Line data    Source code

       1             : // SPDX-License-Identifier: GPL-2.0-only
       2             : /*
       3             :  * vSMPowered(tm) systems specific initialization
       4             :  * Copyright (C) 2005 ScaleMP Inc.
       5             :  *
       6             :  * Ravikiran Thirumalai <kiran@scalemp.com>,
       7             :  * Shai Fultheim <shai@scalemp.com>
       8             :  * Paravirt ops integration: Glauber de Oliveira Costa <gcosta@redhat.com>,
       9             :  *                           Ravikiran Thirumalai <kiran@scalemp.com>
      10             :  */
      11             : 
      12             : #include <linux/init.h>
      13             : #include <linux/pci_ids.h>
      14             : #include <linux/pci_regs.h>
      15             : #include <linux/smp.h>
      16             : #include <linux/irq.h>
      17             : 
      18             : #include <asm/apic.h>
      19             : #include <asm/pci-direct.h>
      20             : #include <asm/io.h>
      21             : #include <asm/paravirt.h>
      22             : #include <asm/setup.h>
      23             : 
      24             : #define TOPOLOGY_REGISTER_OFFSET 0x10
      25             : 
      26             : #ifdef CONFIG_PCI
      27             : static void __init set_vsmp_ctl(void)
      28             : {
      29             :         void __iomem *address;
      30             :         unsigned int cap, ctl, cfg;
      31             : 
      32             :         /* set vSMP magic bits to indicate vSMP capable kernel */
      33             :         cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0);
      34             :         address = early_ioremap(cfg, 8);
      35             :         cap = readl(address);
      36             :         ctl = readl(address + 4);
      37             :         printk(KERN_INFO "vSMP CTL: capabilities:0x%08x  control:0x%08x\n",
      38             :                cap, ctl);
      39             : 
      40             :         /* If possible, let the vSMP foundation route the interrupt optimally */
      41             : #ifdef CONFIG_SMP
      42             :         if (cap & ctl & BIT(8)) {
      43             :                 ctl &= ~BIT(8);
      44             : 
      45             : #ifdef CONFIG_PROC_FS
      46             :                 /* Don't let users change irq affinity via procfs */
      47             :                 no_irq_affinity = 1;
      48             : #endif
      49             :         }
      50             : #endif
      51             : 
      52             :         writel(ctl, address + 4);
      53             :         ctl = readl(address + 4);
      54             :         pr_info("vSMP CTL: control set to:0x%08x\n", ctl);
      55             : 
      56             :         early_iounmap(address, 8);
      57             : }
      58             : static int is_vsmp = -1;
      59             : 
      60             : static void __init detect_vsmp_box(void)
      61             : {
      62             :         is_vsmp = 0;
      63             : 
      64             :         if (!early_pci_allowed())
      65             :                 return;
      66             : 
      67             :         /* Check if we are running on a ScaleMP vSMPowered box */
      68             :         if (read_pci_config(0, 0x1f, 0, PCI_VENDOR_ID) ==
      69             :              (PCI_VENDOR_ID_SCALEMP | (PCI_DEVICE_ID_SCALEMP_VSMP_CTL << 16)))
      70             :                 is_vsmp = 1;
      71             : }
      72             : 
      73             : static int is_vsmp_box(void)
      74             : {
      75             :         if (is_vsmp != -1)
      76             :                 return is_vsmp;
      77             :         else {
      78             :                 WARN_ON_ONCE(1);
      79             :                 return 0;
      80             :         }
      81             : }
      82             : 
      83             : #else
      84           1 : static void __init detect_vsmp_box(void)
      85             : {
      86           1 : }
      87           1 : static int is_vsmp_box(void)
      88             : {
      89           1 :         return 0;
      90             : }
      91             : static void __init set_vsmp_ctl(void)
      92             : {
      93             : }
      94             : #endif
      95             : 
      96             : static void __init vsmp_cap_cpus(void)
      97             : {
      98             : #if !defined(CONFIG_X86_VSMP) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
      99             :         void __iomem *address;
     100             :         unsigned int cfg, topology, node_shift, maxcpus;
     101             : 
     102             :         /*
     103             :          * CONFIG_X86_VSMP is not configured, so limit the number CPUs to the
     104             :          * ones present in the first board, unless explicitly overridden by
     105             :          * setup_max_cpus
     106             :          */
     107             :         if (setup_max_cpus != NR_CPUS)
     108             :                 return;
     109             : 
     110             :         /* Read the vSMP Foundation topology register */
     111             :         cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0);
     112             :         address = early_ioremap(cfg + TOPOLOGY_REGISTER_OFFSET, 4);
     113             :         if (WARN_ON(!address))
     114             :                 return;
     115             : 
     116             :         topology = readl(address);
     117             :         node_shift = (topology >> 16) & 0x7;
     118             :         if (!node_shift)
     119             :                 /* The value 0 should be decoded as 8 */
     120             :                 node_shift = 8;
     121             :         maxcpus = (topology & ((1 << node_shift) - 1)) + 1;
     122             : 
     123             :         pr_info("vSMP CTL: Capping CPUs to %d (CONFIG_X86_VSMP is unset)\n",
     124             :                 maxcpus);
     125             :         setup_max_cpus = maxcpus;
     126             :         early_iounmap(address, 4);
     127             : #endif
     128             : }
     129             : 
     130             : static int apicid_phys_pkg_id(int initial_apic_id, int index_msb)
     131             : {
     132             :         return hard_smp_processor_id() >> index_msb;
     133             : }
     134             : 
     135             : static void vsmp_apic_post_init(void)
     136             : {
     137             :         /* need to update phys_pkg_id */
     138             :         apic->phys_pkg_id = apicid_phys_pkg_id;
     139             : }
     140             : 
     141           1 : void __init vsmp_init(void)
     142             : {
     143           1 :         detect_vsmp_box();
     144           1 :         if (!is_vsmp_box())
     145           1 :                 return;
     146             : 
     147             :         x86_platform.apic_post_init = vsmp_apic_post_init;
     148             : 
     149             :         vsmp_cap_cpus();
     150             : 
     151             :         set_vsmp_ctl();
     152             :         return;
     153             : }