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-rw-r--r--arch/sparc/kernel/unaligned.c548
1 files changed, 548 insertions, 0 deletions
diff --git a/arch/sparc/kernel/unaligned.c b/arch/sparc/kernel/unaligned.c
new file mode 100644
index 000000000000..a6330fbc9dd9
--- /dev/null
+++ b/arch/sparc/kernel/unaligned.c
@@ -0,0 +1,548 @@
+/* $Id: unaligned.c,v 1.23 2001/12/21 00:54:31 davem Exp $
+ * unaligned.c: Unaligned load/store trap handling with special
+ * cases for the kernel to do them more quickly.
+ *
+ * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
+ * Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <asm/ptrace.h>
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+
+/* #define DEBUG_MNA */
+
+enum direction {
+ load, /* ld, ldd, ldh, ldsh */
+ store, /* st, std, sth, stsh */
+ both, /* Swap, ldstub, etc. */
+ fpload,
+ fpstore,
+ invalid,
+};
+
+#ifdef DEBUG_MNA
+static char *dirstrings[] = {
+ "load", "store", "both", "fpload", "fpstore", "invalid"
+};
+#endif
+
+static inline enum direction decode_direction(unsigned int insn)
+{
+ unsigned long tmp = (insn >> 21) & 1;
+
+ if(!tmp)
+ return load;
+ else {
+ if(((insn>>19)&0x3f) == 15)
+ return both;
+ else
+ return store;
+ }
+}
+
+/* 8 = double-word, 4 = word, 2 = half-word */
+static inline int decode_access_size(unsigned int insn)
+{
+ insn = (insn >> 19) & 3;
+
+ if(!insn)
+ return 4;
+ else if(insn == 3)
+ return 8;
+ else if(insn == 2)
+ return 2;
+ else {
+ printk("Impossible unaligned trap. insn=%08x\n", insn);
+ die_if_kernel("Byte sized unaligned access?!?!", current->thread.kregs);
+ return 4; /* just to keep gcc happy. */
+ }
+}
+
+/* 0x400000 = signed, 0 = unsigned */
+static inline int decode_signedness(unsigned int insn)
+{
+ return (insn & 0x400000);
+}
+
+static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
+ unsigned int rd)
+{
+ if(rs2 >= 16 || rs1 >= 16 || rd >= 16) {
+ /* Wheee... */
+ __asm__ __volatile__("save %sp, -0x40, %sp\n\t"
+ "save %sp, -0x40, %sp\n\t"
+ "save %sp, -0x40, %sp\n\t"
+ "save %sp, -0x40, %sp\n\t"
+ "save %sp, -0x40, %sp\n\t"
+ "save %sp, -0x40, %sp\n\t"
+ "save %sp, -0x40, %sp\n\t"
+ "restore; restore; restore; restore;\n\t"
+ "restore; restore; restore;\n\t");
+ }
+}
+
+static inline int sign_extend_imm13(int imm)
+{
+ return imm << 19 >> 19;
+}
+
+static inline unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
+{
+ struct reg_window *win;
+
+ if(reg < 16)
+ return (!reg ? 0 : regs->u_regs[reg]);
+
+ /* Ho hum, the slightly complicated case. */
+ win = (struct reg_window *) regs->u_regs[UREG_FP];
+ return win->locals[reg - 16]; /* yes, I know what this does... */
+}
+
+static inline unsigned long safe_fetch_reg(unsigned int reg, struct pt_regs *regs)
+{
+ struct reg_window __user *win;
+ unsigned long ret;
+
+ if (reg < 16)
+ return (!reg ? 0 : regs->u_regs[reg]);
+
+ /* Ho hum, the slightly complicated case. */
+ win = (struct reg_window __user *) regs->u_regs[UREG_FP];
+
+ if ((unsigned long)win & 3)
+ return -1;
+
+ if (get_user(ret, &win->locals[reg - 16]))
+ return -1;
+
+ return ret;
+}
+
+static inline unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
+{
+ struct reg_window *win;
+
+ if(reg < 16)
+ return &regs->u_regs[reg];
+ win = (struct reg_window *) regs->u_regs[UREG_FP];
+ return &win->locals[reg - 16];
+}
+
+static unsigned long compute_effective_address(struct pt_regs *regs,
+ unsigned int insn)
+{
+ unsigned int rs1 = (insn >> 14) & 0x1f;
+ unsigned int rs2 = insn & 0x1f;
+ unsigned int rd = (insn >> 25) & 0x1f;
+
+ if(insn & 0x2000) {
+ maybe_flush_windows(rs1, 0, rd);
+ return (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
+ } else {
+ maybe_flush_windows(rs1, rs2, rd);
+ return (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
+ }
+}
+
+unsigned long safe_compute_effective_address(struct pt_regs *regs,
+ unsigned int insn)
+{
+ unsigned int rs1 = (insn >> 14) & 0x1f;
+ unsigned int rs2 = insn & 0x1f;
+ unsigned int rd = (insn >> 25) & 0x1f;
+
+ if(insn & 0x2000) {
+ maybe_flush_windows(rs1, 0, rd);
+ return (safe_fetch_reg(rs1, regs) + sign_extend_imm13(insn));
+ } else {
+ maybe_flush_windows(rs1, rs2, rd);
+ return (safe_fetch_reg(rs1, regs) + safe_fetch_reg(rs2, regs));
+ }
+}
+
+/* This is just to make gcc think panic does return... */
+static void unaligned_panic(char *str)
+{
+ panic(str);
+}
+
+#define do_integer_load(dest_reg, size, saddr, is_signed, errh) ({ \
+__asm__ __volatile__ ( \
+ "cmp %1, 8\n\t" \
+ "be 9f\n\t" \
+ " cmp %1, 4\n\t" \
+ "be 6f\n" \
+"4:\t" " ldub [%2], %%l1\n" \
+"5:\t" "ldub [%2 + 1], %%l2\n\t" \
+ "sll %%l1, 8, %%l1\n\t" \
+ "tst %3\n\t" \
+ "be 3f\n\t" \
+ " add %%l1, %%l2, %%l1\n\t" \
+ "sll %%l1, 16, %%l1\n\t" \
+ "sra %%l1, 16, %%l1\n" \
+"3:\t" "b 0f\n\t" \
+ " st %%l1, [%0]\n" \
+"6:\t" "ldub [%2 + 1], %%l2\n\t" \
+ "sll %%l1, 24, %%l1\n" \
+"7:\t" "ldub [%2 + 2], %%g7\n\t" \
+ "sll %%l2, 16, %%l2\n" \
+"8:\t" "ldub [%2 + 3], %%g1\n\t" \
+ "sll %%g7, 8, %%g7\n\t" \
+ "or %%l1, %%l2, %%l1\n\t" \
+ "or %%g7, %%g1, %%g7\n\t" \
+ "or %%l1, %%g7, %%l1\n\t" \
+ "b 0f\n\t" \
+ " st %%l1, [%0]\n" \
+"9:\t" "ldub [%2], %%l1\n" \
+"10:\t" "ldub [%2 + 1], %%l2\n\t" \
+ "sll %%l1, 24, %%l1\n" \
+"11:\t" "ldub [%2 + 2], %%g7\n\t" \
+ "sll %%l2, 16, %%l2\n" \
+"12:\t" "ldub [%2 + 3], %%g1\n\t" \
+ "sll %%g7, 8, %%g7\n\t" \
+ "or %%l1, %%l2, %%l1\n\t" \
+ "or %%g7, %%g1, %%g7\n\t" \
+ "or %%l1, %%g7, %%g7\n" \
+"13:\t" "ldub [%2 + 4], %%l1\n\t" \
+ "st %%g7, [%0]\n" \
+"14:\t" "ldub [%2 + 5], %%l2\n\t" \
+ "sll %%l1, 24, %%l1\n" \
+"15:\t" "ldub [%2 + 6], %%g7\n\t" \
+ "sll %%l2, 16, %%l2\n" \
+"16:\t" "ldub [%2 + 7], %%g1\n\t" \
+ "sll %%g7, 8, %%g7\n\t" \
+ "or %%l1, %%l2, %%l1\n\t" \
+ "or %%g7, %%g1, %%g7\n\t" \
+ "or %%l1, %%g7, %%g7\n\t" \
+ "st %%g7, [%0 + 4]\n" \
+"0:\n\n\t" \
+ ".section __ex_table,#alloc\n\t" \
+ ".word 4b, " #errh "\n\t" \
+ ".word 5b, " #errh "\n\t" \
+ ".word 6b, " #errh "\n\t" \
+ ".word 7b, " #errh "\n\t" \
+ ".word 8b, " #errh "\n\t" \
+ ".word 9b, " #errh "\n\t" \
+ ".word 10b, " #errh "\n\t" \
+ ".word 11b, " #errh "\n\t" \
+ ".word 12b, " #errh "\n\t" \
+ ".word 13b, " #errh "\n\t" \
+ ".word 14b, " #errh "\n\t" \
+ ".word 15b, " #errh "\n\t" \
+ ".word 16b, " #errh "\n\n\t" \
+ ".previous\n\t" \
+ : : "r" (dest_reg), "r" (size), "r" (saddr), "r" (is_signed) \
+ : "l1", "l2", "g7", "g1", "cc"); \
+})
+
+#define store_common(dst_addr, size, src_val, errh) ({ \
+__asm__ __volatile__ ( \
+ "ld [%2], %%l1\n" \
+ "cmp %1, 2\n\t" \
+ "be 2f\n\t" \
+ " cmp %1, 4\n\t" \
+ "be 1f\n\t" \
+ " srl %%l1, 24, %%l2\n\t" \
+ "srl %%l1, 16, %%g7\n" \
+"4:\t" "stb %%l2, [%0]\n\t" \
+ "srl %%l1, 8, %%l2\n" \
+"5:\t" "stb %%g7, [%0 + 1]\n\t" \
+ "ld [%2 + 4], %%g7\n" \
+"6:\t" "stb %%l2, [%0 + 2]\n\t" \
+ "srl %%g7, 24, %%l2\n" \
+"7:\t" "stb %%l1, [%0 + 3]\n\t" \
+ "srl %%g7, 16, %%l1\n" \
+"8:\t" "stb %%l2, [%0 + 4]\n\t" \
+ "srl %%g7, 8, %%l2\n" \
+"9:\t" "stb %%l1, [%0 + 5]\n" \
+"10:\t" "stb %%l2, [%0 + 6]\n\t" \
+ "b 0f\n" \
+"11:\t" " stb %%g7, [%0 + 7]\n" \
+"1:\t" "srl %%l1, 16, %%g7\n" \
+"12:\t" "stb %%l2, [%0]\n\t" \
+ "srl %%l1, 8, %%l2\n" \
+"13:\t" "stb %%g7, [%0 + 1]\n" \
+"14:\t" "stb %%l2, [%0 + 2]\n\t" \
+ "b 0f\n" \
+"15:\t" " stb %%l1, [%0 + 3]\n" \
+"2:\t" "srl %%l1, 8, %%l2\n" \
+"16:\t" "stb %%l2, [%0]\n" \
+"17:\t" "stb %%l1, [%0 + 1]\n" \
+"0:\n\n\t" \
+ ".section __ex_table,#alloc\n\t" \
+ ".word 4b, " #errh "\n\t" \
+ ".word 5b, " #errh "\n\t" \
+ ".word 6b, " #errh "\n\t" \
+ ".word 7b, " #errh "\n\t" \
+ ".word 8b, " #errh "\n\t" \
+ ".word 9b, " #errh "\n\t" \
+ ".word 10b, " #errh "\n\t" \
+ ".word 11b, " #errh "\n\t" \
+ ".word 12b, " #errh "\n\t" \
+ ".word 13b, " #errh "\n\t" \
+ ".word 14b, " #errh "\n\t" \
+ ".word 15b, " #errh "\n\t" \
+ ".word 16b, " #errh "\n\t" \
+ ".word 17b, " #errh "\n\n\t" \
+ ".previous\n\t" \
+ : : "r" (dst_addr), "r" (size), "r" (src_val) \
+ : "l1", "l2", "g7", "g1", "cc"); \
+})
+
+#define do_integer_store(reg_num, size, dst_addr, regs, errh) ({ \
+ unsigned long *src_val; \
+ static unsigned long zero[2] = { 0, }; \
+ \
+ if (reg_num) src_val = fetch_reg_addr(reg_num, regs); \
+ else { \
+ src_val = &zero[0]; \
+ if (size == 8) \
+ zero[1] = fetch_reg(1, regs); \
+ } \
+ store_common(dst_addr, size, src_val, errh); \
+})
+
+extern void smp_capture(void);
+extern void smp_release(void);
+
+#define do_atomic(srcdest_reg, mem, errh) ({ \
+ unsigned long flags, tmp; \
+ \
+ smp_capture(); \
+ local_irq_save(flags); \
+ tmp = *srcdest_reg; \
+ do_integer_load(srcdest_reg, 4, mem, 0, errh); \
+ store_common(mem, 4, &tmp, errh); \
+ local_irq_restore(flags); \
+ smp_release(); \
+})
+
+static inline void advance(struct pt_regs *regs)
+{
+ regs->pc = regs->npc;
+ regs->npc += 4;
+}
+
+static inline int floating_point_load_or_store_p(unsigned int insn)
+{
+ return (insn >> 24) & 1;
+}
+
+static inline int ok_for_kernel(unsigned int insn)
+{
+ return !floating_point_load_or_store_p(insn);
+}
+
+void kernel_mna_trap_fault(struct pt_regs *regs, unsigned int insn) __asm__ ("kernel_mna_trap_fault");
+
+void kernel_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
+{
+ unsigned long g2 = regs->u_regs [UREG_G2];
+ unsigned long fixup = search_extables_range(regs->pc, &g2);
+
+ if (!fixup) {
+ unsigned long address = compute_effective_address(regs, insn);
+ if(address < PAGE_SIZE) {
+ printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference in mna handler");
+ } else
+ printk(KERN_ALERT "Unable to handle kernel paging request in mna handler");
+ printk(KERN_ALERT " at virtual address %08lx\n",address);
+ printk(KERN_ALERT "current->{mm,active_mm}->context = %08lx\n",
+ (current->mm ? current->mm->context :
+ current->active_mm->context));
+ printk(KERN_ALERT "current->{mm,active_mm}->pgd = %08lx\n",
+ (current->mm ? (unsigned long) current->mm->pgd :
+ (unsigned long) current->active_mm->pgd));
+ die_if_kernel("Oops", regs);
+ /* Not reached */
+ }
+ regs->pc = fixup;
+ regs->npc = regs->pc + 4;
+ regs->u_regs [UREG_G2] = g2;
+}
+
+asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
+{
+ enum direction dir = decode_direction(insn);
+ int size = decode_access_size(insn);
+
+ if(!ok_for_kernel(insn) || dir == both) {
+ printk("Unsupported unaligned load/store trap for kernel at <%08lx>.\n",
+ regs->pc);
+ unaligned_panic("Wheee. Kernel does fpu/atomic unaligned load/store.");
+
+ __asm__ __volatile__ ("\n"
+"kernel_unaligned_trap_fault:\n\t"
+ "mov %0, %%o0\n\t"
+ "call kernel_mna_trap_fault\n\t"
+ " mov %1, %%o1\n\t"
+ :
+ : "r" (regs), "r" (insn)
+ : "o0", "o1", "o2", "o3", "o4", "o5", "o7",
+ "g1", "g2", "g3", "g4", "g5", "g7", "cc");
+ } else {
+ unsigned long addr = compute_effective_address(regs, insn);
+
+#ifdef DEBUG_MNA
+ printk("KMNA: pc=%08lx [dir=%s addr=%08lx size=%d] retpc[%08lx]\n",
+ regs->pc, dirstrings[dir], addr, size, regs->u_regs[UREG_RETPC]);
+#endif
+ switch(dir) {
+ case load:
+ do_integer_load(fetch_reg_addr(((insn>>25)&0x1f), regs),
+ size, (unsigned long *) addr,
+ decode_signedness(insn),
+ kernel_unaligned_trap_fault);
+ break;
+
+ case store:
+ do_integer_store(((insn>>25)&0x1f), size,
+ (unsigned long *) addr, regs,
+ kernel_unaligned_trap_fault);
+ break;
+#if 0 /* unsupported */
+ case both:
+ do_atomic(fetch_reg_addr(((insn>>25)&0x1f), regs),
+ (unsigned long *) addr,
+ kernel_unaligned_trap_fault);
+ break;
+#endif
+ default:
+ panic("Impossible kernel unaligned trap.");
+ /* Not reached... */
+ }
+ advance(regs);
+ }
+}
+
+static inline int ok_for_user(struct pt_regs *regs, unsigned int insn,
+ enum direction dir)
+{
+ unsigned int reg;
+ int check = (dir == load) ? VERIFY_READ : VERIFY_WRITE;
+ int size = ((insn >> 19) & 3) == 3 ? 8 : 4;
+
+ if ((regs->pc | regs->npc) & 3)
+ return 0;
+
+ /* Must access_ok() in all the necessary places. */
+#define WINREG_ADDR(regnum) \
+ ((void __user *)(((unsigned long *)regs->u_regs[UREG_FP])+(regnum)))
+
+ reg = (insn >> 25) & 0x1f;
+ if (reg >= 16) {
+ if (!access_ok(check, WINREG_ADDR(reg - 16), size))
+ return -EFAULT;
+ }
+ reg = (insn >> 14) & 0x1f;
+ if (reg >= 16) {
+ if (!access_ok(check, WINREG_ADDR(reg - 16), size))
+ return -EFAULT;
+ }
+ if (!(insn & 0x2000)) {
+ reg = (insn & 0x1f);
+ if (reg >= 16) {
+ if (!access_ok(check, WINREG_ADDR(reg - 16), size))
+ return -EFAULT;
+ }
+ }
+#undef WINREG_ADDR
+ return 0;
+}
+
+void user_mna_trap_fault(struct pt_regs *regs, unsigned int insn) __asm__ ("user_mna_trap_fault");
+
+void user_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
+{
+ siginfo_t info;
+
+ info.si_signo = SIGBUS;
+ info.si_errno = 0;
+ info.si_code = BUS_ADRALN;
+ info.si_addr = (void __user *)safe_compute_effective_address(regs, insn);
+ info.si_trapno = 0;
+ send_sig_info(SIGBUS, &info, current);
+}
+
+asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn)
+{
+ enum direction dir;
+
+ lock_kernel();
+ if(!(current->thread.flags & SPARC_FLAG_UNALIGNED) ||
+ (((insn >> 30) & 3) != 3))
+ goto kill_user;
+ dir = decode_direction(insn);
+ if(!ok_for_user(regs, insn, dir)) {
+ goto kill_user;
+ } else {
+ int size = decode_access_size(insn);
+ unsigned long addr;
+
+ if(floating_point_load_or_store_p(insn)) {
+ printk("User FPU load/store unaligned unsupported.\n");
+ goto kill_user;
+ }
+
+ addr = compute_effective_address(regs, insn);
+ switch(dir) {
+ case load:
+ do_integer_load(fetch_reg_addr(((insn>>25)&0x1f), regs),
+ size, (unsigned long *) addr,
+ decode_signedness(insn),
+ user_unaligned_trap_fault);
+ break;
+
+ case store:
+ do_integer_store(((insn>>25)&0x1f), size,
+ (unsigned long *) addr, regs,
+ user_unaligned_trap_fault);
+ break;
+
+ case both:
+#if 0 /* unsupported */
+ do_atomic(fetch_reg_addr(((insn>>25)&0x1f), regs),
+ (unsigned long *) addr,
+ user_unaligned_trap_fault);
+#else
+ /*
+ * This was supported in 2.4. However, we question
+ * the value of SWAP instruction across word boundaries.
+ */
+ printk("Unaligned SWAP unsupported.\n");
+ goto kill_user;
+#endif
+ break;
+
+ default:
+ unaligned_panic("Impossible user unaligned trap.");
+
+ __asm__ __volatile__ ("\n"
+"user_unaligned_trap_fault:\n\t"
+ "mov %0, %%o0\n\t"
+ "call user_mna_trap_fault\n\t"
+ " mov %1, %%o1\n\t"
+ :
+ : "r" (regs), "r" (insn)
+ : "o0", "o1", "o2", "o3", "o4", "o5", "o7",
+ "g1", "g2", "g3", "g4", "g5", "g7", "cc");
+ goto out;
+ }
+ advance(regs);
+ goto out;
+ }
+
+kill_user:
+ user_mna_trap_fault(regs, insn);
+out:
+ unlock_kernel();
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-22 07:59:33 +0000