Implements dt_processor_hartid() to get the hart ID of the given
device tree node and do some checks if CPU is available and given device
tree node has proper riscv,isa property.
As a helper function dt_get_hartid() is introduced to deal specifically
with reg propery of a CPU device node.
Signed-off-by: Oleksii Kurochko <oleksii.kuroc...@gmail.com>
---
Changes in V3:
- s/dt_processor_cpuid/dt_processor_hartid.
- s/dt_get_cpuid/dt_get_hartid.
- use ~0UL in dt_get_cpuid() and in the comment above it.
- change type for local variable ac in dt_get_cpuid() to unsigned int.
- Update the return errors for dt_processor_cpuid().
- Update the commit message + subject: s/cpuid/hartid.
---
Changes in V2:
- s/of_get_cpu_hwid()/dt_get_cpu_id().
- Update prototype of dt_get_cpu_hwid(), use pointer-to-const for cpun arg.
- Add empty line before last return in dt_get_cpu_hwid().
- s/riscv_of_processor_hartid/dt_processor_cpuid().
- Use pointer-to_const for node argument of dt_processor_cpuid().
- Use for hart_id unsigned long type as according to the spec for RV128
mhartid register will be 128 bit long.
- Update commit message and subject.
- use 'CPU' instead of 'HART'.
- Drop thread argument of dt_get_cpu_id() (of_get_cpu_hwid) as it is
expected to be always 0 according to RISC-V's DTS binding.
---
xen/arch/riscv/include/asm/smp.h | 4 ++
xen/arch/riscv/smpboot.c | 69 ++++++++++++++++++++++++++++++++
2 files changed, 73 insertions(+)
diff --git a/xen/arch/riscv/include/asm/smp.h b/xen/arch/riscv/include/asm/smp.h
index 5e170b57b3..eb58b6576b 100644
--- a/xen/arch/riscv/include/asm/smp.h
+++ b/xen/arch/riscv/include/asm/smp.h
@@ -26,6 +26,10 @@ static inline void set_cpuid_to_hartid(unsigned long cpuid,
void setup_tp(unsigned int cpuid);
+struct dt_device_node;
+int dt_processor_hartid(const struct dt_device_node *node,
+ unsigned long *hartid);
+
#endif
/*
diff --git a/xen/arch/riscv/smpboot.c b/xen/arch/riscv/smpboot.c
index 0f9c2cc54a..b8d18fc3ea 100644
--- a/xen/arch/riscv/smpboot.c
+++ b/xen/arch/riscv/smpboot.c
@@ -1,5 +1,8 @@
#include <xen/cpumask.h>
+#include <xen/device_tree.h>
+#include <xen/errno.h>
#include <xen/init.h>
+#include <xen/types.h>
#include <xen/sections.h>
#include <asm/current.h>
@@ -14,3 +17,69 @@ void __init smp_prepare_boot_cpu(void)
cpumask_set_cpu(0, &cpu_possible_map);
cpumask_set_cpu(0, &cpu_online_map);
}
+
+/**
+ * dt_get_hartid - Get the hartid from a CPU device node
+ *
+ * @cpun: CPU number(logical index) for which device node is required
+ *
+ * Return: The hartid for the CPU node or ~0UL if not found.
+ */
+static unsigned long dt_get_hartid(const struct dt_device_node *cpun)
+{
+ const __be32 *cell;
+ unsigned int ac;
+ uint32_t len;
+
+ ac = dt_n_addr_cells(cpun);
+ cell = dt_get_property(cpun, "reg", &len);
+ if ( !cell || !ac || ((sizeof(*cell) * ac) > len) )
+ return ~0UL;
+
+ return dt_read_number(cell, ac);
+}
+
+/*
+ * Returns the hartid of the given device tree node, or -ENODEV if the node
+ * isn't an enabled and valid RISC-V hart node.
+ */
+int dt_processor_hartid(const struct dt_device_node *node,
+ unsigned long *hartid)
+{
+ const char *isa;
+ int ret;
+
+ if ( !dt_device_is_compatible(node, "riscv") )
+ {
+ printk("Found incompatible CPU\n");
+ return -ENODEV;
+ }
+
+ *hartid = dt_get_hartid(node);
+ if ( *hartid == ~0UL )
+ {
+ printk("Found CPU without CPU ID\n");
+ return -ENODATA;
+ }
+
+ if ( !dt_device_is_available(node))
+ {
+ printk("CPU with hartid=%lu is not available\n", *hartid);
+ return -ENODEV;
+ }
+
+ if ( (ret = dt_property_read_string(node, "riscv,isa", &isa)) )
+ {
+ printk("CPU with hartid=%lu has no \"riscv,isa\" property\n", *hartid);
+ return ret;
+ }
+
+ if ( isa[0] != 'r' || isa[1] != 'v' )
+ {
+ printk("CPU with hartid=%lu has an invalid ISA of \"%s\"\n", *hartid,
+ isa);
+ return -EINVAL;
+ }
+
+ return 0;
+}
--
2.49.0
