Revert "arm64: add fault handling to SWP emulation" (0abe6000) · Commits · e / devices / android_kernel_xiaomi_markw

arch/arm64/kernel/swp_emulate.c

+6 −72

Original line number	Diff line number	Diff line
		@@ -32,71 +32,6 @@
		#include <asm/system_misc.h>
		#include <linux/debugfs.h>

		/*
		* Error-checking SWP macros implemented using ldrex{b}/strex{b}
		*/

		static int swpb(u8 in, u8 out, u8 addr)
		{
		u8 _out;
		int res;
		int err = 0;

		do {
		__asm__ __volatile__(
		"0: ldxrb %w1, %4\n"
		"1: stxrb %w0, %w3, %4\n"
		"2:\n"
		" .section .fixup,\"ax\"\n"
		" .align 2\n"
		"3: mov %w2, %5\n"
		" b 2b\n"
		" .previous\n"
		" .section __ex_table,\"a\"\n"
		" .align 3\n"
		" .quad 0b, 3b\n"
		" .quad 1b, 3b\n"
		" .previous"
		: "=&r" (res), "=r" (_out), "=r" (err)
		: "r" (in), "Q" (addr), "i" (-EFAULT)
		: "cc", "memory");
		} while (err == 0 && res != 0);

		if (err == 0)
		*out = _out;
		return err;
		}

		static int swp(u32 in, u32 out, u32 addr)
		{
		u32 _out;
		int res;
		int err = 0;

		do {
		__asm__ __volatile__(
		"0: ldxr %w1, %4\n"
		"1: stxr %w0, %w3, %4\n"
		"2:\n"
		" .section .fixup,\"ax\"\n"
		" .align 2\n"
		"3: mov %w2, %5\n"
		" b 2b\n"
		" .previous\n"
		" .section __ex_table,\"a\"\n"
		" .align 3\n"
		" .quad 0b, 3b\n"
		" .quad 1b, 3b\n"
		" .previous"
		: "=&r" (res), "=r" (_out), "=r" (err)
		: "r" (in), "Q" (addr), "i" (-EFAULT)
		: "cc", "memory");
		} while (err == 0 && res != 0);

		if (err == 0)
		*out = _out;
		return err;
		}
		/*
		* Macros/defines for extracting register numbers from instruction.
		*/
		@@ -126,7 +61,6 @@ static int swp_handler(struct pt_regs *regs, unsigned int instr)
		u32 destreg, data, type;
		uintptr_t address;
		unsigned int res = 0;
		int err;
		u32 temp32;
		u8 temp8;

		@@ -166,9 +100,9 @@ static int swp_handler(struct pt_regs *regs, unsigned int instr)
		res = -EFAULT;
		}
		if (type == TYPE_SWPB) {
		err = swpb((u8) data, &temp8, (u8 *) address);
		if (err)
		return err;
		do {
		temp8 = ldax8((u8 *) address);
		} while (stlx8((u8 *) address, (u8) data));
		regs->regs[destreg] = temp8;
		regs->pc += 4;
		swpb_count++;
		@@ -177,9 +111,9 @@ static int swp_handler(struct pt_regs *regs, unsigned int instr)
		pr_debug("SWP instruction on unaligned pointer!\n");
		return -EFAULT;
		} else {
		err = swp((u32) data, &temp32, (u32 *) address);
		if (err)
		return err;
		do {
		temp32 = ldax32((u32 *) address);
		} while (stlx32((u32 *) address, (u32) data));
		regs->regs[destreg] = temp32;
		regs->pc += 4;
		swp_count++;