openwrtv4/target/linux/generic/patches-4.4/093-MIPS-store-the-appended-dtb-address-in-a-variable.patch
Daniel Gimpelevich 993ad29359 kernel: Backport pending appended DTB handling patches
Backport patches from upstream Linux kernel which are making the
kernel stores the appended dtb not in the same resisters as defined in
the UHI specification, use a separate variable on MIPS.

Signed-off-by: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
[some modifications]
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2016-09-12 22:36:55 +02:00

132 lines
3.8 KiB
Diff

From 15f37e1588920e010f20b53f04af94e91b8ee714 Mon Sep 17 00:00:00 2001
From: Jonas Gorski <jogo@openwrt.org>
Date: Mon, 20 Jun 2016 11:27:37 +0200
Subject: [PATCH] MIPS: store the appended dtb address in a variable
Instead of rewriting the arguments to match the UHI spec, store the
address of a appended or UHI supplied dtb in fw_supplied_dtb.
That way the original bootloader arugments are kept intact while still
making the use of an appended dtb invisible for mach code.
Mach code can still find out if it is an appended dtb by comparing
fw_arg1 with fw_supplied_dtb.
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: John Crispin <john@phrozen.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Alban Bedel <albeu@free.fr>
Cc: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13699/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
arch/mips/ath79/setup.c | 4 ++--
arch/mips/bmips/setup.c | 4 ++--
arch/mips/include/asm/bootinfo.h | 4 ++++
arch/mips/kernel/head.S | 21 ++++++++++++++-------
arch/mips/kernel/setup.c | 4 ++++
arch/mips/lantiq/prom.c | 4 ++--
arch/mips/pic32/pic32mzda/init.c | 4 ++--
7 files changed, 30 insertions(+), 15 deletions(-)
--- a/arch/mips/ath79/setup.c
+++ b/arch/mips/ath79/setup.c
@@ -207,6 +207,8 @@ void __init plat_mem_setup(void)
fdt_start = fw_getenvl("fdt_start");
if (fdt_start)
__dt_setup_arch((void *)KSEG0ADDR(fdt_start));
+ else if (fw_passed_dtb)
+ __dt_setup_arch((void *)KSEG0ADDR(fw_passed_dtb));
#ifdef CONFIG_BUILTIN_DTB
else
__dt_setup_arch(__dtb_start);
--- a/arch/mips/bmips/setup.c
+++ b/arch/mips/bmips/setup.c
@@ -149,8 +149,8 @@ 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 (fw_arg0 == -2) /* UHI interface */
- dtb = (void *)fw_arg1;
+ else if (fw_passed_dtb) /* UHI interface */
+ dtb = (void *)fw_passed_dtb;
else if (__dtb_start != __dtb_end)
dtb = (void *)__dtb_start;
else
--- a/arch/mips/include/asm/bootinfo.h
+++ b/arch/mips/include/asm/bootinfo.h
@@ -127,6 +127,10 @@ extern char arcs_cmdline[COMMAND_LINE_SI
*/
extern unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
+#ifdef CONFIG_USE_OF
+extern unsigned long fw_passed_dtb;
+#endif
+
/*
* Platform memory detection hook called by setup_arch
*/
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -94,21 +94,24 @@ NESTED(kernel_entry, 16, sp) # kernel
jr t0
0:
+#ifdef CONFIG_USE_OF
#ifdef CONFIG_MIPS_RAW_APPENDED_DTB
- PTR_LA t0, __appended_dtb
+ PTR_LA t2, __appended_dtb
#ifdef CONFIG_CPU_BIG_ENDIAN
li t1, 0xd00dfeed
#else
li t1, 0xedfe0dd0
#endif
- lw t2, (t0)
- bne t1, t2, not_found
- nop
-
- move a1, t0
- PTR_LI a0, -2
-not_found:
+ lw t0, (t2)
+ beq t0, t1, dtb_found
+#endif
+ li t1, -2
+ beq a0, t1, dtb_found
+ move t2, a1
+
+ li t2, 0
+dtb_found:
#endif
PTR_LA t0, __bss_start # clear .bss
LONG_S zero, (t0)
@@ -123,6 +126,10 @@ not_found:
LONG_S a2, fw_arg2
LONG_S a3, fw_arg3
+#ifdef CONFIG_USE_OF
+ LONG_S t2, fw_passed_dtb
+#endif
+
MTC0 zero, CP0_CONTEXT # clear context register
PTR_LA $28, init_thread_union
/* Set the SP after an empty pt_regs. */
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -814,6 +814,10 @@ void __init setup_arch(char **cmdline_p)
unsigned long kernelsp[NR_CPUS];
unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
+#ifdef CONFIG_USE_OF
+unsigned long fw_passed_dtb;
+#endif
+
#ifdef CONFIG_DEBUG_FS
struct dentry *mips_debugfs_dir;
static int __init debugfs_mips(void)