Merge tag 'riscv-for-linus-5.13-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:

 - A fix to avoid over-allocating the kernel's mapping on !MMU systems,
   which could lead to up to 2MiB of lost memory

 - The SiFive address extension errata only manifest on rv64, they are
   now disabled on rv32 where they are unnecessary

 - A pair of late-landing cleanups

* tag 'riscv-for-linus-5.13-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: remove unused handle_exception symbol
  riscv: Consistify protect_kernel_linear_mapping_text_rodata() use
  riscv: enable SiFive errata CIP-453 and CIP-1200 Kconfig only if CONFIG_64BIT=y
  riscv: Only extend kernel reservation if mapped read-only

Author: torvalds

arch/riscv/Kconfig.erratas

@@ -21,7 +21,7 @@ config ERRATA_SIFIVE
 
 config ERRATA_SIFIVE_CIP_453
 	bool "Apply SiFive errata CIP-453"
-	depends on ERRATA_SIFIVE
+	depends on ERRATA_SIFIVE && 64BIT
 	default y
 	help
 	  This will apply the SiFive CIP-453 errata to add sign extension
@@ -32,7 +32,7 @@ config ERRATA_SIFIVE_CIP_453
 
 config ERRATA_SIFIVE_CIP_1200
 	bool "Apply SiFive errata CIP-1200"
-	depends on ERRATA_SIFIVE
+	depends on ERRATA_SIFIVE && 64BIT
 	default y
 	help
 	  This will apply the SiFive CIP-1200 errata to repalce all

arch/riscv/include/asm/set_memory.h

@@ -17,7 +17,6 @@ int set_memory_x(unsigned long addr, int numpages);
 int set_memory_nx(unsigned long addr, int numpages);
 int set_memory_rw_nx(unsigned long addr, int numpages);
 void protect_kernel_text_data(void);
-void protect_kernel_linear_mapping_text_rodata(void);
 #else
 static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; }
 static inline int set_memory_rw(unsigned long addr, int numpages) { return 0; }
@@ -27,6 +26,12 @@ static inline void protect_kernel_text_data(void) {}
 static inline int set_memory_rw_nx(unsigned long addr, int numpages) { return 0; }
 #endif
 
+#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
+void protect_kernel_linear_mapping_text_rodata(void);
+#else
+static inline void protect_kernel_linear_mapping_text_rodata(void) {}
+#endif
+
 int set_direct_map_invalid_noflush(struct page *page);
 int set_direct_map_default_noflush(struct page *page);
 bool kernel_page_present(struct page *page);

arch/riscv/kernel/setup.c

@@ -293,9 +293,7 @@ void __init setup_arch(char **cmdline_p)
 
 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
 		protect_kernel_text_data();
-#if defined(CONFIG_64BIT) && defined(CONFIG_MMU) && !defined(CONFIG_XIP_KERNEL)
 		protect_kernel_linear_mapping_text_rodata();
-#endif
 	}
 
 #ifdef CONFIG_SWIOTLB

arch/riscv/kernel/traps.c

@@ -25,8 +25,6 @@
 
 int show_unhandled_signals = 1;
 
-extern asmlinkage void handle_exception(void);
-
 static DEFINE_SPINLOCK(die_lock);
 
 void die(struct pt_regs *regs, const char *str)

arch/riscv/mm/init.c

@@ -135,11 +135,16 @@ void __init setup_bootmem(void)
 
 	/*
 	 * Reserve from the start of the kernel to the end of the kernel
-	 * and make sure we align the reservation on PMD_SIZE since we will
+	 */
+#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
+	/*
+	 * Make sure we align the reservation on PMD_SIZE since we will
 	 * map the kernel in the linear mapping as read-only: we do not want
 	 * any allocation to happen between _end and the next pmd aligned page.
 	 */
-	memblock_reserve(vmlinux_start, (vmlinux_end - vmlinux_start + PMD_SIZE - 1) & PMD_MASK);
+	vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
+#endif
+	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
 
 	/*
 	 * memblock allocator is not aware of the fact that last 4K bytes of
@@ -640,7 +645,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 #endif
 }
 
-#if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
+#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
 void protect_kernel_linear_mapping_text_rodata(void)
 {
 	unsigned long text_start = (unsigned long)lm_alias(_start);