#define PHYS_OFFSET ((phys_addr_t)__pv_phys_pfn_offset << PAGE_SHIFT)
#define PHYS_PFN_OFFSET (__pv_phys_pfn_offset)
+#ifndef CONFIG_THUMB2_KERNEL
#define __pv_stub(from,to,instr) \
__asm__("@ __pv_stub\n" \
"1: " instr " %0, %1, %2\n" \
: "=r" (to) \
: "r" (from), "I" (__PV_BITS_31_24))
-#define __pv_stub_mov_hi(t) \
- __asm__ volatile("@ __pv_stub_mov\n" \
- "1: mov %R0, %1\n" \
+#define __pv_add_carry_stub(x, y) \
+ __asm__("@ __pv_add_carry_stub\n" \
+ "0: movw %R0, #0\n" \
+ " adds %Q0, %1, %R0, lsl #24\n" \
+ "1: mov %R0, %2\n" \
+ " adc %R0, %R0, #0\n" \
" .pushsection .pv_table,\"a\"\n" \
- " .long 1b - .\n" \
+ " .long 0b - ., 1b - .\n" \
" .popsection\n" \
- : "=r" (t) \
- : "I" (__PV_BITS_7_0))
+ : "=&r" (y) \
+ : "r" (x), "I" (__PV_BITS_7_0) \
+ : "cc")
+
+#else
+#define __pv_stub(from,to,instr) \
+ __asm__("@ __pv_stub\n" \
+ "0: movw %0, #0\n" \
+ " lsl %0, #24\n" \
+ " " instr " %0, %1, %0\n" \
+ " .pushsection .pv_table,\"a\"\n" \
+ " .long 0b - .\n" \
+ " .popsection\n" \
+ : "=&r" (to) \
+ : "r" (from))
#define __pv_add_carry_stub(x, y) \
- __asm__ volatile("@ __pv_add_carry_stub\n" \
- "1: adds %Q0, %1, %2\n" \
+ __asm__("@ __pv_add_carry_stub\n" \
+ "0: movw %R0, #0\n" \
+ " lsls %R0, #24\n" \
+ " adds %Q0, %1, %R0\n" \
+ "1: mvn %R0, #0\n" \
" adc %R0, %R0, #0\n" \
" .pushsection .pv_table,\"a\"\n" \
- " .long 1b - .\n" \
+ " .long 0b - ., 1b - .\n" \
" .popsection\n" \
- : "+r" (y) \
- : "r" (x), "I" (__PV_BITS_31_24) \
+ : "=&r" (y) \
+ : "r" (x) \
: "cc")
+#endif
static inline phys_addr_t __virt_to_phys_nodebug(unsigned long x)
{
if (sizeof(phys_addr_t) == 4) {
__pv_stub(x, t, "add");
} else {
- __pv_stub_mov_hi(t);
__pv_add_carry_stub(x, t);
}
return t;
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 1994-2002 Russell King
- * Copyright (c) 2003 ARM Limited
+ * Copyright (c) 2003, 2020 ARM Limited
* All Rights Reserved
*/
mov r6, r6, lsr #24
cmn r0, #1
#ifdef CONFIG_THUMB2_KERNEL
+ @
+ @ The Thumb-2 versions of the patchable sequences are
+ @
+ @ phys-to-virt: movw <reg>, #offset<31:24>
+ @ lsl <reg>, #24
+ @ sub <VA>, <PA>, <reg>
+ @
+ @ virt-to-phys (non-LPAE): movw <reg>, #offset<31:24>
+ @ lsl <reg>, #24
+ @ add <PA>, <VA>, <reg>
+ @
+ @ virt-to-phys (LPAE): movw <reg>, #offset<31:24>
+ @ lsl <reg>, #24
+ @ adds <PAlo>, <VA>, <reg>
+ @ mov <PAhi>, #offset<39:32>
+ @ adc <PAhi>, <PAhi>, #0
+ @
+ @ In the non-LPAE case, all patchable instructions are MOVW
+ @ instructions, where we need to patch in the offset into the
+ @ second halfword of the opcode (the 16-bit immediate is encoded
+ @ as imm4:i:imm3:imm8)
+ @
+ @ 15 11 10 9 4 3 0 15 14 12 11 8 7 0
+ @ +-----------+---+-------------+------++---+------+----+------+
+ @ MOVW | 1 1 1 1 0 | i | 1 0 0 1 0 0 | imm4 || 0 | imm3 | Rd | imm8 |
+ @ +-----------+---+-------------+------++---+------+----+------+
+ @
+ @ In the LPAE case, we also need to patch in the high word of the
+ @ offset into the immediate field of the MOV instruction, or patch it
+ @ to a MVN instruction if the offset is negative. In this case, we
+ @ need to inspect the first halfword of the opcode, to check whether
+ @ it is MOVW or MOV/MVN, and to perform the MOV to MVN patching if
+ @ needed. The encoding of the immediate is rather complex for values
+ @ of i:imm3 != 0b0000, but fortunately, we never need more than 8 lower
+ @ order bits, which can be patched into imm8 directly (and i:imm3
+ @ cleared)
+ @
+ @ 15 11 10 9 5 0 15 14 12 11 8 7 0
+ @ +-----------+---+---------------------++---+------+----+------+
+ @ MOV | 1 1 1 1 0 | i | 0 0 0 1 0 0 1 1 1 1 || 0 | imm3 | Rd | imm8 |
+ @ MVN | 1 1 1 1 0 | i | 0 0 0 1 1 0 1 1 1 1 || 0 | imm3 | Rd | imm8 |
+ @ +-----------+---+---------------------++---+------+----+------+
+ @
moveq r0, #0x200000 @ set bit 21, mov to mvn instruction
- lsls r6, #24
- beq .Lnext
- clz r7, r6
- lsr r6, #24
- lsl r6, r7
- bic r6, #0x0080
- lsrs r7, #1
- orrcs r6, #0x0080
- orr r6, r6, r7, lsl #12
- orr r6, #0x4000
b .Lnext
.Lloop: add r7, r4
- adds r4, #4
- ldrh ip, [r7, #2]
-ARM_BE8(rev16 ip, ip)
- tst ip, #0x4000
- and ip, #0x8f00
- orrne ip, r6 @ mask in offset bits 31-24
- orreq ip, r0 @ mask in offset bits 7-0
-ARM_BE8(rev16 ip, ip)
- strh ip, [r7, #2]
- bne .Lnext
+ adds r4, #4 @ clears Z flag
+#ifdef CONFIG_ARM_LPAE
ldrh ip, [r7]
ARM_BE8(rev16 ip, ip)
- bic ip, #0x20
- orr ip, ip, r0, lsr #16
+ tst ip, #0x200 @ MOVW has bit 9 set, MVN has it clear
+ bne 0f @ skip to MOVW handling (Z flag is clear)
+ bic ip, #0x20 @ clear bit 5 (MVN -> MOV)
+ orr ip, ip, r0, lsr #16 @ MOV -> MVN if offset < 0
ARM_BE8(rev16 ip, ip)
strh ip, [r7]
+ @ Z flag is set
+0:
+#endif
+ ldrh ip, [r7, #2]
+ARM_BE8(rev16 ip, ip)
+ and ip, #0xf00 @ clear everything except Rd field
+ orreq ip, r0 @ Z flag set -> MOV/MVN -> patch in high bits
+ orrne ip, r6 @ Z flag clear -> MOVW -> patch in low bits
+ARM_BE8(rev16 ip, ip)
+ strh ip, [r7, #2]
#else
#ifdef CONFIG_CPU_ENDIAN_BE8
@ in BE8, we load data in BE, but instructions still in LE
-#define PV_BIT22 0x00004000
+#define PV_BIT24 0x00000001
#define PV_IMM8_MASK 0xff000000
-#define PV_ROT_MASK 0x000f0000
#else
-#define PV_BIT22 0x00400000
+#define PV_BIT24 0x01000000
#define PV_IMM8_MASK 0x000000ff
-#define PV_ROT_MASK 0xf00
#endif
+ @
+ @ The ARM versions of the patchable sequences are
+ @
+ @ phys-to-virt: sub <VA>, <PA>, #offset<31:24>, lsl #24
+ @
+ @ virt-to-phys (non-LPAE): add <PA>, <VA>, #offset<31:24>, lsl #24
+ @
+ @ virt-to-phys (LPAE): movw <reg>, #offset<31:24>
+ @ adds <PAlo>, <VA>, <reg>, lsl #24
+ @ mov <PAhi>, #offset<39:32>
+ @ adc <PAhi>, <PAhi>, #0
+ @
+ @ In the non-LPAE case, all patchable instructions are ADD or SUB
+ @ instructions, where we need to patch in the offset into the
+ @ immediate field of the opcode, which is emitted with the correct
+ @ rotation value. (The effective value of the immediate is imm12<7:0>
+ @ rotated right by [2 * imm12<11:8>] bits)
+ @
+ @ 31 28 27 23 22 20 19 16 15 12 11 0
+ @ +------+-----------------+------+------+-------+
+ @ ADD | cond | 0 0 1 0 1 0 0 0 | Rn | Rd | imm12 |
+ @ SUB | cond | 0 0 1 0 0 1 0 0 | Rn | Rd | imm12 |
+ @ MOV | cond | 0 0 1 1 1 0 1 0 | Rn | Rd | imm12 |
+ @ MVN | cond | 0 0 1 1 1 1 1 0 | Rn | Rd | imm12 |
+ @ +------+-----------------+------+------+-------+
+ @
+ @ In the LPAE case, we use a MOVW instruction to carry the low offset
+ @ word, and patch in the high word of the offset into the immediate
+ @ field of the subsequent MOV instruction, or patch it to a MVN
+ @ instruction if the offset is negative. We can distinguish MOVW
+ @ instructions based on bits 23:22 of the opcode, and ADD/SUB can be
+ @ distinguished from MOV/MVN (all using the encodings above) using
+ @ bit 24.
+ @
+ @ 31 28 27 23 22 20 19 16 15 12 11 0
+ @ +------+-----------------+------+------+-------+
+ @ MOVW | cond | 0 0 1 1 0 0 0 0 | imm4 | Rd | imm12 |
+ @ +------+-----------------+------+------+-------+
+ @
moveq r0, #0x400000 @ set bit 22, mov to mvn instruction
b .Lnext
.Lloop: ldr ip, [r7, r4]
+#ifdef CONFIG_ARM_LPAE
+ tst ip, #PV_BIT24 @ ADD/SUB have bit 24 clear
+ beq 1f
+ARM_BE8(rev ip, ip)
+ tst ip, #0xc00000 @ MOVW has bits 23:22 clear
+ bic ip, ip, #0x400000 @ clear bit 22
+ bfc ip, #0, #12 @ clear imm12 field of MOV[W] instruction
+ orreq ip, ip, r6 @ MOVW -> mask in offset bits 31-24
+ orrne ip, ip, r0 @ MOV -> mask in offset bits 7-0 (or bit 22)
+ARM_BE8(rev ip, ip)
+ b 2f
+1:
+#endif
bic ip, ip, #PV_IMM8_MASK
- tst ip, #PV_ROT_MASK @ check the rotation field
- orrne ip, ip, r6 ARM_BE8(, lsl #24) @ mask in offset bits 31-24
- biceq ip, ip, #PV_BIT22 @ clear bit 22
- orreq ip, ip, r0 ARM_BE8(, ror #8) @ mask in offset bits 7-0 (or bit 22)
+ orr ip, ip, r6 ARM_BE8(, lsl #24) @ mask in offset bits 31-24
+2:
str ip, [r7, r4]
add r4, r4, #4
#endif
projects / users / griffoul / linux.git / commitdiff