diff mbox series

[03/12] riscv: implement module alternatives

Message ID 20220511192921.2223629-4-heiko@sntech.de (mailing list archive)
State New
Headers show
Series riscv: support for Svpbmt and D1 memory types | expand

Commit Message

Heiko Stuebner May 11, 2022, 7:29 p.m. UTC
This allows alternatives to also be applied when loading modules
and follows the implementation of other architectures (e.g. arm64).

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
---
 arch/riscv/errata/sifive/errata.c    | 14 +++++++++-----
 arch/riscv/include/asm/alternative.h |  3 +++
 arch/riscv/kernel/alternative.c      | 18 +++++++++++++----
 arch/riscv/kernel/module.c           | 29 ++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+), 9 deletions(-)

Comments

Christoph Hellwig May 16, 2022, 6:02 a.m. UTC | #1
Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Guo Ren May 16, 2022, 6:54 a.m. UTC | #2
Reviewed-by: Guo Ren <guoren@kernel.org>

On Thu, May 12, 2022 at 3:29 AM Heiko Stuebner <heiko@sntech.de> wrote:
>
> This allows alternatives to also be applied when loading modules
> and follows the implementation of other architectures (e.g. arm64).
>
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
> ---
>  arch/riscv/errata/sifive/errata.c    | 14 +++++++++-----
>  arch/riscv/include/asm/alternative.h |  3 +++
>  arch/riscv/kernel/alternative.c      | 18 +++++++++++++----
>  arch/riscv/kernel/module.c           | 29 ++++++++++++++++++++++++++++
>  4 files changed, 55 insertions(+), 9 deletions(-)
>
> diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
> index 4fe03ac41fd7..3e39587a49dc 100644
> --- a/arch/riscv/errata/sifive/errata.c
> +++ b/arch/riscv/errata/sifive/errata.c
> @@ -4,6 +4,7 @@
>   */
>
>  #include <linux/kernel.h>
> +#include <linux/module.h>
>  #include <linux/string.h>
>  #include <linux/bug.h>
>  #include <asm/patch.h>
> @@ -54,7 +55,8 @@ static struct errata_info_t errata_list[ERRATA_SIFIVE_NUMBER] = {
>         },
>  };
>
> -static u32 __init sifive_errata_probe(unsigned long archid, unsigned long impid)
> +static u32 __init_or_module sifive_errata_probe(unsigned long archid,
> +                                               unsigned long impid)
>  {
>         int idx;
>         u32 cpu_req_errata = 0;
> @@ -66,7 +68,7 @@ static u32 __init sifive_errata_probe(unsigned long archid, unsigned long impid)
>         return cpu_req_errata;
>  }
>
> -static void __init warn_miss_errata(u32 miss_errata)
> +static void __init_or_module warn_miss_errata(u32 miss_errata)
>  {
>         int i;
>
> @@ -79,9 +81,11 @@ static void __init warn_miss_errata(u32 miss_errata)
>         pr_warn("----------------------------------------------------------------\n");
>  }
>
> -void __init sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
> -                                    unsigned long archid, unsigned long impid,
> -                                    unsigned int stage)
> +void __init_or_module sifive_errata_patch_func(struct alt_entry *begin,
> +                                              struct alt_entry *end,
> +                                              unsigned long archid,
> +                                              unsigned long impid,
> +                                              unsigned int stage)
>  {
>         struct alt_entry *alt;
>         u32 cpu_req_errata = sifive_errata_probe(archid, impid);
> diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h
> index 0ff550667e94..0859529ff08e 100644
> --- a/arch/riscv/include/asm/alternative.h
> +++ b/arch/riscv/include/asm/alternative.h
> @@ -20,8 +20,10 @@
>  #include <asm/hwcap.h>
>
>  #define RISCV_ALTERNATIVES_BOOT                0 /* alternatives applied during regular boot */
> +#define RISCV_ALTERNATIVES_MODULE      1 /* alternatives applied during module-init */
>
>  void __init apply_boot_alternatives(void);
> +void apply_module_alternatives(void *start, size_t length);
>
>  struct alt_entry {
>         void *old_ptr;           /* address of original instruciton or data  */
> @@ -43,6 +45,7 @@ void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
>  #else /* CONFIG_RISCV_ALTERNATIVE */
>
>  static inline void apply_boot_alternatives(void) { }
> +static inline void apply_module_alternatives(void *start, size_t length) { }
>
>  #endif /* CONFIG_RISCV_ALTERNATIVE */
>
> diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c
> index 02db62f55bac..223770b3945c 100644
> --- a/arch/riscv/kernel/alternative.c
> +++ b/arch/riscv/kernel/alternative.c
> @@ -7,6 +7,7 @@
>   */
>
>  #include <linux/init.h>
> +#include <linux/module.h>
>  #include <linux/cpu.h>
>  #include <linux/uaccess.h>
>  #include <asm/alternative.h>
> @@ -23,7 +24,7 @@ static struct cpu_manufacturer_info_t {
>
>  static void (*vendor_patch_func)(struct alt_entry *begin, struct alt_entry *end,
>                                  unsigned long archid, unsigned long impid,
> -                                unsigned int stage) __initdata;
> +                                unsigned int stage) __initdata_or_module;
>
>  static inline void __init riscv_fill_cpu_mfr_info(void)
>  {
> @@ -58,9 +59,9 @@ static void __init init_alternative(void)
>   * a feature detect on the boot CPU). No need to worry about other CPUs
>   * here.
>   */
> -static void __init _apply_alternatives(struct alt_entry *begin,
> -                                      struct alt_entry *end,
> -                                      unsigned int stage)
> +static void __init_or_module _apply_alternatives(struct alt_entry *begin,
> +                                                struct alt_entry *end,
> +                                                unsigned int stage)
>  {
>         if (!vendor_patch_func)
>                 return;
> @@ -81,3 +82,12 @@ void __init apply_boot_alternatives(void)
>                             (struct alt_entry *)__alt_end,
>                             RISCV_ALTERNATIVES_BOOT);
>  }
> +
> +#ifdef CONFIG_MODULES
> +void apply_module_alternatives(void *start, size_t length)
> +{
> +       _apply_alternatives((struct alt_entry *)start,
> +                           (struct alt_entry *)(start + length),
> +                           RISCV_ALTERNATIVES_MODULE);
> +}
> +#endif
> diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
> index c29cef90d1dd..91fe16bfaa07 100644
> --- a/arch/riscv/kernel/module.c
> +++ b/arch/riscv/kernel/module.c
> @@ -11,6 +11,7 @@
>  #include <linux/vmalloc.h>
>  #include <linux/sizes.h>
>  #include <linux/pgtable.h>
> +#include <asm/alternative.h>
>  #include <asm/sections.h>
>
>  /*
> @@ -427,3 +428,31 @@ void *module_alloc(unsigned long size)
>                                     __builtin_return_address(0));
>  }
>  #endif
> +
> +static const Elf_Shdr *find_section(const Elf_Ehdr *hdr,
> +                                   const Elf_Shdr *sechdrs,
> +                                   const char *name)
> +{
> +       const Elf_Shdr *s, *se;
> +       const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
> +
> +       for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) {
> +               if (strcmp(name, secstrs + s->sh_name) == 0)
> +                       return s;
> +       }
> +
> +       return NULL;
> +}
> +
> +int module_finalize(const Elf_Ehdr *hdr,
> +                   const Elf_Shdr *sechdrs,
> +                   struct module *me)
> +{
> +       const Elf_Shdr *s;
> +
> +       s = find_section(hdr, sechdrs, ".alternative");
> +       if (s)
> +               apply_module_alternatives((void *)s->sh_addr, s->sh_size);
> +
> +       return 0;
> +}
> --
> 2.35.1
>
diff mbox series

Patch

diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
index 4fe03ac41fd7..3e39587a49dc 100644
--- a/arch/riscv/errata/sifive/errata.c
+++ b/arch/riscv/errata/sifive/errata.c
@@ -4,6 +4,7 @@ 
  */
 
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/string.h>
 #include <linux/bug.h>
 #include <asm/patch.h>
@@ -54,7 +55,8 @@  static struct errata_info_t errata_list[ERRATA_SIFIVE_NUMBER] = {
 	},
 };
 
-static u32 __init sifive_errata_probe(unsigned long archid, unsigned long impid)
+static u32 __init_or_module sifive_errata_probe(unsigned long archid,
+						unsigned long impid)
 {
 	int idx;
 	u32 cpu_req_errata = 0;
@@ -66,7 +68,7 @@  static u32 __init sifive_errata_probe(unsigned long archid, unsigned long impid)
 	return cpu_req_errata;
 }
 
-static void __init warn_miss_errata(u32 miss_errata)
+static void __init_or_module warn_miss_errata(u32 miss_errata)
 {
 	int i;
 
@@ -79,9 +81,11 @@  static void __init warn_miss_errata(u32 miss_errata)
 	pr_warn("----------------------------------------------------------------\n");
 }
 
-void __init sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
-				     unsigned long archid, unsigned long impid,
-				     unsigned int stage)
+void __init_or_module sifive_errata_patch_func(struct alt_entry *begin,
+					       struct alt_entry *end,
+					       unsigned long archid,
+					       unsigned long impid,
+					       unsigned int stage)
 {
 	struct alt_entry *alt;
 	u32 cpu_req_errata = sifive_errata_probe(archid, impid);
diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h
index 0ff550667e94..0859529ff08e 100644
--- a/arch/riscv/include/asm/alternative.h
+++ b/arch/riscv/include/asm/alternative.h
@@ -20,8 +20,10 @@ 
 #include <asm/hwcap.h>
 
 #define RISCV_ALTERNATIVES_BOOT		0 /* alternatives applied during regular boot */
+#define RISCV_ALTERNATIVES_MODULE	1 /* alternatives applied during module-init */
 
 void __init apply_boot_alternatives(void);
+void apply_module_alternatives(void *start, size_t length);
 
 struct alt_entry {
 	void *old_ptr;		 /* address of original instruciton or data  */
@@ -43,6 +45,7 @@  void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
 #else /* CONFIG_RISCV_ALTERNATIVE */
 
 static inline void apply_boot_alternatives(void) { }
+static inline void apply_module_alternatives(void *start, size_t length) { }
 
 #endif /* CONFIG_RISCV_ALTERNATIVE */
 
diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c
index 02db62f55bac..223770b3945c 100644
--- a/arch/riscv/kernel/alternative.c
+++ b/arch/riscv/kernel/alternative.c
@@ -7,6 +7,7 @@ 
  */
 
 #include <linux/init.h>
+#include <linux/module.h>
 #include <linux/cpu.h>
 #include <linux/uaccess.h>
 #include <asm/alternative.h>
@@ -23,7 +24,7 @@  static struct cpu_manufacturer_info_t {
 
 static void (*vendor_patch_func)(struct alt_entry *begin, struct alt_entry *end,
 				 unsigned long archid, unsigned long impid,
-				 unsigned int stage) __initdata;
+				 unsigned int stage) __initdata_or_module;
 
 static inline void __init riscv_fill_cpu_mfr_info(void)
 {
@@ -58,9 +59,9 @@  static void __init init_alternative(void)
  * a feature detect on the boot CPU). No need to worry about other CPUs
  * here.
  */
-static void __init _apply_alternatives(struct alt_entry *begin,
-				       struct alt_entry *end,
-				       unsigned int stage)
+static void __init_or_module _apply_alternatives(struct alt_entry *begin,
+						 struct alt_entry *end,
+						 unsigned int stage)
 {
 	if (!vendor_patch_func)
 		return;
@@ -81,3 +82,12 @@  void __init apply_boot_alternatives(void)
 			    (struct alt_entry *)__alt_end,
 			    RISCV_ALTERNATIVES_BOOT);
 }
+
+#ifdef CONFIG_MODULES
+void apply_module_alternatives(void *start, size_t length)
+{
+	_apply_alternatives((struct alt_entry *)start,
+			    (struct alt_entry *)(start + length),
+			    RISCV_ALTERNATIVES_MODULE);
+}
+#endif
diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index c29cef90d1dd..91fe16bfaa07 100644
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c
@@ -11,6 +11,7 @@ 
 #include <linux/vmalloc.h>
 #include <linux/sizes.h>
 #include <linux/pgtable.h>
+#include <asm/alternative.h>
 #include <asm/sections.h>
 
 /*
@@ -427,3 +428,31 @@  void *module_alloc(unsigned long size)
 				    __builtin_return_address(0));
 }
 #endif
+
+static const Elf_Shdr *find_section(const Elf_Ehdr *hdr,
+				    const Elf_Shdr *sechdrs,
+				    const char *name)
+{
+	const Elf_Shdr *s, *se;
+	const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+
+	for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) {
+		if (strcmp(name, secstrs + s->sh_name) == 0)
+			return s;
+	}
+
+	return NULL;
+}
+
+int module_finalize(const Elf_Ehdr *hdr,
+		    const Elf_Shdr *sechdrs,
+		    struct module *me)
+{
+	const Elf_Shdr *s;
+
+	s = find_section(hdr, sechdrs, ".alternative");
+	if (s)
+		apply_module_alternatives((void *)s->sh_addr, s->sh_size);
+
+	return 0;
+}