Subject: [PATCH v2 02/10] Revert "cxl: Add support for interrupts on the Mellanox CX4"

From: Frederic Barrat <[email-masked]>
Date: Thu, 28 Jun 2018 12:05:01 +0200

From: Alastair D'Silva <[email-masked]>

Remove abandonned capi support for the Mellanox CX4.

This reverts commit a2f67d5ee8d950caaa7a6144cf0bfb256500b73e.

Signed-off-by: Alastair D'Silva <[email-masked]>
---
 arch/powerpc/platforms/powernv/pci-cxl.c  | 84 -----------------------
 arch/powerpc/platforms/powernv/pci-ioda.c |  4 --
 arch/powerpc/platforms/powernv/pci.h      |  2 -
 drivers/misc/cxl/api.c                    | 71 -------------------
 drivers/misc/cxl/base.c                   | 31 ---------
 drivers/misc/cxl/cxl.h                    |  4 --
 drivers/misc/cxl/main.c                   |  2 -
 include/misc/cxl-base.h                   |  4 --
 8 files changed, 202 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-cxl.c b/arch/powerpc/platforms/powernv/pci-cxl.c
index cee003de63af..c447b7f03c09 100644
--- a/arch/powerpc/platforms/powernv/pci-cxl.c
+++ b/arch/powerpc/platforms/powernv/pci-cxl.c
@@ -8,7 +8,6 @@
  */
 
 #include <linux/module.h>
-#include <linux/msi.h>
 #include <asm/pci-bridge.h>
 #include <asm/pnv-pci.h>
 #include <asm/opal.h>
@@ -292,86 +291,3 @@ void pnv_cxl_disable_device(struct pci_dev *dev)
 	cxl_pci_disable_device(dev);
 	cxl_afu_put(afu);
 }
-
-/*
- * This is a special version of pnv_setup_msi_irqs for cards in cxl mode. This
- * function handles setting up the IVTE entries for the XSL to use.
- *
- * We are currently not filling out the MSIX table, since the only currently
- * supported adapter (CX4) uses a custom MSIX table format in cxl mode and it
- * is up to their driver to fill that out. In the future we may fill out the
- * MSIX table (and change the IVTE entries to be an index to the MSIX table)
- * for adapters implementing the Full MSI-X mode described in the CAIA.
- */
-int pnv_cxl_cx4_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
-{
-	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
-	struct pnv_phb *phb = hose->private_data;
-	struct msi_desc *entry;
-	struct cxl_context *ctx = NULL;
-	unsigned int virq;
-	int hwirq;
-	int afu_irq = 0;
-	int rc;
-
-	if (WARN_ON(!phb) || !phb->msi_bmp.bitmap)
-		return -ENODEV;
-
-	if (pdev->no_64bit_msi && !phb->msi32_support)
-		return -ENODEV;
-
-	rc = cxl_cx4_setup_msi_irqs(pdev, nvec, type);
-	if (rc)
-		return rc;
-
-	for_each_pci_msi_entry(entry, pdev) {
-		if (!entry->msi_attrib.is_64 && !phb->msi32_support) {
-			pr_warn("%s: Supports only 64-bit MSIs\n",
-				pci_name(pdev));
-			return -ENXIO;
-		}
-
-		hwirq = cxl_next_msi_hwirq(pdev, &ctx, &afu_irq);
-		if (WARN_ON(hwirq <= 0))
-			return (hwirq ? hwirq : -ENOMEM);
-
-		virq = irq_create_mapping(NULL, hwirq);
-		if (!virq) {
-			pr_warn("%s: Failed to map cxl mode MSI to linux irq\n",
-				pci_name(pdev));
-			return -ENOMEM;
-		}
-
-		rc = pnv_cxl_ioda_msi_setup(pdev, hwirq, virq);
-		if (rc) {
-			pr_warn("%s: Failed to setup cxl mode MSI\n", pci_name(pdev));
-			irq_dispose_mapping(virq);
-			return rc;
-		}
-
-		irq_set_msi_desc(virq, entry);
-	}
-
-	return 0;
-}
-
-void pnv_cxl_cx4_teardown_msi_irqs(struct pci_dev *pdev)
-{
-	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
-	struct pnv_phb *phb = hose->private_data;
-	struct msi_desc *entry;
-	irq_hw_number_t hwirq;
-
-	if (WARN_ON(!phb))
-		return;
-
-	for_each_pci_msi_entry(entry, pdev) {
-		if (!entry->irq)
-			continue;
-		hwirq = virq_to_hw(entry->irq);
-		irq_set_msi_desc(entry->irq, NULL);
-		irq_dispose_mapping(entry->irq);
-	}
-
-	cxl_cx4_teardown_msi_irqs(pdev);
-}
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 5bd0eb6681bc..41f8f0ff4a55 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -3847,10 +3847,6 @@ static const struct pci_controller_ops pnv_npu_ocapi_ioda_controller_ops = {
 const struct pci_controller_ops pnv_cxl_cx4_ioda_controller_ops = {
 	.dma_dev_setup		= pnv_pci_dma_dev_setup,
 	.dma_bus_setup		= pnv_pci_dma_bus_setup,
-#ifdef CONFIG_PCI_MSI
-	.setup_msi_irqs		= pnv_cxl_cx4_setup_msi_irqs,
-	.teardown_msi_irqs	= pnv_cxl_cx4_teardown_msi_irqs,
-#endif
 	.enable_device_hook	= pnv_cxl_enable_device_hook,
 	.disable_device		= pnv_cxl_disable_device,
 	.release_device		= pnv_pci_release_device,
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index eada4b6068cb..ba41913c7e21 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -265,8 +265,6 @@ extern int pnv_npu2_init(struct pnv_phb *phb);
 /* cxl functions */
 extern bool pnv_cxl_enable_device_hook(struct pci_dev *dev);
 extern void pnv_cxl_disable_device(struct pci_dev *dev);
-extern int pnv_cxl_cx4_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type);
-extern void pnv_cxl_cx4_teardown_msi_irqs(struct pci_dev *pdev);

 /* phb ops (cxl switches these when enabling the kernel api on the phb) */
diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
index 21d620e29fea..2e5862b7a074 100644
--- a/drivers/misc/cxl/api.c
+++ b/drivers/misc/cxl/api.c
@@ -11,7 +11,6 @@
 #include <linux/slab.h>
 #include <linux/file.h>
 #include <misc/cxl.h>
-#include <linux/msi.h>
 #include <linux/module.h>
 #include <linux/mount.h>
 #include <linux/sched/mm.h>
@@ -595,73 +594,3 @@ int cxl_get_max_irqs_per_process(struct pci_dev *dev)
 	return afu->irqs_max;
 }
 EXPORT_SYMBOL_GPL(cxl_get_max_irqs_per_process);
-
-/*
- * This is a special interrupt allocation routine called from the PHB's MSI
- * setup function. When capi interrupts are allocated in this manner they must
- * still be associated with a running context, but since the MSI APIs have no
- * way to specify this we use the default context associated with the device.
- *
- * The Mellanox CX4 has a hardware limitation that restricts the maximum AFU
- * interrupt number, so in order to overcome this their driver informs us of
- * the restriction by setting the maximum interrupts per context, and we
- * allocate additional contexts as necessary so that we can keep the AFU
- * interrupt number within the supported range.
- */
-int _cxl_cx4_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
-{
-	struct cxl_context *ctx, *new_ctx, *default_ctx;
-	int remaining;
-	int rc;
-
-	ctx = default_ctx = cxl_get_context(pdev);
-	if (WARN_ON(!default_ctx))
-		return -ENODEV;
-
-	remaining = nvec;
-	while (remaining > 0) {
-		rc = cxl_allocate_afu_irqs(ctx, min(remaining, ctx->afu->irqs_max));
-		if (rc) {
-			pr_warn("%s: Failed to find enough free MSIs\n", pci_name(pdev));
-			return rc;
-		}
-		remaining -= ctx->afu->irqs_max;
-
-		if (ctx != default_ctx && default_ctx->status == STARTED) {
-			WARN_ON(cxl_start_context(ctx,
-				be64_to_cpu(default_ctx->elem->common.wed),
-				NULL));
-		}
-
-		if (remaining > 0) {
-			new_ctx = cxl_dev_context_init(pdev);
-			if (IS_ERR(new_ctx)) {
-				pr_warn("%s: Failed to allocate enough contexts for MSIs\n", pci_name(pdev));
-				return -ENOSPC;
-			}
-			list_add(&new_ctx->extra_irq_contexts, &ctx->extra_irq_contexts);
-			ctx = new_ctx;
-		}
-	}
-
-	return 0;
-}
-/* Exported via cxl_base */
-
-void _cxl_cx4_teardown_msi_irqs(struct pci_dev *pdev)
-{
-	struct cxl_context *ctx, *pos, *tmp;
-
-	ctx = cxl_get_context(pdev);
-	if (WARN_ON(!ctx))
-		return;
-
-	cxl_free_afu_irqs(ctx);
-	list_for_each_entry_safe(pos, tmp, &ctx->extra_irq_contexts, extra_irq_contexts) {
-		cxl_stop_context(pos);
-		cxl_free_afu_irqs(pos);
-		list_del(&pos->extra_irq_contexts);
-		cxl_release_context(pos);
-	}
-}
-/* Exported via cxl_base */
diff --git a/drivers/misc/cxl/base.c b/drivers/misc/cxl/base.c
index cd54ce6f6230..fe90f895bb10 100644
--- a/drivers/misc/cxl/base.c
+++ b/drivers/misc/cxl/base.c
@@ -158,37 +158,6 @@ int cxl_next_msi_hwirq(struct pci_dev *pdev, struct cxl_context **ctx, int *afu_
 }
 EXPORT_SYMBOL_GPL(cxl_next_msi_hwirq);
 
-int cxl_cx4_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
-{
-	int ret;
-	struct cxl_calls *calls;
-
-	calls = cxl_calls_get();
-	if (!calls)
-		return false;
-
-	ret = calls->cxl_cx4_setup_msi_irqs(pdev, nvec, type);
-
-	cxl_calls_put(calls);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(cxl_cx4_setup_msi_irqs);
-
-void cxl_cx4_teardown_msi_irqs(struct pci_dev *pdev)
-{
-	struct cxl_calls *calls;
-
-	calls = cxl_calls_get();
-	if (!calls)
-		return;
-
-	calls->cxl_cx4_teardown_msi_irqs(pdev);
-
-	cxl_calls_put(calls);
-}
-EXPORT_SYMBOL_GPL(cxl_cx4_teardown_msi_irqs);
-
 static int __init cxl_base_init(void)
 {
 	struct device_node *np;
diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index af8794719956..9688fe8b4d80 100644
--- a/drivers/misc/cxl/cxl.h
+++ b/drivers/misc/cxl/cxl.h
@@ -879,16 +879,12 @@ ssize_t cxl_pci_afu_read_err_buffer(struct cxl_afu *afu, char *buf,
 bool _cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu);
 void _cxl_pci_disable_device(struct pci_dev *dev);
 int _cxl_next_msi_hwirq(struct pci_dev *pdev, struct cxl_context **ctx, int *afu_irq);
-int _cxl_cx4_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type);
-void _cxl_cx4_teardown_msi_irqs(struct pci_dev *pdev);
 
 struct cxl_calls {
 	void (*cxl_slbia)(struct mm_struct *mm);
 	bool (*cxl_pci_associate_default_context)(struct pci_dev *dev, struct cxl_afu *afu);
 	void (*cxl_pci_disable_device)(struct pci_dev *dev);
 	int (*cxl_next_msi_hwirq)(struct pci_dev *pdev, struct cxl_context **ctx, int *afu_irq);
-	int (*cxl_cx4_setup_msi_irqs)(struct pci_dev *pdev, int nvec, int type);
-	void (*cxl_cx4_teardown_msi_irqs)(struct pci_dev *pdev);
 
 	struct module *owner;
 };
diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c
index c1ba0d42cbc8..59a904efd104 100644
--- a/drivers/misc/cxl/main.c
+++ b/drivers/misc/cxl/main.c
@@ -107,8 +107,6 @@ static struct cxl_calls cxl_calls = {
 	.cxl_pci_associate_default_context = _cxl_pci_associate_default_context,
 	.cxl_pci_disable_device = _cxl_pci_disable_device,
 	.cxl_next_msi_hwirq = _cxl_next_msi_hwirq,
-	.cxl_cx4_setup_msi_irqs = _cxl_cx4_setup_msi_irqs,
-	.cxl_cx4_teardown_msi_irqs = _cxl_cx4_teardown_msi_irqs,
 	.owner = THIS_MODULE,
 };
 
diff --git a/include/misc/cxl-base.h b/include/misc/cxl-base.h
index b2ebc91fe09a..bb7e629ae492 100644
--- a/include/misc/cxl-base.h
+++ b/include/misc/cxl-base.h
@@ -43,8 +43,6 @@ void cxl_afu_put(struct cxl_afu *afu);
 void cxl_slbia(struct mm_struct *mm);
 bool cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu);
 void cxl_pci_disable_device(struct pci_dev *dev);
-int cxl_cx4_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type);
-void cxl_cx4_teardown_msi_irqs(struct pci_dev *pdev);
 
 #else /* CONFIG_CXL_BASE */
 
@@ -54,8 +52,6 @@ static inline void cxl_afu_put(struct cxl_afu *afu) {}
 static inline void cxl_slbia(struct mm_struct *mm) {}
 static inline bool cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu) { return false; }
 static inline void cxl_pci_disable_device(struct pci_dev *dev) {}
-static inline int cxl_cx4_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type) { return -ENODEV; }
-static inline void cxl_cx4_teardown_msi_irqs(struct pci_dev *pdev) {}
 
 #endif /* CONFIG_CXL_BASE */
 
-- 
2.17.1