cxl: Support the cxl kernel API from a guest

Like on bare-metal, the cxl driver creates a virtual PHB and a pci
device for the AFU. The configuration space of the device is mapped to
the configuration record of the AFU.

Reuse the code defined in afu_cr_read8|16|32() when reading the
configuration space of the AFU device.

Even though the (virtual) AFU device is a pci device, the adapter is
not. So a driver using the cxl kernel API cannot read the VPD of the
adapter through the usual PCI interface. Therefore, we add a call to
the cxl kernel API:
ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count);

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>

1 files changed, 46 insertions, 17 deletions

diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
index 325f9578a556..75ec2f9afe71 100644
--- a/drivers/misc/cxl/api.c
+++ b/drivers/misc/cxl/api.c
@@ -89,28 +89,11 @@ int cxl_release_context(struct cxl_context *ctx)
 }
 EXPORT_SYMBOL_GPL(cxl_release_context);
 
-int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num)
-{
-	if (num == 0)
-		num = ctx->afu->pp_irqs;
-	return afu_allocate_irqs(ctx, num);
-}
-EXPORT_SYMBOL_GPL(cxl_allocate_afu_irqs);
-
-void cxl_free_afu_irqs(struct cxl_context *ctx)
-{
-	afu_irq_name_free(ctx);
-	cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter);
-}
-EXPORT_SYMBOL_GPL(cxl_free_afu_irqs);
-
 static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num)
 {
 	__u16 range;
 	int r;
 
-	WARN_ON(num == 0);
-
 	for (r = 0; r < CXL_IRQ_RANGES; r++) {
 		range = ctx->irqs.range[r];
 		if (num < range) {
@@ -121,6 +104,44 @@ static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num)
 	return 0;
 }
 
+int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num)
+{
+	int res;
+	irq_hw_number_t hwirq;
+
+	if (num == 0)
+		num = ctx->afu->pp_irqs;
+	res = afu_allocate_irqs(ctx, num);
+	if (!res && !cpu_has_feature(CPU_FTR_HVMODE)) {
+		/* In a guest, the PSL interrupt is not multiplexed. It was
+		 * allocated above, and we need to set its handler
+		 */
+		hwirq = cxl_find_afu_irq(ctx, 0);
+		if (hwirq)
+			cxl_map_irq(ctx->afu->adapter, hwirq, cxl_ops->psl_interrupt, ctx, "psl");
+	}
+	return res;
+}
+EXPORT_SYMBOL_GPL(cxl_allocate_afu_irqs);
+
+void cxl_free_afu_irqs(struct cxl_context *ctx)
+{
+	irq_hw_number_t hwirq;
+	unsigned int virq;
+
+	if (!cpu_has_feature(CPU_FTR_HVMODE)) {
+		hwirq = cxl_find_afu_irq(ctx, 0);
+		if (hwirq) {
+			virq = irq_find_mapping(NULL, hwirq);
+			if (virq)
+				cxl_unmap_irq(virq, ctx);
+		}
+	}
+	afu_irq_name_free(ctx);
+	cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter);
+}
+EXPORT_SYMBOL_GPL(cxl_free_afu_irqs);
+
 int cxl_map_afu_irq(struct cxl_context *ctx, int num,
 		    irq_handler_t handler, void *cookie, char *name)
 {
@@ -356,3 +377,11 @@ void cxl_perst_reloads_same_image(struct cxl_afu *afu,
 	afu->adapter->perst_same_image = perst_reloads_same_image;
 }
 EXPORT_SYMBOL_GPL(cxl_perst_reloads_same_image);
+
+ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count)
+{
+	struct cxl_afu *afu = cxl_pci_to_afu(dev);
+
+	return cxl_ops->read_adapter_vpd(afu->adapter, buf, count);
+}
+EXPORT_SYMBOL_GPL(cxl_read_adapter_vpd);