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| -rw-r--r-- | arch/arm64/include/asm/assembler.h | 748 |
1 files changed, 748 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h new file mode 100644 index 000000000..fc3d26c95 --- /dev/null +++ b/arch/arm64/include/asm/assembler.h @@ -0,0 +1,748 @@ +/* + * Based on arch/arm/include/asm/assembler.h, arch/arm/mm/proc-macros.S + * + * Copyright (C) 1996-2000 Russell King + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef __ASSEMBLY__ +#error "Only include this from assembly code" +#endif + +#ifndef __ASM_ASSEMBLER_H +#define __ASM_ASSEMBLER_H + +#include <asm/asm-offsets.h> +#include <asm/cpufeature.h> +#include <asm/debug-monitors.h> +#include <asm/page.h> +#include <asm/pgtable-hwdef.h> +#include <asm/ptrace.h> +#include <asm/thread_info.h> + + .macro save_and_disable_daif, flags + mrs \flags, daif + msr daifset, #0xf + .endm + + .macro disable_daif + msr daifset, #0xf + .endm + + .macro enable_daif + msr daifclr, #0xf + .endm + + .macro restore_daif, flags:req + msr daif, \flags + .endm + + /* Only on aarch64 pstate, PSR_D_BIT is different for aarch32 */ + .macro inherit_daif, pstate:req, tmp:req + and \tmp, \pstate, #(PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT) + msr daif, \tmp + .endm + + /* IRQ is the lowest priority flag, unconditionally unmask the rest. */ + .macro enable_da_f + msr daifclr, #(8 | 4 | 1) + .endm + +/* + * Enable and disable interrupts. + */ + .macro disable_irq + msr daifset, #2 + .endm + + .macro enable_irq + msr daifclr, #2 + .endm + + .macro save_and_disable_irq, flags + mrs \flags, daif + msr daifset, #2 + .endm + + .macro restore_irq, flags + msr daif, \flags + .endm + + .macro enable_dbg + msr daifclr, #8 + .endm + + .macro disable_step_tsk, flgs, tmp + tbz \flgs, #TIF_SINGLESTEP, 9990f + mrs \tmp, mdscr_el1 + bic \tmp, \tmp, #DBG_MDSCR_SS + msr mdscr_el1, \tmp + isb // Synchronise with enable_dbg +9990: + .endm + + /* call with daif masked */ + .macro enable_step_tsk, flgs, tmp + tbz \flgs, #TIF_SINGLESTEP, 9990f + mrs \tmp, mdscr_el1 + orr \tmp, \tmp, #DBG_MDSCR_SS + msr mdscr_el1, \tmp +9990: + .endm + +/* + * SMP data memory barrier + */ + .macro smp_dmb, opt + dmb \opt + .endm + +/* + * RAS Error Synchronization barrier + */ + .macro esb +#ifdef CONFIG_ARM64_RAS_EXTN + hint #16 +#else + nop +#endif + .endm + +/* + * Value prediction barrier + */ + .macro csdb + hint #20 + .endm + +/* + * Clear Branch History instruction + */ + .macro clearbhb + hint #22 + .endm + +/* + * Sanitise a 64-bit bounded index wrt speculation, returning zero if out + * of bounds. + */ + .macro mask_nospec64, idx, limit, tmp + sub \tmp, \idx, \limit + bic \tmp, \tmp, \idx + and \idx, \idx, \tmp, asr #63 + csdb + .endm + +/* + * NOP sequence + */ + .macro nops, num + .rept \num + nop + .endr + .endm + +/* + * Emit an entry into the exception table + */ + .macro _asm_extable, from, to + .pushsection __ex_table, "a" + .align 3 + .long (\from - .), (\to - .) + .popsection + .endm + +#define USER(l, x...) \ +9999: x; \ + _asm_extable 9999b, l + +/* + * Register aliases. + */ +lr .req x30 // link register + +/* + * Vector entry + */ + .macro ventry label + .align 7 + b \label + .endm + +/* + * Select code when configured for BE. + */ +#ifdef CONFIG_CPU_BIG_ENDIAN +#define CPU_BE(code...) code +#else +#define CPU_BE(code...) +#endif + +/* + * Select code when configured for LE. + */ +#ifdef CONFIG_CPU_BIG_ENDIAN +#define CPU_LE(code...) +#else +#define CPU_LE(code...) code +#endif + +/* + * Define a macro that constructs a 64-bit value by concatenating two + * 32-bit registers. Note that on big endian systems the order of the + * registers is swapped. + */ +#ifndef CONFIG_CPU_BIG_ENDIAN + .macro regs_to_64, rd, lbits, hbits +#else + .macro regs_to_64, rd, hbits, lbits +#endif + orr \rd, \lbits, \hbits, lsl #32 + .endm + +/* + * Pseudo-ops for PC-relative adr/ldr/str <reg>, <symbol> where + * <symbol> is within the range +/- 4 GB of the PC. + */ + /* + * @dst: destination register (64 bit wide) + * @sym: name of the symbol + */ + .macro adr_l, dst, sym + adrp \dst, \sym + add \dst, \dst, :lo12:\sym + .endm + + /* + * @dst: destination register (32 or 64 bit wide) + * @sym: name of the symbol + * @tmp: optional 64-bit scratch register to be used if <dst> is a + * 32-bit wide register, in which case it cannot be used to hold + * the address + */ + .macro ldr_l, dst, sym, tmp= + .ifb \tmp + adrp \dst, \sym + ldr \dst, [\dst, :lo12:\sym] + .else + adrp \tmp, \sym + ldr \dst, [\tmp, :lo12:\sym] + .endif + .endm + + /* + * @src: source register (32 or 64 bit wide) + * @sym: name of the symbol + * @tmp: mandatory 64-bit scratch register to calculate the address + * while <src> needs to be preserved. + */ + .macro str_l, src, sym, tmp + adrp \tmp, \sym + str \src, [\tmp, :lo12:\sym] + .endm + + /* + * @dst: Result of per_cpu(sym, smp_processor_id()) (can be SP) + * @sym: The name of the per-cpu variable + * @tmp: scratch register + */ + .macro adr_this_cpu, dst, sym, tmp + adrp \tmp, \sym + add \dst, \tmp, #:lo12:\sym +alternative_if_not ARM64_HAS_VIRT_HOST_EXTN + mrs \tmp, tpidr_el1 +alternative_else + mrs \tmp, tpidr_el2 +alternative_endif + add \dst, \dst, \tmp + .endm + + /* + * @dst: Result of READ_ONCE(per_cpu(sym, smp_processor_id())) + * @sym: The name of the per-cpu variable + * @tmp: scratch register + */ + .macro ldr_this_cpu dst, sym, tmp + adr_l \dst, \sym +alternative_if_not ARM64_HAS_VIRT_HOST_EXTN + mrs \tmp, tpidr_el1 +alternative_else + mrs \tmp, tpidr_el2 +alternative_endif + ldr \dst, [\dst, \tmp] + .endm + +/* + * vma_vm_mm - get mm pointer from vma pointer (vma->vm_mm) + */ + .macro vma_vm_mm, rd, rn + ldr \rd, [\rn, #VMA_VM_MM] + .endm + +/* + * mmid - get context id from mm pointer (mm->context.id) + */ + .macro mmid, rd, rn + ldr \rd, [\rn, #MM_CONTEXT_ID] + .endm +/* + * read_ctr - read CTR_EL0. If the system has mismatched + * cache line sizes, provide the system wide safe value + * from arm64_ftr_reg_ctrel0.sys_val + */ + .macro read_ctr, reg +alternative_if_not ARM64_MISMATCHED_CACHE_LINE_SIZE + mrs \reg, ctr_el0 // read CTR + nop +alternative_else + ldr_l \reg, arm64_ftr_reg_ctrel0 + ARM64_FTR_SYSVAL +alternative_endif + .endm + + +/* + * raw_dcache_line_size - get the minimum D-cache line size on this CPU + * from the CTR register. + */ + .macro raw_dcache_line_size, reg, tmp + mrs \tmp, ctr_el0 // read CTR + ubfm \tmp, \tmp, #16, #19 // cache line size encoding + mov \reg, #4 // bytes per word + lsl \reg, \reg, \tmp // actual cache line size + .endm + +/* + * dcache_line_size - get the safe D-cache line size across all CPUs + */ + .macro dcache_line_size, reg, tmp + read_ctr \tmp + ubfm \tmp, \tmp, #16, #19 // cache line size encoding + mov \reg, #4 // bytes per word + lsl \reg, \reg, \tmp // actual cache line size + .endm + +/* + * raw_icache_line_size - get the minimum I-cache line size on this CPU + * from the CTR register. + */ + .macro raw_icache_line_size, reg, tmp + mrs \tmp, ctr_el0 // read CTR + and \tmp, \tmp, #0xf // cache line size encoding + mov \reg, #4 // bytes per word + lsl \reg, \reg, \tmp // actual cache line size + .endm + +/* + * icache_line_size - get the safe I-cache line size across all CPUs + */ + .macro icache_line_size, reg, tmp + read_ctr \tmp + and \tmp, \tmp, #0xf // cache line size encoding + mov \reg, #4 // bytes per word + lsl \reg, \reg, \tmp // actual cache line size + .endm + +/* + * tcr_set_idmap_t0sz - update TCR.T0SZ so that we can load the ID map + */ + .macro tcr_set_idmap_t0sz, valreg, tmpreg + ldr_l \tmpreg, idmap_t0sz + bfi \valreg, \tmpreg, #TCR_T0SZ_OFFSET, #TCR_TxSZ_WIDTH + .endm + +/* + * tcr_compute_pa_size - set TCR.(I)PS to the highest supported + * ID_AA64MMFR0_EL1.PARange value + * + * tcr: register with the TCR_ELx value to be updated + * pos: IPS or PS bitfield position + * tmp{0,1}: temporary registers + */ + .macro tcr_compute_pa_size, tcr, pos, tmp0, tmp1 + mrs \tmp0, ID_AA64MMFR0_EL1 + // Narrow PARange to fit the PS field in TCR_ELx + ubfx \tmp0, \tmp0, #ID_AA64MMFR0_PARANGE_SHIFT, #3 + mov \tmp1, #ID_AA64MMFR0_PARANGE_MAX + cmp \tmp0, \tmp1 + csel \tmp0, \tmp1, \tmp0, hi + bfi \tcr, \tmp0, \pos, #3 + .endm + +/* + * Macro to perform a data cache maintenance for the interval + * [kaddr, kaddr + size) + * + * op: operation passed to dc instruction + * domain: domain used in dsb instruciton + * kaddr: starting virtual address of the region + * size: size of the region + * Corrupts: kaddr, size, tmp1, tmp2 + */ + .macro __dcache_op_workaround_clean_cache, op, kaddr +alternative_if_not ARM64_WORKAROUND_CLEAN_CACHE + dc \op, \kaddr +alternative_else + dc civac, \kaddr +alternative_endif + .endm + + .macro dcache_by_line_op op, domain, kaddr, size, tmp1, tmp2 + dcache_line_size \tmp1, \tmp2 + add \size, \kaddr, \size + sub \tmp2, \tmp1, #1 + bic \kaddr, \kaddr, \tmp2 +9998: + .ifc \op, cvau + __dcache_op_workaround_clean_cache \op, \kaddr + .else + .ifc \op, cvac + __dcache_op_workaround_clean_cache \op, \kaddr + .else + .ifc \op, cvap + sys 3, c7, c12, 1, \kaddr // dc cvap + .else + dc \op, \kaddr + .endif + .endif + .endif + add \kaddr, \kaddr, \tmp1 + cmp \kaddr, \size + b.lo 9998b + dsb \domain + .endm + +/* + * Macro to perform an instruction cache maintenance for the interval + * [start, end) + * + * start, end: virtual addresses describing the region + * label: A label to branch to on user fault. + * Corrupts: tmp1, tmp2 + */ + .macro invalidate_icache_by_line start, end, tmp1, tmp2, label + icache_line_size \tmp1, \tmp2 + sub \tmp2, \tmp1, #1 + bic \tmp2, \start, \tmp2 +9997: +USER(\label, ic ivau, \tmp2) // invalidate I line PoU + add \tmp2, \tmp2, \tmp1 + cmp \tmp2, \end + b.lo 9997b + dsb ish + isb + .endm + +/* + * reset_pmuserenr_el0 - reset PMUSERENR_EL0 if PMUv3 present + */ + .macro reset_pmuserenr_el0, tmpreg + mrs \tmpreg, id_aa64dfr0_el1 // Check ID_AA64DFR0_EL1 PMUVer + sbfx \tmpreg, \tmpreg, #8, #4 + cmp \tmpreg, #1 // Skip if no PMU present + b.lt 9000f + msr pmuserenr_el0, xzr // Disable PMU access from EL0 +9000: + .endm + +/* + * copy_page - copy src to dest using temp registers t1-t8 + */ + .macro copy_page dest:req src:req t1:req t2:req t3:req t4:req t5:req t6:req t7:req t8:req +9998: ldp \t1, \t2, [\src] + ldp \t3, \t4, [\src, #16] + ldp \t5, \t6, [\src, #32] + ldp \t7, \t8, [\src, #48] + add \src, \src, #64 + stnp \t1, \t2, [\dest] + stnp \t3, \t4, [\dest, #16] + stnp \t5, \t6, [\dest, #32] + stnp \t7, \t8, [\dest, #48] + add \dest, \dest, #64 + tst \src, #(PAGE_SIZE - 1) + b.ne 9998b + .endm + +/* + * Annotate a function as position independent, i.e., safe to be called before + * the kernel virtual mapping is activated. + */ +#define ENDPIPROC(x) \ + .globl __pi_##x; \ + .type __pi_##x, %function; \ + .set __pi_##x, x; \ + .size __pi_##x, . - x; \ + ENDPROC(x) + +/* + * Annotate a function as being unsuitable for kprobes. + */ +#ifdef CONFIG_KPROBES +#define NOKPROBE(x) \ + .pushsection "_kprobe_blacklist", "aw"; \ + .quad x; \ + .popsection; +#else +#define NOKPROBE(x) +#endif + /* + * Emit a 64-bit absolute little endian symbol reference in a way that + * ensures that it will be resolved at build time, even when building a + * PIE binary. This requires cooperation from the linker script, which + * must emit the lo32/hi32 halves individually. + */ + .macro le64sym, sym + .long \sym\()_lo32 + .long \sym\()_hi32 + .endm + + /* + * mov_q - move an immediate constant into a 64-bit register using + * between 2 and 4 movz/movk instructions (depending on the + * magnitude and sign of the operand) + */ + .macro mov_q, reg, val + .if (((\val) >> 31) == 0 || ((\val) >> 31) == 0x1ffffffff) + movz \reg, :abs_g1_s:\val + .else + .if (((\val) >> 47) == 0 || ((\val) >> 47) == 0x1ffff) + movz \reg, :abs_g2_s:\val + .else + movz \reg, :abs_g3:\val + movk \reg, :abs_g2_nc:\val + .endif + movk \reg, :abs_g1_nc:\val + .endif + movk \reg, :abs_g0_nc:\val + .endm + +/* + * Return the current thread_info. + */ + .macro get_thread_info, rd + mrs \rd, sp_el0 + .endm + +/* + * Arrange a physical address in a TTBR register, taking care of 52-bit + * addresses. + * + * phys: physical address, preserved + * ttbr: returns the TTBR value + */ + .macro phys_to_ttbr, ttbr, phys +#ifdef CONFIG_ARM64_PA_BITS_52 + orr \ttbr, \phys, \phys, lsr #46 + and \ttbr, \ttbr, #TTBR_BADDR_MASK_52 +#else + mov \ttbr, \phys +#endif + .endm + + .macro phys_to_pte, pte, phys +#ifdef CONFIG_ARM64_PA_BITS_52 + /* + * We assume \phys is 64K aligned and this is guaranteed by only + * supporting this configuration with 64K pages. + */ + orr \pte, \phys, \phys, lsr #36 + and \pte, \pte, #PTE_ADDR_MASK +#else + mov \pte, \phys +#endif + .endm + + .macro pte_to_phys, phys, pte +#ifdef CONFIG_ARM64_PA_BITS_52 + ubfiz \phys, \pte, #(48 - 16 - 12), #16 + bfxil \phys, \pte, #16, #32 + lsl \phys, \phys, #16 +#else + and \phys, \pte, #PTE_ADDR_MASK +#endif + .endm + +/** + * Errata workaround prior to disable MMU. Insert an ISB immediately prior + * to executing the MSR that will change SCTLR_ELn[M] from a value of 1 to 0. + */ + .macro pre_disable_mmu_workaround +#ifdef CONFIG_QCOM_FALKOR_ERRATUM_E1041 + isb +#endif + .endm + + /* + * frame_push - Push @regcount callee saved registers to the stack, + * starting at x19, as well as x29/x30, and set x29 to + * the new value of sp. Add @extra bytes of stack space + * for locals. + */ + .macro frame_push, regcount:req, extra + __frame st, \regcount, \extra + .endm + + /* + * frame_pop - Pop the callee saved registers from the stack that were + * pushed in the most recent call to frame_push, as well + * as x29/x30 and any extra stack space that may have been + * allocated. + */ + .macro frame_pop + __frame ld + .endm + + .macro __frame_regs, reg1, reg2, op, num + .if .Lframe_regcount == \num + \op\()r \reg1, [sp, #(\num + 1) * 8] + .elseif .Lframe_regcount > \num + \op\()p \reg1, \reg2, [sp, #(\num + 1) * 8] + .endif + .endm + + .macro __frame, op, regcount, extra=0 + .ifc \op, st + .if (\regcount) < 0 || (\regcount) > 10 + .error "regcount should be in the range [0 ... 10]" + .endif + .if ((\extra) % 16) != 0 + .error "extra should be a multiple of 16 bytes" + .endif + .ifdef .Lframe_regcount + .if .Lframe_regcount != -1 + .error "frame_push/frame_pop may not be nested" + .endif + .endif + .set .Lframe_regcount, \regcount + .set .Lframe_extra, \extra + .set .Lframe_local_offset, ((\regcount + 3) / 2) * 16 + stp x29, x30, [sp, #-.Lframe_local_offset - .Lframe_extra]! + mov x29, sp + .endif + + __frame_regs x19, x20, \op, 1 + __frame_regs x21, x22, \op, 3 + __frame_regs x23, x24, \op, 5 + __frame_regs x25, x26, \op, 7 + __frame_regs x27, x28, \op, 9 + + .ifc \op, ld + .if .Lframe_regcount == -1 + .error "frame_push/frame_pop may not be nested" + .endif + ldp x29, x30, [sp], #.Lframe_local_offset + .Lframe_extra + .set .Lframe_regcount, -1 + .endif + .endm + +/* + * Check whether to yield to another runnable task from kernel mode NEON code + * (which runs with preemption disabled). + * + * if_will_cond_yield_neon + * // pre-yield patchup code + * do_cond_yield_neon + * // post-yield patchup code + * endif_yield_neon <label> + * + * where <label> is optional, and marks the point where execution will resume + * after a yield has been performed. If omitted, execution resumes right after + * the endif_yield_neon invocation. Note that the entire sequence, including + * the provided patchup code, will be omitted from the image if CONFIG_PREEMPT + * is not defined. + * + * As a convenience, in the case where no patchup code is required, the above + * sequence may be abbreviated to + * + * cond_yield_neon <label> + * + * Note that the patchup code does not support assembler directives that change + * the output section, any use of such directives is undefined. + * + * The yield itself consists of the following: + * - Check whether the preempt count is exactly 1, in which case disabling + * preemption once will make the task preemptible. If this is not the case, + * yielding is pointless. + * - Check whether TIF_NEED_RESCHED is set, and if so, disable and re-enable + * kernel mode NEON (which will trigger a reschedule), and branch to the + * yield fixup code. + * + * This macro sequence may clobber all CPU state that is not guaranteed by the + * AAPCS to be preserved across an ordinary function call. + */ + + .macro cond_yield_neon, lbl + if_will_cond_yield_neon + do_cond_yield_neon + endif_yield_neon \lbl + .endm + + .macro if_will_cond_yield_neon +#ifdef CONFIG_PREEMPT + get_thread_info x0 + ldr w1, [x0, #TSK_TI_PREEMPT] + ldr x0, [x0, #TSK_TI_FLAGS] + cmp w1, #PREEMPT_DISABLE_OFFSET + csel x0, x0, xzr, eq + tbnz x0, #TIF_NEED_RESCHED, .Lyield_\@ // needs rescheduling? + /* fall through to endif_yield_neon */ + .subsection 1 +.Lyield_\@ : +#else + .section ".discard.cond_yield_neon", "ax" +#endif + .endm + + .macro do_cond_yield_neon + bl kernel_neon_end + bl kernel_neon_begin + .endm + + .macro endif_yield_neon, lbl + .ifnb \lbl + b \lbl + .else + b .Lyield_out_\@ + .endif + .previous +.Lyield_out_\@ : + .endm + + .macro __mitigate_spectre_bhb_loop tmp +#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY +alternative_cb spectre_bhb_patch_loop_iter + mov \tmp, #32 // Patched to correct the immediate +alternative_cb_end +.Lspectre_bhb_loop\@: + b . + 4 + subs \tmp, \tmp, #1 + b.ne .Lspectre_bhb_loop\@ + dsb nsh + isb +#endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */ + .endm + + /* Save/restores x0-x3 to the stack */ + .macro __mitigate_spectre_bhb_fw +#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY + stp x0, x1, [sp, #-16]! + stp x2, x3, [sp, #-16]! + mov w0, #ARM_SMCCC_ARCH_WORKAROUND_3 +alternative_cb arm64_update_smccc_conduit + nop // Patched to SMC/HVC #0 +alternative_cb_end + ldp x2, x3, [sp], #16 + ldp x0, x1, [sp], #16 +#endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */ + .endm +#endif /* __ASM_ASSEMBLER_H */ |