[PATCH 07/10] Revert "powerpc/powernv: Add support for the cxl kernel api on the real phb"

[Frederic Barrat <fbarrat@linux.ibm.com>]

From: Alastair D'Silva <alastair@d-silva.org>

Remove abandonned capi support for the Mellanox CX4.

This reverts commit 4361b03430d685610e5feea3ec7846e8b9ae795f.
---
 arch/powerpc/include/asm/pnv-pci.h        |   7 --
 arch/powerpc/platforms/powernv/pci-cxl.c  | 115 ----------------------
 arch/powerpc/platforms/powernv/pci-ioda.c |  18 +---
 arch/powerpc/platforms/powernv/pci.h      |  13 ---
 4 files changed, 1 insertion(+), 152 deletions(-)

diff --git a/arch/powerpc/include/asm/pnv-pci.h b/arch/powerpc/include/asm/pnv-pci.h
index d2d8c28db336..7f627e3f4da4 100644
--- a/arch/powerpc/include/asm/pnv-pci.h
+++ b/arch/powerpc/include/asm/pnv-pci.h
@@ -50,13 +50,6 @@ int pnv_cxl_alloc_hwirq_ranges(struct cxl_irq_ranges *irqs,
 			       struct pci_dev *dev, int num);
 void pnv_cxl_release_hwirq_ranges(struct cxl_irq_ranges *irqs,
 				  struct pci_dev *dev);
-
-/* Support for the cxl kernel api on the real PHB (instead of vPHB) */
-int pnv_cxl_enable_phb_kernel_api(struct pci_controller *hose, bool enable);
-bool pnv_pci_on_cxl_phb(struct pci_dev *dev);
-struct cxl_afu *pnv_cxl_phb_to_afu(struct pci_controller *hose);
-void pnv_cxl_phb_set_peer_afu(struct pci_dev *dev, struct cxl_afu *afu);
-
 #endif
 
 struct pnv_php_slot {
diff --git a/arch/powerpc/platforms/powernv/pci-cxl.c b/arch/powerpc/platforms/powernv/pci-cxl.c
index c447b7f03c09..1b18111453d7 100644
--- a/arch/powerpc/platforms/powernv/pci-cxl.c
+++ b/arch/powerpc/platforms/powernv/pci-cxl.c
@@ -8,10 +8,8 @@
  */
 
 #include <linux/module.h>
-#include <asm/pci-bridge.h>
 #include <asm/pnv-pci.h>
 #include <asm/opal.h>
-#include <misc/cxl.h>
 
 #include "pci.h"
 
@@ -178,116 +176,3 @@ static inline int get_cxl_module(void)
 #else
 static inline int get_cxl_module(void) { return 0; }
 #endif
-
-/*
- * Sets flags and switches the controller ops to enable the cxl kernel api.
- * Originally the cxl kernel API operated on a virtual PHB, but certain cards
- * such as the Mellanox CX4 use a peer model instead and for these cards the
- * cxl kernel api will operate on the real PHB.
- */
-int pnv_cxl_enable_phb_kernel_api(struct pci_controller *hose, bool enable)
-{
-	struct pnv_phb *phb = hose->private_data;
-	int rc;
-
-	if (!enable) {
-		/*
-		 * Once cxl mode is enabled on the PHB, there is currently no
-		 * known safe method to disable it again, and trying risks a
-		 * checkstop. If we can find a way to safely disable cxl mode
-		 * in the future we can revisit this, but for now the only sane
-		 * thing to do is to refuse to disable cxl mode:
-		 */
-		return -EPERM;
-	}
-
-	/*
-	 * Hold a reference to the cxl module since several PHB operations now
-	 * depend on it, and it would be insane to allow it to be removed so
-	 * long as we are in this mode (and since we can't safely disable this
-	 * mode once enabled...).
-	 */
-	rc = get_cxl_module();
-	if (rc)
-		return rc;
-
-	phb->flags |= PNV_PHB_FLAG_CXL;
-	hose->controller_ops = pnv_cxl_cx4_ioda_controller_ops;
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(pnv_cxl_enable_phb_kernel_api);
-
-bool pnv_pci_on_cxl_phb(struct pci_dev *dev)
-{
-	struct pci_controller *hose = pci_bus_to_host(dev->bus);
-	struct pnv_phb *phb = hose->private_data;
-
-	return !!(phb->flags & PNV_PHB_FLAG_CXL);
-}
-EXPORT_SYMBOL_GPL(pnv_pci_on_cxl_phb);
-
-struct cxl_afu *pnv_cxl_phb_to_afu(struct pci_controller *hose)
-{
-	struct pnv_phb *phb = hose->private_data;
-
-	return (struct cxl_afu *)phb->cxl_afu;
-}
-EXPORT_SYMBOL_GPL(pnv_cxl_phb_to_afu);
-
-void pnv_cxl_phb_set_peer_afu(struct pci_dev *dev, struct cxl_afu *afu)
-{
-	struct pci_controller *hose = pci_bus_to_host(dev->bus);
-	struct pnv_phb *phb = hose->private_data;
-
-	phb->cxl_afu = afu;
-}
-EXPORT_SYMBOL_GPL(pnv_cxl_phb_set_peer_afu);
-
-/*
- * In the peer cxl model, the XSL/PSL is physical function 0, and will be used
- * by other functions on the device for memory access and interrupts. When the
- * other functions are enabled we explicitly take a reference on the cxl
- * function since they will use it, and allocate a default context associated
- * with that function just like the vPHB model of the cxl kernel API.
- */
-bool pnv_cxl_enable_device_hook(struct pci_dev *dev)
-{
-	struct pci_controller *hose = pci_bus_to_host(dev->bus);
-	struct pnv_phb *phb = hose->private_data;
-	struct cxl_afu *afu = phb->cxl_afu;
-
-	if (!pnv_pci_enable_device_hook(dev))
-		return false;
-
-
-	/* No special handling for the cxl function, which is always PF 0 */
-	if (PCI_FUNC(dev->devfn) == 0)
-		return true;
-
-	if (!afu) {
-		dev_WARN(&dev->dev, "Attempted to enable function > 0 on CXL PHB without a peer AFU\n");
-		return false;
-	}
-
-	dev_info(&dev->dev, "Enabling function on CXL enabled PHB with peer AFU\n");
-
-	/* Make sure the peer AFU can't go away while this device is active */
-	cxl_afu_get(afu);
-
-	return cxl_pci_associate_default_context(dev, afu);
-}
-
-void pnv_cxl_disable_device(struct pci_dev *dev)
-{
-	struct pci_controller *hose = pci_bus_to_host(dev->bus);
-	struct pnv_phb *phb = hose->private_data;
-	struct cxl_afu *afu = phb->cxl_afu;
-
-	/* No special handling for cxl function: */
-	if (PCI_FUNC(dev->devfn) == 0)
-		return;
-
-	cxl_pci_disable_device(dev);
-	cxl_afu_put(afu);
-}
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 41f8f0ff4a55..770c67c4e8f7 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -3575,7 +3575,7 @@ static resource_size_t pnv_pci_iov_resource_alignment(struct pci_dev *pdev,
 /* Prevent enabling devices for which we couldn't properly
  * assign a PE
  */
-bool pnv_pci_enable_device_hook(struct pci_dev *dev)
+static bool pnv_pci_enable_device_hook(struct pci_dev *dev)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;
@@ -3843,22 +3843,6 @@ static const struct pci_controller_ops pnv_npu_ocapi_ioda_controller_ops = {
 	.shutdown		= pnv_pci_ioda_shutdown,
 };
 
-#ifdef CONFIG_CXL_BASE
-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,
-	.enable_device_hook	= pnv_cxl_enable_device_hook,
-	.disable_device		= pnv_cxl_disable_device,
-	.release_device		= pnv_pci_release_device,
-	.window_alignment	= pnv_pci_window_alignment,
-	.setup_bridge		= pnv_pci_setup_bridge,
-	.reset_secondary_bus	= pnv_pci_reset_secondary_bus,
-	.dma_set_mask		= pnv_pci_ioda_dma_set_mask,
-	.dma_get_required_mask	= pnv_pci_ioda_dma_get_required_mask,
-	.shutdown		= pnv_pci_ioda_shutdown,
-};
-#endif
-
 static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 					 u64 hub_id, int ioda_type)
 {
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index ba41913c7e21..44dfbc37f547 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -88,7 +88,6 @@ struct pnv_ioda_pe {
 };
 
 #define PNV_PHB_FLAG_EEH	(1 << 0)
-#define PNV_PHB_FLAG_CXL	(1 << 1) /* Real PHB supporting the cxl kernel API */
 
 struct pnv_phb {
 	struct pci_controller	*hose;
@@ -194,9 +193,6 @@ struct pnv_phb {
 		bool nmmu_flush;
 	} npu;
 
-#ifdef CONFIG_CXL_BASE
-	struct cxl_afu *cxl_afu;
-#endif
 	int p2p_target_count;
 };
 
@@ -238,7 +234,6 @@ extern int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type);
 extern void pnv_teardown_msi_irqs(struct pci_dev *pdev);
 extern struct pnv_ioda_pe *pnv_ioda_get_pe(struct pci_dev *dev);
 extern void pnv_set_msi_irq_chip(struct pnv_phb *phb, unsigned int virq);
-extern bool pnv_pci_enable_device_hook(struct pci_dev *dev);
 extern void pnv_pci_ioda2_set_bypass(struct pnv_ioda_pe *pe, bool enable);
 extern int pnv_eeh_post_init(void);
 
@@ -262,12 +257,4 @@ extern void pnv_npu_take_ownership(struct pnv_ioda_pe *npe);
 extern void pnv_npu_release_ownership(struct pnv_ioda_pe *npe);
 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);
-
-
-/* phb ops (cxl switches these when enabling the kernel api on the phb) */
-extern const struct pci_controller_ops pnv_cxl_cx4_ioda_controller_ops;
-
 #endif /* __POWERNV_PCI_H */
-- 
2.17.1