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-rw-r--r--arch/nds32/mm/alignment.c578
1 files changed, 578 insertions, 0 deletions
diff --git a/arch/nds32/mm/alignment.c b/arch/nds32/mm/alignment.c
new file mode 100644
index 000000000..1eb7ded69
--- /dev/null
+++ b/arch/nds32/mm/alignment.c
@@ -0,0 +1,578 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/proc_fs.h>
+#include <linux/uaccess.h>
+#include <linux/sysctl.h>
+#include <asm/unaligned.h>
+
+#define DEBUG(enable, tagged, ...) \
+ do{ \
+ if (enable) { \
+ if (tagged) \
+ pr_warn("[ %30s() ] ", __func__); \
+ pr_warn(__VA_ARGS__); \
+ } \
+ } while (0)
+
+#define RT(inst) (((inst) >> 20) & 0x1FUL)
+#define RA(inst) (((inst) >> 15) & 0x1FUL)
+#define RB(inst) (((inst) >> 10) & 0x1FUL)
+#define SV(inst) (((inst) >> 8) & 0x3UL)
+#define IMM(inst) (((inst) >> 0) & 0x7FFFUL)
+
+#define RA3(inst) (((inst) >> 3) & 0x7UL)
+#define RT3(inst) (((inst) >> 6) & 0x7UL)
+#define IMM3U(inst) (((inst) >> 0) & 0x7UL)
+
+#define RA5(inst) (((inst) >> 0) & 0x1FUL)
+#define RT4(inst) (((inst) >> 5) & 0xFUL)
+
+#define GET_IMMSVAL(imm_value) \
+ (((imm_value >> 14) & 0x1) ? (imm_value - 0x8000) : imm_value)
+
+#define __get8_data(val,addr,err) \
+ __asm__( \
+ "1: lbi.bi %1, [%2], #1\n" \
+ "2:\n" \
+ " .pushsection .text.fixup,\"ax\"\n" \
+ " .align 2\n" \
+ "3: movi %0, #1\n" \
+ " j 2b\n" \
+ " .popsection\n" \
+ " .pushsection __ex_table,\"a\"\n" \
+ " .align 3\n" \
+ " .long 1b, 3b\n" \
+ " .popsection\n" \
+ : "=r" (err), "=&r" (val), "=r" (addr) \
+ : "0" (err), "2" (addr))
+
+#define get16_data(addr, val_ptr) \
+ do { \
+ unsigned int err = 0, v, a = addr; \
+ __get8_data(v,a,err); \
+ *val_ptr = v << 0; \
+ __get8_data(v,a,err); \
+ *val_ptr |= v << 8; \
+ if (err) \
+ goto fault; \
+ *val_ptr = le16_to_cpu(*val_ptr); \
+ } while(0)
+
+#define get32_data(addr, val_ptr) \
+ do { \
+ unsigned int err = 0, v, a = addr; \
+ __get8_data(v,a,err); \
+ *val_ptr = v << 0; \
+ __get8_data(v,a,err); \
+ *val_ptr |= v << 8; \
+ __get8_data(v,a,err); \
+ *val_ptr |= v << 16; \
+ __get8_data(v,a,err); \
+ *val_ptr |= v << 24; \
+ if (err) \
+ goto fault; \
+ *val_ptr = le32_to_cpu(*val_ptr); \
+ } while(0)
+
+#define get_data(addr, val_ptr, len) \
+ if (len == 2) \
+ get16_data(addr, val_ptr); \
+ else \
+ get32_data(addr, val_ptr);
+
+#define set16_data(addr, val) \
+ do { \
+ unsigned int err = 0, *ptr = addr ; \
+ val = le32_to_cpu(val); \
+ __asm__( \
+ "1: sbi.bi %2, [%1], #1\n" \
+ " srli %2, %2, #8\n" \
+ "2: sbi %2, [%1]\n" \
+ "3:\n" \
+ " .pushsection .text.fixup,\"ax\"\n" \
+ " .align 2\n" \
+ "4: movi %0, #1\n" \
+ " j 3b\n" \
+ " .popsection\n" \
+ " .pushsection __ex_table,\"a\"\n" \
+ " .align 3\n" \
+ " .long 1b, 4b\n" \
+ " .long 2b, 4b\n" \
+ " .popsection\n" \
+ : "=r" (err), "+r" (ptr), "+r" (val) \
+ : "0" (err) \
+ ); \
+ if (err) \
+ goto fault; \
+ } while(0)
+
+#define set32_data(addr, val) \
+ do { \
+ unsigned int err = 0, *ptr = addr ; \
+ val = le32_to_cpu(val); \
+ __asm__( \
+ "1: sbi.bi %2, [%1], #1\n" \
+ " srli %2, %2, #8\n" \
+ "2: sbi.bi %2, [%1], #1\n" \
+ " srli %2, %2, #8\n" \
+ "3: sbi.bi %2, [%1], #1\n" \
+ " srli %2, %2, #8\n" \
+ "4: sbi %2, [%1]\n" \
+ "5:\n" \
+ " .pushsection .text.fixup,\"ax\"\n" \
+ " .align 2\n" \
+ "6: movi %0, #1\n" \
+ " j 5b\n" \
+ " .popsection\n" \
+ " .pushsection __ex_table,\"a\"\n" \
+ " .align 3\n" \
+ " .long 1b, 6b\n" \
+ " .long 2b, 6b\n" \
+ " .long 3b, 6b\n" \
+ " .long 4b, 6b\n" \
+ " .popsection\n" \
+ : "=r" (err), "+r" (ptr), "+r" (val) \
+ : "0" (err) \
+ ); \
+ if (err) \
+ goto fault; \
+ } while(0)
+#define set_data(addr, val, len) \
+ if (len == 2) \
+ set16_data(addr, val); \
+ else \
+ set32_data(addr, val);
+#define NDS32_16BIT_INSTRUCTION 0x80000000
+
+extern pte_t va_present(struct mm_struct *mm, unsigned long addr);
+extern pte_t va_kernel_present(unsigned long addr);
+extern int va_readable(struct pt_regs *regs, unsigned long addr);
+extern int va_writable(struct pt_regs *regs, unsigned long addr);
+
+int unalign_access_mode = 0, unalign_access_debug = 0;
+
+static inline unsigned long *idx_to_addr(struct pt_regs *regs, int idx)
+{
+ /* this should be consistent with ptrace.h */
+ if (idx >= 0 && idx <= 25) /* R0-R25 */
+ return &regs->uregs[0] + idx;
+ else if (idx >= 28 && idx <= 30) /* FP, GP, LP */
+ return &regs->fp + (idx - 28);
+ else if (idx == 31) /* SP */
+ return &regs->sp;
+ else
+ return NULL; /* cause a segfault */
+}
+
+static inline unsigned long get_inst(unsigned long addr)
+{
+ return be32_to_cpu(get_unaligned((u32 *) addr));
+}
+
+static inline unsigned long sign_extend(unsigned long val, int len)
+{
+ unsigned long ret = 0;
+ unsigned char *s, *t;
+ int i = 0;
+
+ val = cpu_to_le32(val);
+
+ s = (void *)&val;
+ t = (void *)&ret;
+
+ while (i++ < len)
+ *t++ = *s++;
+
+ if (((*(t - 1)) & 0x80) && (i < 4)) {
+
+ while (i++ <= 4)
+ *t++ = 0xff;
+ }
+
+ return le32_to_cpu(ret);
+}
+
+static inline int do_16(unsigned long inst, struct pt_regs *regs)
+{
+ int imm, regular, load, len, addr_mode, idx_mode;
+ unsigned long unaligned_addr, target_val, source_idx, target_idx,
+ shift = 0;
+ switch ((inst >> 9) & 0x3F) {
+
+ case 0x12: /* LHI333 */
+ imm = 1;
+ regular = 1;
+ load = 1;
+ len = 2;
+ addr_mode = 3;
+ idx_mode = 3;
+ break;
+ case 0x10: /* LWI333 */
+ imm = 1;
+ regular = 1;
+ load = 1;
+ len = 4;
+ addr_mode = 3;
+ idx_mode = 3;
+ break;
+ case 0x11: /* LWI333.bi */
+ imm = 1;
+ regular = 0;
+ load = 1;
+ len = 4;
+ addr_mode = 3;
+ idx_mode = 3;
+ break;
+ case 0x1A: /* LWI450 */
+ imm = 0;
+ regular = 1;
+ load = 1;
+ len = 4;
+ addr_mode = 5;
+ idx_mode = 4;
+ break;
+ case 0x16: /* SHI333 */
+ imm = 1;
+ regular = 1;
+ load = 0;
+ len = 2;
+ addr_mode = 3;
+ idx_mode = 3;
+ break;
+ case 0x14: /* SWI333 */
+ imm = 1;
+ regular = 1;
+ load = 0;
+ len = 4;
+ addr_mode = 3;
+ idx_mode = 3;
+ break;
+ case 0x15: /* SWI333.bi */
+ imm = 1;
+ regular = 0;
+ load = 0;
+ len = 4;
+ addr_mode = 3;
+ idx_mode = 3;
+ break;
+ case 0x1B: /* SWI450 */
+ imm = 0;
+ regular = 1;
+ load = 0;
+ len = 4;
+ addr_mode = 5;
+ idx_mode = 4;
+ break;
+
+ default:
+ return -EFAULT;
+ }
+
+ if (addr_mode == 3) {
+ unaligned_addr = *idx_to_addr(regs, RA3(inst));
+ source_idx = RA3(inst);
+ } else {
+ unaligned_addr = *idx_to_addr(regs, RA5(inst));
+ source_idx = RA5(inst);
+ }
+
+ if (idx_mode == 3)
+ target_idx = RT3(inst);
+ else
+ target_idx = RT4(inst);
+
+ if (imm)
+ shift = IMM3U(inst) * len;
+
+ if (regular)
+ unaligned_addr += shift;
+
+ if (load) {
+ if (!access_ok((void *)unaligned_addr, len))
+ return -EACCES;
+
+ get_data(unaligned_addr, &target_val, len);
+ *idx_to_addr(regs, target_idx) = target_val;
+ } else {
+ if (!access_ok((void *)unaligned_addr, len))
+ return -EACCES;
+ target_val = *idx_to_addr(regs, target_idx);
+ set_data((void *)unaligned_addr, target_val, len);
+ }
+
+ if (!regular)
+ *idx_to_addr(regs, source_idx) = unaligned_addr + shift;
+ regs->ipc += 2;
+
+ return 0;
+fault:
+ return -EACCES;
+}
+
+static inline int do_32(unsigned long inst, struct pt_regs *regs)
+{
+ int imm, regular, load, len, sign_ext;
+ unsigned long unaligned_addr, target_val, shift;
+
+ unaligned_addr = *idx_to_addr(regs, RA(inst));
+
+ switch ((inst >> 25) << 1) {
+
+ case 0x02: /* LHI */
+ imm = 1;
+ regular = 1;
+ load = 1;
+ len = 2;
+ sign_ext = 0;
+ break;
+ case 0x0A: /* LHI.bi */
+ imm = 1;
+ regular = 0;
+ load = 1;
+ len = 2;
+ sign_ext = 0;
+ break;
+ case 0x22: /* LHSI */
+ imm = 1;
+ regular = 1;
+ load = 1;
+ len = 2;
+ sign_ext = 1;
+ break;
+ case 0x2A: /* LHSI.bi */
+ imm = 1;
+ regular = 0;
+ load = 1;
+ len = 2;
+ sign_ext = 1;
+ break;
+ case 0x04: /* LWI */
+ imm = 1;
+ regular = 1;
+ load = 1;
+ len = 4;
+ sign_ext = 0;
+ break;
+ case 0x0C: /* LWI.bi */
+ imm = 1;
+ regular = 0;
+ load = 1;
+ len = 4;
+ sign_ext = 0;
+ break;
+ case 0x12: /* SHI */
+ imm = 1;
+ regular = 1;
+ load = 0;
+ len = 2;
+ sign_ext = 0;
+ break;
+ case 0x1A: /* SHI.bi */
+ imm = 1;
+ regular = 0;
+ load = 0;
+ len = 2;
+ sign_ext = 0;
+ break;
+ case 0x14: /* SWI */
+ imm = 1;
+ regular = 1;
+ load = 0;
+ len = 4;
+ sign_ext = 0;
+ break;
+ case 0x1C: /* SWI.bi */
+ imm = 1;
+ regular = 0;
+ load = 0;
+ len = 4;
+ sign_ext = 0;
+ break;
+
+ default:
+ switch (inst & 0xff) {
+
+ case 0x01: /* LH */
+ imm = 0;
+ regular = 1;
+ load = 1;
+ len = 2;
+ sign_ext = 0;
+ break;
+ case 0x05: /* LH.bi */
+ imm = 0;
+ regular = 0;
+ load = 1;
+ len = 2;
+ sign_ext = 0;
+ break;
+ case 0x11: /* LHS */
+ imm = 0;
+ regular = 1;
+ load = 1;
+ len = 2;
+ sign_ext = 1;
+ break;
+ case 0x15: /* LHS.bi */
+ imm = 0;
+ regular = 0;
+ load = 1;
+ len = 2;
+ sign_ext = 1;
+ break;
+ case 0x02: /* LW */
+ imm = 0;
+ regular = 1;
+ load = 1;
+ len = 4;
+ sign_ext = 0;
+ break;
+ case 0x06: /* LW.bi */
+ imm = 0;
+ regular = 0;
+ load = 1;
+ len = 4;
+ sign_ext = 0;
+ break;
+ case 0x09: /* SH */
+ imm = 0;
+ regular = 1;
+ load = 0;
+ len = 2;
+ sign_ext = 0;
+ break;
+ case 0x0D: /* SH.bi */
+ imm = 0;
+ regular = 0;
+ load = 0;
+ len = 2;
+ sign_ext = 0;
+ break;
+ case 0x0A: /* SW */
+ imm = 0;
+ regular = 1;
+ load = 0;
+ len = 4;
+ sign_ext = 0;
+ break;
+ case 0x0E: /* SW.bi */
+ imm = 0;
+ regular = 0;
+ load = 0;
+ len = 4;
+ sign_ext = 0;
+ break;
+
+ default:
+ return -EFAULT;
+ }
+ }
+
+ if (imm)
+ shift = GET_IMMSVAL(IMM(inst)) * len;
+ else
+ shift = *idx_to_addr(regs, RB(inst)) << SV(inst);
+
+ if (regular)
+ unaligned_addr += shift;
+
+ if (load) {
+
+ if (!access_ok((void *)unaligned_addr, len))
+ return -EACCES;
+
+ get_data(unaligned_addr, &target_val, len);
+
+ if (sign_ext)
+ *idx_to_addr(regs, RT(inst)) =
+ sign_extend(target_val, len);
+ else
+ *idx_to_addr(regs, RT(inst)) = target_val;
+ } else {
+
+ if (!access_ok((void *)unaligned_addr, len))
+ return -EACCES;
+
+ target_val = *idx_to_addr(regs, RT(inst));
+ set_data((void *)unaligned_addr, target_val, len);
+ }
+
+ if (!regular)
+ *idx_to_addr(regs, RA(inst)) = unaligned_addr + shift;
+
+ regs->ipc += 4;
+
+ return 0;
+fault:
+ return -EACCES;
+}
+
+int do_unaligned_access(unsigned long addr, struct pt_regs *regs)
+{
+ unsigned long inst;
+ int ret = -EFAULT;
+ mm_segment_t seg;
+
+ inst = get_inst(regs->ipc);
+
+ DEBUG((unalign_access_debug > 0), 1,
+ "Faulting addr: 0x%08lx, pc: 0x%08lx [inst: 0x%08lx ]\n", addr,
+ regs->ipc, inst);
+
+ seg = force_uaccess_begin();
+ if (inst & NDS32_16BIT_INSTRUCTION)
+ ret = do_16((inst >> 16) & 0xffff, regs);
+ else
+ ret = do_32(inst, regs);
+ force_uaccess_end(seg);
+
+ return ret;
+}
+
+#ifdef CONFIG_PROC_FS
+
+static struct ctl_table alignment_tbl[3] = {
+ {
+ .procname = "enable",
+ .data = &unalign_access_mode,
+ .maxlen = sizeof(unalign_access_mode),
+ .mode = 0666,
+ .proc_handler = &proc_dointvec
+ }
+ ,
+ {
+ .procname = "debug_info",
+ .data = &unalign_access_debug,
+ .maxlen = sizeof(unalign_access_debug),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec
+ }
+ ,
+ {}
+};
+
+static struct ctl_table nds32_sysctl_table[2] = {
+ {
+ .procname = "unaligned_access",
+ .mode = 0555,
+ .child = alignment_tbl},
+ {}
+};
+
+static struct ctl_path nds32_path[2] = {
+ {.procname = "nds32"},
+ {}
+};
+
+/*
+ * Initialize nds32 alignment-correction interface
+ */
+static int __init nds32_sysctl_init(void)
+{
+ register_sysctl_paths(nds32_path, nds32_sysctl_table);
+ return 0;
+}
+
+__initcall(nds32_sysctl_init);
+#endif /* CONFIG_PROC_FS */
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