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PCI/MSI: Support allocating virtual MSI interrupts

For NTB devices, we want to be able to trigger MSI interrupts through a memory window. In these cases we may want to use more interrupts than the NTB PCI device has available in its MSI-X table. We allow for this by creating a new 'virtual' interrupt. These interrupts are allocated as usual but are not programmed into the MSI-X table (as there may not be space for them). The MSI address and data will then handled through an NTB MSI library introduced later in this series.

Logan Gunthorpe committed 7 years ago

Commit d7cc6091 parent a944ccc3 files · +62 −9Browse files

Unified · Split

3 files
  1. drivers/pci/msi.c +45 −9
  2. include/linux/msi.h +8 −0
  3. include/linux/pci.h +9 −0
drivers/pci/msi.c+45−9
@@ -192,6 +192,9 @@ static void msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag) · 191 unmodified lines
192 192
193static void __iomem *pci_msix_desc_addr(struct msi_desc *desc)193static void __iomem *pci_msix_desc_addr(struct msi_desc *desc)
194{194{
195 if (desc->msi_attrib.is_virtual)
196 return NULL;
197
195 return desc->mask_base +198 return desc->mask_base +
196 desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;199 desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
197}200}
@@ -206,14 +209,19 @@ static void __iomem *pci_msix_desc_addr(struct msi_desc *desc) · 8 unmodified lines
206u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag)209u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag)
207{210{
208 u32 mask_bits = desc->masked;211 u32 mask_bits = desc->masked;
212 void __iomem *desc_addr;
209 213
210 if (pci_msi_ignore_mask)214 if (pci_msi_ignore_mask)
211 return 0;215 return 0;
216 desc_addr = pci_msix_desc_addr(desc);
217 if (!desc_addr)
218 return 0;
212 219
213 mask_bits &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;220 mask_bits &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
214 if (flag)221 if (flag)
215 mask_bits |= PCI_MSIX_ENTRY_CTRL_MASKBIT;222 mask_bits |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
216 writel(mask_bits, pci_msix_desc_addr(desc) + PCI_MSIX_ENTRY_VECTOR_CTRL);223
224 writel(mask_bits, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
217 225
218 return mask_bits;226 return mask_bits;
219}227}
@@ -273,6 +281,11 @@ void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg) · 53 unmodified lines
273 if (entry->msi_attrib.is_msix) {281 if (entry->msi_attrib.is_msix) {
274 void __iomem *base = pci_msix_desc_addr(entry);282 void __iomem *base = pci_msix_desc_addr(entry);
275 283
284 if (!base) {
285 WARN_ON(1);
286 return;
287 }
288
276 msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);289 msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
277 msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);290 msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
278 msg->data = readl(base + PCI_MSIX_ENTRY_DATA);291 msg->data = readl(base + PCI_MSIX_ENTRY_DATA);
@@ -303,6 +316,9 @@ void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg) · 24 unmodified lines
303 } else if (entry->msi_attrib.is_msix) {316 } else if (entry->msi_attrib.is_msix) {
304 void __iomem *base = pci_msix_desc_addr(entry);317 void __iomem *base = pci_msix_desc_addr(entry);
305 318
319 if (!base)
320 goto skip;
321
306 writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR);322 writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR);
307 writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR);323 writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR);
308 writel(msg->data, base + PCI_MSIX_ENTRY_DATA);324 writel(msg->data, base + PCI_MSIX_ENTRY_DATA);
@@ -327,7 +343,13 @@ void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg) · 18 unmodified lines
327 msg->data);343 msg->data);
328 }344 }
329 }345 }
346
347skip:
330 entry->msg = *msg;348 entry->msg = *msg;
349
350 if (entry->write_msi_msg)
351 entry->write_msi_msg(entry, entry->write_msi_msg_data);
352
331}353}
332 354
333void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg)355void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg)
@@ -550,6 +572,7 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd) · 216 unmodified lines
550 572
551 entry->msi_attrib.is_msix = 0;573 entry->msi_attrib.is_msix = 0;
552 entry->msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT);574 entry->msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT);
575 entry->msi_attrib.is_virtual = 0;
553 entry->msi_attrib.entry_nr = 0;576 entry->msi_attrib.entry_nr = 0;
554 entry->msi_attrib.maskbit = !!(control & PCI_MSI_FLAGS_MASKBIT);577 entry->msi_attrib.maskbit = !!(control & PCI_MSI_FLAGS_MASKBIT);
555 entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */578 entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */
@@ -674,6 +697,7 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base, · 118 unmodified lines
674 struct irq_affinity_desc *curmsk, *masks = NULL;697 struct irq_affinity_desc *curmsk, *masks = NULL;
675 struct msi_desc *entry;698 struct msi_desc *entry;
676 int ret, i;699 int ret, i;
700 int vec_count = pci_msix_vec_count(dev);
677 701
678 if (affd)702 if (affd)
679 masks = irq_create_affinity_masks(nvec, affd);703 masks = irq_create_affinity_masks(nvec, affd);
@@ -696,6 +720,10 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base, · 16 unmodified lines
696 entry->msi_attrib.entry_nr = entries[i].entry;720 entry->msi_attrib.entry_nr = entries[i].entry;
697 else721 else
698 entry->msi_attrib.entry_nr = i;722 entry->msi_attrib.entry_nr = i;
723
724 entry->msi_attrib.is_virtual =
725 entry->msi_attrib.entry_nr >= vec_count;
726
699 entry->msi_attrib.default_irq = dev->irq;727 entry->msi_attrib.default_irq = dev->irq;
700 entry->mask_base = base;728 entry->mask_base = base;
701 729
@@ -714,12 +742,19 @@ static void msix_program_entries(struct pci_dev *dev, · 12 unmodified lines
714{742{
715 struct msi_desc *entry;743 struct msi_desc *entry;
716 int i = 0;744 int i = 0;
745 void __iomem *desc_addr;
717 746
718 for_each_pci_msi_entry(entry, dev) {747 for_each_pci_msi_entry(entry, dev) {
719 if (entries)748 if (entries)
720 entries[i++].vector = entry->irq;749 entries[i++].vector = entry->irq;
721 entry->masked = readl(pci_msix_desc_addr(entry) +750
722 PCI_MSIX_ENTRY_VECTOR_CTRL);751 desc_addr = pci_msix_desc_addr(entry);
752 if (desc_addr)
753 entry->masked = readl(desc_addr +
754 PCI_MSIX_ENTRY_VECTOR_CTRL);
755 else
756 entry->masked = 0;
757
723 msix_mask_irq(entry, 1);758 msix_mask_irq(entry, 1);
724 }759 }
725}760}
@@ -932,7 +967,7 @@ int pci_msix_vec_count(struct pci_dev *dev) · 206 unmodified lines
932EXPORT_SYMBOL(pci_msix_vec_count);967EXPORT_SYMBOL(pci_msix_vec_count);
933 968
934static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,969static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
935 int nvec, struct irq_affinity *affd)970 int nvec, struct irq_affinity *affd, int flags)
936{971{
937 int nr_entries;972 int nr_entries;
938 int i, j;973 int i, j;
@@ -943,7 +978,7 @@ static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, · 4 unmodified lines
943 nr_entries = pci_msix_vec_count(dev);978 nr_entries = pci_msix_vec_count(dev);
944 if (nr_entries < 0)979 if (nr_entries < 0)
945 return nr_entries;980 return nr_entries;
946 if (nvec > nr_entries)981 if (nvec > nr_entries && !(flags & PCI_IRQ_VIRTUAL))
947 return nr_entries;982 return nr_entries;
948 983
949 if (entries) {984 if (entries) {
@@ -1079,7 +1114,8 @@ EXPORT_SYMBOL(pci_enable_msi); · 129 unmodified lines
1079 1114
1080static int __pci_enable_msix_range(struct pci_dev *dev,1115static int __pci_enable_msix_range(struct pci_dev *dev,
1081 struct msix_entry *entries, int minvec,1116 struct msix_entry *entries, int minvec,
1082 int maxvec, struct irq_affinity *affd)1117 int maxvec, struct irq_affinity *affd,
1118 int flags)
1083{1119{
1084 int rc, nvec = maxvec;1120 int rc, nvec = maxvec;
1085 1121
@@ -1096,7 +1132,7 @@ static int __pci_enable_msix_range(struct pci_dev *dev, · 10 unmodified lines
1096 return -ENOSPC;1132 return -ENOSPC;
1097 }1133 }
1098 1134
1099 rc = __pci_enable_msix(dev, entries, nvec, affd);1135 rc = __pci_enable_msix(dev, entries, nvec, affd, flags);
1100 if (rc == 0)1136 if (rc == 0)
1101 return nvec;1137 return nvec;
1102 1138
@@ -1127,7 +1163,7 @@ static int __pci_enable_msix_range(struct pci_dev *dev, · 24 unmodified lines
1127int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,1163int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
1128 int minvec, int maxvec)1164 int minvec, int maxvec)
1129{1165{
1130 return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL);1166 return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL, 0);
1131}1167}
1132EXPORT_SYMBOL(pci_enable_msix_range);1168EXPORT_SYMBOL(pci_enable_msix_range);
1133 1169
@@ -1167,7 +1203,7 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, · 33 unmodified lines
1167 1203
1168 if (flags & PCI_IRQ_MSIX) {1204 if (flags & PCI_IRQ_MSIX) {
1169 msix_vecs = __pci_enable_msix_range(dev, NULL, min_vecs,1205 msix_vecs = __pci_enable_msix_range(dev, NULL, min_vecs,
1170 max_vecs, affd);1206 max_vecs, affd, flags);
1171 if (msix_vecs > 0)1207 if (msix_vecs > 0)
1172 return msix_vecs;1208 return msix_vecs;
1173 }1209 }
include/linux/msi.h+8−0
@@ -64,6 +64,10 @@ struct ti_sci_inta_msi_desc { · 63 unmodified lines
64 * @msg: The last set MSI message cached for reuse64 * @msg: The last set MSI message cached for reuse
65 * @affinity: Optional pointer to a cpu affinity mask for this descriptor65 * @affinity: Optional pointer to a cpu affinity mask for this descriptor
66 *66 *
67 * @write_msi_msg: Callback that may be called when the MSI message
68 * address or data changes
69 * @write_msi_msg_data: Data parameter for the callback.
70 *
67 * @masked: [PCI MSI/X] Mask bits71 * @masked: [PCI MSI/X] Mask bits
68 * @is_msix: [PCI MSI/X] True if MSI-X72 * @is_msix: [PCI MSI/X] True if MSI-X
69 * @multiple: [PCI MSI/X] log2 num of messages allocated73 * @multiple: [PCI MSI/X] log2 num of messages allocated
@@ -90,6 +94,9 @@ struct msi_desc { · 20 unmodified lines
90 const void *iommu_cookie;94 const void *iommu_cookie;
91#endif95#endif
92 96
97 void (*write_msi_msg)(struct msi_desc *entry, void *data);
98 void *write_msi_msg_data;
99
93 union {100 union {
94 /* PCI MSI/X specific data */101 /* PCI MSI/X specific data */
95 struct {102 struct {
@@ -100,6 +107,7 @@ struct msi_desc { · 4 unmodified lines
100 u8 multi_cap : 3;107 u8 multi_cap : 3;
101 u8 maskbit : 1;108 u8 maskbit : 1;
102 u8 is_64 : 1;109 u8 is_64 : 1;
110 u8 is_virtual : 1;
103 u16 entry_nr;111 u16 entry_nr;
104 unsigned default_irq;112 unsigned default_irq;
105 } msi_attrib;113 } msi_attrib;
include/linux/pci.h+9−0
@@ -1362,6 +1362,15 @@ int pci_set_vga_state(struct pci_dev *pdev, bool decode, · 1361 unmodified lines
1362#define PCI_IRQ_MSI (1 << 1) /* Allow MSI interrupts */1362#define PCI_IRQ_MSI (1 << 1) /* Allow MSI interrupts */
1363#define PCI_IRQ_MSIX (1 << 2) /* Allow MSI-X interrupts */1363#define PCI_IRQ_MSIX (1 << 2) /* Allow MSI-X interrupts */
1364#define PCI_IRQ_AFFINITY (1 << 3) /* Auto-assign affinity */1364#define PCI_IRQ_AFFINITY (1 << 3) /* Auto-assign affinity */
1365
1366/*
1367 * Virtual interrupts allow for more interrupts to be allocated
1368 * than the device has interrupts for. These are not programmed
1369 * into the device's MSI-X table and must be handled by some
1370 * other driver means.
1371 */
1372#define PCI_IRQ_VIRTUAL (1 << 4)
1373
1365#define PCI_IRQ_ALL_TYPES \1374#define PCI_IRQ_ALL_TYPES \
1366 (PCI_IRQ_LEGACY | PCI_IRQ_MSI | PCI_IRQ_MSIX)1375 (PCI_IRQ_LEGACY | PCI_IRQ_MSI | PCI_IRQ_MSIX)
1367 1376

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