[PATCH v10 15/26] sfc: obtain root decoder with enough HPA free space

[<alucerop@amd.com>]

From: Alejandro Lucero <alucerop@amd.com>

Asking for available HPA space is the previous step to try to obtain
an HPA range suitable to accel driver purposes.

Add this call to efx cxl initialization.

Make sfc cxl build dependent on CXL region.

Signed-off-by: Alejandro Lucero <alucerop@amd.com>
Reviewed-by: Martin Habets <habetsm.xilinx@gmail.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/net/ethernet/sfc/Kconfig   |  1 +
 drivers/net/ethernet/sfc/efx_cxl.c | 23 ++++++++++++++++++++++-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/sfc/Kconfig b/drivers/net/ethernet/sfc/Kconfig
index 0ce4a9cd5590..f2bc7f5fbccf 100644
--- a/drivers/net/ethernet/sfc/Kconfig
+++ b/drivers/net/ethernet/sfc/Kconfig
@@ -69,6 +69,7 @@ config SFC_CXL
 	bool "Solarflare SFC9100-family CXL support"
 	depends on SFC && CXL_BUS && !(SFC=y && CXL_BUS=m)
 	depends on CXL_BUS >= CXL_BUS
+	depends on CXL_REGION
 	default SFC
 
 source "drivers/net/ethernet/sfc/falcon/Kconfig"
diff --git a/drivers/net/ethernet/sfc/efx_cxl.c b/drivers/net/ethernet/sfc/efx_cxl.c
index 774e1cb4b1cb..a9ff84143e5d 100644
--- a/drivers/net/ethernet/sfc/efx_cxl.c
+++ b/drivers/net/ethernet/sfc/efx_cxl.c
@@ -25,6 +25,7 @@ int efx_cxl_init(struct efx_probe_data *probe_data)
 	struct pci_dev *pci_dev = efx->pci_dev;
 	DECLARE_BITMAP(expected, CXL_MAX_CAPS);
 	DECLARE_BITMAP(found, CXL_MAX_CAPS);
+	resource_size_t max_size;
 	struct mds_info sfc_mds_info;
 	struct efx_cxl *cxl;
 
@@ -102,6 +103,24 @@ int efx_cxl_init(struct efx_probe_data *probe_data)
 		goto err_regs;
 	}
 
+	cxl->cxlrd = cxl_get_hpa_freespace(cxl->cxlmd, 1,
+					   CXL_DECODER_F_RAM | CXL_DECODER_F_TYPE2,
+					   &max_size);
+
+	if (IS_ERR(cxl->cxlrd)) {
+		pci_err(pci_dev, "cxl_get_hpa_freespace failed\n");
+		rc = PTR_ERR(cxl->cxlrd);
+		goto err_regs;
+	}
+
+	if (max_size < EFX_CTPIO_BUFFER_SIZE) {
+		pci_err(pci_dev, "%s: not enough free HPA space %pap < %u\n",
+			__func__, &max_size, EFX_CTPIO_BUFFER_SIZE);
+		rc = -ENOSPC;
+		cxl_put_root_decoder(cxl->cxlrd);
+		goto err_regs;
+	}
+
 	probe_data->cxl = cxl;
 
 	return 0;
@@ -114,8 +133,10 @@ int efx_cxl_init(struct efx_probe_data *probe_data)
 
 void efx_cxl_exit(struct efx_probe_data *probe_data)
 {
-	if (probe_data->cxl)
+	if (probe_data->cxl) {
+		cxl_put_root_decoder(probe_data->cxl->cxlrd);
 		kfree(probe_data->cxl);
+	}
 }
 
 MODULE_IMPORT_NS("CXL");
-- 
2.17.1