soc: fsl: qe: avoid IS_ERR_VALUE in ucc_fast.c

When building this on a 64-bit platform gcc rightly warns that the
error checking is broken (-ENOMEM stored in an u32 does not compare
greater than (unsigned long)-MAX_ERRNO). Instead, change the
ucc_fast_[tr]x_virtual_fifo_base_offset members to s32 and use an
ordinary check-for-negative. Also, this avoids treating 0 as "this
cannot have been returned from qe_muram_alloc() so don't free it".

Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

drivers/soc/fsl/qe/ucc_fast.c

@@ -197,6 +197,8 @@ int ucc_fast_init(struct ucc_fast_info * uf_info, struct ucc_fast_private ** ucc
 			__func__);
 		return -ENOMEM;
 	}
+	uccf->ucc_fast_tx_virtual_fifo_base_offset = -1;
+	uccf->ucc_fast_rx_virtual_fifo_base_offset = -1;
 
 	/* Fill fast UCC structure */
 	uccf->uf_info = uf_info;
@@ -265,10 +267,9 @@ int ucc_fast_init(struct ucc_fast_info * uf_info, struct ucc_fast_private ** ucc
 	/* Allocate memory for Tx Virtual Fifo */
 	uccf->ucc_fast_tx_virtual_fifo_base_offset =
 	    qe_muram_alloc(uf_info->utfs, UCC_FAST_VIRT_FIFO_REGS_ALIGNMENT);
-	if (IS_ERR_VALUE(uccf->ucc_fast_tx_virtual_fifo_base_offset)) {
+	if (uccf->ucc_fast_tx_virtual_fifo_base_offset < 0) {
 		printk(KERN_ERR "%s: cannot allocate MURAM for TX FIFO\n",
 			__func__);
-		uccf->ucc_fast_tx_virtual_fifo_base_offset = 0;
 		ucc_fast_free(uccf);
 		return -ENOMEM;
 	}
@@ -278,10 +279,9 @@ int ucc_fast_init(struct ucc_fast_info * uf_info, struct ucc_fast_private ** ucc
 		qe_muram_alloc(uf_info->urfs +
 			   UCC_FAST_RECEIVE_VIRTUAL_FIFO_SIZE_FUDGE_FACTOR,
 			   UCC_FAST_VIRT_FIFO_REGS_ALIGNMENT);
-	if (IS_ERR_VALUE(uccf->ucc_fast_rx_virtual_fifo_base_offset)) {
+	if (uccf->ucc_fast_rx_virtual_fifo_base_offset < 0) {
 		printk(KERN_ERR "%s: cannot allocate MURAM for RX FIFO\n",
 			__func__);
-		uccf->ucc_fast_rx_virtual_fifo_base_offset = 0;
 		ucc_fast_free(uccf);
 		return -ENOMEM;
 	}
@@ -384,11 +384,8 @@ void ucc_fast_free(struct ucc_fast_private * uccf)
 	if (!uccf)
 		return;
 
-	if (uccf->ucc_fast_tx_virtual_fifo_base_offset)
-		qe_muram_free(uccf->ucc_fast_tx_virtual_fifo_base_offset);
-
-	if (uccf->ucc_fast_rx_virtual_fifo_base_offset)
-		qe_muram_free(uccf->ucc_fast_rx_virtual_fifo_base_offset);
+	qe_muram_free(uccf->ucc_fast_tx_virtual_fifo_base_offset);
+	qe_muram_free(uccf->ucc_fast_rx_virtual_fifo_base_offset);
 
 	if (uccf->uf_regs)
 		iounmap(uccf->uf_regs);

include/soc/fsl/qe/ucc_fast.h

@@ -188,9 +188,9 @@ struct ucc_fast_private {
 	int stopped_tx;		/* Whether channel has been stopped for Tx
 				   (STOP_TX, etc.) */
 	int stopped_rx;		/* Whether channel has been stopped for Rx */
-	u32 ucc_fast_tx_virtual_fifo_base_offset;/* pointer to base of Tx
+	s32 ucc_fast_tx_virtual_fifo_base_offset;/* pointer to base of Tx
 						    virtual fifo */
-	u32 ucc_fast_rx_virtual_fifo_base_offset;/* pointer to base of Rx
+	s32 ucc_fast_rx_virtual_fifo_base_offset;/* pointer to base of Rx
 						    virtual fifo */
 #ifdef STATISTICS
 	u32 tx_frames;		/* Transmitted frames counter. */