cxl: Support to flash a new image on the adapter from a guest

The new flash.c file contains the logic to flash a new image on the
adapter, through a hcall. It is an iterative process, with chunks of
data of 1M at a time. There are also 2 phases: write and verify. The
flash operation itself is driven from a user-land tool.
Once flashing is successful, an rtas call is made to update the device
tree with the new properties values for the adapter and the AFU(s)

Add a new char device for the adapter, so that the flash tool can
access the card, even if there is no valid AFU on it.

Co-authored-by: Frederic Barrat <fbarrat@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, 7 insertions, 4 deletions

diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c
index df4d49a6c67a..e16046292dd6 100644
--- a/drivers/misc/cxl/file.c
+++ b/drivers/misc/cxl/file.c
@@ -26,9 +26,7 @@
 #include "trace.h"
 
 #define CXL_NUM_MINORS 256 /* Total to reserve */
-#define CXL_DEV_MINORS 13   /* 1 control + 4 AFUs * 3 (dedicated/master/shared) */
 
-#define CXL_CARD_MINOR(adapter) (adapter->adapter_num * CXL_DEV_MINORS)
 #define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice))
 #define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1)
 #define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2)
@@ -36,7 +34,6 @@
 #define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu))
 #define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu))
 
-#define CXL_DEVT_ADAPTER(dev) (MINOR(dev) / CXL_DEV_MINORS)
 #define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)
 
 #define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)
@@ -446,7 +443,8 @@ static const struct file_operations afu_master_fops = {
 
 static char *cxl_devnode(struct device *dev, umode_t *mode)
 {
-        if (CXL_DEVT_IS_CARD(dev->devt)) {
+        if (cpu_has_feature(CPU_FTR_HVMODE) &&
+            CXL_DEVT_IS_CARD(dev->devt)) {
                 /*
                  * These minor numbers will eventually be used to program the
                  * PSL and AFUs once we have dynamic reprogramming support
@@ -547,6 +545,11 @@ int cxl_register_adapter(struct cxl *adapter)
         return device_register(&adapter->dev);
 }
 
+dev_t cxl_get_dev(void)
+{
+        return cxl_dev;
+}
+
 int __init cxl_file_init(void)
 {
         int rc;