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Message-ID: <9b599221-3c15-909c-168a-766c554827d9@linux-m68k.org>
Date: Sat, 13 Jun 2020 01:33:16 +1000
From: Greg Ungerer <gerg@...ux-m68k.org>
To: Marc Kleine-Budde <mkl@...gutronix.de>,
kernel test robot <lkp@...el.com>,
Henning Colliander <henning.colliander@...dente.se>
Cc: kbuild-all@...ts.01.org, linux-kernel@...r.kernel.org,
Jimmy Assarsson <extja@...ser.com>,
Christer Beskow <chbe@...ser.com>
Subject: Re: drivers/net/can/kvaser_pciefd.c:801:17: sparse: sparse: cast
removes address space '<asn:2>' of expression
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@...el.com>
>>
>>
>> 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
>>
>> ---
>> 0-DAY CI Kernel Test Service, Intel Corporation
>> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
>>
>
>
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