xref: /linux/drivers/net/ethernet/intel/ice/ice_irq.c (revision a34b0e4e21d6be3c3d620aa7f9dfbf0e9550c19e)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2023, Intel Corporation. */
3 
4 #include "ice.h"
5 #include "ice_lib.h"
6 #include "ice_irq.h"
7 
8 /**
9  * ice_init_irq_tracker - initialize interrupt tracker
10  * @pf: board private structure
11  * @max_vectors: maximum number of vectors that tracker can hold
12  * @num_static: number of preallocated interrupts
13  */
14 static void
15 ice_init_irq_tracker(struct ice_pf *pf, unsigned int max_vectors,
16 		     unsigned int num_static)
17 {
18 	pf->irq_tracker.num_entries = max_vectors;
19 	pf->irq_tracker.num_static = num_static;
20 	xa_init_flags(&pf->irq_tracker.entries, XA_FLAGS_ALLOC);
21 }
22 
23 static int
24 ice_init_virt_irq_tracker(struct ice_pf *pf, u32 base, u32 num_entries)
25 {
26 	pf->virt_irq_tracker.bm = bitmap_zalloc(num_entries, GFP_KERNEL);
27 	if (!pf->virt_irq_tracker.bm)
28 		return -ENOMEM;
29 
30 	pf->virt_irq_tracker.num_entries = num_entries;
31 	pf->virt_irq_tracker.base = base;
32 
33 	return 0;
34 }
35 
36 /**
37  * ice_deinit_irq_tracker - free xarray tracker
38  * @pf: board private structure
39  */
40 static void ice_deinit_irq_tracker(struct ice_pf *pf)
41 {
42 	xa_destroy(&pf->irq_tracker.entries);
43 }
44 
45 static void ice_deinit_virt_irq_tracker(struct ice_pf *pf)
46 {
47 	bitmap_free(pf->virt_irq_tracker.bm);
48 }
49 
50 /**
51  * ice_free_irq_res - free a block of resources
52  * @pf: board private structure
53  * @index: starting index previously returned by ice_get_res
54  */
55 static void ice_free_irq_res(struct ice_pf *pf, u16 index)
56 {
57 	struct ice_irq_entry *entry;
58 
59 	entry = xa_erase(&pf->irq_tracker.entries, index);
60 	kfree(entry);
61 }
62 
63 /**
64  * ice_get_irq_res - get an interrupt resource
65  * @pf: board private structure
66  * @dyn_allowed: allow entry to be dynamically allocated
67  *
68  * Allocate new irq entry in the free slot of the tracker. Since xarray
69  * is used, always allocate new entry at the lowest possible index. Set
70  * proper allocation limit for maximum tracker entries.
71  *
72  * Returns allocated irq entry or NULL on failure.
73  */
74 static struct ice_irq_entry *ice_get_irq_res(struct ice_pf *pf,
75 					     bool dyn_allowed)
76 {
77 	struct xa_limit limit = { .max = pf->irq_tracker.num_entries - 1,
78 				  .min = 0 };
79 	unsigned int num_static = pf->irq_tracker.num_static - 1;
80 	struct ice_irq_entry *entry;
81 	unsigned int index;
82 	int ret;
83 
84 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
85 	if (!entry)
86 		return NULL;
87 
88 	/* only already allocated if the caller says so */
89 	if (!dyn_allowed)
90 		limit.max = num_static;
91 
92 	ret = xa_alloc(&pf->irq_tracker.entries, &index, entry, limit,
93 		       GFP_KERNEL);
94 
95 	if (ret) {
96 		kfree(entry);
97 		entry = NULL;
98 	} else {
99 		entry->index = index;
100 		entry->dynamic = index > num_static;
101 	}
102 
103 	return entry;
104 }
105 
106 #define ICE_RDMA_AEQ_MSIX 1
107 static int ice_get_default_msix_amount(struct ice_pf *pf)
108 {
109 	return ICE_MIN_LAN_OICR_MSIX + netif_get_num_default_rss_queues() +
110 	       (test_bit(ICE_FLAG_FD_ENA, pf->flags) ? ICE_FDIR_MSIX : 0) +
111 	       (ice_is_rdma_ena(pf) ? netif_get_num_default_rss_queues() +
112 				      ICE_RDMA_AEQ_MSIX : 0);
113 }
114 
115 /**
116  * ice_clear_interrupt_scheme - Undo things done by ice_init_interrupt_scheme
117  * @pf: board private structure
118  */
119 void ice_clear_interrupt_scheme(struct ice_pf *pf)
120 {
121 	pci_free_irq_vectors(pf->pdev);
122 	ice_deinit_irq_tracker(pf);
123 	ice_deinit_virt_irq_tracker(pf);
124 }
125 
126 /**
127  * ice_init_interrupt_scheme - Determine proper interrupt scheme
128  * @pf: board private structure to initialize
129  */
130 int ice_init_interrupt_scheme(struct ice_pf *pf)
131 {
132 	int total_vectors = pf->hw.func_caps.common_cap.num_msix_vectors;
133 	int vectors;
134 
135 	/* load default PF MSI-X range */
136 	if (!pf->msix.min)
137 		pf->msix.min = ICE_MIN_MSIX;
138 
139 	if (!pf->msix.max)
140 		pf->msix.max = min(total_vectors,
141 				   ice_get_default_msix_amount(pf));
142 
143 	pf->msix.total = total_vectors;
144 	pf->msix.rest = total_vectors - pf->msix.max;
145 
146 	if (pci_msix_can_alloc_dyn(pf->pdev))
147 		vectors = pf->msix.min;
148 	else
149 		vectors = pf->msix.max;
150 
151 	vectors = pci_alloc_irq_vectors(pf->pdev, pf->msix.min, vectors,
152 					PCI_IRQ_MSIX);
153 	if (vectors < 0)
154 		return vectors;
155 
156 	ice_init_irq_tracker(pf, pf->msix.max, vectors);
157 
158 	return ice_init_virt_irq_tracker(pf, pf->msix.max, pf->msix.rest);
159 }
160 
161 /**
162  * ice_alloc_irq - Allocate new interrupt vector
163  * @pf: board private structure
164  * @dyn_allowed: allow dynamic allocation of the interrupt
165  *
166  * Allocate new interrupt vector for a given owner id.
167  * return struct msi_map with interrupt details and track
168  * allocated interrupt appropriately.
169  *
170  * This function reserves new irq entry from the irq_tracker.
171  * if according to the tracker information all interrupts that
172  * were allocated with ice_pci_alloc_irq_vectors are already used
173  * and dynamically allocated interrupts are supported then new
174  * interrupt will be allocated with pci_msix_alloc_irq_at.
175  *
176  * Some callers may only support dynamically allocated interrupts.
177  * This is indicated with dyn_allowed flag.
178  *
179  * On failure, return map with negative .index. The caller
180  * is expected to check returned map index.
181  *
182  */
183 struct msi_map ice_alloc_irq(struct ice_pf *pf, bool dyn_allowed)
184 {
185 	struct msi_map map = { .index = -ENOENT };
186 	struct device *dev = ice_pf_to_dev(pf);
187 	struct ice_irq_entry *entry;
188 
189 	entry = ice_get_irq_res(pf, dyn_allowed);
190 	if (!entry)
191 		return map;
192 
193 	if (pci_msix_can_alloc_dyn(pf->pdev) && entry->dynamic) {
194 		map = pci_msix_alloc_irq_at(pf->pdev, entry->index, NULL);
195 		if (map.index < 0)
196 			goto exit_free_res;
197 		dev_dbg(dev, "allocated new irq at index %d\n", map.index);
198 	} else {
199 		map.index = entry->index;
200 		map.virq = pci_irq_vector(pf->pdev, map.index);
201 	}
202 
203 	return map;
204 
205 exit_free_res:
206 	dev_err(dev, "Could not allocate irq at idx %d\n", entry->index);
207 	ice_free_irq_res(pf, entry->index);
208 	return map;
209 }
210 
211 /**
212  * ice_free_irq - Free interrupt vector
213  * @pf: board private structure
214  * @map: map with interrupt details
215  *
216  * Remove allocated interrupt from the interrupt tracker. If interrupt was
217  * allocated dynamically, free respective interrupt vector.
218  */
219 void ice_free_irq(struct ice_pf *pf, struct msi_map map)
220 {
221 	struct ice_irq_entry *entry;
222 
223 	entry = xa_load(&pf->irq_tracker.entries, map.index);
224 
225 	if (!entry) {
226 		dev_err(ice_pf_to_dev(pf), "Failed to get MSIX interrupt entry at index %d",
227 			map.index);
228 		return;
229 	}
230 
231 	dev_dbg(ice_pf_to_dev(pf), "Free irq at index %d\n", map.index);
232 
233 	if (entry->dynamic)
234 		pci_msix_free_irq(pf->pdev, map);
235 
236 	ice_free_irq_res(pf, map.index);
237 }
238 
239 /**
240  * ice_virt_get_irqs - get irqs for SR-IOV usacase
241  * @pf: pointer to PF structure
242  * @needed: number of irqs to get
243  *
244  * This returns the first MSI-X vector index in PF space that is used by this
245  * VF. This index is used when accessing PF relative registers such as
246  * GLINT_VECT2FUNC and GLINT_DYN_CTL.
247  * This will always be the OICR index in the AVF driver so any functionality
248  * using vf->first_vector_idx for queue configuration_id: id of VF which will
249  * use this irqs
250  */
251 int ice_virt_get_irqs(struct ice_pf *pf, u32 needed)
252 {
253 	int res = bitmap_find_next_zero_area(pf->virt_irq_tracker.bm,
254 					     pf->virt_irq_tracker.num_entries,
255 					     0, needed, 0);
256 
257 	if (res >= pf->virt_irq_tracker.num_entries)
258 		return -ENOENT;
259 
260 	bitmap_set(pf->virt_irq_tracker.bm, res, needed);
261 
262 	/* conversion from number in bitmap to global irq index */
263 	return res + pf->virt_irq_tracker.base;
264 }
265 
266 /**
267  * ice_virt_free_irqs - free irqs used by the VF
268  * @pf: pointer to PF structure
269  * @index: first index to be free
270  * @irqs: number of irqs to free
271  */
272 void ice_virt_free_irqs(struct ice_pf *pf, u32 index, u32 irqs)
273 {
274 	bitmap_clear(pf->virt_irq_tracker.bm, index - pf->virt_irq_tracker.base,
275 		     irqs);
276 }
277