85xx: Add support for not releasing secondary cores via 'mp_holdoff'

Some OSes require that secondary cores not be initialized when they
are booted (eg VxWorks).  By default when U-Boot is compiled with the
CONFIG_MP option all secondary cores are brought out of reset and held
in spinloops.  Setting the "mp_holdoff" environment variable to 'yes'
or '1' will cause U-Boot to leave secondary cores in their default
state.

Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

diff --git a/arch/powerpc/cpu/mpc85xx/fdt.c b/arch/powerpc/cpu/mpc85xx/fdt.c
index 45403641cfa03eca0a805e9482eda5137a1d9df2..53e059655483361c0e850842c17dd671d062381f 100644 (file)
--- a/arch/powerpc/cpu/mpc85xx/fdt.c
+++ b/arch/powerpc/cpu/mpc85xx/fdt.c
@@ -48,6 +48,7 @@ void ft_fixup_cpu(void *blob, u64 memory_limit)
        ulong spin_tbl_addr = get_spin_phys_addr();
        u32 bootpg = determine_mp_bootpg();
        u32 id = get_my_id();
+       const char *enable_method;
 
        off = fdt_node_offset_by_prop_value(blob, -1, "device_type", "cpu", 4);
        while (off != -FDT_ERR_NOTFOUND) {
@@ -63,10 +64,25 @@ void ft_fixup_cpu(void *blob, u64 memory_limit)
                                fdt_setprop_string(blob, off, "status",
                                                                "disabled");
                        }
+
+                       if (hold_cores_in_reset(0)) {
+#ifdef CONFIG_FSL_CORENET
+                               /* Cores held in reset, use BRR to release */
+                               enable_method = "fsl,brr-holdoff";
+#else
+                               /* Cores held in reset, use EEBPCR to release */
+                               enable_method = "fsl,eebpcr-holdoff";
+#endif
+                       } else {
+                               /* Cores out of reset and in a spin-loop */
+                               enable_method = "spin-table";
+
+                               fdt_setprop(blob, off, "cpu-release-addr",
+                                               &val, sizeof(val));
+                       }
+
                        fdt_setprop_string(blob, off, "enable-method",
-                                                       "spin-table");
-                       fdt_setprop(blob, off, "cpu-release-addr",
-                                       &val, sizeof(val));
+                                                       enable_method);
                } else {
                        printf ("cpu NULL\n");
                }

diff --git a/arch/powerpc/cpu/mpc85xx/mp.c b/arch/powerpc/cpu/mpc85xx/mp.c
index 603baef1bd493645ee62a0617fa83c8296acd61e..a019b1bdb13fd90bda59d6ba8edea90ff4cddf91 100644 (file)
--- a/arch/powerpc/cpu/mpc85xx/mp.c
+++ b/arch/powerpc/cpu/mpc85xx/mp.c
@@ -36,6 +36,27 @@ u32 get_my_id()
        return mfspr(SPRN_PIR);
 }
 
+/*
+ * Determine if U-Boot should keep secondary cores in reset, or let them out
+ * of reset and hold them in a spinloop
+ */
+int hold_cores_in_reset(int verbose)
+{
+       const char *s = getenv("mp_holdoff");
+
+       /* Default to no, overriden by 'y', 'yes', 'Y', 'Yes', or '1' */
+       if (s && (*s == 'y' || *s == 'Y' || *s == '1')) {
+               if (verbose) {
+                       puts("Secondary cores are being held in reset.\n");
+                       puts("See 'mp_holdoff' environment variable\n");
+               }
+
+               return 1;
+       }
+
+       return 0;
+}
+
 int cpu_reset(int nr)
 {
        volatile ccsr_pic_t *pic = (void *)(CONFIG_SYS_MPC8xxx_PIC_ADDR);
@@ -51,6 +72,9 @@ int cpu_status(int nr)
 {
        u32 *table, id = get_my_id();
 
+       if (hold_cores_in_reset(1))
+               return 0;
+
        if (nr == id) {
                table = (u32 *)get_spin_virt_addr();
                printf("table base @ 0x%p\n", table);
@@ -133,6 +157,9 @@ int cpu_release(int nr, int argc, char * const argv[])
        u32 i, val, *table = (u32 *)get_spin_virt_addr() + nr * NUM_BOOT_ENTRY;
        u64 boot_addr;
 
+       if (hold_cores_in_reset(1))
+               return 0;
+
        if (nr == get_my_id()) {
                printf("Invalid to release the boot core.\n\n");
                return 1;
@@ -353,6 +380,10 @@ void setup_mp(void)
        ulong fixup = (ulong)&__secondary_start_page;
        u32 bootpg = determine_mp_bootpg();
 
+       /* Some OSes expect secondary cores to be held in reset */
+       if (hold_cores_in_reset(0))
+               return;
+
        /* Store the bootpg's SDRAM address for use by secondary CPU cores */
        __bootpg_addr = bootpg;
 

diff --git a/arch/powerpc/cpu/mpc85xx/mp.h b/arch/powerpc/cpu/mpc85xx/mp.h
index 3422cc107009ac66582302b338da3f6a8671779b..87bac3715268df45949dc892f68d610450c1e17d 100644 (file)
--- a/arch/powerpc/cpu/mpc85xx/mp.h
+++ b/arch/powerpc/cpu/mpc85xx/mp.h
@@ -6,6 +6,7 @@
 ulong get_spin_phys_addr(void);
 ulong get_spin_virt_addr(void);
 u32 get_my_id(void);
+int hold_cores_in_reset(int verbose);
 
 #define BOOT_ENTRY_ADDR_UPPER  0
 #define BOOT_ENTRY_ADDR_LOWER  1