Re: drivers/net/can/kvaser_pciefd.c:801:17: sparse: sparse: cast removes address space '<asn:2>' of expression
From: Greg Ungerer
Date: Fri Jun 12 2020 - 11:33:25 EST
Hi Marc,
On 12/6/20 5:48 pm, Marc Kleine-Budde wrote:
the k-build robot found this sparse problem, triggered by building a CAN driver
for m68k. Is this a problem in our CAN driver or in the m68k headers?
I suspect a problem with the m68k (specifically non-mmu) headers.
On 6/12/20 7:28 AM, kernel test robot wrote:
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: b791d1bdf9212d944d749a5c7ff6febdba241771
commit: 26ad340e582d3d5958ed8456a1911d79cfb567b4 can: kvaser_pciefd: Add driver for Kvaser PCIEcan devices
date: 11 months ago
config: m68k-randconfig-s032-20200612 (attached as .config)
compiler: m68k-linux-gcc (GCC) 9.3.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.1-250-g42323db3-dirty
git checkout 26ad340e582d3d5958ed8456a1911d79cfb567b4
# save the attached .config to linux build tree
make W=1 C=1 ARCH=m68k CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>
sparse warnings: (new ones prefixed by >>)
drivers/net/can/kvaser_pciefd.c:801:17: sparse: sparse: cast removes address space '<asn:2>' of expression
drivers/net/can/kvaser_pciefd.c:805:17: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:77:24: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
I think this one is due to not forcing the volatile cast in __raw_write().
So this change will fix that:
diff --git a/arch/m68k/include/asm/io_no.h b/arch/m68k/include/asm/io_no.h
index 0498192e1d98..1bc739f1f1ad 100644
--- a/arch/m68k/include/asm/io_no.h
+++ b/arch/m68k/include/asm/io_no.h
@@ -14,15 +14,15 @@
* that behavior here first before we include asm-generic/io.h.
*/
#define __raw_readb(addr) \
- ({ unsigned char __v = (*(volatile unsigned char *) (addr)); __v; })
+ ({ u8 __v = (*(__force volatile u8 *) (addr)); __v; })
#define __raw_readw(addr) \
- ({ unsigned short __v = (*(volatile unsigned short *) (addr)); __v; })
+ ({ u16 __v = (*(__force volatile u16 *) (addr)); __v; })
#define __raw_readl(addr) \
- ({ unsigned int __v = (*(volatile unsigned int *) (addr)); __v; })
+ ({ u32 __v = (*(__force volatile u32 *) (addr)); __v; })
-#define __raw_writeb(b, addr) (void)((*(volatile unsigned char *) (addr)) = (b))
-#define __raw_writew(b, addr) (void)((*(volatile unsigned short *) (addr)) = (b))
-#define __raw_writel(b, addr) (void)((*(volatile unsigned int *) (addr)) = (b))
+#define __raw_writeb(b, addr) (void)((*(__force volatile u8 *) (addr)) = (b))
+#define __raw_writew(b, addr) (void)((*(__force volatile u16 *) (addr)) = (b))
+#define __raw_writel(b, addr) (void)((*(__force volatile u32 *) (addr)) = (b))
#if defined(CONFIG_COLDFIRE)
/*
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
This one I am not sure about yet.
Still investigating.
Regards
Greg
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:77:24: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:77:24: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:77:24: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast removes address space '<asn:2>' of expression
arch/m68k/include/asm/io_no.h:78:16: sparse: sparse: cast to restricted __le32
vim +801 drivers/net/can/kvaser_pciefd.c
764
765 static netdev_tx_t kvaser_pciefd_start_xmit(struct sk_buff *skb,
766 struct net_device *netdev)
767 {
768 struct kvaser_pciefd_can *can = netdev_priv(netdev);
769 unsigned long irq_flags;
770 struct kvaser_pciefd_tx_packet packet;
771 int nwords;
772 u8 count;
773
774 if (can_dropped_invalid_skb(netdev, skb))
775 return NETDEV_TX_OK;
776
777 nwords = kvaser_pciefd_prepare_tx_packet(&packet, can, skb);
778
779 spin_lock_irqsave(&can->echo_lock, irq_flags);
780
781 /* Prepare and save echo skb in internal slot */
782 can_put_echo_skb(skb, netdev, can->echo_idx);
783
784 /* Move echo index to the next slot */
785 can->echo_idx = (can->echo_idx + 1) % can->can.echo_skb_max;
786
787 /* Write header to fifo */
788 iowrite32(packet.header[0],
789 can->reg_base + KVASER_PCIEFD_KCAN_FIFO_REG);
790 iowrite32(packet.header[1],
791 can->reg_base + KVASER_PCIEFD_KCAN_FIFO_REG);
792
793 if (nwords) {
794 u32 data_last = ((u32 *)packet.data)[nwords - 1];
795
796 /* Write data to fifo, except last word */
797 iowrite32_rep(can->reg_base +
798 KVASER_PCIEFD_KCAN_FIFO_REG, packet.data,
799 nwords - 1);
800 /* Write last word to end of fifo */
> 801 __raw_writel(data_last, can->reg_base +
802 KVASER_PCIEFD_KCAN_FIFO_LAST_REG);
803 } else {
804 /* Complete write to fifo */
805 __raw_writel(0, can->reg_base +
806 KVASER_PCIEFD_KCAN_FIFO_LAST_REG);
807 }
808
809 count = ioread32(can->reg_base + KVASER_PCIEFD_KCAN_TX_NPACKETS_REG);
810 /* No room for a new message, stop the queue until at least one
811 * successful transmit
812 */
813 if (count >= KVASER_PCIEFD_CAN_TX_MAX_COUNT ||
814 can->can.echo_skb[can->echo_idx])
815 netif_stop_queue(netdev);
816
817 spin_unlock_irqrestore(&can->echo_lock, irq_flags);
818
819 return NETDEV_TX_OK;
820 }
821
---
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