1 /*
2  * libcxgb_ppm.h: Chelsio common library for T3/T4/T5 iSCSI ddp operation
3  *
4  * Copyright (c) 2016 Chelsio Communications, Inc. All rights reserved.
5  *
6  * This software is available to you under a choice of one of two
7  * licenses.  You may choose to be licensed under the terms of the GNU
8  * General Public License (GPL) Version 2, available from the file
9  * COPYING in the main directory of this source tree, or the
10  * OpenIB.org BSD license below:
11  *
12  *     Redistribution and use in source and binary forms, with or
13  *     without modification, are permitted provided that the following
14  *     conditions are met:
15  *
16  *      - Redistributions of source code must retain the above
17  *        copyright notice, this list of conditions and the following
18  *        disclaimer.
19  *
20  *      - Redistributions in binary form must reproduce the above
21  *        copyright notice, this list of conditions and the following
22  *        disclaimer in the documentation and/or other materials
23  *        provided with the distribution.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32  * SOFTWARE.
33  *
34  * Written by: Karen Xie (kxie@chelsio.com)
35  */
36 
37 #ifndef	__LIBCXGB_PPM_H__
38 #define	__LIBCXGB_PPM_H__
39 
40 #include <linux/kernel.h>
41 #include <linux/errno.h>
42 #include <linux/types.h>
43 #include <linux/debugfs.h>
44 #include <linux/list.h>
45 #include <linux/netdevice.h>
46 #include <linux/scatterlist.h>
47 #include <linux/skbuff.h>
48 #include <linux/vmalloc.h>
49 #include <linux/bitmap.h>
50 
51 struct cxgbi_pagepod_hdr {
52 	u32 vld_tid;
53 	u32 pgsz_tag_clr;
54 	u32 max_offset;
55 	u32 page_offset;
56 	u64 rsvd;
57 };
58 
59 #define PPOD_PAGES_MAX			4
60 struct cxgbi_pagepod {
61 	struct cxgbi_pagepod_hdr hdr;
62 	__be64 addr[PPOD_PAGES_MAX + 1];
63 };
64 
65 /* ddp tag format
66  * for a 32-bit tag:
67  * bit #
68  * 31 .....   .....  0
69  *     X   Y...Y Z...Z, where
70  *     ^   ^^^^^ ^^^^
71  *     |   |      |____ when ddp bit = 0: color bits
72  *     |   |
73  *     |   |____ when ddp bit = 0: idx into the ddp memory region
74  *     |
75  *     |____ ddp bit: 0 - ddp tag, 1 - non-ddp tag
76  *
77  *  [page selector:2] [sw/free bits] [0] [idx] [color:6]
78  */
79 
80 #define DDP_PGIDX_MAX		4
81 #define DDP_PGSZ_BASE_SHIFT	12	/* base page 4K */
82 
83 struct cxgbi_task_tag_info {
84 	unsigned char flags;
85 #define CXGBI_PPOD_INFO_FLAG_VALID	0x1
86 #define CXGBI_PPOD_INFO_FLAG_MAPPED	0x2
87 	unsigned char cid;
88 	unsigned short pg_shift;
89 	unsigned int npods;
90 	unsigned int idx;
91 	unsigned int tag;
92 	struct cxgbi_pagepod_hdr hdr;
93 	int nents;
94 	int nr_pages;
95 	struct scatterlist *sgl;
96 };
97 
98 struct cxgbi_tag_format {
99 	unsigned char pgsz_order[DDP_PGIDX_MAX];
100 	unsigned char pgsz_idx_dflt;
101 	unsigned char free_bits:4;
102 	unsigned char color_bits:4;
103 	unsigned char idx_bits;
104 	unsigned char rsvd_bits;
105 	unsigned int  no_ddp_mask;
106 	unsigned int  idx_mask;
107 	unsigned int  color_mask;
108 	unsigned int  idx_clr_mask;
109 	unsigned int  rsvd_mask;
110 };
111 
112 struct cxgbi_ppod_data {
113 	unsigned char pg_idx:2;
114 	unsigned char color:6;
115 	unsigned char chan_id;
116 	unsigned short npods;
117 	unsigned long caller_data;
118 };
119 
120 /* per cpu ppm pool */
121 struct cxgbi_ppm_pool {
122 	unsigned int base;		/* base index */
123 	unsigned int next;		/* next possible free index */
124 	spinlock_t lock;		/* ppm pool lock */
125 	unsigned long bmap[0];
126 } ____cacheline_aligned_in_smp;
127 
128 struct cxgbi_ppm {
129 	struct kref refcnt;
130 	struct net_device *ndev;	/* net_device, 1st port */
131 	struct pci_dev *pdev;
132 	void *lldev;
133 	void **ppm_pp;
134 	struct cxgbi_tag_format tformat;
135 	unsigned int ppmax;
136 	unsigned int llimit;
137 	unsigned int base_idx;
138 
139 	unsigned int pool_rsvd;
140 	unsigned int pool_index_max;
141 	struct cxgbi_ppm_pool __percpu *pool;
142 	/* map lock */
143 	spinlock_t map_lock;		/* ppm map lock */
144 	unsigned int bmap_index_max;
145 	unsigned int next;
146 	unsigned long *ppod_bmap;
147 	struct cxgbi_ppod_data ppod_data[0];
148 };
149 
150 #define DDP_THRESHOLD		512
151 
152 #define PPOD_PAGES_SHIFT	2       /*  4 pages per pod */
153 
154 #define IPPOD_SIZE               sizeof(struct cxgbi_pagepod)  /*  64 */
155 #define PPOD_SIZE_SHIFT         6
156 
157 /* page pods are allocated in groups of this size (must be power of 2) */
158 #define PPOD_CLUSTER_SIZE	16U
159 
160 #define ULPMEM_DSGL_MAX_NPPODS	16	/*  1024/PPOD_SIZE */
161 #define ULPMEM_IDATA_MAX_NPPODS	3	/* (PPOD_SIZE * 3 + ulptx hdr) < 256B */
162 #define PCIE_MEMWIN_MAX_NPPODS	16	/*  1024/PPOD_SIZE */
163 
164 #define PPOD_COLOR_SHIFT	0
165 #define PPOD_COLOR(x)		((x) << PPOD_COLOR_SHIFT)
166 
167 #define PPOD_IDX_SHIFT          6
168 #define PPOD_IDX_MAX_SIZE       24
169 
170 #define PPOD_TID_SHIFT		0
171 #define PPOD_TID(x)		((x) << PPOD_TID_SHIFT)
172 
173 #define PPOD_TAG_SHIFT		6
174 #define PPOD_TAG(x)		((x) << PPOD_TAG_SHIFT)
175 
176 #define PPOD_VALID_SHIFT	24
177 #define PPOD_VALID(x)		((x) << PPOD_VALID_SHIFT)
178 #define PPOD_VALID_FLAG		PPOD_VALID(1U)
179 
180 #define PPOD_PI_EXTRACT_CTL_SHIFT	31
181 #define PPOD_PI_EXTRACT_CTL(x)		((x) << PPOD_PI_EXTRACT_CTL_SHIFT)
182 #define PPOD_PI_EXTRACT_CTL_FLAG	V_PPOD_PI_EXTRACT_CTL(1U)
183 
184 #define PPOD_PI_TYPE_SHIFT		29
185 #define PPOD_PI_TYPE_MASK		0x3
186 #define PPOD_PI_TYPE(x)			((x) << PPOD_PI_TYPE_SHIFT)
187 
188 #define PPOD_PI_CHECK_CTL_SHIFT		27
189 #define PPOD_PI_CHECK_CTL_MASK		0x3
190 #define PPOD_PI_CHECK_CTL(x)		((x) << PPOD_PI_CHECK_CTL_SHIFT)
191 
192 #define PPOD_PI_REPORT_CTL_SHIFT	25
193 #define PPOD_PI_REPORT_CTL_MASK		0x3
194 #define PPOD_PI_REPORT_CTL(x)		((x) << PPOD_PI_REPORT_CTL_SHIFT)
195 
196 static inline int cxgbi_ppm_is_ddp_tag(struct cxgbi_ppm *ppm, u32 tag)
197 {
198 	return !(tag & ppm->tformat.no_ddp_mask);
199 }
200 
201 static inline int cxgbi_ppm_sw_tag_is_usable(struct cxgbi_ppm *ppm,
202 					     u32 tag)
203 {
204 	/* the sw tag must be using <= 31 bits */
205 	return !(tag & 0x80000000U);
206 }
207 
208 static inline int cxgbi_ppm_make_non_ddp_tag(struct cxgbi_ppm *ppm,
209 					     u32 sw_tag,
210 					     u32 *final_tag)
211 {
212 	struct cxgbi_tag_format *tformat = &ppm->tformat;
213 
214 	if (!cxgbi_ppm_sw_tag_is_usable(ppm, sw_tag)) {
215 		pr_info("sw_tag 0x%x NOT usable.\n", sw_tag);
216 		return -EINVAL;
217 	}
218 
219 	if (!sw_tag) {
220 		*final_tag = tformat->no_ddp_mask;
221 	} else {
222 		unsigned int shift = tformat->idx_bits + tformat->color_bits;
223 		u32 lower = sw_tag & tformat->idx_clr_mask;
224 		u32 upper = (sw_tag >> shift) << (shift + 1);
225 
226 		*final_tag = upper | tformat->no_ddp_mask | lower;
227 	}
228 	return 0;
229 }
230 
231 static inline u32 cxgbi_ppm_decode_non_ddp_tag(struct cxgbi_ppm *ppm,
232 					       u32 tag)
233 {
234 	struct cxgbi_tag_format *tformat = &ppm->tformat;
235 	unsigned int shift = tformat->idx_bits + tformat->color_bits;
236 	u32 lower = tag & tformat->idx_clr_mask;
237 	u32 upper = (tag >> tformat->rsvd_bits) << shift;
238 
239 	return upper | lower;
240 }
241 
242 static inline u32 cxgbi_ppm_ddp_tag_get_idx(struct cxgbi_ppm *ppm,
243 					    u32 ddp_tag)
244 {
245 	u32 hw_idx = (ddp_tag >> PPOD_IDX_SHIFT) &
246 			ppm->tformat.idx_mask;
247 
248 	return hw_idx - ppm->base_idx;
249 }
250 
251 static inline u32 cxgbi_ppm_make_ddp_tag(unsigned int hw_idx,
252 					 unsigned char color)
253 {
254 	return (hw_idx << PPOD_IDX_SHIFT) | ((u32)color);
255 }
256 
257 static inline unsigned long
258 cxgbi_ppm_get_tag_caller_data(struct cxgbi_ppm *ppm,
259 			      u32 ddp_tag)
260 {
261 	u32 idx = cxgbi_ppm_ddp_tag_get_idx(ppm, ddp_tag);
262 
263 	return ppm->ppod_data[idx].caller_data;
264 }
265 
266 /* sw bits are the free bits */
267 static inline int cxgbi_ppm_ddp_tag_update_sw_bits(struct cxgbi_ppm *ppm,
268 						   u32 val, u32 orig_tag,
269 						   u32 *final_tag)
270 {
271 	struct cxgbi_tag_format *tformat = &ppm->tformat;
272 	u32 v = val >> tformat->free_bits;
273 
274 	if (v) {
275 		pr_info("sw_bits 0x%x too large, avail bits %u.\n",
276 			val, tformat->free_bits);
277 		return -EINVAL;
278 	}
279 	if (!cxgbi_ppm_is_ddp_tag(ppm, orig_tag))
280 		return -EINVAL;
281 
282 	*final_tag = (val << tformat->rsvd_bits) |
283 		     (orig_tag & ppm->tformat.rsvd_mask);
284 	return 0;
285 }
286 
287 static inline void cxgbi_ppm_ppod_clear(struct cxgbi_pagepod *ppod)
288 {
289 	ppod->hdr.vld_tid = 0U;
290 }
291 
292 static inline void cxgbi_tagmask_check(unsigned int tagmask,
293 				       struct cxgbi_tag_format *tformat)
294 {
295 	unsigned int bits = fls(tagmask);
296 
297 	/* reserve top most 2 bits for page selector */
298 	tformat->free_bits = 32 - 2 - bits;
299 	tformat->rsvd_bits = bits;
300 	tformat->color_bits = PPOD_IDX_SHIFT;
301 	tformat->idx_bits = bits - 1 - PPOD_IDX_SHIFT;
302 	tformat->no_ddp_mask = 1 << (bits - 1);
303 	tformat->idx_mask = (1 << tformat->idx_bits) - 1;
304 	tformat->color_mask = (1 << PPOD_IDX_SHIFT) - 1;
305 	tformat->idx_clr_mask = (1 << (bits - 1)) - 1;
306 	tformat->rsvd_mask = (1 << bits) - 1;
307 
308 	pr_info("ippm: tagmask 0x%x, rsvd %u=%u+%u+1, mask 0x%x,0x%x, "
309 		"pg %u,%u,%u,%u.\n",
310 		tagmask, tformat->rsvd_bits, tformat->idx_bits,
311 		tformat->color_bits, tformat->no_ddp_mask, tformat->rsvd_mask,
312 		tformat->pgsz_order[0], tformat->pgsz_order[1],
313 		tformat->pgsz_order[2], tformat->pgsz_order[3]);
314 }
315 
316 int cxgbi_ppm_find_page_index(struct cxgbi_ppm *ppm, unsigned long pgsz);
317 void cxgbi_ppm_make_ppod_hdr(struct cxgbi_ppm *ppm, u32 tag,
318 			     unsigned int tid, unsigned int offset,
319 			     unsigned int length,
320 			     struct cxgbi_pagepod_hdr *hdr);
321 void cxgbi_ppm_ppod_release(struct cxgbi_ppm *, u32 idx);
322 int cxgbi_ppm_ppods_reserve(struct cxgbi_ppm *, unsigned short nr_pages,
323 			    u32 per_tag_pg_idx, u32 *ppod_idx, u32 *ddp_tag,
324 			    unsigned long caller_data);
325 int cxgbi_ppm_init(void **ppm_pp, struct net_device *, struct pci_dev *,
326 		   void *lldev, struct cxgbi_tag_format *,
327 		   unsigned int ppmax, unsigned int llimit,
328 		   unsigned int start,
329 		   unsigned int reserve_factor);
330 int cxgbi_ppm_release(struct cxgbi_ppm *ppm);
331 void cxgbi_tagmask_check(unsigned int tagmask, struct cxgbi_tag_format *);
332 unsigned int cxgbi_tagmask_set(unsigned int ppmax);
333 
334 #endif	/*__LIBCXGB_PPM_H__*/
335