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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] xen/riscv: introduce functionality to work with CPU info
commit b6c8f34a902955ed69670b48bc1d799fc83caba8
Author: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
AuthorDate: Mon Sep 30 10:11:18 2024 +0200
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Mon Sep 30 10:11:18 2024 +0200
xen/riscv: introduce functionality to work with CPU info
Introduce struct pcpu_info to store pCPU-related information.
Initially, it includes only processor_id and hart id, but it
will be extended to include guest CPU information and
temporary variables for saving/restoring vCPU registers.
Add set_processor_id() function to set processor_id stored in
pcpu_info.
Define smp_processor_id() to provide accurate information,
replacing the previous "dummy" value of 0.
Initialize tp registers to point to pcpu_info[0].
Set processor_id to 0 for logical CPU 0 and store the physical
CPU ID in pcpu_info[0].
Introduce helpers for getting/setting hart_id ( physical CPU id
in RISC-V terms ) from Xen CPU id.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
xen/arch/riscv/Makefile | 1 +
xen/arch/riscv/include/asm/current.h | 27 ++++++++++++++++++++++++++-
xen/arch/riscv/include/asm/processor.h | 3 ---
xen/arch/riscv/include/asm/smp.h | 18 ++++++++++++++++++
xen/arch/riscv/riscv64/asm-offsets.c | 3 +++
xen/arch/riscv/riscv64/head.S | 14 ++++++++++++++
xen/arch/riscv/setup.c | 5 +++++
xen/arch/riscv/smp.c | 15 +++++++++++++++
8 files changed, 82 insertions(+), 4 deletions(-)
diff --git a/xen/arch/riscv/Makefile b/xen/arch/riscv/Makefile
index d192be7b55..6832549133 100644
--- a/xen/arch/riscv/Makefile
+++ b/xen/arch/riscv/Makefile
@@ -5,6 +5,7 @@ obj-$(CONFIG_RISCV_64) += riscv64/
obj-y += sbi.o
obj-y += setup.o
obj-y += shutdown.o
+obj-y += smp.o
obj-y += stubs.o
obj-y += traps.o
obj-y += vm_event.o
diff --git a/xen/arch/riscv/include/asm/current.h
b/xen/arch/riscv/include/asm/current.h
index aedb6dc732..6f1ec4e190 100644
--- a/xen/arch/riscv/include/asm/current.h
+++ b/xen/arch/riscv/include/asm/current.h
@@ -3,12 +3,37 @@
#ifndef __ASM_CURRENT_H
#define __ASM_CURRENT_H
-#include <xen/lib.h>
+#include <xen/bug.h>
+#include <xen/cache.h>
#include <xen/percpu.h>
+
#include <asm/processor.h>
#ifndef __ASSEMBLY__
+register struct pcpu_info *tp asm ( "tp" );
+
+struct pcpu_info {
+ unsigned int processor_id; /* Xen CPU id */
+ unsigned long hart_id; /* physical CPU id */
+} __cacheline_aligned;
+
+/* tp points to one of these */
+extern struct pcpu_info pcpu_info[NR_CPUS];
+
+#define set_processor_id(id) do { \
+ tp->processor_id = (id); \
+} while (0)
+
+static inline unsigned int smp_processor_id(void)
+{
+ unsigned int id = tp->processor_id;
+
+ BUG_ON(id >= NR_CPUS);
+
+ return id;
+}
+
/* Which VCPU is "current" on this PCPU. */
DECLARE_PER_CPU(struct vcpu *, curr_vcpu);
diff --git a/xen/arch/riscv/include/asm/processor.h
b/xen/arch/riscv/include/asm/processor.h
index 3ae164c265..e42b353b4c 100644
--- a/xen/arch/riscv/include/asm/processor.h
+++ b/xen/arch/riscv/include/asm/processor.h
@@ -12,9 +12,6 @@
#ifndef __ASSEMBLY__
-/* TODO: need to be implemeted */
-#define smp_processor_id() 0
-
/* On stack VCPU state */
struct cpu_user_regs
{
diff --git a/xen/arch/riscv/include/asm/smp.h b/xen/arch/riscv/include/asm/smp.h
index b1ea91b1eb..a824be8e78 100644
--- a/xen/arch/riscv/include/asm/smp.h
+++ b/xen/arch/riscv/include/asm/smp.h
@@ -5,6 +5,8 @@
#include <xen/cpumask.h>
#include <xen/percpu.h>
+#include <asm/current.h>
+
DECLARE_PER_CPU(cpumask_var_t, cpu_sibling_mask);
DECLARE_PER_CPU(cpumask_var_t, cpu_core_mask);
@@ -14,6 +16,22 @@ DECLARE_PER_CPU(cpumask_var_t, cpu_core_mask);
*/
#define park_offline_cpus false
+/*
+ * Mapping between Xen logical cpu index and hartid.
+ */
+static inline unsigned long cpuid_to_hartid(unsigned long cpuid)
+{
+ return pcpu_info[cpuid].hart_id;
+}
+
+static inline void set_cpuid_to_hartid(unsigned long cpuid,
+ unsigned long hartid)
+{
+ pcpu_info[cpuid].hart_id = hartid;
+}
+
+void setup_tp(unsigned int cpuid);
+
#endif
/*
diff --git a/xen/arch/riscv/riscv64/asm-offsets.c
b/xen/arch/riscv/riscv64/asm-offsets.c
index 9f663b9510..3b5daf3b36 100644
--- a/xen/arch/riscv/riscv64/asm-offsets.c
+++ b/xen/arch/riscv/riscv64/asm-offsets.c
@@ -1,5 +1,6 @@
#define COMPILE_OFFSETS
+#include <asm/current.h>
#include <asm/processor.h>
#include <xen/types.h>
@@ -50,4 +51,6 @@ void asm_offsets(void)
OFFSET(CPU_USER_REGS_SSTATUS, struct cpu_user_regs, sstatus);
OFFSET(CPU_USER_REGS_PREGS, struct cpu_user_regs, pregs);
BLANK();
+ DEFINE(PCPU_INFO_SIZE, sizeof(struct pcpu_info));
+ BLANK();
}
diff --git a/xen/arch/riscv/riscv64/head.S b/xen/arch/riscv/riscv64/head.S
index 3261e9fce8..2a1b3dad91 100644
--- a/xen/arch/riscv/riscv64/head.S
+++ b/xen/arch/riscv/riscv64/head.S
@@ -1,4 +1,5 @@
#include <asm/asm.h>
+#include <asm/asm-offsets.h>
#include <asm/riscv_encoding.h>
.section .text.header, "ax", %progbits
@@ -55,6 +56,10 @@ FUNC(start)
*/
jal reset_stack
+ /* Xen's boot cpu id is equal to 0 so setup TP register for it */
+ li a0, 0
+ jal setup_tp
+
/* restore hart_id ( bootcpu_id ) and dtb address */
mv a0, s0
mv a1, s1
@@ -72,6 +77,15 @@ FUNC(reset_stack)
ret
END(reset_stack)
+/* void setup_tp(unsigned int xen_cpuid); */
+FUNC(setup_tp)
+ la t0, pcpu_info
+ li t1, PCPU_INFO_SIZE
+ mul t1, a0, t1
+ add tp, t0, t1
+ ret
+END(setup_tp)
+
.section .text.ident, "ax", %progbits
FUNC(turn_on_mmu)
diff --git a/xen/arch/riscv/setup.c b/xen/arch/riscv/setup.c
index ace5ab91e3..b9850a9801 100644
--- a/xen/arch/riscv/setup.c
+++ b/xen/arch/riscv/setup.c
@@ -9,6 +9,7 @@
#include <public/version.h>
#include <asm/early_printk.h>
+#include <asm/smp.h>
#include <asm/traps.h>
void arch_get_xen_caps(xen_capabilities_info_t *info)
@@ -25,6 +26,10 @@ void __init noreturn start_xen(unsigned long bootcpu_id,
{
remove_identity_mapping();
+ set_processor_id(0);
+
+ set_cpuid_to_hartid(0, bootcpu_id);
+
trap_init();
setup_fixmap_mappings();
diff --git a/xen/arch/riscv/smp.c b/xen/arch/riscv/smp.c
new file mode 100644
index 0000000000..4ca6a4e892
--- /dev/null
+++ b/xen/arch/riscv/smp.c
@@ -0,0 +1,15 @@
+#include <xen/smp.h>
+
+/*
+ * FIXME: make pcpu_info[] dynamically allocated when necessary
+ * functionality will be ready
+ */
+/*
+ * tp points to one of these per cpu.
+ *
+ * hart_id would be valid (no matter which value) if its
+ * processor_id field is valid (less than NR_CPUS).
+ */
+struct pcpu_info pcpu_info[NR_CPUS] = { [0 ... NR_CPUS - 1] = {
+ .processor_id = NR_CPUS,
+}};
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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