MIPS: BCM63XX: provide DMA masks for ethernet devices [Linux 5.0]

MIPS: BCM63XX: provide DMA masks for ethernet devices [Linux 5.0]

This Linux kernel change "MIPS: BCM63XX: provide DMA masks for ethernet devices" is included in the Linux 5.0 release. This change is authored by Jonas Gorski <jonas.gorski [at] gmail.com> on Thu Feb 21 10:56:42 2019 +0100. The commit for this change in Linux stable tree is 18836b4 (patch).

MIPS: BCM63XX: provide DMA masks for ethernet devices

The switch to the generic dma ops made dma masks mandatory, breaking
devices having them not set. In case of bcm63xx, it broke ethernet with
the following warning when trying to up the device:

[    2.633123] ------------[ cut here ]------------
[    2.637949] WARNING: CPU: 0 PID: 325 at ./include/linux/dma-mapping.h:516 bcm_enetsw_open+0x160/0xbbc
[    2.647423] Modules linked in: gpio_button_hotplug
[    2.652361] CPU: 0 PID: 325 Comm: ip Not tainted 4.19.16 #0
[    2.658080] Stack : 80520000 804cd3ec 00000000 00000000 804ccc00 87085bdc 87d3f9d4 804f9a17
[    2.666707]         8049cf18 00000145 80a942a0 00000204 80ac0000 10008400 87085b90 eb3d5ab7
[    2.675325]         00000000 00000000 80ac0000 000022b0 00000000 00000000 00000007 00000000
[    2.683954]         0000007a 80500000 0013b381 00000000 80000000 00000000 804a1664 80289878
[    2.692572]         00000009 00000204 80ac0000 00000200 00000002 00000000 00000000 80a90000
[    2.701191]         ...
[    2.703701] Call Trace:
[    2.706244] [<8001f3c8>] show_stack+0x58/0x100
[    2.710840] [<800336e4>] __warn+0xe4/0x118
[    2.715049] [<800337d4>] warn_slowpath_null+0x48/0x64
[    2.720237] [<80289878>] bcm_enetsw_open+0x160/0xbbc
[    2.725347] [<802d1d4c>] __dev_open+0xf8/0x16c
[    2.729913] [<802d20cc>] __dev_change_flags+0x100/0x1c4
[    2.735290] [<802d21b8>] dev_change_flags+0x28/0x70
[    2.740326] [<803539e0>] devinet_ioctl+0x310/0x7b0
[    2.745250] [<80355fd8>] inet_ioctl+0x1f8/0x224
[    2.749939] [<802af290>] sock_ioctl+0x30c/0x488
[    2.754632] [<80112b34>] do_vfs_ioctl+0x740/0x7dc
[    2.759459] [<80112c20>] ksys_ioctl+0x50/0x94
[    2.763955] [<800240b8>] syscall_common+0x34/0x58
[    2.768782] ---[ end trace fb1a6b14d74e28b6 ]---
[    2.773544] bcm63xx_enetsw bcm63xx_enetsw.0: cannot allocate rx ring 512

Fix this by adding appropriate DMA masks for the platform devices.

Fixes: f8c55dc6e828 ("MIPS: use generic dma noncoherent ops for simple noncoherent platforms")
Signed-off-by: Jonas Gorski <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Florian Fainelli <[email protected]>
Signed-off-by: Paul Burton <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Ralf Baechle <[email protected]>
Cc: James Hogan <[email protected]>
Cc: [email protected] # v4.19+

There are 8 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 arch/mips/bcm63xx/dev-enet.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/mips/bcm63xx/dev-enet.c b/arch/mips/bcm63xx/dev-enet.c
index 07b4c65..8e73d65 100644
--- a/arch/mips/bcm63xx/dev-enet.c
+++ b/arch/mips/bcm63xx/dev-enet.c
@@ -70,6 +70,8 @@ static __init void bcm63xx_enetdmac_regs_init(void)

 static int shared_device_registered;

+static u64 enet_dmamask = DMA_BIT_MASK(32);
+
 static struct resource enet0_res[] = {
    {
        .start      = -1, /* filled at runtime */
@@ -99,6 +101,8 @@ static __init void bcm63xx_enetdmac_regs_init(void)
    .resource   = enet0_res,
    .dev        = {
        .platform_data = &enet0_pd,
+       .dma_mask = &enet_dmamask,
+       .coherent_dma_mask = DMA_BIT_MASK(32),
    },
 };

@@ -131,6 +135,8 @@ static __init void bcm63xx_enetdmac_regs_init(void)
    .resource   = enet1_res,
    .dev        = {
        .platform_data = &enet1_pd,
+       .dma_mask = &enet_dmamask,
+       .coherent_dma_mask = DMA_BIT_MASK(32),
    },
 };

@@ -157,6 +163,8 @@ static __init void bcm63xx_enetdmac_regs_init(void)
    .resource   = enetsw_res,
    .dev        = {
        .platform_data = &enetsw_pd,
+       .dma_mask = &enet_dmamask,
+       .coherent_dma_mask = DMA_BIT_MASK(32),
    },
 };

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