apply FEAT_LSUI instruction to emulate deprecated swpX instruction.
Signed-off-by: Yeoreum Yun yeoreum.yun@arm.com --- arch/arm64/kernel/armv8_deprecated.c | 52 ++++++++++++++++++++++++++-- 1 file changed, 50 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c index d15e35f1075c..424cf51d554f 100644 --- a/arch/arm64/kernel/armv8_deprecated.c +++ b/arch/arm64/kernel/armv8_deprecated.c @@ -13,6 +13,7 @@ #include <linux/uaccess.h>
#include <asm/cpufeature.h> +#include <asm/lsui.h> #include <asm/insn.h> #include <asm/sysreg.h> #include <asm/system_misc.h> @@ -86,6 +87,53 @@ static unsigned int __maybe_unused aarch32_check_condition(u32 opcode, u32 psr) * Rn = address */
+#ifdef CONFIG_AS_HAS_LSUI +static __always_inline int +__lsui_user_swp_asm(unsigned int *data, unsigned int addr) +{ + int err = 0; + unsigned int temp; + + asm volatile("// __lsui_user_swp_asm\n" + __LSUI_PREAMBLE + "1: swpt %w1, %w2, [%3]\n" + " mov %w1, %w2\n" + "2:\n" + _ASM_EXTABLE_UACCESS_ERR(1b, 2b, %w0) + : "+r" (err), "+r" (*data), "=&r" (temp) + : "r" ((unsigned long)addr) + : "memory"); + + return err; +} + +static __always_inline int +__lsui_user_swpb_asm(unsigned int *data, unsigned int addr) +{ + unsigned char idx; + int err; + unsigned int addr_al; + union { + unsigned int var; + unsigned char raw[4]; + } data_al; + + idx = addr & (sizeof(unsigned int) - 1); + addr_al = ALIGN_DOWN(addr, sizeof(unsigned int)); + + if (get_user(data_al.var, (unsigned int *)(unsigned long)addr_al)) + return -EFAULT; + + data_al.raw[idx] = *data; + + err = __lsui_user_swp_asm(&data_al.var, addr_al); + if (!err) + *data = data_al.raw[idx]; + + return err; +} +#endif /* CONFIG_AS_HAS_LSUI */ + /* * Error-checking SWP macros implemented using ldxr{b}/stxr{b} */ @@ -128,9 +176,9 @@ LLSC_USER_SWPX() LLSC_USER_SWPX(b)
#define __user_swp_asm(data, addr) \ - __llsc_user_swp_asm(data, addr) + __lsui_llsc_body(user_swp_asm, data, addr) #define __user_swpb_asm(data, addr) \ - __llsc_user_swpb_asm(data, addr) + __lsui_llsc_body(user_swpb_asm, data, addr)
/* * Bit 22 of the instruction encoding distinguishes between