XDMA: fix build for Centos and RHEL

Change the checks for kernel versions to include checks for RHEL
versions in case they are present.
Add HAS_MMIOWB, ACCESS_OK_2_ARGS, HAS_WAKE_UP, and HAS_WAKE_UP_ONE
and use them

XDMA/linux-kernel/libxdma/libxdma.c

@@ -56,7 +56,7 @@ MODULE_PARM_DESC(desc_blen_max,
 #define XDMA_PERF_NUM_DESC 128
 
 /* Kernel version adaptative code */
-#if KERNEL_VERSION(4, 19, 0) <= LINUX_VERSION_CODE
+#if HAS_SWAKE_UP_ONE
 /* since 4.18, using simple wait queues is not recommended
  * except for realtime constraint (see swait.h comments)
  * and will likely be removed in future kernel versions
@@ -64,7 +64,7 @@ MODULE_PARM_DESC(desc_blen_max,
 #define xlx_wake_up	swake_up_one
 #define xlx_wait_event_interruptible_timeout \
 			swait_event_interruptible_timeout_exclusive
-#elif KERNEL_VERSION(4, 6, 0) <= LINUX_VERSION_CODE
+#elif HAS_SWAKE_UP
 #define xlx_wake_up	swake_up
 #define xlx_wait_event_interruptible_timeout \
 			swait_event_interruptible_timeout
@@ -696,7 +696,7 @@ static struct xdma_transfer *engine_start(struct xdma_engine *engine)
 	dbg_tfr("ioread32(0x%p) (dummy read flushes writes).\n",
 		&engine->regs->status);
 
-#if KERNEL_VERSION(5, 1, 0) >= LINUX_VERSION_CODE
+#if HAS_MMIOWB
 	mmiowb();
 #endif
 
@@ -3152,7 +3152,7 @@ static int transfer_init(struct xdma_engine *engine,
 	/* lock the engine state */
 	spin_lock_irqsave(&engine->lock, flags);
 	/* initialize wait queue */
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0)
+#if HAS_SWAKE_UP
 	init_swait_queue_head(&xfer->wq);
 #else
 	init_waitqueue_head(&xfer->wq);
@@ -3229,7 +3229,7 @@ static int transfer_init_cyclic(struct xdma_engine *engine,
 	memset(xfer, 0, sizeof(*xfer));
 
 	/* initialize wait queue */
-#if KERNEL_VERSION(4, 6, 0) <= LINUX_VERSION_CODE
+#if HAS_SWAKE_UP
 	init_swait_queue_head(&xfer->wq);
 #else
 	init_waitqueue_head(&xfer->wq);
@@ -4004,7 +4004,7 @@ int xdma_performance_submit(struct xdma_dev *xdev, struct xdma_engine *engine)
 	transfer->cyclic = 1;
 
 	/* initialize wait queue */
-#if KERNEL_VERSION(4, 6, 0) <= LINUX_VERSION_CODE
+#if HAS_SWAKE_UP
 	init_swait_queue_head(&transfer->wq);
 #else
 	init_waitqueue_head(&transfer->wq);
@@ -4084,7 +4084,7 @@ static struct xdma_dev *alloc_dev_instance(struct pci_dev *pdev)
 		spin_lock_init(&engine->lock);
 		mutex_init(&engine->desc_lock);
 		INIT_LIST_HEAD(&engine->transfer_list);
-#if KERNEL_VERSION(4, 6, 0) <= LINUX_VERSION_CODE
+#if HAS_SWAKE_UP
 		init_swait_queue_head(&engine->shutdown_wq);
 		init_swait_queue_head(&engine->xdma_perf_wq);
 #else
@@ -4098,7 +4098,7 @@ static struct xdma_dev *alloc_dev_instance(struct pci_dev *pdev)
 		spin_lock_init(&engine->lock);
 		mutex_init(&engine->desc_lock);
 		INIT_LIST_HEAD(&engine->transfer_list);
-#if KERNEL_VERSION(4, 6, 0) <= LINUX_VERSION_CODE
+#if HAS_SWAKE_UP
 		init_swait_queue_head(&engine->shutdown_wq);
 		init_swait_queue_head(&engine->xdma_perf_wq);
 #else

XDMA/linux-kernel/libxdma/libxdma.h

@@ -31,9 +31,32 @@
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <linux/workqueue.h>
-#if	KERNEL_VERSION(4, 6, 0) <= LINUX_VERSION_CODE
+
+/* Add compatibility checking for RHEL versions */
+#if defined(RHEL_RELEASE_CODE)
+#	define ACCESS_OK_2_ARGS (RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(8, 0))
+#else
+#	define ACCESS_OK_2_ARGS (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0))
+#endif
+
+#if defined(RHEL_RELEASE_CODE)
+#	define HAS_MMIOWB (RHEL_RELEASE_CODE <= RHEL_RELEASE_VERSION(8, 0))
+#else
+#	define HAS_MMIOWB (LINUX_VERSION_CODE <= KERNEL_VERSION(5, 1, 0))
+#endif
+
+#if defined(RHEL_RELEASE_CODE)
+#	define HAS_SWAKE_UP_ONE (RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(8, 0))
+#	define HAS_SWAKE_UP (RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(8, 0))
+#else
+#	define HAS_SWAKE_UP_ONE (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 19, 0))
+#	define HAS_SWAKE_UP (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0))
+#endif
+
+#if	HAS_SWAKE_UP
 #include <linux/swait.h>
 #endif
+
 /*
  *  if the config bar is fixed, the driver does not neeed to search through
  *  all of the bars
@@ -417,7 +440,7 @@ struct xdma_transfer {
 	int desc_num;			/* number of descriptors in transfer */
 	int desc_index;			/* index for 1st desc. in transfer */
 	enum dma_data_direction dir;
-#if	KERNEL_VERSION(4, 6, 0) <= LINUX_VERSION_CODE
+#if	HAS_SWAKE_UP
 	struct swait_queue_head wq;
 #else
 	wait_queue_head_t wq;		/* wait queue for transfer completion */
@@ -503,7 +526,7 @@ struct xdma_engine {
 	dma_addr_t poll_mode_bus;	/* bus addr for descriptor writeback */
 
 	/* Members associated with interrupt mode support */
-#if	KERNEL_VERSION(4, 6, 0) <= LINUX_VERSION_CODE
+#if	HAS_SWAKE_UP
 	struct swait_queue_head shutdown_wq;
 #else
 	wait_queue_head_t shutdown_wq;	/* wait queue for shutdown sync */
@@ -522,7 +545,7 @@ struct xdma_engine {
 
 	/* for performance test support */
 	struct xdma_performance_ioctl *xdma_perf;	/* perf test control */
-#if	KERNEL_VERSION(4, 6, 0) <= LINUX_VERSION_CODE
+#if	HAS_SWAKE_UP
 	struct swait_queue_head xdma_perf_wq;
 #else
 	wait_queue_head_t xdma_perf_wq;	/* Perf test sync */

XDMA/linux-kernel/xdma/cdev_ctrl.c

@@ -24,7 +24,7 @@
 #include "xdma_cdev.h"
 #include "cdev_ctrl.h"
 
-#if KERNEL_VERSION(5, 0, 0) <= LINUX_VERSION_CODE
+#if ACCESS_OK_2_ARGS
 #define xlx_access_ok(X, Y, Z) access_ok(Y, Z)
 #else
 #define xlx_access_ok(X, Y, Z) access_ok(X, Y, Z)

XDMA/linux-kernel/xdma/cdev_sgdma.c

@@ -611,7 +611,7 @@ static int ioctl_do_perf_start(struct xdma_engine *engine, unsigned long arg)
 	enable_perf(engine);
 	dbg_perf("transfer_size = %d\n", engine->xdma_perf->transfer_size);
 	/* initialize wait queue */
-#if KERNEL_VERSION(4, 6, 0) <= LINUX_VERSION_CODE
+#if HAS_SWAKE_UP
 	init_swait_queue_head(&engine->xdma_perf_wq);
 #else
 	init_waitqueue_head(&engine->xdma_perf_wq);

XDMA/linux-kernel/xdma/cdev_xvc.c

@@ -213,7 +213,7 @@ static long xvc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		pr_info("copy back tdo_buf failed: %d/%u.\n", rv, total_bytes);
 
 unlock:
-#if KERNEL_VERSION(5, 1, 0) >= LINUX_VERSION_CODE
+#if HAS_MMIOWB
 	mmiowb();
 #endif
 	spin_unlock(&xcdev->lock);