MIPS: of: Introduce helper function to get DTB

Selection of the DTB to be used was burried in more or less readable
code in head.S. Move this code into a inline helper function and
use it.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>

diff --git a/arch/mips/ath79/setup.c b/arch/mips/ath79/setup.c
index 7e7bf9c..891f495 100644 (file)
--- a/arch/mips/ath79/setup.c
+++ b/arch/mips/ath79/setup.c
@@ -213,16 +213,17 @@ unsigned int get_c0_compare_int(void)
 
 void __init plat_mem_setup(void)
 {
-       unsigned long fdt_start;
+       void *dtb;
 
        set_io_port_base(KSEG1);
 
        /* Get the position of the FDT passed by the bootloader */
-       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));
+       dtb = (void *)fw_getenvl("fdt_start");
+       if (dtb == NULL)
+               dtb = get_fdt();
+
+       if (dtb)
+               __dt_setup_arch((void *)KSEG0ADDR(dtb));
 
        ath79_reset_base = ioremap(AR71XX_RESET_BASE,
                                           AR71XX_RESET_SIZE);

diff --git a/arch/mips/bmips/setup.c b/arch/mips/bmips/setup.c
index 10e31d9..95f8f10 100644 (file)
--- a/arch/mips/bmips/setup.c
+++ b/arch/mips/bmips/setup.c
@@ -161,11 +161,10 @@ void __init plat_mem_setup(void)
        /* intended to somewhat resemble ARM; see Documentation/arm/booting.rst */
        if (fw_arg0 == 0 && fw_arg1 == 0xffffffff)
                dtb = phys_to_virt(fw_arg2);
-       else if (fw_passed_dtb) /* UHI interface or appended dtb */
-               dtb = (void *)fw_passed_dtb;
-       else if (&__dtb_start != &__dtb_end)
-               dtb = (void *)__dtb_start;
        else
+               dtb = get_fdt();
+
+       if (!dtb)
                panic("no dtb found");
 
        __dt_setup_arch(dtb);

diff --git a/arch/mips/generic/init.c b/arch/mips/generic/init.c
index 68763fc..1842cdd 100644 (file)
--- a/arch/mips/generic/init.c
+++ b/arch/mips/generic/init.c
@@ -39,14 +39,13 @@ void __init *plat_get_fdt(void)
                /* Already set up */
                return (void *)fdt;
 
-       if (fw_passed_dtb && !fdt_check_header((void *)fw_passed_dtb)) {
+       fdt = (void *)get_fdt();
+       if (fdt && !fdt_check_header(fdt)) {
                /*
                 * We have been provided with the appropriate device tree for
                 * the board. Make use of it & search for any machine struct
                 * based upon the root compatible string.
                 */
-               fdt = (void *)fw_passed_dtb;
-
                for_each_mips_machine(check_mach) {
                        match = mips_machine_is_compatible(check_mach, fdt);
                        if (match) {

diff --git a/arch/mips/include/asm/bootinfo.h b/arch/mips/include/asm/bootinfo.h
index aa03b12..5be10ec 100644 (file)
--- a/arch/mips/include/asm/bootinfo.h
+++ b/arch/mips/include/asm/bootinfo.h
@@ -112,7 +112,27 @@ 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;
+#include <linux/libfdt.h>
+#include <linux/of_fdt.h>
+
+extern char __appended_dtb[];
+
+static inline void *get_fdt(void)
+{
+       if (IS_ENABLED(CONFIG_MIPS_RAW_APPENDED_DTB) ||
+           IS_ENABLED(CONFIG_MIPS_ELF_APPENDED_DTB))
+               if (fdt_magic(&__appended_dtb) == FDT_MAGIC)
+                       return &__appended_dtb;
+
+       if (fw_arg0 == -2) /* UHI interface */
+               return (void *)fw_arg1;
+
+       if (IS_ENABLED(CONFIG_BUILTIN_DTB))
+               if (&__dtb_start != &__dtb_end)
+                       return &__dtb_start;
+
+       return NULL;
+}
 #endif
 
 /*

diff --git a/arch/mips/include/asm/octeon/octeon.h b/arch/mips/include/asm/octeon/octeon.h
index 08d48f3..7e714ae 100644 (file)
--- a/arch/mips/include/asm/octeon/octeon.h
+++ b/arch/mips/include/asm/octeon/octeon.h
@@ -282,7 +282,6 @@ union octeon_cvmemctl {
 extern void octeon_check_cpu_bist(void);
 
 int octeon_prune_device_tree(void);
-extern const char __appended_dtb;
 extern const char __dtb_octeon_3xxx_begin;
 extern const char __dtb_octeon_68xx_begin;
 

diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
index 61b7358..b825ed4 100644 (file)
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -93,33 +93,6 @@ NESTED(kernel_entry, 16, sp)                 # kernel entry point
        jr      t0
 0:
 
-#ifdef CONFIG_USE_OF
-#if defined(CONFIG_MIPS_RAW_APPENDED_DTB) || \
-       defined(CONFIG_MIPS_ELF_APPENDED_DTB)
-
-       PTR_LA          t2, __appended_dtb
-
-#ifdef CONFIG_CPU_BIG_ENDIAN
-       li              t1, 0xd00dfeed
-#else  /* !CONFIG_CPU_BIG_ENDIAN */
-       li              t1, 0xedfe0dd0
-#endif /* !CONFIG_CPU_BIG_ENDIAN */
-       lw              t0, (t2)
-       beq             t0, t1, dtb_found
-#endif /* CONFIG_MIPS_RAW_APPENDED_DTB || CONFIG_MIPS_ELF_APPENDED_DTB */
-       li              t1, -2
-       move            t2, a1
-       beq             a0, t1, dtb_found
-
-#ifdef CONFIG_BUILTIN_DTB
-       PTR_LA  t2, __dtb_start
-       PTR_LA  t1, __dtb_end
-       bne             t1, t2, dtb_found
-#endif /* CONFIG_BUILTIN_DTB */
-
-       li              t2, 0
-dtb_found:
-#endif /* CONFIG_USE_OF */
        PTR_LA          t0, __bss_start         # clear .bss
        LONG_S          zero, (t0)
        PTR_LA          t1, __bss_stop - LONGSIZE
@@ -133,10 +106,6 @@ dtb_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
 #ifdef CONFIG_64BIT
        MTC0            zero, CP0_XCONTEXT

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 7e1f8e2..3785c72 100644 (file)
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -792,10 +792,6 @@ 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 3639371..bc9f58f 100644 (file)
--- a/arch/mips/lantiq/prom.c
+++ b/arch/mips/lantiq/prom.c
@@ -73,11 +73,8 @@ void __init plat_mem_setup(void)
 
        set_io_port_base((unsigned long) KSEG1);
 
-       if (fw_passed_dtb) /* UHI interface */
-               dtb = (void *)fw_passed_dtb;
-       else if (&__dtb_start != &__dtb_end)
-               dtb = (void *)__dtb_start;
-       else
+       dtb = get_fdt();
+       if (dtb == NULL)
                panic("no dtb found");
 
        /*

diff --git a/arch/mips/pic32/pic32mzda/init.c b/arch/mips/pic32/pic32mzda/init.c
index 1897aa8..764f2d0 100644 (file)
--- a/arch/mips/pic32/pic32mzda/init.c
+++ b/arch/mips/pic32/pic32mzda/init.c
@@ -21,24 +21,11 @@ const char *get_system_type(void)
        return "PIC32MZDA";
 }
 
-static ulong get_fdtaddr(void)
-{
-       ulong ftaddr = 0;
-
-       if (fw_passed_dtb && !fw_arg2 && !fw_arg3)
-               return (ulong)fw_passed_dtb;
-
-       if (&__dtb_start < &__dtb_end)
-               ftaddr = (ulong)__dtb_start;
-
-       return ftaddr;
-}
-
 void __init plat_mem_setup(void)
 {
        void *dtb;
 
-       dtb = (void *)get_fdtaddr();
+       dtb = get_fdt();
        if (!dtb) {
                pr_err("pic32: no DTB found.\n");
                return;

diff --git a/arch/mips/ralink/of.c b/arch/mips/ralink/of.c
index 2c9af61..8286c35 100644 (file)
--- a/arch/mips/ralink/of.c
+++ b/arch/mips/ralink/of.c
@@ -64,20 +64,15 @@ static int __init early_init_dt_find_memory(unsigned long node,
 
 void __init plat_mem_setup(void)
 {
-       void *dtb = NULL;
+       void *dtb;
 
        set_io_port_base(KSEG1);
 
        /*
         * Load the builtin devicetree. This causes the chosen node to be
-        * parsed resulting in our memory appearing. fw_passed_dtb is used
-        * by CONFIG_MIPS_APPENDED_RAW_DTB as well.
+        * parsed resulting in our memory appearing.
         */
-       if (fw_passed_dtb)
-               dtb = (void *)fw_passed_dtb;
-       else if (&__dtb_start != &__dtb_end)
-               dtb = (void *)__dtb_start;
-
+       dtb = get_fdt();
        __dt_setup_arch(dtb);
 
        of_scan_flat_dt(early_init_dt_find_memory, NULL);