xref: /openbmc/linux/drivers/usb/host/ehci-mem.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2001 by David Brownell
4  */
5 
6 /* this file is part of ehci-hcd.c */
7 
8 /*-------------------------------------------------------------------------*/
9 
10 /*
11  * There's basically three types of memory:
12  *	- data used only by the HCD ... kmalloc is fine
13  *	- async and periodic schedules, shared by HC and HCD ... these
14  *	  need to use dma_pool or dma_alloc_coherent
15  *	- driver buffers, read/written by HC ... single shot DMA mapped
16  *
17  * There's also "register" data (e.g. PCI or SOC), which is memory mapped.
18  * No memory seen by this driver is pageable.
19  */
20 
21 /*-------------------------------------------------------------------------*/
22 
23 /* Allocate the key transfer structures from the previously allocated pool */
24 
25 static inline void ehci_qtd_init(struct ehci_hcd *ehci, struct ehci_qtd *qtd,
26 				  dma_addr_t dma)
27 {
28 	memset (qtd, 0, sizeof *qtd);
29 	qtd->qtd_dma = dma;
30 	qtd->hw_token = cpu_to_hc32(ehci, QTD_STS_HALT);
31 	qtd->hw_next = EHCI_LIST_END(ehci);
32 	qtd->hw_alt_next = EHCI_LIST_END(ehci);
33 	INIT_LIST_HEAD (&qtd->qtd_list);
34 }
35 
36 static struct ehci_qtd *ehci_qtd_alloc (struct ehci_hcd *ehci, gfp_t flags)
37 {
38 	struct ehci_qtd		*qtd;
39 	dma_addr_t		dma;
40 
41 	qtd = dma_pool_alloc (ehci->qtd_pool, flags, &dma);
42 	if (qtd != NULL) {
43 		ehci_qtd_init(ehci, qtd, dma);
44 	}
45 	return qtd;
46 }
47 
48 static inline void ehci_qtd_free (struct ehci_hcd *ehci, struct ehci_qtd *qtd)
49 {
50 	dma_pool_free (ehci->qtd_pool, qtd, qtd->qtd_dma);
51 }
52 
53 
54 static void qh_destroy(struct ehci_hcd *ehci, struct ehci_qh *qh)
55 {
56 	/* clean qtds first, and know this is not linked */
57 	if (!list_empty (&qh->qtd_list) || qh->qh_next.ptr) {
58 		ehci_dbg (ehci, "unused qh not empty!\n");
59 		BUG ();
60 	}
61 	if (qh->dummy)
62 		ehci_qtd_free (ehci, qh->dummy);
63 	dma_pool_free(ehci->qh_pool, qh->hw, qh->qh_dma);
64 	kfree(qh);
65 }
66 
67 static struct ehci_qh *ehci_qh_alloc (struct ehci_hcd *ehci, gfp_t flags)
68 {
69 	struct ehci_qh		*qh;
70 	dma_addr_t		dma;
71 
72 	qh = kzalloc(sizeof *qh, GFP_ATOMIC);
73 	if (!qh)
74 		goto done;
75 	qh->hw = (struct ehci_qh_hw *)
76 		dma_pool_zalloc(ehci->qh_pool, flags, &dma);
77 	if (!qh->hw)
78 		goto fail;
79 	qh->qh_dma = dma;
80 	// INIT_LIST_HEAD (&qh->qh_list);
81 	INIT_LIST_HEAD (&qh->qtd_list);
82 	INIT_LIST_HEAD(&qh->unlink_node);
83 
84 	/* dummy td enables safe urb queuing */
85 	qh->dummy = ehci_qtd_alloc (ehci, flags);
86 	if (qh->dummy == NULL) {
87 		ehci_dbg (ehci, "no dummy td\n");
88 		goto fail1;
89 	}
90 done:
91 	return qh;
92 fail1:
93 	dma_pool_free(ehci->qh_pool, qh->hw, qh->qh_dma);
94 fail:
95 	kfree(qh);
96 	return NULL;
97 }
98 
99 /*-------------------------------------------------------------------------*/
100 
101 /* The queue heads and transfer descriptors are managed from pools tied
102  * to each of the "per device" structures.
103  * This is the initialisation and cleanup code.
104  */
105 
106 static void ehci_mem_cleanup (struct ehci_hcd *ehci)
107 {
108 	if (ehci->async)
109 		qh_destroy(ehci, ehci->async);
110 	ehci->async = NULL;
111 
112 	if (ehci->dummy)
113 		qh_destroy(ehci, ehci->dummy);
114 	ehci->dummy = NULL;
115 
116 	/* DMA consistent memory and pools */
117 	dma_pool_destroy(ehci->qtd_pool);
118 	ehci->qtd_pool = NULL;
119 	dma_pool_destroy(ehci->qh_pool);
120 	ehci->qh_pool = NULL;
121 	dma_pool_destroy(ehci->itd_pool);
122 	ehci->itd_pool = NULL;
123 	dma_pool_destroy(ehci->sitd_pool);
124 	ehci->sitd_pool = NULL;
125 
126 	if (ehci->periodic)
127 		dma_free_coherent(ehci_to_hcd(ehci)->self.sysdev,
128 			ehci->periodic_size * sizeof (u32),
129 			ehci->periodic, ehci->periodic_dma);
130 	ehci->periodic = NULL;
131 
132 	/* shadow periodic table */
133 	kfree(ehci->pshadow);
134 	ehci->pshadow = NULL;
135 }
136 
137 /* remember to add cleanup code (above) if you add anything here */
138 static int ehci_mem_init (struct ehci_hcd *ehci, gfp_t flags)
139 {
140 	int i;
141 
142 	/* QTDs for control/bulk/intr transfers */
143 	ehci->qtd_pool = dma_pool_create ("ehci_qtd",
144 			ehci_to_hcd(ehci)->self.sysdev,
145 			sizeof (struct ehci_qtd),
146 			32 /* byte alignment (for hw parts) */,
147 			4096 /* can't cross 4K */);
148 	if (!ehci->qtd_pool) {
149 		goto fail;
150 	}
151 
152 	/* QHs for control/bulk/intr transfers */
153 	ehci->qh_pool = dma_pool_create ("ehci_qh",
154 			ehci_to_hcd(ehci)->self.sysdev,
155 			sizeof(struct ehci_qh_hw),
156 			32 /* byte alignment (for hw parts) */,
157 			4096 /* can't cross 4K */);
158 	if (!ehci->qh_pool) {
159 		goto fail;
160 	}
161 	ehci->async = ehci_qh_alloc (ehci, flags);
162 	if (!ehci->async) {
163 		goto fail;
164 	}
165 
166 	/* ITD for high speed ISO transfers */
167 	ehci->itd_pool = dma_pool_create ("ehci_itd",
168 			ehci_to_hcd(ehci)->self.sysdev,
169 			sizeof (struct ehci_itd),
170 			32 /* byte alignment (for hw parts) */,
171 			4096 /* can't cross 4K */);
172 	if (!ehci->itd_pool) {
173 		goto fail;
174 	}
175 
176 	/* SITD for full/low speed split ISO transfers */
177 	ehci->sitd_pool = dma_pool_create ("ehci_sitd",
178 			ehci_to_hcd(ehci)->self.sysdev,
179 			sizeof (struct ehci_sitd),
180 			32 /* byte alignment (for hw parts) */,
181 			4096 /* can't cross 4K */);
182 	if (!ehci->sitd_pool) {
183 		goto fail;
184 	}
185 
186 	/* Hardware periodic table */
187 	ehci->periodic = (__le32 *)
188 		dma_alloc_coherent(ehci_to_hcd(ehci)->self.sysdev,
189 			ehci->periodic_size * sizeof(__le32),
190 			&ehci->periodic_dma, flags);
191 	if (ehci->periodic == NULL) {
192 		goto fail;
193 	}
194 
195 	if (ehci->use_dummy_qh) {
196 		struct ehci_qh_hw	*hw;
197 		ehci->dummy = ehci_qh_alloc(ehci, flags);
198 		if (!ehci->dummy)
199 			goto fail;
200 
201 		hw = ehci->dummy->hw;
202 		hw->hw_next = EHCI_LIST_END(ehci);
203 		hw->hw_qtd_next = EHCI_LIST_END(ehci);
204 		hw->hw_alt_next = EHCI_LIST_END(ehci);
205 		ehci->dummy->hw = hw;
206 
207 		for (i = 0; i < ehci->periodic_size; i++)
208 			ehci->periodic[i] = cpu_to_hc32(ehci,
209 					ehci->dummy->qh_dma);
210 	} else {
211 		for (i = 0; i < ehci->periodic_size; i++)
212 			ehci->periodic[i] = EHCI_LIST_END(ehci);
213 	}
214 
215 	/* software shadow of hardware table */
216 	ehci->pshadow = kcalloc(ehci->periodic_size, sizeof(void *), flags);
217 	if (ehci->pshadow != NULL)
218 		return 0;
219 
220 fail:
221 	ehci_dbg (ehci, "couldn't init memory\n");
222 	ehci_mem_cleanup (ehci);
223 	return -ENOMEM;
224 }
225