A couple of chips require special handling in order to make SMP secondary
boot and/or exception vectors work correctly. Take care of these in
setup.c.
Signed-off-by: Kevin Cernekee <cernekee@xxxxxxxxx>
---
arch/mips/bmips/setup.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 99 insertions(+), 2 deletions(-)
diff --git a/arch/mips/bmips/setup.c b/arch/mips/bmips/setup.c
index ac402ed..fae800e 100644
--- a/arch/mips/bmips/setup.c
+++ b/arch/mips/bmips/setup.c
@@ -8,9 +8,12 @@
*/
#include <linux/init.h>
+#include <linux/bitops.h>
#include <linux/bootmem.h>
#include <linux/clk-provider.h>
#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
@@ -18,9 +21,92 @@
#include <asm/addrspace.h>
#include <asm/bmips.h>
#include <asm/bootinfo.h>
+#include <asm/cpu-type.h>
+#include <asm/mipsregs.h>
#include <asm/prom.h>
#include <asm/smp-ops.h>
#include <asm/time.h>
+#include <asm/traps.h>
+
+#define RELO_NORMAL_VEC BIT(18)
+
+#define REG_BCM6328_OTP ((void __iomem *)CKSEG1ADDR(0x1000062c))
+#define BCM6328_TP1_DISABLED BIT(9)
+
+static const unsigned long kbase = VMLINUX_LOAD_ADDRESS & 0xfff00000;
+
+struct bmips_quirk {
+ const char *compatible;
+ void (*quirk_fn)(void);
+};
+
+static void kbase_setup(void)
+{
+ __raw_writel(kbase | RELO_NORMAL_VEC,
+ BMIPS_GET_CBR() + BMIPS_RELO_VECTOR_CONTROL_1);
+ ebase = kbase;
+}
+
+static void bcm3384_viper_quirks(void)
+{
+ /*
+ * Some experimental CM boxes are set up to let CM own the Viper TP0
+ * and let Linux own TP1. This requires moving the kernel
+ * load address to a non-conflicting region (e.g. via
+ * CONFIG_PHYSICAL_START) and supplying an alternate DTB.
+ * If we detect this condition, we need to move the MIPS exception
+ * vectors up to an area that we own.
+ *
+ * This is distinct from the OTHER special case mentioned in
+ * smp-bmips.c (boot on TP1, but enable SMP, then TP0 becomes our
+ * logical CPU#1). For the Viper TP1 case, SMP is off limits.
+ *
+ * Also note that many BMIPS435x CPUs do not have a
+ * BMIPS_RELO_VECTOR_CONTROL_1 register, so it isn't safe to just
+ * write VMLINUX_LOAD_ADDRESS into that register on every SoC.
+ */
+ board_ebase_setup = &kbase_setup;
+ bmips_smp_enabled = 0;
+}
+
+static void bcm63xx_fixup_cpu1(void)
+{
+ /*
+ * The bootloader has set up the CPU1 reset vector at
+ * 0xa000_0200.
+ * This conflicts with the special interrupt vector (IV).
+ * The bootloader has also set up CPU1 to respond to the wrong
+ * IPI interrupt.
+ * Here we will start up CPU1 in the background and ask it to
+ * reconfigure itself then go back to sleep.
+ */
+ memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20);
+ __sync();
+ set_c0_cause(C_SW0);
+ cpumask_set_cpu(1, &bmips_booted_mask);
+}
+
+static void bcm6328_quirks(void)
+{
+ /* Check CPU1 status in OTP (it is usually disabled) */
+ if (__raw_readl(REG_BCM6328_OTP) & BCM6328_TP1_DISABLED)
+ bmips_smp_enabled = 0;
+ else
+ bcm63xx_fixup_cpu1();
+}
+
+static void bcm6368_quirks(void)
+{
+ bcm63xx_fixup_cpu1();
+}
+
+static const struct bmips_quirk bmips_quirk_list[] = {
+ { "brcm,bcm3384-viper", &bcm3384_viper_quirks },
+ { "brcm,bcm33843-viper", &bcm3384_viper_quirks },
+ { "brcm,bcm6328", &bcm6328_quirks },
+ { "brcm,bcm6368", &bcm6368_quirks },
+ { },
+};
void __init prom_init(void)
{
@@ -53,7 +139,8 @@ void __init plat_time_init(void)
void __init plat_mem_setup(void)
{
- void *dtb = __dtb_start;
+ void *dtb;
+ const struct bmips_quirk *q;
set_io_port_base(0);
ioport_resource.start = 0;
@@ -62,10 +149,20 @@ void __init plat_mem_setup(void)
/* intended to somewhat resemble ARM; see Documentation/arm/Booting */
if (fw_arg0 == 0 && fw_arg1 == 0xffffffff)
dtb = phys_to_virt(fw_arg2);
+ else if (__dtb_start != __dtb_end)
+ dtb = (void *)__dtb_start;
+ else
+ panic("no dtb found");
__dt_setup_arch(dtb);
-
strlcpy(arcs_cmdline, boot_command_line, COMMAND_LINE_SIZE);
+
+ for (q = bmips_quirk_list; q->quirk_fn; q++) {
+ if (of_flat_dt_is_compatible(of_get_flat_dt_root(),
+ q->compatible)) {
+ q->quirk_fn();
+ }
+ }
}
void __init device_tree_init(void)
--
2.1.1
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