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Diffstat (limited to 'arch/x86/kernel/vsmp_64.c')
| -rw-r--r-- | arch/x86/kernel/vsmp_64.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/x86/kernel/vsmp_64.c b/arch/x86/kernel/vsmp_64.c new file mode 100644 index 000000000..796cfaa46 --- /dev/null +++ b/arch/x86/kernel/vsmp_64.c @@ -0,0 +1,153 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * vSMPowered(tm) systems specific initialization + * Copyright (C) 2005 ScaleMP Inc. + * + * Ravikiran Thirumalai <kiran@scalemp.com>, + * Shai Fultheim <shai@scalemp.com> + * Paravirt ops integration: Glauber de Oliveira Costa <gcosta@redhat.com>, + * Ravikiran Thirumalai <kiran@scalemp.com> + */ + +#include <linux/init.h> +#include <linux/pci_ids.h> +#include <linux/pci_regs.h> +#include <linux/smp.h> +#include <linux/irq.h> + +#include <asm/apic.h> +#include <asm/pci-direct.h> +#include <asm/io.h> +#include <asm/paravirt.h> +#include <asm/setup.h> + +#define TOPOLOGY_REGISTER_OFFSET 0x10 + +#ifdef CONFIG_PCI +static void __init set_vsmp_ctl(void) +{ + void __iomem *address; + unsigned int cap, ctl, cfg; + + /* set vSMP magic bits to indicate vSMP capable kernel */ + cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0); + address = early_ioremap(cfg, 8); + cap = readl(address); + ctl = readl(address + 4); + printk(KERN_INFO "vSMP CTL: capabilities:0x%08x control:0x%08x\n", + cap, ctl); + + /* If possible, let the vSMP foundation route the interrupt optimally */ +#ifdef CONFIG_SMP + if (cap & ctl & BIT(8)) { + ctl &= ~BIT(8); + +#ifdef CONFIG_PROC_FS + /* Don't let users change irq affinity via procfs */ + no_irq_affinity = 1; +#endif + } +#endif + + writel(ctl, address + 4); + ctl = readl(address + 4); + pr_info("vSMP CTL: control set to:0x%08x\n", ctl); + + early_iounmap(address, 8); +} +static int is_vsmp = -1; + +static void __init detect_vsmp_box(void) +{ + is_vsmp = 0; + + if (!early_pci_allowed()) + return; + + /* Check if we are running on a ScaleMP vSMPowered box */ + if (read_pci_config(0, 0x1f, 0, PCI_VENDOR_ID) == + (PCI_VENDOR_ID_SCALEMP | (PCI_DEVICE_ID_SCALEMP_VSMP_CTL << 16))) + is_vsmp = 1; +} + +static int is_vsmp_box(void) +{ + if (is_vsmp != -1) + return is_vsmp; + else { + WARN_ON_ONCE(1); + return 0; + } +} + +#else +static void __init detect_vsmp_box(void) +{ +} +static int is_vsmp_box(void) +{ + return 0; +} +static void __init set_vsmp_ctl(void) +{ +} +#endif + +static void __init vsmp_cap_cpus(void) +{ +#if !defined(CONFIG_X86_VSMP) && defined(CONFIG_SMP) && defined(CONFIG_PCI) + void __iomem *address; + unsigned int cfg, topology, node_shift, maxcpus; + + /* + * CONFIG_X86_VSMP is not configured, so limit the number CPUs to the + * ones present in the first board, unless explicitly overridden by + * setup_max_cpus + */ + if (setup_max_cpus != NR_CPUS) + return; + + /* Read the vSMP Foundation topology register */ + cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0); + address = early_ioremap(cfg + TOPOLOGY_REGISTER_OFFSET, 4); + if (WARN_ON(!address)) + return; + + topology = readl(address); + node_shift = (topology >> 16) & 0x7; + if (!node_shift) + /* The value 0 should be decoded as 8 */ + node_shift = 8; + maxcpus = (topology & ((1 << node_shift) - 1)) + 1; + + pr_info("vSMP CTL: Capping CPUs to %d (CONFIG_X86_VSMP is unset)\n", + maxcpus); + setup_max_cpus = maxcpus; + early_iounmap(address, 4); +#endif +} + +static int apicid_phys_pkg_id(int initial_apic_id, int index_msb) +{ + return hard_smp_processor_id() >> index_msb; +} + +static void vsmp_apic_post_init(void) +{ + /* need to update phys_pkg_id */ + apic->phys_pkg_id = apicid_phys_pkg_id; +} + +void __init vsmp_init(void) +{ + detect_vsmp_box(); + if (!is_vsmp_box()) + return; + + x86_platform.apic_post_init = vsmp_apic_post_init; + + vsmp_cap_cpus(); + + set_vsmp_ctl(); + return; +} |