diff mbox series

[-next,V13,2/3] riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK

Message ID 20230614013018.2168426-3-guoren@kernel.org (mailing list archive)
State Accepted
Commit dd69d07a5a6c5a9ada85321ab0695e7978fc6f3e
Headers show
Series riscv: Add independent irq/softirq stacks support | expand

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conchuod/tree_selection success Guessed tree name to be for-next at HEAD d5e45e810e0e
conchuod/fixes_present success Fixes tag not required for -next series
conchuod/maintainers_pattern success MAINTAINERS pattern errors before the patch: 6 and now 6
conchuod/verify_signedoff success Signed-off-by tag matches author and committer
conchuod/kdoc success Errors and warnings before: 0 this patch: 0
conchuod/build_rv64_clang_allmodconfig success Errors and warnings before: 8 this patch: 8
conchuod/module_param success Was 0 now: 0
conchuod/build_rv64_gcc_allmodconfig success Errors and warnings before: 8 this patch: 8
conchuod/build_rv32_defconfig success Build OK
conchuod/dtb_warn_rv64 success Errors and warnings before: 3 this patch: 3
conchuod/header_inline success No static functions without inline keyword in header files
conchuod/checkpatch warning CHECK: Concatenated strings should use spaces between elements CHECK: Consider using #include <linux/smp.h> instead of <asm/smp.h> CHECK: Lines should not end with a '(' CHECK: Unbalanced braces around else statement CHECK: spaces preferred around that '/' (ctx:VxV) WARNING: unnecessary whitespace before a quoted newline
conchuod/build_rv64_nommu_k210_defconfig success Build OK
conchuod/verify_fixes success No Fixes tag
conchuod/build_rv64_nommu_virt_defconfig success Build OK

Commit Message

Guo Ren June 14, 2023, 1:30 a.m. UTC 
From: Guo Ren <guoren@linux.alibaba.com>

Add the HAVE_SOFTIRQ_ON_OWN_STACK feature for the IRQ_STACKS config, and
the irq and softirq use the same irq_stack of percpu.

Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
 arch/riscv/Kconfig      |  6 ++++--
 arch/riscv/kernel/irq.c | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index a8368fe7be14..f515cb101c19 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -591,11 +591,13 @@  config FPU
 	  If you don't know what to do here, say Y.
 
 config IRQ_STACKS
-	bool "Independent irq stacks" if EXPERT
+	bool "Independent irq & softirq stacks" if EXPERT
 	default y
 	select HAVE_IRQ_EXIT_ON_IRQ_STACK
+	select HAVE_SOFTIRQ_ON_OWN_STACK
 	help
-	  Add independent irq stacks for percpu to prevent kernel stack overflows.
+	  Add independent irq & softirq stacks for percpu to prevent kernel stack
+	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
 
 endmenu # "Platform type"
 
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
index a1dcf8e43b3c..d0577cc6a081 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -11,6 +11,9 @@ 
 #include <linux/module.h>
 #include <linux/seq_file.h>
 #include <asm/sbi.h>
+#include <asm/smp.h>
+#include <asm/softirq_stack.h>
+#include <asm/stacktrace.h>
 
 static struct fwnode_handle *(*__get_intc_node)(void);
 
@@ -56,6 +59,38 @@  static void init_irq_stacks(void)
 		per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
 }
 #endif /* CONFIG_VMAP_STACK */
+
+#ifdef CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK
+void do_softirq_own_stack(void)
+{
+#ifdef CONFIG_IRQ_STACKS
+	if (on_thread_stack()) {
+		ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id())
+					+ IRQ_STACK_SIZE/sizeof(ulong);
+		__asm__ __volatile(
+		"addi	sp, sp, -"RISCV_SZPTR  "\n"
+		REG_S"  ra, (sp)		\n"
+		"addi	sp, sp, -"RISCV_SZPTR  "\n"
+		REG_S"  s0, (sp)		\n"
+		"addi	s0, sp, 2*"RISCV_SZPTR "\n"
+		"move	sp, %[sp]		\n"
+		"call	__do_softirq		\n"
+		"addi	sp, s0, -2*"RISCV_SZPTR"\n"
+		REG_L"  s0, (sp)		\n"
+		"addi	sp, sp, "RISCV_SZPTR   "\n"
+		REG_L"  ra, (sp)		\n"
+		"addi	sp, sp, "RISCV_SZPTR   "\n"
+		:
+		: [sp] "r" (sp)
+		: "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
+		  "t0", "t1", "t2", "t3", "t4", "t5", "t6",
+		  "memory");
+	} else
+#endif
+		__do_softirq();
+}
+#endif /* CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK */
+
 #else
 static void init_irq_stacks(void) {}
 #endif /* CONFIG_IRQ_STACKS */