cxl: Isolate a few bare-metal-specific calls

BugLink: http://bugs.launchpad.net/bugs/1588468

A few functions are mostly common between bare-metal and guest and
just need minor tuning. To avoid crowding the backend API, introduce a
few 'if' based on the CPU being in HV mode.
Co-authored-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from commit ea2d1f95)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/misc/cxl/context.c

@@ -95,7 +95,8 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master,
 		return i;
 
 	ctx->pe = i;
-	ctx->elem = &ctx->afu->spa[i];
+	if (cpu_has_feature(CPU_FTR_HVMODE))
+		ctx->elem = &ctx->afu->spa[i];
 	ctx->pe_inserted = false;
 
 	/*

drivers/misc/cxl/cxl.h

@@ -561,8 +561,11 @@ static inline bool cxl_adapter_link_ok(struct cxl *cxl)
 {
 	struct pci_dev *pdev;
 
-	pdev = to_pci_dev(cxl->dev.parent);
-	return !pci_channel_offline(pdev);
+	if (cpu_has_feature(CPU_FTR_HVMODE)) {
+		pdev = to_pci_dev(cxl->dev.parent);
+		return !pci_channel_offline(pdev);
+	}
+	return true;
 }
 
 static inline void __iomem *_cxl_p1_addr(struct cxl *cxl, cxl_p1_reg_t reg)

drivers/misc/cxl/debugfs.c

@@ -118,6 +118,10 @@ void cxl_debugfs_afu_remove(struct cxl_afu *afu)
 int __init cxl_debugfs_init(void)
 {
 	struct dentry *ent;
+
+	if (!cpu_has_feature(CPU_FTR_HVMODE))
+		return 0;
+
 	ent = debugfs_create_dir("cxl", NULL);
 	if (IS_ERR(ent))
 		return PTR_ERR(ent);

drivers/misc/cxl/fault.c

@@ -254,14 +254,17 @@ void cxl_handle_fault(struct work_struct *fault_work)
 	u64 dar = ctx->dar;
 	struct mm_struct *mm = NULL;
 
-	if (cxl_p2n_read(ctx->afu, CXL_PSL_DSISR_An) != dsisr ||
-	    cxl_p2n_read(ctx->afu, CXL_PSL_DAR_An) != dar ||
-	    cxl_p2n_read(ctx->afu, CXL_PSL_PEHandle_An) != ctx->pe) {
-		/* Most likely explanation is harmless - a dedicated process
-		 * has detached and these were cleared by the PSL purge, but
-		 * warn about it just in case */
-		dev_notice(&ctx->afu->dev, "cxl_handle_fault: Translation fault regs changed\n");
-		return;
+	if (cpu_has_feature(CPU_FTR_HVMODE)) {
+		if (cxl_p2n_read(ctx->afu, CXL_PSL_DSISR_An) != dsisr ||
+		    cxl_p2n_read(ctx->afu, CXL_PSL_DAR_An) != dar ||
+		    cxl_p2n_read(ctx->afu, CXL_PSL_PEHandle_An) != ctx->pe) {
+			/* Most likely explanation is harmless - a dedicated
+			 * process has detached and these were cleared by the
+			 * PSL purge, but warn about it just in case
+			 */
+			dev_notice(&ctx->afu->dev, "cxl_handle_fault: Translation fault regs changed\n");
+			return;
+		}
 	}
 
 	/* Early return if the context is being / has been detached */