1/*
2 *  IBM eServer eHCA Infiniband device driver for Linux on POWER
3 *
4 *  internal queue handling
5 *
6 *  Authors: Waleri Fomin <fomin@de.ibm.com>
7 *           Reinhard Ernst <rernst@de.ibm.com>
8 *           Christoph Raisch <raisch@de.ibm.com>
9 *
10 *  Copyright (c) 2005 IBM Corporation
11 *
12 *  This source code is distributed under a dual license of GPL v2.0 and OpenIB
13 *  BSD.
14 *
15 * OpenIB BSD License
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are met:
19 *
20 * Redistributions of source code must retain the above copyright notice, this
21 * list of conditions and the following disclaimer.
22 *
23 * Redistributions in binary form must reproduce the above copyright notice,
24 * this list of conditions and the following disclaimer in the documentation
25 * and/or other materials
26 * provided with the distribution.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
29 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
32 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
35 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
36 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 */
40
41#include <linux/slab.h>
42
43#include "ehca_tools.h"
44#include "ipz_pt_fn.h"
45#include "ehca_classes.h"
46
47#define PAGES_PER_KPAGE (PAGE_SIZE >> EHCA_PAGESHIFT)
48
49struct kmem_cache *small_qp_cache;
50
51void *ipz_qpageit_get_inc(struct ipz_queue *queue)
52{
53	void *ret = ipz_qeit_get(queue);
54	queue->current_q_offset += queue->pagesize;
55	if (queue->current_q_offset > queue->queue_length) {
56		queue->current_q_offset -= queue->pagesize;
57		ret = NULL;
58	}
59	if (((u64)ret) % queue->pagesize) {
60		ehca_gen_err("ERROR!! not at PAGE-Boundary");
61		return NULL;
62	}
63	return ret;
64}
65
66void *ipz_qeit_eq_get_inc(struct ipz_queue *queue)
67{
68	void *ret = ipz_qeit_get(queue);
69	u64 last_entry_in_q = queue->queue_length - queue->qe_size;
70
71	queue->current_q_offset += queue->qe_size;
72	if (queue->current_q_offset > last_entry_in_q) {
73		queue->current_q_offset = 0;
74		queue->toggle_state = (~queue->toggle_state) & 1;
75	}
76
77	return ret;
78}
79
80int ipz_queue_abs_to_offset(struct ipz_queue *queue, u64 addr, u64 *q_offset)
81{
82	int i;
83	for (i = 0; i < queue->queue_length / queue->pagesize; i++) {
84		u64 page = (u64)virt_to_abs(queue->queue_pages[i]);
85		if (addr >= page && addr < page + queue->pagesize) {
86			*q_offset = addr - page + i * queue->pagesize;
87			return 0;
88		}
89	}
90	return -EINVAL;
91}
92
93#if PAGE_SHIFT < EHCA_PAGESHIFT
94#error Kernel pages must be at least as large than eHCA pages (4K) !
95#endif
96
97/*
98 * allocate pages for queue:
99 * outer loop allocates whole kernel pages (page aligned) and
100 * inner loop divides a kernel page into smaller hca queue pages
101 */
102static int alloc_queue_pages(struct ipz_queue *queue, const u32 nr_of_pages)
103{
104	int k, f = 0;
105	u8 *kpage;
106
107	while (f < nr_of_pages) {
108		kpage = (u8 *)get_zeroed_page(GFP_KERNEL);
109		if (!kpage)
110			goto out;
111
112		for (k = 0; k < PAGES_PER_KPAGE && f < nr_of_pages; k++) {
113			queue->queue_pages[f] = (struct ipz_page *)kpage;
114			kpage += EHCA_PAGESIZE;
115			f++;
116		}
117	}
118	return 1;
119
120out:
121	for (f = 0; f < nr_of_pages && queue->queue_pages[f];
122	     f += PAGES_PER_KPAGE)
123		free_page((unsigned long)(queue->queue_pages)[f]);
124	return 0;
125}
126
127static int alloc_small_queue_page(struct ipz_queue *queue, struct ehca_pd *pd)
128{
129	int order = ilog2(queue->pagesize) - 9;
130	struct ipz_small_queue_page *page;
131	unsigned long bit;
132
133	mutex_lock(&pd->lock);
134
135	if (!list_empty(&pd->free[order]))
136		page = list_entry(pd->free[order].next,
137				  struct ipz_small_queue_page, list);
138	else {
139		page = kmem_cache_zalloc(small_qp_cache, GFP_KERNEL);
140		if (!page)
141			goto out;
142
143		page->page = get_zeroed_page(GFP_KERNEL);
144		if (!page->page) {
145			kmem_cache_free(small_qp_cache, page);
146			goto out;
147		}
148
149		list_add(&page->list, &pd->free[order]);
150	}
151
152	bit = find_first_zero_bit(page->bitmap, IPZ_SPAGE_PER_KPAGE >> order);
153	__set_bit(bit, page->bitmap);
154	page->fill++;
155
156	if (page->fill == IPZ_SPAGE_PER_KPAGE >> order)
157		list_move(&page->list, &pd->full[order]);
158
159	mutex_unlock(&pd->lock);
160
161	queue->queue_pages[0] = (void *)(page->page | (bit << (order + 9)));
162	queue->small_page = page;
163	queue->offset = bit << (order + 9);
164	return 1;
165
166out:
167	ehca_err(pd->ib_pd.device, "failed to allocate small queue page");
168	mutex_unlock(&pd->lock);
169	return 0;
170}
171
172static void free_small_queue_page(struct ipz_queue *queue, struct ehca_pd *pd)
173{
174	int order = ilog2(queue->pagesize) - 9;
175	struct ipz_small_queue_page *page = queue->small_page;
176	unsigned long bit;
177	int free_page = 0;
178
179	bit = ((unsigned long)queue->queue_pages[0] & ~PAGE_MASK)
180		>> (order + 9);
181
182	mutex_lock(&pd->lock);
183
184	__clear_bit(bit, page->bitmap);
185	page->fill--;
186
187	if (page->fill == 0) {
188		list_del(&page->list);
189		free_page = 1;
190	}
191
192	if (page->fill == (IPZ_SPAGE_PER_KPAGE >> order) - 1)
193		/* the page was full until we freed the chunk */
194		list_move_tail(&page->list, &pd->free[order]);
195
196	mutex_unlock(&pd->lock);
197
198	if (free_page) {
199		free_page(page->page);
200		kmem_cache_free(small_qp_cache, page);
201	}
202}
203
204int ipz_queue_ctor(struct ehca_pd *pd, struct ipz_queue *queue,
205		   const u32 nr_of_pages, const u32 pagesize,
206		   const u32 qe_size, const u32 nr_of_sg,
207		   int is_small)
208{
209	if (pagesize > PAGE_SIZE) {
210		ehca_gen_err("FATAL ERROR: pagesize=%x "
211			     "is greater than kernel page size", pagesize);
212		return 0;
213	}
214
215	/* init queue fields */
216	queue->queue_length = nr_of_pages * pagesize;
217	queue->pagesize = pagesize;
218	queue->qe_size = qe_size;
219	queue->act_nr_of_sg = nr_of_sg;
220	queue->current_q_offset = 0;
221	queue->toggle_state = 1;
222	queue->small_page = NULL;
223
224	/* allocate queue page pointers */
225	queue->queue_pages = kzalloc(nr_of_pages * sizeof(void *), GFP_KERNEL);
226	if (!queue->queue_pages) {
227		queue->queue_pages = vzalloc(nr_of_pages * sizeof(void *));
228		if (!queue->queue_pages) {
229			ehca_gen_err("Couldn't allocate queue page list");
230			return 0;
231		}
232	}
233
234	/* allocate actual queue pages */
235	if (is_small) {
236		if (!alloc_small_queue_page(queue, pd))
237			goto ipz_queue_ctor_exit0;
238	} else
239		if (!alloc_queue_pages(queue, nr_of_pages))
240			goto ipz_queue_ctor_exit0;
241
242	return 1;
243
244ipz_queue_ctor_exit0:
245	ehca_gen_err("Couldn't alloc pages queue=%p "
246		 "nr_of_pages=%x",  queue, nr_of_pages);
247	if (is_vmalloc_addr(queue->queue_pages))
248		vfree(queue->queue_pages);
249	else
250		kfree(queue->queue_pages);
251
252	return 0;
253}
254
255int ipz_queue_dtor(struct ehca_pd *pd, struct ipz_queue *queue)
256{
257	int i, nr_pages;
258
259	if (!queue || !queue->queue_pages) {
260		ehca_gen_dbg("queue or queue_pages is NULL");
261		return 0;
262	}
263
264	if (queue->small_page)
265		free_small_queue_page(queue, pd);
266	else {
267		nr_pages = queue->queue_length / queue->pagesize;
268		for (i = 0; i < nr_pages; i += PAGES_PER_KPAGE)
269			free_page((unsigned long)queue->queue_pages[i]);
270	}
271
272	if (is_vmalloc_addr(queue->queue_pages))
273		vfree(queue->queue_pages);
274	else
275		kfree(queue->queue_pages);
276
277	return 1;
278}
279
280int ehca_init_small_qp_cache(void)
281{
282	small_qp_cache = kmem_cache_create("ehca_cache_small_qp",
283					   sizeof(struct ipz_small_queue_page),
284					   0, SLAB_HWCACHE_ALIGN, NULL);
285	if (!small_qp_cache)
286		return -ENOMEM;
287
288	return 0;
289}
290
291void ehca_cleanup_small_qp_cache(void)
292{
293	kmem_cache_destroy(small_qp_cache);
294}
295