platsmp.c 3.5 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136
  1. /*
  2. * This file contains Xilinx specific SMP code, used to start up
  3. * the second processor.
  4. *
  5. * Copyright (C) 2011-2013 Xilinx
  6. *
  7. * based on linux/arch/arm/mach-realview/platsmp.c
  8. *
  9. * Copyright (C) 2002 ARM Ltd.
  10. *
  11. * This software is licensed under the terms of the GNU General Public
  12. * License version 2, as published by the Free Software Foundation, and
  13. * may be copied, distributed, and modified under those terms.
  14. *
  15. * This program is distributed in the hope that it will be useful,
  16. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18. * GNU General Public License for more details.
  19. */
  20. #include <linux/export.h>
  21. #include <linux/jiffies.h>
  22. #include <linux/init.h>
  23. #include <linux/io.h>
  24. #include <asm/cacheflush.h>
  25. #include <asm/smp_scu.h>
  26. #include <linux/irqchip/arm-gic.h>
  27. #include "common.h"
  28. /*
  29. * Store number of cores in the system
  30. * Because of scu_get_core_count() must be in __init section and can't
  31. * be called from zynq_cpun_start() because it is in __cpuinit section.
  32. */
  33. static int ncores;
  34. int __cpuinit zynq_cpun_start(u32 address, int cpu)
  35. {
  36. u32 trampoline_code_size = &zynq_secondary_trampoline_end -
  37. &zynq_secondary_trampoline;
  38. if (cpu > ncores) {
  39. pr_warn("CPU No. is not available in the system\n");
  40. return -1;
  41. }
  42. /* MS: Expectation that SLCR are directly map and accessible */
  43. /* Not possible to jump to non aligned address */
  44. if (!(address & 3) && (!address || (address >= trampoline_code_size))) {
  45. /* Store pointer to ioremap area which points to address 0x0 */
  46. static u8 __iomem *zero;
  47. u32 trampoline_size = &zynq_secondary_trampoline_jump -
  48. &zynq_secondary_trampoline;
  49. zynq_slcr_cpu_stop(cpu);
  50. if (__pa(PAGE_OFFSET)) {
  51. zero = ioremap(0, trampoline_code_size);
  52. if (!zero) {
  53. pr_warn("BOOTUP jump vectors not accessible\n");
  54. return -1;
  55. }
  56. } else {
  57. zero = (__force u8 __iomem *)PAGE_OFFSET;
  58. }
  59. /*
  60. * This is elegant way how to jump to any address
  61. * 0x0: Load address at 0x8 to r0
  62. * 0x4: Jump by mov instruction
  63. * 0x8: Jumping address
  64. */
  65. memcpy((__force void *)zero, &zynq_secondary_trampoline,
  66. trampoline_size);
  67. writel(address, zero + trampoline_size);
  68. flush_cache_all();
  69. outer_flush_range(0, trampoline_code_size);
  70. smp_wmb();
  71. if (__pa(PAGE_OFFSET))
  72. iounmap(zero);
  73. zynq_slcr_cpu_start(cpu);
  74. return 0;
  75. }
  76. pr_warn("Can't start CPU%d: Wrong starting address %x\n", cpu, address);
  77. return -1;
  78. }
  79. EXPORT_SYMBOL(zynq_cpun_start);
  80. static int __cpuinit zynq_boot_secondary(unsigned int cpu,
  81. struct task_struct *idle)
  82. {
  83. return zynq_cpun_start(virt_to_phys(secondary_startup), cpu);
  84. }
  85. /*
  86. * Initialise the CPU possible map early - this describes the CPUs
  87. * which may be present or become present in the system.
  88. */
  89. static void __init zynq_smp_init_cpus(void)
  90. {
  91. int i;
  92. ncores = scu_get_core_count(zynq_scu_base);
  93. for (i = 0; i < ncores && i < CONFIG_NR_CPUS; i++)
  94. set_cpu_possible(i, true);
  95. }
  96. static void __init zynq_smp_prepare_cpus(unsigned int max_cpus)
  97. {
  98. int i;
  99. /*
  100. * Initialise the present map, which describes the set of CPUs
  101. * actually populated at the present time.
  102. */
  103. for (i = 0; i < max_cpus; i++)
  104. set_cpu_present(i, true);
  105. scu_enable(zynq_scu_base);
  106. }
  107. struct smp_operations zynq_smp_ops __initdata = {
  108. .smp_init_cpus = zynq_smp_init_cpus,
  109. .smp_prepare_cpus = zynq_smp_prepare_cpus,
  110. .smp_boot_secondary = zynq_boot_secondary,
  111. #ifdef CONFIG_HOTPLUG_CPU
  112. .cpu_die = zynq_platform_cpu_die,
  113. #endif
  114. };