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-rw-r--r--arch/arc/kernel/setup.c119
1 files changed, 85 insertions, 34 deletions
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index feb90093e6b1..7b2340996cf8 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -199,20 +199,36 @@ static void read_arc_build_cfg_regs(void)
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, ap);
if (ap.ver) {
cpu->extn.ap_num = 2 << ap.num;
- cpu->extn.ap_full = !!ap.min;
+ cpu->extn.ap_full = !ap.min;
}
READ_BCR(ARC_REG_SMART_BCR, bcr);
@@ -462,43 +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;