1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2018 ARM Limited, All Rights Reserved.
  4 * Author: Marc Zyngier <marc.zyngier@arm.com>
  5 */
  6
  7#define pr_fmt(fmt) "GICv3: " fmt
  8
  9#include <linux/dma-iommu.h>
 10#include <linux/irq.h>
 11#include <linux/irqdomain.h>
 12#include <linux/kernel.h>
 13#include <linux/msi.h>
 14#include <linux/of_address.h>
 15#include <linux/of_pci.h>
 16#include <linux/slab.h>
 17#include <linux/spinlock.h>
 18
 19#include <linux/irqchip/arm-gic-v3.h>
 20
 21struct mbi_range {
 22	u32			spi_start;
 23	u32			nr_spis;
 24	unsigned long		*bm;
 25};
 26
 27static DEFINE_MUTEX(mbi_lock);
 28static phys_addr_t		mbi_phys_base;
 29static struct mbi_range		*mbi_ranges;
 30static unsigned int		mbi_range_nr;
 31
 32static struct irq_chip mbi_irq_chip = {
 33	.name			= "MBI",
 34	.irq_mask		= irq_chip_mask_parent,
 35	.irq_unmask		= irq_chip_unmask_parent,
 36	.irq_eoi		= irq_chip_eoi_parent,
 37	.irq_set_type		= irq_chip_set_type_parent,
 38	.irq_set_affinity	= irq_chip_set_affinity_parent,
 39};
 40
 41static int mbi_irq_gic_domain_alloc(struct irq_domain *domain,
 42				       unsigned int virq,
 43				       irq_hw_number_t hwirq)
 44{
 45	struct irq_fwspec fwspec;
 46	struct irq_data *d;
 47	int err;
 48
 49	/*
 50	 * Using ACPI? There is no MBI support in the spec, you
 51	 * shouldn't even be here.
 52	 */
 53	if (!is_of_node(domain->parent->fwnode))
 54		return -EINVAL;
 55
 56	/*
 57	 * Let's default to edge. This is consistent with traditional
 58	 * MSIs, and systems requiring level signaling will just
 59	 * enforce the trigger on their own.
 60	 */
 61	fwspec.fwnode = domain->parent->fwnode;
 62	fwspec.param_count = 3;
 63	fwspec.param[0] = 0;
 64	fwspec.param[1] = hwirq - 32;
 65	fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
 66
 67	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
 68	if (err)
 69		return err;
 70
 71	d = irq_domain_get_irq_data(domain->parent, virq);
 72	return d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
 73}
 74
 75static void mbi_free_msi(struct mbi_range *mbi, unsigned int hwirq,
 76			 int nr_irqs)
 77{
 78	mutex_lock(&mbi_lock);
 79	bitmap_release_region(mbi->bm, hwirq - mbi->spi_start,
 80			      get_count_order(nr_irqs));
 81	mutex_unlock(&mbi_lock);
 82}
 83
 84static int mbi_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 85				   unsigned int nr_irqs, void *args)
 86{
 87	msi_alloc_info_t *info = args;
 88	struct mbi_range *mbi = NULL;
 89	int hwirq, offset, i, err = 0;
 90
 91	mutex_lock(&mbi_lock);
 92	for (i = 0; i < mbi_range_nr; i++) {
 93		offset = bitmap_find_free_region(mbi_ranges[i].bm,
 94						 mbi_ranges[i].nr_spis,
 95						 get_count_order(nr_irqs));
 96		if (offset >= 0) {
 97			mbi = &mbi_ranges[i];
 98			break;
 99		}
100	}
101	mutex_unlock(&mbi_lock);
102
103	if (!mbi)
104		return -ENOSPC;
105
106	hwirq = mbi->spi_start + offset;
107
108	err = iommu_dma_prepare_msi(info->desc,
109				    mbi_phys_base + GICD_SETSPI_NSR);
110	if (err)
111		return err;
112
113	for (i = 0; i < nr_irqs; i++) {
114		err = mbi_irq_gic_domain_alloc(domain, virq + i, hwirq + i);
115		if (err)
116			goto fail;
117
118		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
119					      &mbi_irq_chip, mbi);
120	}
121
122	return 0;
123
124fail:
125	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
126	mbi_free_msi(mbi, hwirq, nr_irqs);
127	return err;
128}
129
130static void mbi_irq_domain_free(struct irq_domain *domain,
131				unsigned int virq, unsigned int nr_irqs)
132{
133	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
134	struct mbi_range *mbi = irq_data_get_irq_chip_data(d);
135
136	mbi_free_msi(mbi, d->hwirq, nr_irqs);
137	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
138}
139
140static const struct irq_domain_ops mbi_domain_ops = {
141	.alloc			= mbi_irq_domain_alloc,
142	.free			= mbi_irq_domain_free,
143};
144
145static void mbi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
146{
147	msg[0].address_hi = upper_32_bits(mbi_phys_base + GICD_SETSPI_NSR);
148	msg[0].address_lo = lower_32_bits(mbi_phys_base + GICD_SETSPI_NSR);
149	msg[0].data = data->parent_data->hwirq;
150
151	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), msg);
152}
153
154#ifdef CONFIG_PCI_MSI
155/* PCI-specific irqchip */
156static void mbi_mask_msi_irq(struct irq_data *d)
157{
158	pci_msi_mask_irq(d);
159	irq_chip_mask_parent(d);
160}
161
162static void mbi_unmask_msi_irq(struct irq_data *d)
163{
164	pci_msi_unmask_irq(d);
165	irq_chip_unmask_parent(d);
166}
167
168static struct irq_chip mbi_msi_irq_chip = {
169	.name			= "MSI",
170	.irq_mask		= mbi_mask_msi_irq,
171	.irq_unmask		= mbi_unmask_msi_irq,
172	.irq_eoi		= irq_chip_eoi_parent,
173	.irq_compose_msi_msg	= mbi_compose_msi_msg,
174	.irq_write_msi_msg	= pci_msi_domain_write_msg,
175};
176
177static struct msi_domain_info mbi_msi_domain_info = {
178	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
179		   MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
180	.chip	= &mbi_msi_irq_chip,
181};
182
183static int mbi_allocate_pci_domain(struct irq_domain *nexus_domain,
184				   struct irq_domain **pci_domain)
185{
186	*pci_domain = pci_msi_create_irq_domain(nexus_domain->parent->fwnode,
187						&mbi_msi_domain_info,
188						nexus_domain);
189	if (!*pci_domain)
190		return -ENOMEM;
191
192	return 0;
193}
194#else
195static int mbi_allocate_pci_domain(struct irq_domain *nexus_domain,
196				   struct irq_domain **pci_domain)
197{
198	*pci_domain = NULL;
199	return 0;
200}
201#endif
202
203static void mbi_compose_mbi_msg(struct irq_data *data, struct msi_msg *msg)
204{
205	mbi_compose_msi_msg(data, msg);
206
207	msg[1].address_hi = upper_32_bits(mbi_phys_base + GICD_CLRSPI_NSR);
208	msg[1].address_lo = lower_32_bits(mbi_phys_base + GICD_CLRSPI_NSR);
209	msg[1].data = data->parent_data->hwirq;
210
211	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), &msg[1]);
212}
213
214/* Platform-MSI specific irqchip */
215static struct irq_chip mbi_pmsi_irq_chip = {
216	.name			= "pMSI",
217	.irq_set_type		= irq_chip_set_type_parent,
218	.irq_compose_msi_msg	= mbi_compose_mbi_msg,
219	.flags			= IRQCHIP_SUPPORTS_LEVEL_MSI,
220};
221
222static struct msi_domain_ops mbi_pmsi_ops = {
223};
224
225static struct msi_domain_info mbi_pmsi_domain_info = {
226	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
227		   MSI_FLAG_LEVEL_CAPABLE),
228	.ops	= &mbi_pmsi_ops,
229	.chip	= &mbi_pmsi_irq_chip,
230};
231
232static int mbi_allocate_domains(struct irq_domain *parent)
233{
234	struct irq_domain *nexus_domain, *pci_domain, *plat_domain;
235	int err;
236
237	nexus_domain = irq_domain_create_tree(parent->fwnode,
238					      &mbi_domain_ops, NULL);
239	if (!nexus_domain)
240		return -ENOMEM;
241
242	irq_domain_update_bus_token(nexus_domain, DOMAIN_BUS_NEXUS);
243	nexus_domain->parent = parent;
244
245	err = mbi_allocate_pci_domain(nexus_domain, &pci_domain);
246
247	plat_domain = platform_msi_create_irq_domain(parent->fwnode,
248						     &mbi_pmsi_domain_info,
249						     nexus_domain);
250
251	if (err || !plat_domain) {
252		if (plat_domain)
253			irq_domain_remove(plat_domain);
254		if (pci_domain)
255			irq_domain_remove(pci_domain);
256		irq_domain_remove(nexus_domain);
257		return -ENOMEM;
258	}
259
260	return 0;
261}
262
263int __init mbi_init(struct fwnode_handle *fwnode, struct irq_domain *parent)
264{
265	struct device_node *np;
266	const __be32 *reg;
267	int ret, n;
268
269	np = to_of_node(fwnode);
270
271	if (!of_property_read_bool(np, "msi-controller"))
272		return 0;
273
274	n = of_property_count_elems_of_size(np, "mbi-ranges", sizeof(u32));
275	if (n <= 0 || n % 2)
276		return -EINVAL;
277
278	mbi_range_nr = n / 2;
279	mbi_ranges = kcalloc(mbi_range_nr, sizeof(*mbi_ranges), GFP_KERNEL);
280	if (!mbi_ranges)
281		return -ENOMEM;
282
283	for (n = 0; n < mbi_range_nr; n++) {
284		ret = of_property_read_u32_index(np, "mbi-ranges", n * 2,
285						 &mbi_ranges[n].spi_start);
286		if (ret)
287			goto err_free_mbi;
288		ret = of_property_read_u32_index(np, "mbi-ranges", n * 2 + 1,
289						 &mbi_ranges[n].nr_spis);
290		if (ret)
291			goto err_free_mbi;
292
293		mbi_ranges[n].bm = kcalloc(BITS_TO_LONGS(mbi_ranges[n].nr_spis),
294					   sizeof(long), GFP_KERNEL);
295		if (!mbi_ranges[n].bm) {
296			ret = -ENOMEM;
297			goto err_free_mbi;
298		}
299		pr_info("MBI range [%d:%d]\n", mbi_ranges[n].spi_start,
300			mbi_ranges[n].spi_start + mbi_ranges[n].nr_spis - 1);
301	}
302
303	reg = of_get_property(np, "mbi-alias", NULL);
304	if (reg) {
305		mbi_phys_base = of_translate_address(np, reg);
306		if (mbi_phys_base == (phys_addr_t)OF_BAD_ADDR) {
307			ret = -ENXIO;
308			goto err_free_mbi;
309		}
310	} else {
311		struct resource res;
312
313		if (of_address_to_resource(np, 0, &res)) {
314			ret = -ENXIO;
315			goto err_free_mbi;
316		}
317
318		mbi_phys_base = res.start;
319	}
320
321	pr_info("Using MBI frame %pa\n", &mbi_phys_base);
322
323	ret = mbi_allocate_domains(parent);
324	if (ret)
325		goto err_free_mbi;
326
327	return 0;
328
329err_free_mbi:
330	if (mbi_ranges) {
331		for (n = 0; n < mbi_range_nr; n++)
332			kfree(mbi_ranges[n].bm);
333		kfree(mbi_ranges);
334	}
335
336	return ret;
337}