From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- arch/sparc/kernel/unaligned_32.c | 282 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 282 insertions(+) create mode 100644 arch/sparc/kernel/unaligned_32.c (limited to 'arch/sparc/kernel/unaligned_32.c') diff --git a/arch/sparc/kernel/unaligned_32.c b/arch/sparc/kernel/unaligned_32.c new file mode 100644 index 0000000000..455f0258c7 --- /dev/null +++ b/arch/sparc/kernel/unaligned_32.c @@ -0,0 +1,282 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "kernel.h" + +enum direction { + load, /* ld, ldd, ldh, ldsh */ + store, /* st, std, sth, stsh */ + both, /* Swap, ldstub, etc. */ + fpload, + fpstore, + invalid, +}; + +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_window32 *win; + + if(reg < 16) + return (!reg ? 0 : regs->u_regs[reg]); + + /* Ho hum, the slightly complicated case. */ + win = (struct reg_window32 *) 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_window32 __user *win; + unsigned long ret; + + if (reg < 16) + return (!reg ? 0 : regs->u_regs[reg]); + + /* Ho hum, the slightly complicated case. */ + win = (struct reg_window32 __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_window32 *win; + + if(reg < 16) + return ®s->u_regs[reg]; + win = (struct reg_window32 *) 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("%s", str); +} + +/* una_asm.S */ +extern int do_int_load(unsigned long *dest_reg, int size, + unsigned long *saddr, int is_signed); +extern int __do_int_store(unsigned long *dst_addr, int size, + unsigned long *src_val); + +static int do_int_store(int reg_num, int size, unsigned long *dst_addr, + struct pt_regs *regs) +{ + unsigned long zero[2] = { 0, 0 }; + unsigned long *src_val; + + 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); + } + return __do_int_store(dst_addr, size, src_val); +} + +extern void smp_capture(void); +extern void smp_release(void); + +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); +} + +static void kernel_mna_trap_fault(struct pt_regs *regs, unsigned int insn) +{ + const struct exception_table_entry *entry; + + entry = search_exception_tables(regs->pc); + if (!entry) { + 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 = entry->fixup; + regs->npc = regs->pc + 4; +} + +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."); + } else { + unsigned long addr = compute_effective_address(regs, insn); + int err; + + perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr); + switch (dir) { + case load: + err = do_int_load(fetch_reg_addr(((insn>>25)&0x1f), + regs), + size, (unsigned long *) addr, + decode_signedness(insn)); + break; + + case store: + err = do_int_store(((insn>>25)&0x1f), size, + (unsigned long *) addr, regs); + break; + default: + panic("Impossible kernel unaligned trap."); + /* Not reached... */ + } + if (err) + kernel_mna_trap_fault(regs, insn); + else + advance(regs); + } +} + +asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn) +{ + send_sig_fault(SIGBUS, BUS_ADRALN, + (void __user *)safe_compute_effective_address(regs, insn), + current); +} -- cgit v1.2.3