cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ams-delta-fiq-handler.S (8777B)


      1/* SPDX-License-Identifier: GPL-2.0-only */
      2/*
      3 *  linux/arch/arm/mach-omap1/ams-delta-fiq-handler.S
      4 *
      5 *  Based on  linux/arch/arm/lib/floppydma.S
      6 *  Renamed and modified to work with 2.6 kernel by Matt Callow
      7 *  Copyright (C) 1995, 1996 Russell King
      8 *  Copyright (C) 2004 Pete Trapps
      9 *  Copyright (C) 2006 Matt Callow
     10 *  Copyright (C) 2010 Janusz Krzysztofik
     11 */
     12
     13#include <linux/linkage.h>
     14#include <linux/platform_data/ams-delta-fiq.h>
     15#include <linux/platform_data/gpio-omap.h>
     16#include <linux/soc/ti/omap1-io.h>
     17
     18#include <asm/assembler.h>
     19#include <asm/irq.h>
     20
     21#include "hardware.h"
     22#include "ams-delta-fiq.h"
     23#include "board-ams-delta.h"
     24#include "iomap.h"
     25
     26/*
     27 * OMAP1510 GPIO related symbol copied from arch/arm/mach-omap1/gpio15xx.c.
     28 * Unfortunately, it was not placed in a separate header file.
     29 */
     30#define OMAP1510_GPIO_BASE		0xFFFCE000
     31
     32/* GPIO register bitmasks */
     33#define KEYBRD_DATA_MASK		(0x1 << AMS_DELTA_GPIO_PIN_KEYBRD_DATA)
     34#define KEYBRD_CLK_MASK			(0x1 << AMS_DELTA_GPIO_PIN_KEYBRD_CLK)
     35#define MODEM_IRQ_MASK			(0x1 << AMS_DELTA_GPIO_PIN_MODEM_IRQ)
     36#define HOOK_SWITCH_MASK		(0x1 << AMS_DELTA_GPIO_PIN_HOOK_SWITCH)
     37#define OTHERS_MASK			(MODEM_IRQ_MASK | HOOK_SWITCH_MASK)
     38
     39/* IRQ handler register bitmasks */
     40#define DEFERRED_FIQ_MASK		OMAP_IRQ_BIT(INT_DEFERRED_FIQ)
     41#define GPIO_BANK1_MASK  		OMAP_IRQ_BIT(INT_GPIO_BANK1)
     42
     43/* Driver buffer byte offsets */
     44#define BUF_MASK			(FIQ_MASK * 4)
     45#define BUF_STATE			(FIQ_STATE * 4)
     46#define BUF_KEYS_CNT			(FIQ_KEYS_CNT * 4)
     47#define BUF_TAIL_OFFSET			(FIQ_TAIL_OFFSET * 4)
     48#define BUF_HEAD_OFFSET			(FIQ_HEAD_OFFSET * 4)
     49#define BUF_BUF_LEN			(FIQ_BUF_LEN * 4)
     50#define BUF_KEY				(FIQ_KEY * 4)
     51#define BUF_MISSED_KEYS			(FIQ_MISSED_KEYS * 4)
     52#define BUF_BUFFER_START		(FIQ_BUFFER_START * 4)
     53#define BUF_GPIO_INT_MASK		(FIQ_GPIO_INT_MASK * 4)
     54#define BUF_KEYS_HICNT			(FIQ_KEYS_HICNT * 4)
     55#define BUF_IRQ_PEND			(FIQ_IRQ_PEND * 4)
     56#define BUF_SIR_CODE_L1			(FIQ_SIR_CODE_L1 * 4)
     57#define BUF_SIR_CODE_L2			(IRQ_SIR_CODE_L2 * 4)
     58#define BUF_CNT_INT_00			(FIQ_CNT_INT_00 * 4)
     59#define BUF_CNT_INT_KEY			(FIQ_CNT_INT_KEY * 4)
     60#define BUF_CNT_INT_MDM			(FIQ_CNT_INT_MDM * 4)
     61#define BUF_CNT_INT_03			(FIQ_CNT_INT_03 * 4)
     62#define BUF_CNT_INT_HSW			(FIQ_CNT_INT_HSW * 4)
     63#define BUF_CNT_INT_05			(FIQ_CNT_INT_05 * 4)
     64#define BUF_CNT_INT_06			(FIQ_CNT_INT_06 * 4)
     65#define BUF_CNT_INT_07			(FIQ_CNT_INT_07 * 4)
     66#define BUF_CNT_INT_08			(FIQ_CNT_INT_08 * 4)
     67#define BUF_CNT_INT_09			(FIQ_CNT_INT_09 * 4)
     68#define BUF_CNT_INT_10			(FIQ_CNT_INT_10 * 4)
     69#define BUF_CNT_INT_11			(FIQ_CNT_INT_11 * 4)
     70#define BUF_CNT_INT_12			(FIQ_CNT_INT_12 * 4)
     71#define BUF_CNT_INT_13			(FIQ_CNT_INT_13 * 4)
     72#define BUF_CNT_INT_14			(FIQ_CNT_INT_14 * 4)
     73#define BUF_CNT_INT_15			(FIQ_CNT_INT_15 * 4)
     74#define BUF_CIRC_BUFF			(FIQ_CIRC_BUFF * 4)
     75
     76
     77/*
     78 * Register usage
     79 * r8  - temporary
     80 * r9  - the driver buffer
     81 * r10 - temporary
     82 * r11 - interrupts mask
     83 * r12 - base pointers
     84 * r13 - interrupts status
     85 */
     86
     87	.text
     88
     89	.global qwerty_fiqin_end
     90
     91ENTRY(qwerty_fiqin_start)
     92	@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
     93	@ FIQ intrrupt handler
     94	ldr r12, omap_ih1_base			@ set pointer to level1 handler
     95
     96	ldr r11, [r12, #IRQ_MIR_REG_OFFSET]	@ fetch interrupts mask
     97
     98	ldr r13, [r12, #IRQ_ITR_REG_OFFSET]	@ fetch interrupts status
     99	bics r13, r13, r11			@ clear masked - any left?
    100	beq exit				@ none - spurious FIQ? exit
    101
    102	ldr r10, [r12, #IRQ_SIR_FIQ_REG_OFFSET]	@ get requested interrupt number
    103
    104	mov r8, #2				@ reset FIQ agreement
    105	str r8, [r12, #IRQ_CONTROL_REG_OFFSET]
    106
    107	cmp r10, #(INT_GPIO_BANK1 - NR_IRQS_LEGACY)	@ is it GPIO interrupt?
    108	beq gpio				@ yes - process it
    109
    110	mov r8, #1
    111	orr r8, r11, r8, lsl r10		@ mask spurious interrupt
    112	str r8, [r12, #IRQ_MIR_REG_OFFSET]
    113exit:
    114	subs	pc, lr, #4			@ return from FIQ
    115	@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
    116
    117
    118	@@@@@@@@@@@@@@@@@@@@@@@@@@@
    119gpio:	@ GPIO bank interrupt handler
    120	ldr r12, omap1510_gpio_base		@ set base pointer to GPIO bank
    121
    122	ldr r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ fetch GPIO interrupts mask
    123restart:
    124	ldr r13, [r12, #OMAP1510_GPIO_INT_STATUS]	@ fetch status bits
    125	bics r13, r13, r11			@ clear masked - any left?
    126	beq exit				@ no - spurious interrupt? exit
    127
    128	orr r11, r11, r13			@ mask all requested interrupts
    129	str r11, [r12, #OMAP1510_GPIO_INT_MASK]
    130
    131	str r13, [r12, #OMAP1510_GPIO_INT_STATUS] @ ack all requested interrupts
    132
    133	ands r10, r13, #KEYBRD_CLK_MASK		@ extract keyboard status - set?
    134	beq hksw				@ no - try next source
    135
    136
    137	@@@@@@@@@@@@@@@@@@@@@@
    138	@ Keyboard clock FIQ mode interrupt handler
    139	@ r10 now contains KEYBRD_CLK_MASK, use it
    140	bic r11, r11, r10				@ unmask it
    141	str r11, [r12, #OMAP1510_GPIO_INT_MASK]
    142
    143	@ Process keyboard data
    144	ldr r8, [r12, #OMAP1510_GPIO_DATA_INPUT]	@ fetch GPIO input
    145
    146	ldr r10, [r9, #BUF_STATE]		@ fetch kbd interface state
    147	cmp r10, #0				@ are we expecting start bit?
    148	bne data				@ no - go to data processing
    149
    150	ands r8, r8, #KEYBRD_DATA_MASK		@ check start bit - detected?
    151	beq hksw				@ no - try next source
    152
    153	@ r8 contains KEYBRD_DATA_MASK, use it
    154	str r8, [r9, #BUF_STATE]		@ enter data processing state
    155	@ r10 already contains 0, reuse it
    156	str r10, [r9, #BUF_KEY]			@ clear keycode
    157	mov r10, #2				@ reset input bit mask
    158	str r10, [r9, #BUF_MASK]
    159
    160	@ Mask other GPIO line interrupts till key done
    161	str r11, [r9, #BUF_GPIO_INT_MASK]	@ save mask for later restore
    162	mvn r11, #KEYBRD_CLK_MASK		@ prepare all except kbd mask
    163	str r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ store into the mask register
    164
    165	b restart				@ restart
    166
    167data:	ldr r10, [r9, #BUF_MASK]		@ fetch current input bit mask
    168
    169	@ r8 still contains GPIO input bits
    170	ands r8, r8, #KEYBRD_DATA_MASK		@ is keyboard data line low?
    171	ldreq r8, [r9, #BUF_KEY]		@ yes - fetch collected so far,
    172	orreq r8, r8, r10			@ set 1 at current mask position
    173	streq r8, [r9, #BUF_KEY]		@ and save back
    174
    175	mov r10, r10, lsl #1			@ shift mask left
    176	bics r10, r10, #0x800			@ have we got all the bits?
    177	strne r10, [r9, #BUF_MASK]		@ not yet - store the mask
    178	bne restart				@ and restart
    179
    180	@ r10 already contains 0, reuse it
    181	str r10, [r9, #BUF_STATE]		@ reset state to start
    182
    183	@ Key done - restore interrupt mask
    184	ldr r10, [r9, #BUF_GPIO_INT_MASK]	@ fetch saved mask
    185	and r11, r11, r10			@ unmask all saved as unmasked
    186	str r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ restore into the mask register
    187
    188	@ Try appending the keycode to the circular buffer
    189	ldr r10, [r9, #BUF_KEYS_CNT]		@ get saved keystrokes count
    190	ldr r8, [r9, #BUF_BUF_LEN]		@ get buffer size
    191	cmp r10, r8				@ is buffer full?
    192	beq hksw				@ yes - key lost, next source
    193
    194	add r10, r10, #1			@ incremet keystrokes counter
    195	str r10, [r9, #BUF_KEYS_CNT]
    196
    197	ldr r10, [r9, #BUF_TAIL_OFFSET]		@ get buffer tail offset
    198	@ r8 already contains buffer size
    199	cmp r10, r8				@ end of buffer?
    200	moveq r10, #0				@ yes - rewind to buffer start
    201
    202	ldr r12, [r9, #BUF_BUFFER_START]	@ get buffer start address
    203	add r12, r12, r10, LSL #2		@ calculate buffer tail address
    204	ldr r8, [r9, #BUF_KEY]			@ get last keycode
    205	str r8, [r12]				@ append it to the buffer tail
    206
    207	add r10, r10, #1			@ increment buffer tail offset
    208	str r10, [r9, #BUF_TAIL_OFFSET]
    209
    210	ldr r10, [r9, #BUF_CNT_INT_KEY]		@ increment interrupts counter
    211	add r10, r10, #1
    212	str r10, [r9, #BUF_CNT_INT_KEY]
    213	@@@@@@@@@@@@@@@@@@@@@@@@
    214
    215
    216hksw:	@Is hook switch interrupt requested?
    217	tst r13, #HOOK_SWITCH_MASK 		@ is hook switch status bit set?
    218	beq mdm					@ no - try next source
    219
    220
    221	@@@@@@@@@@@@@@@@@@@@@@@@
    222	@ Hook switch interrupt FIQ mode simple handler
    223
    224	@ Don't toggle active edge, the switch always bounces
    225
    226	@ Increment hook switch interrupt counter
    227	ldr r10, [r9, #BUF_CNT_INT_HSW]
    228	add r10, r10, #1
    229	str r10, [r9, #BUF_CNT_INT_HSW]
    230	@@@@@@@@@@@@@@@@@@@@@@@@
    231
    232
    233mdm:	@Is it a modem interrupt?
    234	tst r13, #MODEM_IRQ_MASK 		@ is modem status bit set?
    235	beq irq					@ no - check for next interrupt
    236
    237
    238	@@@@@@@@@@@@@@@@@@@@@@@@
    239	@ Modem FIQ mode interrupt handler stub
    240
    241	@ Increment modem interrupt counter
    242	ldr r10, [r9, #BUF_CNT_INT_MDM]
    243	add r10, r10, #1
    244	str r10, [r9, #BUF_CNT_INT_MDM]
    245	@@@@@@@@@@@@@@@@@@@@@@@@
    246
    247
    248irq:	@ Place deferred_fiq interrupt request
    249	ldr r12, deferred_fiq_ih_base		@ set pointer to IRQ handler
    250	mov r10, #DEFERRED_FIQ_MASK		@ set deferred_fiq bit
    251	str r10, [r12, #IRQ_ISR_REG_OFFSET] 	@ place it in the ISR register
    252
    253	ldr r12, omap1510_gpio_base		@ set pointer back to GPIO bank
    254	b restart				@ check for next GPIO interrupt
    255	@@@@@@@@@@@@@@@@@@@@@@@@@@@
    256
    257
    258/*
    259 * Virtual addresses for IO
    260 */
    261omap_ih1_base:
    262	.word OMAP1_IO_ADDRESS(OMAP_IH1_BASE)
    263deferred_fiq_ih_base:
    264	.word OMAP1_IO_ADDRESS(DEFERRED_FIQ_IH_BASE)
    265omap1510_gpio_base:
    266	.word OMAP1_IO_ADDRESS(OMAP1510_GPIO_BASE)
    267qwerty_fiqin_end:
    268
    269/*
    270 * Check the size of the FIQ,
    271 * it cannot go beyond 0xffff0200, and is copied to 0xffff001c
    272 */
    273.if (qwerty_fiqin_end - qwerty_fiqin_start) > (0x200 - 0x1c)
    274	.err
    275.endif