riscv: andes_plic: init plic by scanning each cpu node

Initialize plic driver by ofnode_for_each_subnode() instead
of cpu_get_count().

This way can support to skip some harts which maybe marked as
unavailable, but the cpu node exists indeed.

Signed-off-by: Rick Chen <rick@andestech.com>
Cc: KC Lin <kclin@andestech.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/arch/riscv/lib/andes_plic.c b/arch/riscv/lib/andes_plic.c
index 2ffe49ac9011fa691d5d0d62b341a1cb91960c23..28568e4e2b6f7f0468d0b8fa5023b1af0d294a17 100644 (file)
--- a/arch/riscv/lib/andes_plic.c
+++ b/arch/riscv/lib/andes_plic.c
@@ -44,15 +44,12 @@ static int init_plic(void);
                }                                                       \
        } while (0)
 
-static int enable_ipi(int harts)
+static int enable_ipi(int hart)
 {
-       int i;
-       int en = ENABLE_HART_IPI;
+       int en;
 
-       for (i = 0; i < harts; i++) {
-               en = en >> i;
-               writel(en, (void __iomem *)ENABLE_REG(gd->arch.plic, i));
-       }
+       en = ENABLE_HART_IPI >> hart;
+       writel(en, (void __iomem *)ENABLE_REG(gd->arch.plic, hart));
 
        return 0;
 }
@@ -60,18 +57,35 @@ static int enable_ipi(int harts)
 static int init_plic(void)
 {
        struct udevice *dev;
+       ofnode node;
        int ret;
+       u32 reg;
 
        ret = uclass_find_first_device(UCLASS_CPU, &dev);
        if (ret)
                return ret;
 
        if (ret == 0 && dev) {
-               ret = cpu_get_count(dev);
-               if (ret < 0)
-                       return ret;
+               ofnode_for_each_subnode(node, dev_ofnode(dev->parent)) {
+                       const char *device_type;
+
+                       device_type = ofnode_read_string(node, "device_type");
+                       if (!device_type)
+                               continue;
+
+                       if (strcmp(device_type, "cpu"))
+                               continue;
+
+                       /* skip if hart is marked as not available */
+                       if (!ofnode_is_available(node))
+                               continue;
+
+                       /* read hart ID of CPU */
+                       ret = ofnode_read_u32(node, "reg", &reg);
+                       if (ret == 0)
+                               enable_ipi(reg);
+               }
 
-               enable_ipi(ret);
                return 0;
        }