and makes it harder to integrate them with the rest of the device driver. The timeouts are also currently hard-coded, and can't be tweaked without affecting other qdio drivers (ie. qeth). But due to recent enhancements to the qdio layer, zfcp can actually take full control of the Request Queue completion processing. It merely needs to opt-out from the qdio layer mechanisms by setting the scan_threshold to 0, and then use qdio_inspect_queue() to scan for completions. So re-implement the tasklet & timer mechanism in zfcp, while initially copying the scan conditions from qdio's handle_outbound() and qdio_outbound_tasklet(). One minor behavioural change is that zfcp_qdio_send() will unconditionally reduce the timeout to 1 HZ, rather than leaving it at 10 Hz if it was last armed by the tasklet. This just makes things more consistent. Also note that we can drop a lot of the accumulated cruft in qdio_outbound_tasklet(), as zfcp doesn't even use PCI interrupt requests any longer. This also slightly touches the Response Queue processing, as qdio_get_next_buffers() will no longer implicitly scan for Request Queue completions. So complete the migration to qdio_inspect_queue() here as well and make the tasklet_schedule() visible. Link: https://lore.kernel.org/r/018d3ddd029f8d6ac00cf4184880288c637c4fd1.1618417667.git.bblock@linux.ibm.com Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-14 17:08:04 +00:00
struct tasklet_struct request_tasklet;
struct timer_list request_timer;
struct zfcp_adapter *adapter;
u16 max_sbale_per_sbal;
u16 max_sbale_per_req;
};
/**
* struct zfcp_qdio_req - qdio queue related values for a request
* @sbtype: sbal type flags for sbale 0
* @sbal_number: number of free sbals
* @sbal_first: first sbal for this request
* @sbal_last: last sbal for this request
* @sbal_limit: last possible sbal for this request
* @sbale_curr: current sbale at creation of this request
* @qdio_outb_usage: usage of outbound queue
*/
struct zfcp_qdio_req {
u8 sbtype;
u8 sbal_number;
u8 sbal_first;
u8 sbal_last;
u8 sbal_limit;
u8 sbale_curr;
u16 qdio_outb_usage;
};
/**
* zfcp_qdio_sbale_req - return pointer to sbale on req_q for a request
* @qdio: pointer to struct zfcp_qdio
* @q_req: pointer to struct zfcp_qdio_req
* Returns: pointer to qdio_buffer_element (sbale) structure
*/
static inline struct qdio_buffer_element *
zfcp_qdio_sbale_req(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
return &qdio->req_q[q_req->sbal_last]->element[0];
}
/**
* zfcp_qdio_sbale_curr - return current sbale on req_q for a request
* @qdio: pointer to struct zfcp_qdio
* @q_req: pointer to struct zfcp_qdio_req
* Returns: pointer to qdio_buffer_element (sbale) structure
*/
static inline struct qdio_buffer_element *
zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
return &qdio->req_q[q_req->sbal_last]->element[q_req->sbale_curr];
}
/**
* zfcp_qdio_req_init - initialize qdio request
* @qdio: request queue where to start putting the request
* @q_req: the qdio request to start
* @req_id: The request id
* @sbtype: type flags to set for all sbals
* @data: First data block
* @len: Length of first data block
*
* This is the start of putting the request into the queue, the last
* step is passing the request to zfcp_qdio_send. The request queue
* lock must be held during the whole process from init to send.
*/
static inline
void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
u64 req_id, u8 sbtype, void *data, u32 len)
{
struct qdio_buffer_element *sbale;
int count = min(atomic_read(&qdio->req_q_free),
ZFCP_QDIO_MAX_SBALS_PER_REQ);
q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx;
q_req->sbal_number = 1;
q_req->sbtype = sbtype;
q_req->sbale_curr = 1;
q_req->sbal_limit = (q_req->sbal_first + count - 1)
% QDIO_MAX_BUFFERS_PER_Q;
sbale = zfcp_qdio_sbale_req(qdio, q_req);
sbale->addr = req_id;
sbale->eflags = 0;
sbale->sflags = SBAL_SFLAGS0_COMMAND | sbtype;
if (unlikely(!data))
return;
sbale++;
sbale->addr = virt_to_phys(data);
sbale->length = len;
}
/**
* zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests
* @qdio: pointer to struct zfcp_qdio
* @q_req: pointer to struct zfcp_queue_req
* @data: pointer to data
* @len: length of data
*
* This is only required for single sbal requests, calling it when
* wrapping around to the next sbal is a bug.
*/
static inline
void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
void *data, u32 len)
{
struct qdio_buffer_element *sbale;
BUG_ON(q_req->sbale_curr == qdio->max_sbale_per_sbal - 1);
q_req->sbale_curr++;
sbale = zfcp_qdio_sbale_curr(qdio, q_req);
sbale->addr = virt_to_phys(data);
sbale->length = len;
}
/**
* zfcp_qdio_set_sbale_last - set last entry flag in current sbale
* @qdio: pointer to struct zfcp_qdio
* @q_req: pointer to struct zfcp_queue_req
*/
static inline
void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio,
struct zfcp_qdio_req *q_req)
{
struct qdio_buffer_element *sbale;
sbale = zfcp_qdio_sbale_curr(qdio, q_req);
sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY;
}
/**
* zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data
* @sg: The scatterlist where to check the data size
*
* Returns: 1 when one sbale is enough for the data in the scatterlist,
* 0 if not.
*/
static inline
int zfcp_qdio_sg_one_sbale(struct scatterlist *sg)
{
return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN;
}
/**
* zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal
* @qdio: pointer to struct zfcp_qdio
* @q_req: The current zfcp_qdio_req
*/
static inline
void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio *qdio,
struct zfcp_qdio_req *q_req)
{
q_req->sbale_curr = qdio->max_sbale_per_sbal - 1;
}
/**
* zfcp_qdio_sbal_limit - set the sbal limit for a request in q_req
* @qdio: pointer to struct zfcp_qdio
* @q_req: The current zfcp_qdio_req
* @max_sbals: maximum number of SBALs allowed
*/
static inline
void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
struct zfcp_qdio_req *q_req, int max_sbals)
{
int count = min(atomic_read(&qdio->req_q_free), max_sbals);
q_req->sbal_limit = (q_req->sbal_first + count - 1) %
QDIO_MAX_BUFFERS_PER_Q;
}
/**
* zfcp_qdio_set_data_div - set data division count
* @qdio: pointer to struct zfcp_qdio
* @q_req: The current zfcp_qdio_req
* @count: The data division count
*/
static inline
void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio,
struct zfcp_qdio_req *q_req, u32 count)
{
struct qdio_buffer_element *sbale;
sbale = qdio->req_q[q_req->sbal_first]->element;
sbale->length = count;
}
/**
* zfcp_qdio_real_bytes - count bytes used
* @sg: pointer to struct scatterlist
*/
static inline
unsigned int zfcp_qdio_real_bytes(struct scatterlist *sg)
{
unsigned int real_bytes = 0;
for (; sg; sg = sg_next(sg))
real_bytes += sg->length;
return real_bytes;
}
/**
* zfcp_qdio_set_scount - set SBAL count value
* @qdio: pointer to struct zfcp_qdio
* @q_req: The current zfcp_qdio_req
*/
static inline
void zfcp_qdio_set_scount(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
struct qdio_buffer_element *sbale;
sbale = qdio->req_q[q_req->sbal_first]->element;
sbale->scount = q_req->sbal_number - 1;
}
#endif /* ZFCP_QDIO_H */