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>

diff --git a/arch/mips/ath79/setup.c b/arch/mips/ath79/setup.c
index 7adab18..2ec9100 100644 (file)
--- a/arch/mips/ath79/setup.c
+++ b/arch/mips/ath79/setup.c
@@ -204,8 +204,8 @@ 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_arg0 == -2)
-               __dt_setup_arch((void *)KSEG0ADDR(fw_arg1));
+       else if (fw_passed_dtb)
+               __dt_setup_arch((void *)KSEG0ADDR(fw_passed_dtb));
 
        if (mips_machtype != ATH79_MACH_GENERIC_OF) {
                ath79_reset_base = ioremap_nocache(AR71XX_RESET_BASE,

diff --git a/arch/mips/bmips/setup.c b/arch/mips/bmips/setup.c
index f146d12..6776042 100644 (file)
--- a/arch/mips/bmips/setup.c
+++ b/arch/mips/bmips/setup.c
@@ -162,8 +162,8 @@ 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

diff --git a/arch/mips/include/asm/bootinfo.h b/arch/mips/include/asm/bootinfo.h
index 9f67033..ee9f5f2 100644 (file)
--- a/arch/mips/include/asm/bootinfo.h
+++ b/arch/mips/include/asm/bootinfo.h
@@ -127,6 +127,10 @@ extern char arcs_cmdline[COMMAND_LINE_SIZE];
  */
 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
  */

diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
index 56e8fed..cf05220 100644 (file)
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -93,21 +93,24 @@ NESTED(kernel_entry, 16, sp)                        # kernel entry point
        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
+       lw              t0, (t2)
+       beq             t0, t1, dtb_found
+#endif
+       li              t1, -2
+       beq             a0, t1, dtb_found
+       move            t2, a1
 
-       move            a1, t0
-       PTR_LI          a0, -2
-not_found:
+       li              t2, 0
+dtb_found:
 #endif
        PTR_LA          t0, __bss_start         # clear .bss
        LONG_S          zero, (t0)
@@ -122,6 +125,10 @@ 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.  */

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index ef408a0..36cf8d6 100644 (file)
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -875,6 +875,10 @@ 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)

diff --git a/arch/mips/lantiq/prom.c b/arch/mips/lantiq/prom.c
index 5f693ac..4cbb000 100644 (file)
--- a/arch/mips/lantiq/prom.c
+++ b/arch/mips/lantiq/prom.c
@@ -74,8 +74,8 @@ void __init plat_mem_setup(void)
 
        set_io_port_base((unsigned long) KSEG1);
 
-       if (fw_arg0 == -2) /* UHI interface */
-               dtb = (void *)fw_arg1;
+       if (fw_passed_dtb) /* UHI interface */
+               dtb = (void *)fw_passed_dtb;
        else if (__dtb_start != __dtb_end)
                dtb = (void *)__dtb_start;
        else

diff --git a/arch/mips/pic32/pic32mzda/init.c b/arch/mips/pic32/pic32mzda/init.c
index 775ff90..a794037 100644 (file)
--- a/arch/mips/pic32/pic32mzda/init.c
+++ b/arch/mips/pic32/pic32mzda/init.c
@@ -33,8 +33,8 @@ static ulong get_fdtaddr(void)
 {
        ulong ftaddr = 0;
 
-       if ((fw_arg0 == -2) && fw_arg1 && !fw_arg2 && !fw_arg3)
-               return (ulong)fw_arg1;
+       if (fw_passed_dtb && !fw_arg2 && !fw_arg3)
+               return (ulong)fw_passed_dtb;
 
        if (__dtb_start < __dtb_end)
                ftaddr = (ulong)__dtb_start;