brcm47xx: backport MIPS fix adding struct device for the SoC

It's needed to:
1) Fix GPIOLIB_IRQCHIP as in 4.19 there is no bcma revert anymore
2) Fix /sys/devices/
3) Fix dma_zalloc_coherent() regression

It still needs a bcma change that will follow later.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

2 files changed, 140 insertions, 2 deletions

diff --git a/target/linux/brcm47xx/patches-4.19/031-v5.0-MIPS-BCM47XX-Setup-struct-device-for-the-SoC.patch b/target/linux/brcm47xx/patches-4.19/031-v5.0-MIPS-BCM47XX-Setup-struct-device-for-the-SoC.patch
new file mode 100644
index 0000000000..e3c1d45a3e
--- /dev/null
+++ b/target/linux/brcm47xx/patches-4.19/031-v5.0-MIPS-BCM47XX-Setup-struct-device-for-the-SoC.patch
@@ -0,0 +1,138 @@
+From 321c46b91550adc03054125fa7a1639390608e1a Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Thu, 3 Jan 2019 08:34:17 +0100
+Subject: [PATCH] MIPS: BCM47XX: Setup struct device for the SoC
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+So far we never had any device registered for the SoC. This resulted in
+some small issues that we kept ignoring like:
+1) Not working GPIOLIB_IRQCHIP (gpiochip_irqchip_add_key() failing)
+2) Lack of proper tree in the /sys/devices/
+3) mips_dma_alloc_coherent() silently handling empty coherent_dma_mask
+
+Kernel 4.19 came with a lot of DMA changes and caused a regression on
+bcm47xx. Starting with the commit f8c55dc6e828 ("MIPS: use generic dma
+noncoherent ops for simple noncoherent platforms") DMA coherent
+allocations just fail. Example:
+[    1.114914] bgmac_bcma bcma0:2: Allocation of TX ring 0x200 failed
+[    1.121215] bgmac_bcma bcma0:2: Unable to alloc memory for DMA
+[    1.127626] bgmac_bcma: probe of bcma0:2 failed with error -12
+[    1.133838] bgmac_bcma: Broadcom 47xx GBit MAC driver loaded
+
+The bgmac driver also triggers a WARNING:
+[    0.959486] ------------[ cut here ]------------
+[    0.964387] WARNING: CPU: 0 PID: 1 at ./include/linux/dma-mapping.h:516 bgmac_enet_probe+0x1b4/0x5c4
+[    0.973751] Modules linked in:
+[    0.976913] CPU: 0 PID: 1 Comm: swapper Not tainted 4.19.9 #0
+[    0.982750] Stack : 804a0000 804597c4 00000000 00000000 80458fd8 8381bc2c 838282d4 80481a47
+[    0.991367]         8042e3ec 00000001 804d38f0 00000204 83980000 00000065 8381bbe0 6f55b24f
+[    0.999975]         00000000 00000000 80520000 00002018 00000000 00000075 00000007 00000000
+[    1.008583]         00000000 80480000 000ee811 00000000 00000000 00000000 80432c00 80248db8
+[    1.017196]         00000009 00000204 83980000 803ad7b0 00000000 801feeec 00000000 804d0000
+[    1.025804]         ...
+[    1.028325] Call Trace:
+[    1.030875] [<8000aef8>] show_stack+0x58/0x100
+[    1.035513] [<8001f8b4>] __warn+0xe4/0x118
+[    1.039708] [<8001f9a4>] warn_slowpath_null+0x48/0x64
+[    1.044935] [<80248db8>] bgmac_enet_probe+0x1b4/0x5c4
+[    1.050101] [<802498e0>] bgmac_probe+0x558/0x590
+[    1.054906] [<80252fd0>] bcma_device_probe+0x38/0x70
+[    1.060017] [<8020e1e8>] really_probe+0x170/0x2e8
+[    1.064891] [<8020e714>] __driver_attach+0xa4/0xec
+[    1.069784] [<8020c1e0>] bus_for_each_dev+0x58/0xb0
+[    1.074833] [<8020d590>] bus_add_driver+0xf8/0x218
+[    1.079731] [<8020ef24>] driver_register+0xcc/0x11c
+[    1.084804] [<804b54cc>] bgmac_init+0x1c/0x44
+[    1.089258] [<8000121c>] do_one_initcall+0x7c/0x1a0
+[    1.094343] [<804a1d34>] kernel_init_freeable+0x150/0x218
+[    1.099886] [<803a082c>] kernel_init+0x10/0x104
+[    1.104583] [<80005878>] ret_from_kernel_thread+0x14/0x1c
+[    1.110107] ---[ end trace f441c0d873d1fb5b ]---
+
+This patch setups a "struct device" (and passes it to the bcma) which
+allows fixing all the mentioned problems. It'll also require a tiny bcma
+patch which will follow through the wireless tree & its maintainer.
+
+Fixes: f8c55dc6e828 ("MIPS: use generic dma noncoherent ops for simple noncoherent platforms")
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Signed-off-by: Paul Burton <paul.burton@mips.com>
+Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
+Cc: Christoph Hellwig <hch@lst.de>
+Cc: Linus Walleij <linus.walleij@linaro.org>
+Cc: linux-wireless@vger.kernel.org
+Cc: Ralf Baechle <ralf@linux-mips.org>
+Cc: James Hogan <jhogan@kernel.org>
+Cc: linux-mips@linux-mips.org
+Cc: linux-kernel@vger.kernel.org
+Cc: stable@vger.kernel.org # v4.19+
+---
+ arch/mips/bcm47xx/setup.c     | 31 +++++++++++++++++++++++++++++++
+ include/linux/bcma/bcma_soc.h |  1 +
+ 2 files changed, 32 insertions(+)
+
+--- a/arch/mips/bcm47xx/setup.c
++++ b/arch/mips/bcm47xx/setup.c
+@@ -173,6 +173,31 @@ void __init plat_mem_setup(void)
+ 	pm_power_off = bcm47xx_machine_halt;
+ }
+ 
++#ifdef CONFIG_BCM47XX_BCMA
++static struct device * __init bcm47xx_setup_device(void)
++{
++	struct device *dev;
++	int err;
++
++	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
++	if (!dev)
++		return NULL;
++
++	err = dev_set_name(dev, "bcm47xx_soc");
++	if (err) {
++		pr_err("Failed to set SoC device name: %d\n", err);
++		kfree(dev);
++		return NULL;
++	}
++
++	err = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
++	if (err)
++		pr_err("Failed to set SoC DMA mask: %d\n", err);
++
++	return dev;
++}
++#endif
++
+ /*
+  * This finishes bus initialization doing things that were not possible without
+  * kmalloc. Make sure to call it late enough (after mm_init).
+@@ -183,6 +208,10 @@ void __init bcm47xx_bus_setup(void)
+ 	if (bcm47xx_bus_type == BCM47XX_BUS_TYPE_BCMA) {
+ 		int err;
+ 
++		bcm47xx_bus.bcma.dev = bcm47xx_setup_device();
++		if (!bcm47xx_bus.bcma.dev)
++			panic("Failed to setup SoC device\n");
++
+ 		err = bcma_host_soc_init(&bcm47xx_bus.bcma);
+ 		if (err)
+ 			panic("Failed to initialize BCMA bus (err %d)", err);
+@@ -235,6 +264,8 @@ static int __init bcm47xx_register_bus_c
+ #endif
+ #ifdef CONFIG_BCM47XX_BCMA
+ 	case BCM47XX_BUS_TYPE_BCMA:
++		if (device_register(bcm47xx_bus.bcma.dev))
++			pr_err("Failed to register SoC device\n");
+ 		bcma_bus_register(&bcm47xx_bus.bcma.bus);
+ 		break;
+ #endif
+--- a/include/linux/bcma/bcma_soc.h
++++ b/include/linux/bcma/bcma_soc.h
+@@ -6,6 +6,7 @@
+ 
+ struct bcma_soc {
+ 	struct bcma_bus bus;
++	struct device *dev;
+ };
+ 
+ int __init bcma_host_soc_register(struct bcma_soc *soc);
diff --git a/target/linux/brcm47xx/patches-4.19/830-huawei_e970_support.patch b/target/linux/brcm47xx/patches-4.19/830-huawei_e970_support.patch
index 309c2172b8..4d43b9960b 100644
--- a/target/linux/brcm47xx/patches-4.19/830-huawei_e970_support.patch
+++ b/target/linux/brcm47xx/patches-4.19/830-huawei_e970_support.patch
@@ -8,7 +8,7 @@
  #include <asm/bootinfo.h>
  #include <asm/idle.h>
  #include <asm/prom.h>
-@@ -225,6 +226,33 @@ static struct fixed_phy_status bcm47xx_f
+@@ -254,6 +255,33 @@ static struct fixed_phy_status bcm47xx_f
  	.duplex	= DUPLEX_FULL,
  };
  
@@ -42,7 +42,7 @@
  static int __init bcm47xx_register_bus_complete(void)
  {
  	switch (bcm47xx_bus_type) {
-@@ -244,6 +272,7 @@ static int __init bcm47xx_register_bus_c
+@@ -275,6 +303,7 @@ static int __init bcm47xx_register_bus_c
  	bcm47xx_workarounds();
  
  	fixed_phy_add(PHY_POLL, 0, &bcm47xx_fixed_phy_status, -1);