+++ /dev/null
-From f36b3119d83e03c9d0c684b8712b66a979c48124 Mon Sep 17 00:00:00 2001
-From: Phil Elwell <phil@raspberrypi.org>
-Date: Mon, 16 Jul 2018 14:40:13 +0100
-Subject: [PATCH] dwc-otg: FIQ: Fix "bad mode in data abort handler"
-
-Create a semi-static mapping for the USB registers early in the boot
-process, before additional kernel threads are started, so all threads
-will have the mappings from the start. This avoids the need for
-data aborts to lazily update them.
-
-See: https://github.com/raspberrypi/linux/issues/2450
-
-Signed-off-by: Floris Bos <bos@je-eigen-domein.nl>
----
- arch/arm/mach-bcm/board_bcm2835.c | 69 +++++++++++++++++++++++
- drivers/usb/host/dwc_otg/dwc_otg_driver.c | 2 +-
- 2 files changed, 70 insertions(+), 1 deletion(-)
-
---- a/arch/arm/mach-bcm/board_bcm2835.c
-+++ b/arch/arm/mach-bcm/board_bcm2835.c
-@@ -15,6 +15,7 @@
- #include <linux/init.h>
- #include <linux/irqchip.h>
- #include <linux/of_address.h>
-+#include <linux/of_fdt.h>
- #include <asm/system_info.h>
-
- #include <asm/mach/arch.h>
-@@ -22,6 +23,9 @@
-
- #include "platsmp.h"
-
-+#define BCM2835_USB_VIRT_BASE 0xf0980000
-+#define BCM2835_USB_VIRT_MPHI 0xf0006000
-+
- static void __init bcm2835_init(void)
- {
- struct device_node *np = of_find_node_by_path("/system");
-@@ -34,6 +38,70 @@ static void __init bcm2835_init(void)
- system_serial_low = val64;
- }
-
-+/*
-+ * We need to map registers that are going to be accessed by the FIQ
-+ * very early, before any kernel threads are spawned. Because if done
-+ * later, the mapping tables are not updated instantly but lazily upon
-+ * first access through a data abort handler. While that is fine
-+ * when executing regular kernel code, if the first access in a specific
-+ * thread happens while running FIQ code this will result in a panic.
-+ *
-+ * For more background see the following old mailing list thread:
-+ * https://www.spinics.net/lists/arm-kernel/msg325250.html
-+ */
-+static int __init bcm2835_map_usb(unsigned long node, const char *uname,
-+ int depth, void *data)
-+{
-+ struct map_desc map[2];
-+ const __be32 *reg;
-+ int len;
-+ unsigned long p2b_offset = *((unsigned long *) data);
-+
-+ if (!of_flat_dt_is_compatible(node, "brcm,bcm2708-usb"))
-+ return 0;
-+ reg = of_get_flat_dt_prop(node, "reg", &len);
-+ if (!reg || len != (sizeof(unsigned long) * 4))
-+ return 0;
-+
-+ /* Use information about the physical addresses of the
-+ * registers from the device tree, but use legacy
-+ * iotable_init() static mapping function to map them,
-+ * as ioremap() is not functional at this stage in boot.
-+ */
-+ map[0].virtual = (unsigned long) BCM2835_USB_VIRT_BASE;
-+ map[0].pfn = __phys_to_pfn(be32_to_cpu(reg[0]) - p2b_offset);
-+ map[0].length = be32_to_cpu(reg[1]);
-+ map[0].type = MT_DEVICE;
-+ map[1].virtual = (unsigned long) BCM2835_USB_VIRT_MPHI;
-+ map[1].pfn = __phys_to_pfn(be32_to_cpu(reg[2]) - p2b_offset);
-+ map[1].length = be32_to_cpu(reg[3]);
-+ map[1].type = MT_DEVICE;
-+ iotable_init(map, 2);
-+
-+ return 1;
-+}
-+
-+static void __init bcm2835_map_io(void)
-+{
-+ const __be32 *ranges;
-+ int soc, len;
-+ unsigned long p2b_offset;
-+
-+ debug_ll_io_init();
-+
-+ /* Find out how to map bus to physical address first from soc/ranges */
-+ soc = of_get_flat_dt_subnode_by_name(of_get_flat_dt_root(), "soc");
-+ if (soc < 0)
-+ return;
-+ ranges = of_get_flat_dt_prop(soc, "ranges", &len);
-+ if (!ranges || len < (sizeof(unsigned long) * 3))
-+ return;
-+ p2b_offset = be32_to_cpu(ranges[0]) - be32_to_cpu(ranges[1]);
-+
-+ /* Now search for bcm2708-usb node in device tree */
-+ of_scan_flat_dt(bcm2835_map_usb, &p2b_offset);
-+}
-+
- static const char * const bcm2835_compat[] = {
- #ifdef CONFIG_ARCH_MULTI_V6
- "brcm,bcm2835",
-@@ -46,6 +114,7 @@ static const char * const bcm2835_compat
- };
-
- DT_MACHINE_START(BCM2835, "BCM2835")
-+ .map_io = bcm2835_map_io,
- .init_machine = bcm2835_init,
- .dt_compat = bcm2835_compat,
- .smp = smp_ops(bcm2836_smp_ops),
---- a/drivers/usb/host/dwc_otg/dwc_otg_driver.c
-+++ b/drivers/usb/host/dwc_otg/dwc_otg_driver.c
-@@ -837,7 +837,7 @@ static int dwc_otg_driver_probe(
- retval = -ENOMEM;
- goto fail;
- }
-- dev_dbg(&_dev->dev, "base=0x%08x\n",
-+ dev_info(&_dev->dev, "base=0x%08x\n",
- (unsigned)dwc_otg_device->os_dep.base);
- #endif
-
projects / openwrt / openwrt.git / blobdiff