Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-3.10.git] / arch / x86 / kernel / vsmp_64.c
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 #include <linux/irq.h>
20
21 #include <asm/apic.h>
22 #include <asm/pci-direct.h>
23 #include <asm/io.h>
24 #include <asm/paravirt.h>
25 #include <asm/setup.h>
26
27 #define TOPOLOGY_REGISTER_OFFSET 0x10
28
29 #if defined CONFIG_PCI && defined CONFIG_PARAVIRT
30 /*
31  * Interrupt control on vSMPowered systems:
32  * ~AC is a shadow of IF.  If IF is 'on' AC should be 'off'
33  * and vice versa.
34  */
35
36 static unsigned long vsmp_save_fl(void)
37 {
38         unsigned long flags = native_save_fl();
39
40         if (!(flags & X86_EFLAGS_IF) || (flags & X86_EFLAGS_AC))
41                 flags &= ~X86_EFLAGS_IF;
42         return flags;
43 }
44 PV_CALLEE_SAVE_REGS_THUNK(vsmp_save_fl);
45
46 static void vsmp_restore_fl(unsigned long flags)
47 {
48         if (flags & X86_EFLAGS_IF)
49                 flags &= ~X86_EFLAGS_AC;
50         else
51                 flags |= X86_EFLAGS_AC;
52         native_restore_fl(flags);
53 }
54 PV_CALLEE_SAVE_REGS_THUNK(vsmp_restore_fl);
55
56 static void vsmp_irq_disable(void)
57 {
58         unsigned long flags = native_save_fl();
59
60         native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC);
61 }
62 PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_disable);
63
64 static void vsmp_irq_enable(void)
65 {
66         unsigned long flags = native_save_fl();
67
68         native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC));
69 }
70 PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_enable);
71
72 static unsigned __init_or_module vsmp_patch(u8 type, u16 clobbers, void *ibuf,
73                                   unsigned long addr, unsigned len)
74 {
75         switch (type) {
76         case PARAVIRT_PATCH(pv_irq_ops.irq_enable):
77         case PARAVIRT_PATCH(pv_irq_ops.irq_disable):
78         case PARAVIRT_PATCH(pv_irq_ops.save_fl):
79         case PARAVIRT_PATCH(pv_irq_ops.restore_fl):
80                 return paravirt_patch_default(type, clobbers, ibuf, addr, len);
81         default:
82                 return native_patch(type, clobbers, ibuf, addr, len);
83         }
84
85 }
86
87 static void __init set_vsmp_pv_ops(void)
88 {
89         void __iomem *address;
90         unsigned int cap, ctl, cfg;
91
92         /* set vSMP magic bits to indicate vSMP capable kernel */
93         cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0);
94         address = early_ioremap(cfg, 8);
95         cap = readl(address);
96         ctl = readl(address + 4);
97         printk(KERN_INFO "vSMP CTL: capabilities:0x%08x  control:0x%08x\n",
98                cap, ctl);
99
100         /* If possible, let the vSMP foundation route the interrupt optimally */
101 #ifdef CONFIG_SMP
102         if (cap & ctl & BIT(8)) {
103                 ctl &= ~BIT(8);
104 #ifdef CONFIG_PROC_FS
105                 /* Don't let users change irq affinity via procfs */
106                 no_irq_affinity = 1;
107 #endif
108         }
109 #endif
110
111         if (cap & ctl & (1 << 4)) {
112                 /* Setup irq ops and turn on vSMP  IRQ fastpath handling */
113                 pv_irq_ops.irq_disable = PV_CALLEE_SAVE(vsmp_irq_disable);
114                 pv_irq_ops.irq_enable  = PV_CALLEE_SAVE(vsmp_irq_enable);
115                 pv_irq_ops.save_fl  = PV_CALLEE_SAVE(vsmp_save_fl);
116                 pv_irq_ops.restore_fl  = PV_CALLEE_SAVE(vsmp_restore_fl);
117                 pv_init_ops.patch = vsmp_patch;
118                 ctl &= ~(1 << 4);
119         }
120         writel(ctl, address + 4);
121         ctl = readl(address + 4);
122         pr_info("vSMP CTL: control set to:0x%08x\n", ctl);
123
124         early_iounmap(address, 8);
125 }
126 #else
127 static void __init set_vsmp_pv_ops(void)
128 {
129 }
130 #endif
131
132 #ifdef CONFIG_PCI
133 static int is_vsmp = -1;
134
135 static void __init detect_vsmp_box(void)
136 {
137         is_vsmp = 0;
138
139         if (!early_pci_allowed())
140                 return;
141
142         /* Check if we are running on a ScaleMP vSMPowered box */
143         if (read_pci_config(0, 0x1f, 0, PCI_VENDOR_ID) ==
144              (PCI_VENDOR_ID_SCALEMP | (PCI_DEVICE_ID_SCALEMP_VSMP_CTL << 16)))
145                 is_vsmp = 1;
146 }
147
148 int is_vsmp_box(void)
149 {
150         if (is_vsmp != -1)
151                 return is_vsmp;
152         else {
153                 WARN_ON_ONCE(1);
154                 return 0;
155         }
156 }
157
158 #else
159 static void __init detect_vsmp_box(void)
160 {
161 }
162 int is_vsmp_box(void)
163 {
164         return 0;
165 }
166 #endif
167
168 static void __init vsmp_cap_cpus(void)
169 {
170 #if !defined(CONFIG_X86_VSMP) && defined(CONFIG_SMP)
171         void __iomem *address;
172         unsigned int cfg, topology, node_shift, maxcpus;
173
174         /*
175          * CONFIG_X86_VSMP is not configured, so limit the number CPUs to the
176          * ones present in the first board, unless explicitly overridden by
177          * setup_max_cpus
178          */
179         if (setup_max_cpus != NR_CPUS)
180                 return;
181
182         /* Read the vSMP Foundation topology register */
183         cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0);
184         address = early_ioremap(cfg + TOPOLOGY_REGISTER_OFFSET, 4);
185         if (WARN_ON(!address))
186                 return;
187
188         topology = readl(address);
189         node_shift = (topology >> 16) & 0x7;
190         if (!node_shift)
191                 /* The value 0 should be decoded as 8 */
192                 node_shift = 8;
193         maxcpus = (topology & ((1 << node_shift) - 1)) + 1;
194
195         pr_info("vSMP CTL: Capping CPUs to %d (CONFIG_X86_VSMP is unset)\n",
196                 maxcpus);
197         setup_max_cpus = maxcpus;
198         early_iounmap(address, 4);
199 #endif
200 }
201
202 static int apicid_phys_pkg_id(int initial_apic_id, int index_msb)
203 {
204         return hard_smp_processor_id() >> index_msb;
205 }
206
207 /*
208  * In vSMP, all cpus should be capable of handling interrupts, regardless of
209  * the APIC used.
210  */
211 static void fill_vector_allocation_domain(int cpu, struct cpumask *retmask,
212                                           const struct cpumask *mask)
213 {
214         cpumask_setall(retmask);
215 }
216
217 static void vsmp_apic_post_init(void)
218 {
219         /* need to update phys_pkg_id */
220         apic->phys_pkg_id = apicid_phys_pkg_id;
221         apic->vector_allocation_domain = fill_vector_allocation_domain;
222 }
223
224 void __init vsmp_init(void)
225 {
226         detect_vsmp_box();
227         if (!is_vsmp_box())
228                 return;
229
230         x86_platform.apic_post_init = vsmp_apic_post_init;
231
232         vsmp_cap_cpus();
233
234         set_vsmp_pv_ops();
235         return;
236 }