1 /* 2 * vSMPowered(tm) systems specific initialization 3 * Copyright (C) 2005 ScaleMP Inc. 4 * 5 * Use of this code is subject to the terms and conditions of the 6 * GNU general public license version 2. See "COPYING" or 7 * http://www.gnu.org/licenses/gpl.html 8 * 9 * Ravikiran Thirumalai <kiran@scalemp.com>, 10 * Shai Fultheim <shai@scalemp.com> 11 * Paravirt ops integration: Glauber de Oliveira Costa <gcosta@redhat.com>, 12 * Ravikiran Thirumalai <kiran@scalemp.com> 13 */ 14 15 #include <linux/init.h> 16 #include <linux/pci_ids.h> 17 #include <linux/pci_regs.h> 18 #include <linux/smp.h> 19 20 #include <asm/apic.h> 21 #include <asm/pci-direct.h> 22 #include <asm/io.h> 23 #include <asm/paravirt.h> 24 #include <asm/setup.h> 25 26 #define TOPOLOGY_REGISTER_OFFSET 0x10 27 28 #if defined CONFIG_PCI && defined CONFIG_PARAVIRT 29 /* 30 * Interrupt control on vSMPowered systems: 31 * ~AC is a shadow of IF. If IF is 'on' AC should be 'off' 32 * and vice versa. 33 */ 34 35 static unsigned long vsmp_save_fl(void) 36 { 37 unsigned long flags = native_save_fl(); 38 39 if (!(flags & X86_EFLAGS_IF) || (flags & X86_EFLAGS_AC)) 40 flags &= ~X86_EFLAGS_IF; 41 return flags; 42 } 43 PV_CALLEE_SAVE_REGS_THUNK(vsmp_save_fl); 44 45 static void vsmp_restore_fl(unsigned long flags) 46 { 47 if (flags & X86_EFLAGS_IF) 48 flags &= ~X86_EFLAGS_AC; 49 else 50 flags |= X86_EFLAGS_AC; 51 native_restore_fl(flags); 52 } 53 PV_CALLEE_SAVE_REGS_THUNK(vsmp_restore_fl); 54 55 static void vsmp_irq_disable(void) 56 { 57 unsigned long flags = native_save_fl(); 58 59 native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC); 60 } 61 PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_disable); 62 63 static void vsmp_irq_enable(void) 64 { 65 unsigned long flags = native_save_fl(); 66 67 native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC)); 68 } 69 PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_enable); 70 71 static unsigned __init_or_module vsmp_patch(u8 type, u16 clobbers, void *ibuf, 72 unsigned long addr, unsigned len) 73 { 74 switch (type) { 75 case PARAVIRT_PATCH(pv_irq_ops.irq_enable): 76 case PARAVIRT_PATCH(pv_irq_ops.irq_disable): 77 case PARAVIRT_PATCH(pv_irq_ops.save_fl): 78 case PARAVIRT_PATCH(pv_irq_ops.restore_fl): 79 return paravirt_patch_default(type, clobbers, ibuf, addr, len); 80 default: 81 return native_patch(type, clobbers, ibuf, addr, len); 82 } 83 84 } 85 86 static void __init set_vsmp_pv_ops(void) 87 { 88 void __iomem *address; 89 unsigned int cap, ctl, cfg; 90 91 /* set vSMP magic bits to indicate vSMP capable kernel */ 92 cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0); 93 address = early_ioremap(cfg, 8); 94 cap = readl(address); 95 ctl = readl(address + 4); 96 printk(KERN_INFO "vSMP CTL: capabilities:0x%08x control:0x%08x\n", 97 cap, ctl); 98 if (cap & ctl & (1 << 4)) { 99 /* Setup irq ops and turn on vSMP IRQ fastpath handling */ 100 pv_irq_ops.irq_disable = PV_CALLEE_SAVE(vsmp_irq_disable); 101 pv_irq_ops.irq_enable = PV_CALLEE_SAVE(vsmp_irq_enable); 102 pv_irq_ops.save_fl = PV_CALLEE_SAVE(vsmp_save_fl); 103 pv_irq_ops.restore_fl = PV_CALLEE_SAVE(vsmp_restore_fl); 104 pv_init_ops.patch = vsmp_patch; 105 106 ctl &= ~(1 << 4); 107 writel(ctl, address + 4); 108 ctl = readl(address + 4); 109 printk(KERN_INFO "vSMP CTL: control set to:0x%08x\n", ctl); 110 } 111 112 early_iounmap(address, 8); 113 } 114 #else 115 static void __init set_vsmp_pv_ops(void) 116 { 117 } 118 #endif 119 120 #ifdef CONFIG_PCI 121 static int is_vsmp = -1; 122 123 static void __init detect_vsmp_box(void) 124 { 125 is_vsmp = 0; 126 127 if (!early_pci_allowed()) 128 return; 129 130 /* Check if we are running on a ScaleMP vSMPowered box */ 131 if (read_pci_config(0, 0x1f, 0, PCI_VENDOR_ID) == 132 (PCI_VENDOR_ID_SCALEMP | (PCI_DEVICE_ID_SCALEMP_VSMP_CTL << 16))) 133 is_vsmp = 1; 134 } 135 136 int is_vsmp_box(void) 137 { 138 if (is_vsmp != -1) 139 return is_vsmp; 140 else { 141 WARN_ON_ONCE(1); 142 return 0; 143 } 144 } 145 146 #else 147 static void __init detect_vsmp_box(void) 148 { 149 } 150 int is_vsmp_box(void) 151 { 152 return 0; 153 } 154 #endif 155 156 static void __init vsmp_cap_cpus(void) 157 { 158 #if !defined(CONFIG_X86_VSMP) && defined(CONFIG_SMP) 159 void __iomem *address; 160 unsigned int cfg, topology, node_shift, maxcpus; 161 162 /* 163 * CONFIG_X86_VSMP is not configured, so limit the number CPUs to the 164 * ones present in the first board, unless explicitly overridden by 165 * setup_max_cpus 166 */ 167 if (setup_max_cpus != NR_CPUS) 168 return; 169 170 /* Read the vSMP Foundation topology register */ 171 cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0); 172 address = early_ioremap(cfg + TOPOLOGY_REGISTER_OFFSET, 4); 173 if (WARN_ON(!address)) 174 return; 175 176 topology = readl(address); 177 node_shift = (topology >> 16) & 0x7; 178 if (!node_shift) 179 /* The value 0 should be decoded as 8 */ 180 node_shift = 8; 181 maxcpus = (topology & ((1 << node_shift) - 1)) + 1; 182 183 pr_info("vSMP CTL: Capping CPUs to %d (CONFIG_X86_VSMP is unset)\n", 184 maxcpus); 185 setup_max_cpus = maxcpus; 186 early_iounmap(address, 4); 187 #endif 188 } 189 190 void __init vsmp_init(void) 191 { 192 detect_vsmp_box(); 193 if (!is_vsmp_box()) 194 return; 195 196 vsmp_cap_cpus(); 197 198 set_vsmp_pv_ops(); 199 return; 200 } 201