linux/arch/arm/mm/abort-macro.S

/*
 * The ARM LDRD and Thumb LDRSB instructions use bit 20/11 (ARM/Thumb)
 * differently than every other instruction, so it is set to 0 (write)
 * even though the instructions are read instructions. This means that
 * during an abort the instructions will be treated as a write and the
 * handler will raise a signal from unwriteable locations if they
 * fault. We have to specifically check for these instructions
 * from the abort handlers to treat them properly.
 *
 */

	.macro	do_thumb_abort, fsr, pc, psr, tmp
	tst	\psr, #PSR_T_BIT
	beq	not_thumb
	ldrh	\tmp, [\pc]			@ Read aborted Thumb instruction
	and	\tmp, \tmp, # 0xfe00		@ Mask opcode field
	cmp	\tmp, # 0x5600			@ Is it ldrsb?
	orreq	\tmp, \tmp, #1 << 11		@ Set L-bit if yes
	tst	\tmp, #1 << 11			@ L = 0 -> write
	orreq	\psr, \psr, #1 << 11		@ yes.
	b	do_DataAbort
not_thumb:
	.endm

/*
 * We check for the following instruction encoding for LDRD.
 *
 * [27:25] == 000
 *   [7:4] == 1101
 *    [20] == 0
 */
	.macro	do_ldrd_abort, tmp, insn
	tst	\insn, #0x0e100000		@ [27:25,20] == 0
	bne	not_ldrd
	and	\tmp, \insn, #0x000000f0	@ [7:4] == 1101
	cmp	\tmp, #0x000000d0
	beq	do_DataAbort
not_ldrd:
	.endm
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! 2005-04-17 02:20:36 +04:00			`/*`
			`* The ARM LDRD and Thumb LDRSB instructions use bit 20/11 (ARM/Thumb)`
			`* differently than every other instruction, so it is set to 0 (write)`
			`* even though the instructions are read instructions. This means that`
			`* during an abort the instructions will be treated as a write and the`
			`* handler will raise a signal from unwriteable locations if they`
			`* fault. We have to specifically check for these instructions`
			`* from the abort handlers to treat them properly.`
			`*`
			`*/`

ARM: entry: abort-macro: specify registers to be used for macros Require all callers of abort macros to specify the registers to be used. This improves the documentation at the callsites as to which registers are being used by this assembly code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 2011-06-26 16:42:01 +04:00			`.macro do_thumb_abort, fsr, pc, psr, tmp`
			`tst \psr, #PSR_T_BIT`
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! 2005-04-17 02:20:36 +04:00			`beq not_thumb`
ARM: entry: abort-macro: specify registers to be used for macros Require all callers of abort macros to specify the registers to be used. This improves the documentation at the callsites as to which registers are being used by this assembly code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 2011-06-26 16:42:01 +04:00			`ldrh \tmp, [\pc] @ Read aborted Thumb instruction`
			`and \tmp, \tmp, # 0xfe00 @ Mask opcode field`
			`cmp \tmp, # 0x5600 @ Is it ldrsb?`
			`orreq \tmp, \tmp, #1 << 11 @ Set L-bit if yes`
			`tst \tmp, #1 << 11 @ L = 0 -> write`
			`orreq \psr, \psr, #1 << 11 @ yes.`
ARM: entry: data abort: tail-call the main data abort handler Tail-call the main C data abort handler code from the per-CPU helper code. Update the comments in the code wrt the new calling and return register state. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 2011-06-26 19:01:26 +04:00			`b do_DataAbort`
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! 2005-04-17 02:20:36 +04:00			`not_thumb:`
			`.endm`

			`/*`
ARM: entry: abort-macro: specify registers to be used for macros Require all callers of abort macros to specify the registers to be used. This improves the documentation at the callsites as to which registers are being used by this assembly code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 2011-06-26 16:42:01 +04:00			`* We check for the following instruction encoding for LDRD.`
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! 2005-04-17 02:20:36 +04:00			`*`
ARM: entry: abort-macro: specify registers to be used for macros Require all callers of abort macros to specify the registers to be used. This improves the documentation at the callsites as to which registers are being used by this assembly code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 2011-06-26 16:42:01 +04:00			`* [27:25] == 000`
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! 2005-04-17 02:20:36 +04:00			`* [7:4] == 1101`
			`* [20] == 0`
			`*/`
ARM: entry: abort-macro: specify registers to be used for macros Require all callers of abort macros to specify the registers to be used. This improves the documentation at the callsites as to which registers are being used by this assembly code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 2011-06-26 16:42:01 +04:00			`.macro do_ldrd_abort, tmp, insn`
ARM: entry: abort-macro: simplify do_ldrd_abort We can test bits 27:25 and 20 of the instruction at the same time; there's no need to separate out the check of bit 20. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 2011-06-26 16:51:44 +04:00			`tst \insn, #0x0e100000 @ [27:25,20] == 0`
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! 2005-04-17 02:20:36 +04:00			`bne not_ldrd`
ARM: entry: abort-macro: specify registers to be used for macros Require all callers of abort macros to specify the registers to be used. This improves the documentation at the callsites as to which registers are being used by this assembly code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 2011-06-26 16:42:01 +04:00			`and \tmp, \insn, #0x000000f0 @ [7:4] == 1101`
			`cmp \tmp, #0x000000d0`
ARM: entry: data abort: tail-call the main data abort handler Tail-call the main C data abort handler code from the per-CPU helper code. Update the comments in the code wrt the new calling and return register state. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 2011-06-26 19:01:26 +04:00			`beq do_DataAbort`
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! 2005-04-17 02:20:36 +04:00			`not_ldrd:`
			`.endm`