ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/arch/csky/abiv1/alignment.c b/marvell/linux/arch/csky/abiv1/alignment.c
new file mode 100644
index 0000000..2df115d
--- /dev/null
+++ b/marvell/linux/arch/csky/abiv1/alignment.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/kernel.h>
+#include <linux/uaccess.h>
+#include <linux/ptrace.h>
+
+static int align_kern_enable = 1;
+static int align_usr_enable = 1;
+static int align_kern_count = 0;
+static int align_usr_count = 0;
+
+static inline uint32_t get_ptreg(struct pt_regs *regs, uint32_t rx)
+{
+ return rx == 15 ? regs->lr : *((uint32_t *)&(regs->a0) - 2 + rx);
+}
+
+static inline void put_ptreg(struct pt_regs *regs, uint32_t rx, uint32_t val)
+{
+ if (rx == 15)
+ regs->lr = val;
+ else
+ *((uint32_t *)&(regs->a0) - 2 + rx) = val;
+}
+
+/*
+ * Get byte-value from addr and set it to *valp.
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int ldb_asm(uint32_t addr, uint32_t *valp)
+{
+ uint32_t val;
+ int err;
+
+ asm volatile (
+ "movi %0, 0\n"
+ "1:\n"
+ "ldb %1, (%2)\n"
+ "br 3f\n"
+ "2:\n"
+ "movi %0, 1\n"
+ "br 3f\n"
+ ".section __ex_table,\"a\"\n"
+ ".align 2\n"
+ ".long 1b, 2b\n"
+ ".previous\n"
+ "3:\n"
+ : "=&r"(err), "=r"(val)
+ : "r" (addr)
+ );
+
+ *valp = val;
+
+ return err;
+}
+
+/*
+ * Put byte-value to addr.
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int stb_asm(uint32_t addr, uint32_t val)
+{
+ int err;
+
+ asm volatile (
+ "movi %0, 0\n"
+ "1:\n"
+ "stb %1, (%2)\n"
+ "br 3f\n"
+ "2:\n"
+ "movi %0, 1\n"
+ "br 3f\n"
+ ".section __ex_table,\"a\"\n"
+ ".align 2\n"
+ ".long 1b, 2b\n"
+ ".previous\n"
+ "3:\n"
+ : "=&r"(err)
+ : "r"(val), "r" (addr)
+ );
+
+ return err;
+}
+
+/*
+ * Get half-word from [rx + imm]
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int ldh_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
+{
+ uint32_t byte0, byte1;
+
+ if (ldb_asm(addr, &byte0))
+ return 1;
+ addr += 1;
+ if (ldb_asm(addr, &byte1))
+ return 1;
+
+ byte0 |= byte1 << 8;
+ put_ptreg(regs, rz, byte0);
+
+ return 0;
+}
+
+/*
+ * Store half-word to [rx + imm]
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int sth_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
+{
+ uint32_t byte0, byte1;
+
+ byte0 = byte1 = get_ptreg(regs, rz);
+
+ byte0 &= 0xff;
+
+ if (stb_asm(addr, byte0))
+ return 1;
+
+ addr += 1;
+ byte1 = (byte1 >> 8) & 0xff;
+ if (stb_asm(addr, byte1))
+ return 1;
+
+ return 0;
+}
+
+/*
+ * Get word from [rx + imm]
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int ldw_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
+{
+ uint32_t byte0, byte1, byte2, byte3;
+
+ if (ldb_asm(addr, &byte0))
+ return 1;
+
+ addr += 1;
+ if (ldb_asm(addr, &byte1))
+ return 1;
+
+ addr += 1;
+ if (ldb_asm(addr, &byte2))
+ return 1;
+
+ addr += 1;
+ if (ldb_asm(addr, &byte3))
+ return 1;
+
+ byte0 |= byte1 << 8;
+ byte0 |= byte2 << 16;
+ byte0 |= byte3 << 24;
+
+ put_ptreg(regs, rz, byte0);
+
+ return 0;
+}
+
+/*
+ * Store word to [rx + imm]
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int stw_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
+{
+ uint32_t byte0, byte1, byte2, byte3;
+
+ byte0 = byte1 = byte2 = byte3 = get_ptreg(regs, rz);
+
+ byte0 &= 0xff;
+
+ if (stb_asm(addr, byte0))
+ return 1;
+
+ addr += 1;
+ byte1 = (byte1 >> 8) & 0xff;
+ if (stb_asm(addr, byte1))
+ return 1;
+
+ addr += 1;
+ byte2 = (byte2 >> 16) & 0xff;
+ if (stb_asm(addr, byte2))
+ return 1;
+
+ addr += 1;
+ byte3 = (byte3 >> 24) & 0xff;
+ if (stb_asm(addr, byte3))
+ return 1;
+
+ return 0;
+}
+
+extern int fixup_exception(struct pt_regs *regs);
+
+#define OP_LDH 0xc000
+#define OP_STH 0xd000
+#define OP_LDW 0x8000
+#define OP_STW 0x9000
+
+void csky_alignment(struct pt_regs *regs)
+{
+ int ret;
+ uint16_t tmp;
+ uint32_t opcode = 0;
+ uint32_t rx = 0;
+ uint32_t rz = 0;
+ uint32_t imm = 0;
+ uint32_t addr = 0;
+
+ if (!user_mode(regs))
+ goto kernel_area;
+
+ if (!align_usr_enable) {
+ pr_err("%s user disabled.\n", __func__);
+ goto bad_area;
+ }
+
+ align_usr_count++;
+
+ ret = get_user(tmp, (uint16_t *)instruction_pointer(regs));
+ if (ret) {
+ pr_err("%s get_user failed.\n", __func__);
+ goto bad_area;
+ }
+
+ goto good_area;
+
+kernel_area:
+ if (!align_kern_enable) {
+ pr_err("%s kernel disabled.\n", __func__);
+ goto bad_area;
+ }
+
+ align_kern_count++;
+
+ tmp = *(uint16_t *)instruction_pointer(regs);
+
+good_area:
+ opcode = (uint32_t)tmp;
+
+ rx = opcode & 0xf;
+ imm = (opcode >> 4) & 0xf;
+ rz = (opcode >> 8) & 0xf;
+ opcode &= 0xf000;
+
+ if (rx == 0 || rx == 1 || rz == 0 || rz == 1)
+ goto bad_area;
+
+ switch (opcode) {
+ case OP_LDH:
+ addr = get_ptreg(regs, rx) + (imm << 1);
+ ret = ldh_c(regs, rz, addr);
+ break;
+ case OP_LDW:
+ addr = get_ptreg(regs, rx) + (imm << 2);
+ ret = ldw_c(regs, rz, addr);
+ break;
+ case OP_STH:
+ addr = get_ptreg(regs, rx) + (imm << 1);
+ ret = sth_c(regs, rz, addr);
+ break;
+ case OP_STW:
+ addr = get_ptreg(regs, rx) + (imm << 2);
+ ret = stw_c(regs, rz, addr);
+ break;
+ }
+
+ if (ret)
+ goto bad_area;
+
+ regs->pc += 2;
+
+ return;
+
+bad_area:
+ if (!user_mode(regs)) {
+ if (fixup_exception(regs))
+ return;
+
+ bust_spinlocks(1);
+ pr_alert("%s opcode: %x, rz: %d, rx: %d, imm: %d, addr: %x.\n",
+ __func__, opcode, rz, rx, imm, addr);
+ show_regs(regs);
+ bust_spinlocks(0);
+ make_task_dead(SIGKILL);
+ }
+
+ force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)addr);
+}
+
+static struct ctl_table alignment_tbl[5] = {
+ {
+ .procname = "kernel_enable",
+ .data = &align_kern_enable,
+ .maxlen = sizeof(align_kern_enable),
+ .mode = 0666,
+ .proc_handler = &proc_dointvec
+ },
+ {
+ .procname = "user_enable",
+ .data = &align_usr_enable,
+ .maxlen = sizeof(align_usr_enable),
+ .mode = 0666,
+ .proc_handler = &proc_dointvec
+ },
+ {
+ .procname = "kernel_count",
+ .data = &align_kern_count,
+ .maxlen = sizeof(align_kern_count),
+ .mode = 0666,
+ .proc_handler = &proc_dointvec
+ },
+ {
+ .procname = "user_count",
+ .data = &align_usr_count,
+ .maxlen = sizeof(align_usr_count),
+ .mode = 0666,
+ .proc_handler = &proc_dointvec
+ },
+ {}
+};
+
+static struct ctl_table sysctl_table[2] = {
+ {
+ .procname = "csky_alignment",
+ .mode = 0555,
+ .child = alignment_tbl},
+ {}
+};
+
+static struct ctl_path sysctl_path[2] = {
+ {.procname = "csky"},
+ {}
+};
+
+static int __init csky_alignment_init(void)
+{
+ register_sysctl_paths(sysctl_path, sysctl_table);
+ return 0;
+}
+
+arch_initcall(csky_alignment_init);