xref: /openbmc/linux/drivers/usb/host/ehci-mem.c (revision be709d48)
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_alloc(ehci->qh_pool, flags, &dma);
77 	if (!qh->hw)
78 		goto fail;
79 	memset(qh->hw, 0, sizeof *qh->hw);
80 	qh->qh_dma = dma;
81 	// INIT_LIST_HEAD (&qh->qh_list);
82 	INIT_LIST_HEAD (&qh->qtd_list);
83 	INIT_LIST_HEAD(&qh->unlink_node);
84 
85 	/* dummy td enables safe urb queuing */
86 	qh->dummy = ehci_qtd_alloc (ehci, flags);
87 	if (qh->dummy == NULL) {
88 		ehci_dbg (ehci, "no dummy td\n");
89 		goto fail1;
90 	}
91 done:
92 	return qh;
93 fail1:
94 	dma_pool_free(ehci->qh_pool, qh->hw, qh->qh_dma);
95 fail:
96 	kfree(qh);
97 	return NULL;
98 }
99 
100 /*-------------------------------------------------------------------------*/
101 
102 /* The queue heads and transfer descriptors are managed from pools tied
103  * to each of the "per device" structures.
104  * This is the initialisation and cleanup code.
105  */
106 
107 static void ehci_mem_cleanup (struct ehci_hcd *ehci)
108 {
109 	if (ehci->async)
110 		qh_destroy(ehci, ehci->async);
111 	ehci->async = NULL;
112 
113 	if (ehci->dummy)
114 		qh_destroy(ehci, ehci->dummy);
115 	ehci->dummy = NULL;
116 
117 	/* DMA consistent memory and pools */
118 	dma_pool_destroy(ehci->qtd_pool);
119 	ehci->qtd_pool = NULL;
120 	dma_pool_destroy(ehci->qh_pool);
121 	ehci->qh_pool = NULL;
122 	dma_pool_destroy(ehci->itd_pool);
123 	ehci->itd_pool = NULL;
124 	dma_pool_destroy(ehci->sitd_pool);
125 	ehci->sitd_pool = NULL;
126 
127 	if (ehci->periodic)
128 		dma_free_coherent(ehci_to_hcd(ehci)->self.sysdev,
129 			ehci->periodic_size * sizeof (u32),
130 			ehci->periodic, ehci->periodic_dma);
131 	ehci->periodic = NULL;
132 
133 	/* shadow periodic table */
134 	kfree(ehci->pshadow);
135 	ehci->pshadow = NULL;
136 }
137 
138 /* remember to add cleanup code (above) if you add anything here */
139 static int ehci_mem_init (struct ehci_hcd *ehci, gfp_t flags)
140 {
141 	int i;
142 
143 	/* QTDs for control/bulk/intr transfers */
144 	ehci->qtd_pool = dma_pool_create ("ehci_qtd",
145 			ehci_to_hcd(ehci)->self.sysdev,
146 			sizeof (struct ehci_qtd),
147 			32 /* byte alignment (for hw parts) */,
148 			4096 /* can't cross 4K */);
149 	if (!ehci->qtd_pool) {
150 		goto fail;
151 	}
152 
153 	/* QHs for control/bulk/intr transfers */
154 	ehci->qh_pool = dma_pool_create ("ehci_qh",
155 			ehci_to_hcd(ehci)->self.sysdev,
156 			sizeof(struct ehci_qh_hw),
157 			32 /* byte alignment (for hw parts) */,
158 			4096 /* can't cross 4K */);
159 	if (!ehci->qh_pool) {
160 		goto fail;
161 	}
162 	ehci->async = ehci_qh_alloc (ehci, flags);
163 	if (!ehci->async) {
164 		goto fail;
165 	}
166 
167 	/* ITD for high speed ISO transfers */
168 	ehci->itd_pool = dma_pool_create ("ehci_itd",
169 			ehci_to_hcd(ehci)->self.sysdev,
170 			sizeof (struct ehci_itd),
171 			32 /* byte alignment (for hw parts) */,
172 			4096 /* can't cross 4K */);
173 	if (!ehci->itd_pool) {
174 		goto fail;
175 	}
176 
177 	/* SITD for full/low speed split ISO transfers */
178 	ehci->sitd_pool = dma_pool_create ("ehci_sitd",
179 			ehci_to_hcd(ehci)->self.sysdev,
180 			sizeof (struct ehci_sitd),
181 			32 /* byte alignment (for hw parts) */,
182 			4096 /* can't cross 4K */);
183 	if (!ehci->sitd_pool) {
184 		goto fail;
185 	}
186 
187 	/* Hardware periodic table */
188 	ehci->periodic = (__le32 *)
189 		dma_alloc_coherent(ehci_to_hcd(ehci)->self.sysdev,
190 			ehci->periodic_size * sizeof(__le32),
191 			&ehci->periodic_dma, flags);
192 	if (ehci->periodic == NULL) {
193 		goto fail;
194 	}
195 
196 	if (ehci->use_dummy_qh) {
197 		struct ehci_qh_hw	*hw;
198 		ehci->dummy = ehci_qh_alloc(ehci, flags);
199 		if (!ehci->dummy)
200 			goto fail;
201 
202 		hw = ehci->dummy->hw;
203 		hw->hw_next = EHCI_LIST_END(ehci);
204 		hw->hw_qtd_next = EHCI_LIST_END(ehci);
205 		hw->hw_alt_next = EHCI_LIST_END(ehci);
206 		ehci->dummy->hw = hw;
207 
208 		for (i = 0; i < ehci->periodic_size; i++)
209 			ehci->periodic[i] = cpu_to_hc32(ehci,
210 					ehci->dummy->qh_dma);
211 	} else {
212 		for (i = 0; i < ehci->periodic_size; i++)
213 			ehci->periodic[i] = EHCI_LIST_END(ehci);
214 	}
215 
216 	/* software shadow of hardware table */
217 	ehci->pshadow = kcalloc(ehci->periodic_size, sizeof(void *), flags);
218 	if (ehci->pshadow != NULL)
219 		return 0;
220 
221 fail:
222 	ehci_dbg (ehci, "couldn't init memory\n");
223 	ehci_mem_cleanup (ehci);
224 	return -ENOMEM;
225 }
226