LoongArch: Humanize the CRMD line when showing registers

Example output looks like:

[   xx.xxxxxx]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)

Some initial machinery for this pretty-printing format has been included
in this patch as well.

Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c
index 434a771..97af825 100644 (file)
--- a/arch/loongarch/kernel/traps.c
+++ b/arch/loongarch/kernel/traps.c
@@ -3,6 +3,7 @@
  * Author: Huacai Chen <chenhuacai@loongson.cn>
  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
  */
+#include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/bug.h>
 #include <linux/compiler.h>
@@ -153,6 +154,54 @@ static void show_code(unsigned int *pc, bool user)
        pr_cont("\n");
 }
 
+static void print_bool_fragment(const char *key, unsigned long val, bool first)
+{
+       /* e.g. "+PG", "-DA" */
+       pr_cont("%s%c%s", first ? "" : " ", val ? '+' : '-', key);
+}
+
+static void print_plv_fragment(const char *key, int val)
+{
+       /* e.g. "PLV0", "PPLV3" */
+       pr_cont("%s%d", key, val);
+}
+
+static void print_memory_type_fragment(const char *key, unsigned long val)
+{
+       const char *humanized_type;
+
+       switch (val) {
+       case 0:
+               humanized_type = "SUC";
+               break;
+       case 1:
+               humanized_type = "CC";
+               break;
+       case 2:
+               humanized_type = "WUC";
+               break;
+       default:
+               pr_cont(" %s=Reserved(%lu)", key, val);
+               return;
+       }
+
+       /* e.g. " DATM=WUC" */
+       pr_cont(" %s=%s", key, humanized_type);
+}
+
+static void print_crmd(unsigned long x)
+{
+       printk(" CRMD: %08lx (", x);
+       print_plv_fragment("PLV", (int) FIELD_GET(CSR_CRMD_PLV, x));
+       print_bool_fragment("IE", FIELD_GET(CSR_CRMD_IE, x), false);
+       print_bool_fragment("DA", FIELD_GET(CSR_CRMD_DA, x), false);
+       print_bool_fragment("PG", FIELD_GET(CSR_CRMD_PG, x), false);
+       print_memory_type_fragment("DACF", FIELD_GET(CSR_CRMD_DACF, x));
+       print_memory_type_fragment("DACM", FIELD_GET(CSR_CRMD_DACM, x));
+       print_bool_fragment("WE", FIELD_GET(CSR_CRMD_WE, x), false);
+       pr_cont(")\n");
+}
+
 static void __show_regs(const struct pt_regs *regs)
 {
        const int field = 2 * sizeof(unsigned long);
@@ -194,7 +243,7 @@ static void __show_regs(const struct pt_regs *regs)
 #undef GPR_FIELD
 
        /* Print saved important CSRs */
-       printk(" CRMD: %08lx\n", regs->csr_crmd);
+       print_crmd(regs->csr_crmd);
        printk(" PRMD: %08lx\n", regs->csr_prmd);
        printk(" EUEN: %08lx\n", regs->csr_euen);
        printk(" ECFG: %08lx\n", regs->csr_ecfg);