1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (c) 2005-2014 Brocade Communications Systems, Inc.
4 * Copyright (c) 2014- QLogic Corporation.
5 * All rights reserved
6 * www.qlogic.com
7 *
8 * Linux driver for QLogic BR-series Fibre Channel Host Bus Adapter.
9 */
10
11#ifndef __BFA_FCPIM_H__
12#define __BFA_FCPIM_H__
13
14#include "bfa.h"
15#include "bfa_svc.h"
16#include "bfi_ms.h"
17#include "bfa_defs_svc.h"
18#include "bfa_cs.h"
19
20/* FCP module related definitions */
21#define BFA_IO_MAX BFI_IO_MAX
22#define BFA_FWTIO_MAX 2000
23
24struct bfa_fcp_mod_s;
25struct bfa_iotag_s {
26 struct list_head qe; /* queue element */
27 u16 tag; /* FW IO tag */
28};
29
30struct bfa_itn_s {
31 bfa_isr_func_t isr;
32};
33
34void bfa_itn_create(struct bfa_s *bfa, struct bfa_rport_s *rport,
35 void (*isr)(struct bfa_s *bfa, struct bfi_msg_s *m));
36void bfa_itn_isr(struct bfa_s *bfa, struct bfi_msg_s *m);
37void bfa_iotag_attach(struct bfa_fcp_mod_s *fcp);
38void bfa_fcp_res_recfg(struct bfa_s *bfa, u16 num_ioim_fw, u16 max_ioim_fw);
39
40#define BFA_FCP_MOD(_hal) (&(_hal)->modules.fcp_mod)
41#define BFA_MEM_FCP_KVA(__bfa) (&(BFA_FCP_MOD(__bfa)->kva_seg))
42#define BFA_IOTAG_FROM_TAG(_fcp, _tag) \
43 (&(_fcp)->iotag_arr[(_tag & BFA_IOIM_IOTAG_MASK)])
44#define BFA_ITN_FROM_TAG(_fcp, _tag) \
45 ((_fcp)->itn_arr + ((_tag) & ((_fcp)->num_itns - 1)))
46#define BFA_SNSINFO_FROM_TAG(_fcp, _tag) \
47 bfa_mem_get_dmabuf_kva(_fcp, (_tag & BFA_IOIM_IOTAG_MASK), \
48 BFI_IOIM_SNSLEN)
49
50
51#define BFA_ITNIM_MIN 32
52#define BFA_ITNIM_MAX 1024
53
54#define BFA_IOIM_MIN 8
55#define BFA_IOIM_MAX 2000
56
57#define BFA_TSKIM_MIN 4
58#define BFA_TSKIM_MAX 512
59#define BFA_FCPIM_PATHTOV_DEF (30 * 1000) /* in millisecs */
60#define BFA_FCPIM_PATHTOV_MAX (90 * 1000) /* in millisecs */
61
62
63#define bfa_itnim_ioprofile_update(__itnim, __index) \
64 (__itnim->ioprofile.iocomps[__index]++)
65
66#define BFA_IOIM_RETRY_TAG_OFFSET 11
67#define BFA_IOIM_IOTAG_MASK 0x07ff /* 2K IOs */
68#define BFA_IOIM_RETRY_MAX 7
69
70/* Buckets are are 512 bytes to 2MB */
71static inline u32
72bfa_ioim_get_index(u32 n) {
73 int pos = 0;
74 if (n >= (1UL)<<22)
75 return BFA_IOBUCKET_MAX - 1;
76 n >>= 8;
77 if (n >= (1UL)<<16) {
78 n >>= 16;
79 pos += 16;
80 }
81 if (n >= 1 << 8) {
82 n >>= 8;
83 pos += 8;
84 }
85 if (n >= 1 << 4) {
86 n >>= 4;
87 pos += 4;
88 }
89 if (n >= 1 << 2) {
90 n >>= 2;
91 pos += 2;
92 }
93 if (n >= 1 << 1)
94 pos += 1;
95
96 return (n == 0) ? (0) : pos;
97}
98
99/*
100 * forward declarations
101 */
102struct bfa_ioim_s;
103struct bfa_tskim_s;
104struct bfad_ioim_s;
105struct bfad_tskim_s;
106
107typedef void (*bfa_fcpim_profile_t) (struct bfa_ioim_s *ioim);
108
109struct bfa_fcpim_s {
110 struct bfa_s *bfa;
111 struct bfa_fcp_mod_s *fcp;
112 struct bfa_itnim_s *itnim_arr;
113 struct bfa_ioim_s *ioim_arr;
114 struct bfa_ioim_sp_s *ioim_sp_arr;
115 struct bfa_tskim_s *tskim_arr;
116 int num_itnims;
117 int num_tskim_reqs;
118 u32 path_tov;
119 u16 q_depth;
120 u8 reqq; /* Request queue to be used */
121 struct list_head itnim_q; /* queue of active itnim */
122 struct list_head ioim_resfree_q; /* IOs waiting for f/w */
123 struct list_head ioim_comp_q; /* IO global comp Q */
124 struct list_head tskim_free_q;
125 struct list_head tskim_unused_q; /* Unused tskim Q */
126 u32 ios_active; /* current active IOs */
127 u32 delay_comp;
128 struct bfa_fcpim_del_itn_stats_s del_itn_stats;
129 bfa_boolean_t ioredirect;
130 bfa_boolean_t io_profile;
131 time64_t io_profile_start_time;
132 bfa_fcpim_profile_t profile_comp;
133 bfa_fcpim_profile_t profile_start;
134};
135
136/* Max FCP dma segs required */
137#define BFA_FCP_DMA_SEGS BFI_IOIM_SNSBUF_SEGS
138
139struct bfa_fcp_mod_s {
140 struct bfa_s *bfa;
141 struct list_head iotag_ioim_free_q; /* free IO resources */
142 struct list_head iotag_tio_free_q; /* free IO resources */
143 struct list_head iotag_unused_q; /* unused IO resources*/
144 struct bfa_iotag_s *iotag_arr;
145 struct bfa_itn_s *itn_arr;
146 int max_ioim_reqs;
147 int num_ioim_reqs;
148 int num_fwtio_reqs;
149 int num_itns;
150 struct bfa_dma_s snsbase[BFA_FCP_DMA_SEGS];
151 struct bfa_fcpim_s fcpim;
152 struct bfa_mem_dma_s dma_seg[BFA_FCP_DMA_SEGS];
153 struct bfa_mem_kva_s kva_seg;
154 int throttle_update_required;
155};
156
157/*
158 * IO state machine events
159 */
160enum bfa_ioim_event {
161 BFA_IOIM_SM_START = 1, /* io start request from host */
162 BFA_IOIM_SM_COMP_GOOD = 2, /* io good comp, resource free */
163 BFA_IOIM_SM_COMP = 3, /* io comp, resource is free */
164 BFA_IOIM_SM_COMP_UTAG = 4, /* io comp, resource is free */
165 BFA_IOIM_SM_DONE = 5, /* io comp, resource not free */
166 BFA_IOIM_SM_FREE = 6, /* io resource is freed */
167 BFA_IOIM_SM_ABORT = 7, /* abort request from scsi stack */
168 BFA_IOIM_SM_ABORT_COMP = 8, /* abort from f/w */
169 BFA_IOIM_SM_ABORT_DONE = 9, /* abort completion from f/w */
170 BFA_IOIM_SM_QRESUME = 10, /* CQ space available to queue IO */
171 BFA_IOIM_SM_SGALLOCED = 11, /* SG page allocation successful */
172 BFA_IOIM_SM_SQRETRY = 12, /* sequence recovery retry */
173 BFA_IOIM_SM_HCB = 13, /* bfa callback complete */
174 BFA_IOIM_SM_CLEANUP = 14, /* IO cleanup from itnim */
175 BFA_IOIM_SM_TMSTART = 15, /* IO cleanup from tskim */
176 BFA_IOIM_SM_TMDONE = 16, /* IO cleanup from tskim */
177 BFA_IOIM_SM_HWFAIL = 17, /* IOC h/w failure event */
178 BFA_IOIM_SM_IOTOV = 18, /* ITN offline TOV */
179};
180
181struct bfa_ioim_s;
182typedef void (*bfa_ioim_sm_t)(struct bfa_ioim_s *, enum bfa_ioim_event);
183
184/*
185 * BFA IO (initiator mode)
186 */
187struct bfa_ioim_s {
188 struct list_head qe; /* queue elememt */
189 bfa_ioim_sm_t sm; /* BFA ioim state machine */
190 struct bfa_s *bfa; /* BFA module */
191 struct bfa_fcpim_s *fcpim; /* parent fcpim module */
192 struct bfa_itnim_s *itnim; /* i-t-n nexus for this IO */
193 struct bfad_ioim_s *dio; /* driver IO handle */
194 u16 iotag; /* FWI IO tag */
195 u16 abort_tag; /* unqiue abort request tag */
196 u16 nsges; /* number of SG elements */
197 u16 nsgpgs; /* number of SG pages */
198 struct bfa_sgpg_s *sgpg; /* first SG page */
199 struct list_head sgpg_q; /* allocated SG pages */
200 struct bfa_cb_qe_s hcb_qe; /* bfa callback qelem */
201 bfa_cb_cbfn_t io_cbfn; /* IO completion handler */
202 struct bfa_ioim_sp_s *iosp; /* slow-path IO handling */
203 u8 reqq; /* Request queue for I/O */
204 u8 mode; /* IO is passthrough or not */
205 u64 start_time; /* IO's Profile start val */
206};
207
208struct bfa_ioim_sp_s {
209 struct bfi_msg_s comp_rspmsg; /* IO comp f/w response */
210 struct bfa_sgpg_wqe_s sgpg_wqe; /* waitq elem for sgpg */
211 struct bfa_reqq_wait_s reqq_wait; /* to wait for room in reqq */
212 bfa_boolean_t abort_explicit; /* aborted by OS */
213 struct bfa_tskim_s *tskim; /* Relevant TM cmd */
214};
215
216enum bfa_tskim_event {
217 BFA_TSKIM_SM_START = 1, /* TM command start */
218 BFA_TSKIM_SM_DONE = 2, /* TM completion */
219 BFA_TSKIM_SM_QRESUME = 3, /* resume after qfull */
220 BFA_TSKIM_SM_HWFAIL = 5, /* IOC h/w failure event */
221 BFA_TSKIM_SM_HCB = 6, /* BFA callback completion */
222 BFA_TSKIM_SM_IOS_DONE = 7, /* IO and sub TM completions */
223 BFA_TSKIM_SM_CLEANUP = 8, /* TM cleanup on ITN offline */
224 BFA_TSKIM_SM_CLEANUP_DONE = 9, /* TM abort completion */
225 BFA_TSKIM_SM_UTAG = 10, /* TM completion unknown tag */
226};
227
228struct bfa_tskim_s;
229typedef void (*bfa_tskim_sm_t)(struct bfa_tskim_s *, enum bfa_tskim_event);
230
231/*
232 * BFA Task management command (initiator mode)
233 */
234struct bfa_tskim_s {
235 struct list_head qe;
236 bfa_tskim_sm_t sm;
237 struct bfa_s *bfa; /* BFA module */
238 struct bfa_fcpim_s *fcpim; /* parent fcpim module */
239 struct bfa_itnim_s *itnim; /* i-t-n nexus for this IO */
240 struct bfad_tskim_s *dtsk; /* driver task mgmt cmnd */
241 bfa_boolean_t notify; /* notify itnim on TM comp */
242 struct scsi_lun lun; /* lun if applicable */
243 enum fcp_tm_cmnd tm_cmnd; /* task management command */
244 u16 tsk_tag; /* FWI IO tag */
245 u8 tsecs; /* timeout in seconds */
246 struct bfa_reqq_wait_s reqq_wait; /* to wait for room in reqq */
247 struct list_head io_q; /* queue of affected IOs */
248 struct bfa_wc_s wc; /* waiting counter */
249 struct bfa_cb_qe_s hcb_qe; /* bfa callback qelem */
250 enum bfi_tskim_status tsk_status; /* TM status */
251};
252
253/*
254 * itnim state machine event
255 */
256enum bfa_itnim_event {
257 BFA_ITNIM_SM_CREATE = 1, /* itnim is created */
258 BFA_ITNIM_SM_ONLINE = 2, /* itnim is online */
259 BFA_ITNIM_SM_OFFLINE = 3, /* itnim is offline */
260 BFA_ITNIM_SM_FWRSP = 4, /* firmware response */
261 BFA_ITNIM_SM_DELETE = 5, /* deleting an existing itnim */
262 BFA_ITNIM_SM_CLEANUP = 6, /* IO cleanup completion */
263 BFA_ITNIM_SM_SLER = 7, /* second level error recovery */
264 BFA_ITNIM_SM_HWFAIL = 8, /* IOC h/w failure event */
265 BFA_ITNIM_SM_QRESUME = 9, /* queue space available */
266};
267
268struct bfa_itnim_s;
269typedef void (*bfa_itnim_sm_t)(struct bfa_itnim_s *, enum bfa_itnim_event);
270
271/*
272 * BFA i-t-n (initiator mode)
273 */
274struct bfa_itnim_s {
275 struct list_head qe; /* queue element */
276 bfa_itnim_sm_t sm; /* i-t-n im BFA state machine */
277 struct bfa_s *bfa; /* bfa instance */
278 struct bfa_rport_s *rport; /* bfa rport */
279 void *ditn; /* driver i-t-n structure */
280 struct bfi_mhdr_s mhdr; /* pre-built mhdr */
281 u8 msg_no; /* itnim/rport firmware handle */
282 u8 reqq; /* CQ for requests */
283 struct bfa_cb_qe_s hcb_qe; /* bfa callback qelem */
284 struct list_head pending_q; /* queue of pending IO requests */
285 struct list_head io_q; /* queue of active IO requests */
286 struct list_head io_cleanup_q; /* IO being cleaned up */
287 struct list_head tsk_q; /* queue of active TM commands */
288 struct list_head delay_comp_q; /* queue of failed inflight cmds */
289 bfa_boolean_t seq_rec; /* SQER supported */
290 bfa_boolean_t is_online; /* itnim is ONLINE for IO */
291 bfa_boolean_t iotov_active; /* IO TOV timer is active */
292 struct bfa_wc_s wc; /* waiting counter */
293 struct bfa_timer_s timer; /* pending IO TOV */
294 struct bfa_reqq_wait_s reqq_wait; /* to wait for room in reqq */
295 struct bfa_fcpim_s *fcpim; /* fcpim module */
296 struct bfa_itnim_iostats_s stats;
297 struct bfa_itnim_ioprofile_s ioprofile;
298};
299
300#define bfa_itnim_is_online(_itnim) ((_itnim)->is_online)
301#define BFA_FCPIM(_hal) (&(_hal)->modules.fcp_mod.fcpim)
302#define BFA_IOIM_TAG_2_ID(_iotag) ((_iotag) & BFA_IOIM_IOTAG_MASK)
303#define BFA_IOIM_FROM_TAG(_fcpim, _iotag) \
304 (&fcpim->ioim_arr[(_iotag & BFA_IOIM_IOTAG_MASK)])
305#define BFA_TSKIM_FROM_TAG(_fcpim, _tmtag) \
306 (&fcpim->tskim_arr[_tmtag & (fcpim->num_tskim_reqs - 1)])
307
308#define bfa_io_profile_start_time(_bfa) \
309 ((_bfa)->modules.fcp_mod.fcpim.io_profile_start_time)
310#define bfa_fcpim_get_io_profile(_bfa) \
311 ((_bfa)->modules.fcp_mod.fcpim.io_profile)
312#define bfa_ioim_update_iotag(__ioim) do { \
313 uint16_t k = (__ioim)->iotag >> BFA_IOIM_RETRY_TAG_OFFSET; \
314 k++; (__ioim)->iotag &= BFA_IOIM_IOTAG_MASK; \
315 (__ioim)->iotag |= k << BFA_IOIM_RETRY_TAG_OFFSET; \
316} while (0)
317
318static inline bfa_boolean_t
319bfa_ioim_maxretry_reached(struct bfa_ioim_s *ioim)
320{
321 uint16_t k = ioim->iotag >> BFA_IOIM_RETRY_TAG_OFFSET;
322 if (k < BFA_IOIM_RETRY_MAX)
323 return BFA_FALSE;
324 return BFA_TRUE;
325}
326
327/*
328 * function prototypes
329 */
330void bfa_ioim_attach(struct bfa_fcpim_s *fcpim);
331void bfa_ioim_isr(struct bfa_s *bfa, struct bfi_msg_s *msg);
332void bfa_ioim_good_comp_isr(struct bfa_s *bfa,
333 struct bfi_msg_s *msg);
334void bfa_ioim_cleanup(struct bfa_ioim_s *ioim);
335void bfa_ioim_cleanup_tm(struct bfa_ioim_s *ioim,
336 struct bfa_tskim_s *tskim);
337void bfa_ioim_iocdisable(struct bfa_ioim_s *ioim);
338void bfa_ioim_tov(struct bfa_ioim_s *ioim);
339
340void bfa_tskim_attach(struct bfa_fcpim_s *fcpim);
341void bfa_tskim_isr(struct bfa_s *bfa, struct bfi_msg_s *msg);
342void bfa_tskim_iodone(struct bfa_tskim_s *tskim);
343void bfa_tskim_iocdisable(struct bfa_tskim_s *tskim);
344void bfa_tskim_cleanup(struct bfa_tskim_s *tskim);
345void bfa_tskim_res_recfg(struct bfa_s *bfa, u16 num_tskim_fw);
346
347void bfa_itnim_meminfo(struct bfa_iocfc_cfg_s *cfg, u32 *km_len);
348void bfa_itnim_attach(struct bfa_fcpim_s *fcpim);
349void bfa_itnim_iocdisable(struct bfa_itnim_s *itnim);
350void bfa_itnim_isr(struct bfa_s *bfa, struct bfi_msg_s *msg);
351void bfa_itnim_iodone(struct bfa_itnim_s *itnim);
352void bfa_itnim_tskdone(struct bfa_itnim_s *itnim);
353bfa_boolean_t bfa_itnim_hold_io(struct bfa_itnim_s *itnim);
354
355/*
356 * bfa fcpim module API functions
357 */
358void bfa_fcpim_path_tov_set(struct bfa_s *bfa, u16 path_tov);
359u16 bfa_fcpim_path_tov_get(struct bfa_s *bfa);
360u16 bfa_fcpim_qdepth_get(struct bfa_s *bfa);
361bfa_status_t bfa_fcpim_port_iostats(struct bfa_s *bfa,
362 struct bfa_itnim_iostats_s *stats, u8 lp_tag);
363void bfa_fcpim_add_stats(struct bfa_itnim_iostats_s *fcpim_stats,
364 struct bfa_itnim_iostats_s *itnim_stats);
365bfa_status_t bfa_fcpim_profile_on(struct bfa_s *bfa, time64_t time);
366bfa_status_t bfa_fcpim_profile_off(struct bfa_s *bfa);
367
368#define bfa_fcpim_ioredirect_enabled(__bfa) \
369 (((struct bfa_fcpim_s *)(BFA_FCPIM(__bfa)))->ioredirect)
370
371#define bfa_fcpim_get_next_reqq(__bfa, __qid) \
372{ \
373 struct bfa_fcpim_s *__fcpim = BFA_FCPIM(__bfa); \
374 __fcpim->reqq++; \
375 __fcpim->reqq &= (BFI_IOC_MAX_CQS - 1); \
376 *(__qid) = __fcpim->reqq; \
377}
378
379#define bfa_iocfc_map_msg_to_qid(__msg, __qid) \
380 *(__qid) = (u8)((__msg) & (BFI_IOC_MAX_CQS - 1));
381/*
382 * bfa itnim API functions
383 */
384struct bfa_itnim_s *bfa_itnim_create(struct bfa_s *bfa,
385 struct bfa_rport_s *rport, void *itnim);
386void bfa_itnim_delete(struct bfa_itnim_s *itnim);
387void bfa_itnim_online(struct bfa_itnim_s *itnim, bfa_boolean_t seq_rec);
388void bfa_itnim_offline(struct bfa_itnim_s *itnim);
389void bfa_itnim_clear_stats(struct bfa_itnim_s *itnim);
390bfa_status_t bfa_itnim_get_ioprofile(struct bfa_itnim_s *itnim,
391 struct bfa_itnim_ioprofile_s *ioprofile);
392
393#define bfa_itnim_get_reqq(__ioim) (((struct bfa_ioim_s *)__ioim)->itnim->reqq)
394
395/*
396 * BFA completion callback for bfa_itnim_online().
397 */
398void bfa_cb_itnim_online(void *itnim);
399
400/*
401 * BFA completion callback for bfa_itnim_offline().
402 */
403void bfa_cb_itnim_offline(void *itnim);
404void bfa_cb_itnim_tov_begin(void *itnim);
405void bfa_cb_itnim_tov(void *itnim);
406
407/*
408 * BFA notification to FCS/driver for second level error recovery.
409 * Atleast one I/O request has timedout and target is unresponsive to
410 * repeated abort requests. Second level error recovery should be initiated
411 * by starting implicit logout and recovery procedures.
412 */
413void bfa_cb_itnim_sler(void *itnim);
414
415/*
416 * bfa ioim API functions
417 */
418struct bfa_ioim_s *bfa_ioim_alloc(struct bfa_s *bfa,
419 struct bfad_ioim_s *dio,
420 struct bfa_itnim_s *itnim,
421 u16 nsgles);
422
423void bfa_ioim_free(struct bfa_ioim_s *ioim);
424void bfa_ioim_start(struct bfa_ioim_s *ioim);
425bfa_status_t bfa_ioim_abort(struct bfa_ioim_s *ioim);
426void bfa_ioim_delayed_comp(struct bfa_ioim_s *ioim,
427 bfa_boolean_t iotov);
428/*
429 * I/O completion notification.
430 *
431 * @param[in] dio driver IO structure
432 * @param[in] io_status IO completion status
433 * @param[in] scsi_status SCSI status returned by target
434 * @param[in] sns_len SCSI sense length, 0 if none
435 * @param[in] sns_info SCSI sense data, if any
436 * @param[in] residue Residual length
437 *
438 * @return None
439 */
440void bfa_cb_ioim_done(void *bfad, struct bfad_ioim_s *dio,
441 enum bfi_ioim_status io_status,
442 u8 scsi_status, int sns_len,
443 u8 *sns_info, s32 residue);
444
445/*
446 * I/O good completion notification.
447 */
448void bfa_cb_ioim_good_comp(void *bfad, struct bfad_ioim_s *dio);
449
450/*
451 * I/O abort completion notification
452 */
453void bfa_cb_ioim_abort(void *bfad, struct bfad_ioim_s *dio);
454
455/*
456 * bfa tskim API functions
457 */
458struct bfa_tskim_s *bfa_tskim_alloc(struct bfa_s *bfa,
459 struct bfad_tskim_s *dtsk);
460void bfa_tskim_free(struct bfa_tskim_s *tskim);
461void bfa_tskim_start(struct bfa_tskim_s *tskim,
462 struct bfa_itnim_s *itnim, struct scsi_lun lun,
463 enum fcp_tm_cmnd tm, u8 t_secs);
464void bfa_cb_tskim_done(void *bfad, struct bfad_tskim_s *dtsk,
465 enum bfi_tskim_status tsk_status);
466
467void bfa_fcpim_lunmask_rp_update(struct bfa_s *bfa, wwn_t lp_wwn,
468 wwn_t rp_wwn, u16 rp_tag, u8 lp_tag);
469bfa_status_t bfa_fcpim_lunmask_update(struct bfa_s *bfa, u32 on_off);
470bfa_status_t bfa_fcpim_lunmask_query(struct bfa_s *bfa, void *buf);
471bfa_status_t bfa_fcpim_lunmask_delete(struct bfa_s *bfa, u16 vf_id,
472 wwn_t *pwwn, wwn_t rpwwn, struct scsi_lun lun);
473bfa_status_t bfa_fcpim_lunmask_add(struct bfa_s *bfa, u16 vf_id,
474 wwn_t *pwwn, wwn_t rpwwn, struct scsi_lun lun);
475bfa_status_t bfa_fcpim_lunmask_clear(struct bfa_s *bfa);
476u16 bfa_fcpim_read_throttle(struct bfa_s *bfa);
477bfa_status_t bfa_fcpim_write_throttle(struct bfa_s *bfa, u16 value);
478bfa_status_t bfa_fcpim_throttle_set(struct bfa_s *bfa, u16 value);
479bfa_status_t bfa_fcpim_throttle_get(struct bfa_s *bfa, void *buf);
480u16 bfa_fcpim_get_throttle_cfg(struct bfa_s *bfa, u16 drv_cfg_param);
481
482#endif /* __BFA_FCPIM_H__ */
483

source code of linux/drivers/scsi/bfa/bfa_fcpim.h