1 files changed, 102 insertions, 42 deletions

diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index 2e018b8c2e19..7b2340996cf8 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -123,6 +123,7 @@ static void read_arc_build_cfg_regs(void)
         struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
         const struct id_to_str *tbl;
         struct bcr_isa_arcv2 isa;
+        struct bcr_actionpoint ap;
 
         FIX_PTR(cpu);
 
@@ -195,20 +196,40 @@ static void read_arc_build_cfg_regs(void)
                 cpu->bpu.full = bpu.ft;
                 cpu->bpu.num_cache = 256 << bpu.bce;
                 cpu->bpu.num_pred = 2048 << bpu.pte;
+                cpu->bpu.ret_stk = 4 << bpu.rse;
 
                 if (cpu->core.family >= 0x54) {
-                        unsigned int exec_ctrl;
 
-                        READ_BCR(AUX_EXEC_CTRL, exec_ctrl);
-                        cpu->extn.dual_enb = !(exec_ctrl & 1);
+                        struct bcr_uarch_build_arcv2 uarch;
 
-                        /* dual issue always present for this core */
-                        cpu->extn.dual = 1;
+                        /*
+                         * The first 0x54 core (uarch maj:min 0:1 or 0:2) was
+                         * dual issue only (HS4x). But next uarch rev (1:0)
+                         * allows it be configured for single issue (HS3x)
+                         * Ensure we fiddle with dual issue only on HS4x
+                         */
+                        READ_BCR(ARC_REG_MICRO_ARCH_BCR, uarch);
+
+                        if (uarch.prod == 4) {
+                                unsigned int exec_ctrl;
+
+                                /* dual issue hardware always present */
+                                cpu->extn.dual = 1;
+
+                                READ_BCR(AUX_EXEC_CTRL, exec_ctrl);
+
+                                /* dual issue hardware enabled ? */
+                                cpu->extn.dual_enb = !(exec_ctrl & 1);
+
+                        }
                 }
         }
 
-        READ_BCR(ARC_REG_AP_BCR, bcr);
-        cpu->extn.ap = bcr.ver ? 1 : 0;
+        READ_BCR(ARC_REG_AP_BCR, ap);
+        if (ap.ver) {
+                cpu->extn.ap_num = 2 << ap.num;
+                cpu->extn.ap_full = !ap.min;
+        }
 
         READ_BCR(ARC_REG_SMART_BCR, bcr);
         cpu->extn.smart = bcr.ver ? 1 : 0;
@@ -216,8 +237,6 @@ static void read_arc_build_cfg_regs(void)
         READ_BCR(ARC_REG_RTT_BCR, bcr);
         cpu->extn.rtt = bcr.ver ? 1 : 0;
 
-        cpu->extn.debug = cpu->extn.ap | cpu->extn.smart | cpu->extn.rtt;
-
         READ_BCR(ARC_REG_ISA_CFG_BCR, isa);
 
         /* some hacks for lack of feature BCR info in old ARC700 cores */
@@ -299,10 +318,10 @@ static char *arc_cpu_mumbojumbo(int cpu_id, char *buf, int len)
 
         if (cpu->bpu.ver)
                 n += scnprintf(buf + n, len - n,
-                              "BPU\t\t: %s%s match, cache:%d, Predict Table:%d",
+                              "BPU\t\t: %s%s match, cache:%d, Predict Table:%d Return stk: %d",
                               IS_AVAIL1(cpu->bpu.full, "full"),
                               IS_AVAIL1(!cpu->bpu.full, "partial"),
-                              cpu->bpu.num_cache, cpu->bpu.num_pred);
+                              cpu->bpu.num_cache, cpu->bpu.num_pred, cpu->bpu.ret_stk);
 
         if (is_isa_arcv2()) {
                 struct bcr_lpb lpb;
@@ -336,11 +355,17 @@ static char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len)
                                IS_AVAIL1(cpu->extn.fpu_sp, "SP "),
                                IS_AVAIL1(cpu->extn.fpu_dp, "DP "));
 
-        if (cpu->extn.debug)
-                n += scnprintf(buf + n, len - n, "DEBUG\t\t: %s%s%s\n",
-                               IS_AVAIL1(cpu->extn.ap, "ActionPoint "),
+        if (cpu->extn.ap_num | cpu->extn.smart | cpu->extn.rtt) {
+                n += scnprintf(buf + n, len - n, "DEBUG\t\t: %s%s",
                                IS_AVAIL1(cpu->extn.smart, "smaRT "),
                                IS_AVAIL1(cpu->extn.rtt, "RTT "));
+                if (cpu->extn.ap_num) {
+                        n += scnprintf(buf + n, len - n, "ActionPoint %d/%s",
+                                       cpu->extn.ap_num,
+                                       cpu->extn.ap_full ? "full":"min");
+                }
+                n += scnprintf(buf + n, len - n, "\n");
+        }
 
         if (cpu->dccm.sz || cpu->iccm.sz)
                 n += scnprintf(buf + n, len - n, "Extn [CCM]\t: DCCM @ %x, %d KB / ICCM: @ %x, %d KB\n",
@@ -453,43 +478,78 @@ void setup_processor(void)
         arc_chk_core_config();
 }
 
-static inline int is_kernel(unsigned long addr)
+static inline bool uboot_arg_invalid(unsigned long addr)
 {
-        if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
-                return 1;
-        return 0;
+        /*
+         * Check that it is a untranslated address (although MMU is not enabled
+         * yet, it being a high address ensures this is not by fluke)
+         */
+        if (addr < PAGE_OFFSET)
+                return true;
+
+        /* Check that address doesn't clobber resident kernel image */
+        return addr >= (unsigned long)_stext && addr <= (unsigned long)_end;
 }
 
-void __init setup_arch(char **cmdline_p)
+#define IGNORE_ARGS             "Ignore U-boot args: "
+
+/* uboot_tag values for U-boot - kernel ABI revision 0; see head.S */
+#define UBOOT_TAG_NONE          0
+#define UBOOT_TAG_CMDLINE       1
+#define UBOOT_TAG_DTB           2
+
+void __init handle_uboot_args(void)
 {
-#ifdef CONFIG_ARC_UBOOT_SUPPORT
-        /* make sure that uboot passed pointer to cmdline/dtb is valid */
-        if (uboot_tag && is_kernel((unsigned long)uboot_arg))
-                panic("Invalid uboot arg\n");
-
-        /* See if u-boot passed an external Device Tree blob */
-        machine_desc = setup_machine_fdt(uboot_arg);    /* uboot_tag == 2 */
-        if (!machine_desc)
-#endif
-        {
-                /* No, so try the embedded one */
+        bool use_embedded_dtb = true;
+        bool append_cmdline = false;
+
+        /* check that we know this tag */
+        if (uboot_tag != UBOOT_TAG_NONE &&
+            uboot_tag != UBOOT_TAG_CMDLINE &&
+            uboot_tag != UBOOT_TAG_DTB) {
+                pr_warn(IGNORE_ARGS "invalid uboot tag: '%08x'\n", uboot_tag);
+                goto ignore_uboot_args;
+        }
+
+        if (uboot_tag != UBOOT_TAG_NONE &&
+            uboot_arg_invalid((unsigned long)uboot_arg)) {
+                pr_warn(IGNORE_ARGS "invalid uboot arg: '%px'\n", uboot_arg);
+                goto ignore_uboot_args;
+        }
+
+        /* see if U-boot passed an external Device Tree blob */
+        if (uboot_tag == UBOOT_TAG_DTB) {
+                machine_desc = setup_machine_fdt((void *)uboot_arg);
+
+                /* external Device Tree blob is invalid - use embedded one */
+                use_embedded_dtb = !machine_desc;
+        }
+
+        if (uboot_tag == UBOOT_TAG_CMDLINE)
+                append_cmdline = true;
+
+ignore_uboot_args:
+
+        if (use_embedded_dtb) {
                 machine_desc = setup_machine_fdt(__dtb_start);
                 if (!machine_desc)
                         panic("Embedded DT invalid\n");
+        }
 
-                /*
-                 * If we are here, it is established that @uboot_arg didn't
-                 * point to DT blob. Instead if u-boot says it is cmdline,
-                 * append to embedded DT cmdline.
-                 * setup_machine_fdt() would have populated @boot_command_line
-                 */
-                if (uboot_tag == 1) {
-                        /* Ensure a whitespace between the 2 cmdlines */
-                        strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
-                        strlcat(boot_command_line, uboot_arg,
-                                COMMAND_LINE_SIZE);
-                }
+        /*
+         * NOTE: @boot_command_line is populated by setup_machine_fdt() so this
+         * append processing can only happen after.
+         */
+        if (append_cmdline) {
+                /* Ensure a whitespace between the 2 cmdlines */
+                strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
+                strlcat(boot_command_line, uboot_arg, COMMAND_LINE_SIZE);
         }
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+        handle_uboot_args();
 
         /* Save unparsed command line copy for /proc/cmdline */
         *cmdline_p = boot_command_line;