| Gregory CLEMENT | 009f131 | 2012-08-02 11:16:29 +0300 | [diff] [blame] | 1 | /* |
| 2 | * Coherency fabric: low level functions |
| 3 | * |
| 4 | * Copyright (C) 2012 Marvell |
| 5 | * |
| 6 | * Gregory CLEMENT <gregory.clement@free-electrons.com> |
| 7 | * |
| 8 | * This file is licensed under the terms of the GNU General Public |
| 9 | * License version 2. This program is licensed "as is" without any |
| 10 | * warranty of any kind, whether express or implied. |
| 11 | * |
| 12 | * This file implements the assembly function to add a CPU to the |
| 13 | * coherency fabric. This function is called by each of the secondary |
| 14 | * CPUs during their early boot in an SMP kernel, this why this |
| 15 | * function have to callable from assembly. It can also be called by a |
| 16 | * primary CPU from C code during its boot. |
| 17 | */ |
| 18 | |
| 19 | #include <linux/linkage.h> |
| 20 | #define ARMADA_XP_CFB_CTL_REG_OFFSET 0x0 |
| 21 | #define ARMADA_XP_CFB_CFG_REG_OFFSET 0x4 |
| 22 | |
| Ben Dooks | bca028e | 2013-02-01 10:36:22 +0000 | [diff] [blame] | 23 | #include <asm/assembler.h> |
| 24 | |
| Gregory CLEMENT | 009f131 | 2012-08-02 11:16:29 +0300 | [diff] [blame] | 25 | .text |
| 26 | /* |
| 27 | * r0: Coherency fabric base register address |
| 28 | * r1: HW CPU id |
| 29 | */ |
| 30 | ENTRY(ll_set_cpu_coherent) |
| 31 | /* Create bit by cpu index */ |
| 32 | mov r3, #(1 << 24) |
| 33 | lsl r1, r3, r1 |
| Ben Dooks | bca028e | 2013-02-01 10:36:22 +0000 | [diff] [blame] | 34 | ARM_BE8(rev r1, r1) |
| Gregory CLEMENT | 009f131 | 2012-08-02 11:16:29 +0300 | [diff] [blame] | 35 | |
| 36 | /* Add CPU to SMP group - Atomic */ |
| 37 | add r3, r0, #ARMADA_XP_CFB_CTL_REG_OFFSET |
| Nadav Haklai | b60b61d | 2013-05-23 10:54:02 +0200 | [diff] [blame] | 38 | 1: |
| 39 | ldrex r2, [r3] |
| Gregory CLEMENT | 009f131 | 2012-08-02 11:16:29 +0300 | [diff] [blame] | 40 | orr r2, r2, r1 |
| Nadav Haklai | b60b61d | 2013-05-23 10:54:02 +0200 | [diff] [blame] | 41 | strex r0, r2, [r3] |
| 42 | cmp r0, #0 |
| 43 | bne 1b |
| Gregory CLEMENT | 009f131 | 2012-08-02 11:16:29 +0300 | [diff] [blame] | 44 | |
| 45 | /* Enable coherency on CPU - Atomic */ |
| Nadav Haklai | b60b61d | 2013-05-23 10:54:02 +0200 | [diff] [blame] | 46 | add r3, r3, #ARMADA_XP_CFB_CFG_REG_OFFSET |
| 47 | 1: |
| 48 | ldrex r2, [r3] |
| Gregory CLEMENT | 009f131 | 2012-08-02 11:16:29 +0300 | [diff] [blame] | 49 | orr r2, r2, r1 |
| Nadav Haklai | b60b61d | 2013-05-23 10:54:02 +0200 | [diff] [blame] | 50 | strex r0, r2, [r3] |
| 51 | cmp r0, #0 |
| 52 | bne 1b |
| Gregory CLEMENT | 009f131 | 2012-08-02 11:16:29 +0300 | [diff] [blame] | 53 | |
| 54 | dsb |
| 55 | |
| 56 | mov r0, #0 |
| 57 | mov pc, lr |
| 58 | ENDPROC(ll_set_cpu_coherent) |