[PATCH 2/3] CXL: Snoop control

[Ryan Grimm]

Add mode to opal call.  SNOOP control turns CAPP unit snooping on/off.  This is
needed for the following reset patch, which turns snoops off in the CAPP
recovery path.

Signed-off-by: Ryan Grimm <grimm at linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/opal.h           | 12 ++++++++++++
 arch/powerpc/include/asm/pnv-pci.h        |  2 +-
 arch/powerpc/platforms/powernv/pci-ioda.c |  4 ++--
 drivers/misc/cxl/pci.c                    |  6 +++++-
 4 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 5d073e5..965e232 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -676,6 +676,18 @@ enum {
 	OPAL_PHB3_NUM_PEST_REGS = 256
 };
 
+/* CAPI modes for PHB */
+enum {
+        OPAL_PHB_CAPI_MODE_PCIE         = 0,
+        OPAL_PHB_CAPI_MODE_CAPI         = 1,
+        OPAL_PHB_CAPI_MODE_SNOOP_OFF    = 2,
+        OPAL_PHB_CAPI_MODE_SNOOP_ON     = 3,
+};
+
+/* CAPI feature flags (in device-tree) */
+#define OPAL_PHB_CAPI_FLAG_SNOOP_CONTROL        0x00000001
+#define OPAL_PHB_CAPI_FLAG_REVERT_TO_PCIE       0x00000002
+
 struct OpalIoPhbErrorCommon {
 	__be32 version;
 	__be32 ioType;
diff --git a/arch/powerpc/include/asm/pnv-pci.h b/arch/powerpc/include/asm/pnv-pci.h
index f09a22f..e18082c 100644
--- a/arch/powerpc/include/asm/pnv-pci.h
+++ b/arch/powerpc/include/asm/pnv-pci.h
@@ -13,7 +13,7 @@
 #include <linux/pci.h>
 #include <misc/cxl.h>
 
-int pnv_phb_to_cxl(struct pci_dev *dev);
+int pnv_phb_to_cxl(struct pci_dev *dev, uint64_t mode);
 int pnv_cxl_ioda_msi_setup(struct pci_dev *dev, unsigned int hwirq,
 			   unsigned int virq);
 int pnv_cxl_alloc_hwirqs(struct pci_dev *dev, int num);
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 468a0f2..acacc1b 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1363,7 +1363,7 @@ struct device_node *pnv_pci_to_phb_node(struct pci_dev *dev)
 }
 EXPORT_SYMBOL(pnv_pci_to_phb_node);
 
-int pnv_phb_to_cxl(struct pci_dev *dev)
+int pnv_phb_to_cxl(struct pci_dev *dev, uint64_t mode)
 {
 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
 	struct pnv_phb *phb = hose->private_data;
@@ -1376,7 +1376,7 @@ int pnv_phb_to_cxl(struct pci_dev *dev)
 
 	pe_info(pe, "Switching PHB to CXL\n");
 
-	rc = opal_pci_set_phb_cxl_mode(phb->opal_id, 1, pe->pe_number);
+	rc = opal_pci_set_phb_cxl_mode(phb->opal_id, mode, pe->pe_number);
 	if (rc)
 		dev_err(&dev->dev, "opal_pci_set_phb_cxl_mode failed: %i\n", rc);
 
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 26cacc1..9aa95f9 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -924,7 +924,7 @@ static struct cxl *cxl_init_adapter(struct pci_dev *dev)
 	if ((rc = init_implementation_adapter_regs(adapter, dev)))
 		goto err3;
 
-	if ((rc = pnv_phb_to_cxl(dev)))
+	if ((rc = pnv_phb_to_cxl(dev, OPAL_PHB_CAPI_MODE_CAPI)))
 		goto err3;
 
 	if ((rc = cxl_register_psl_err_irq(adapter)))
@@ -1009,6 +1009,10 @@ static int cxl_probe(struct pci_dev *dev, const struct pci_device_id *id)
 			dev_err(&dev->dev, "AFU %i failed to initialise: %i\n", slice, rc);
 	}
 
+	if ((rc = pnv_phb_to_cxl(dev, OPAL_PHB_CAPI_MODE_SNOOP_ON))) {
+		dev_err(&dev->dev, "enable capp snoops: %i\n", rc);
+	}
+
 	return 0;
 }
 
-- 
1.9.1