diff options
Diffstat (limited to 'arch/x86/kernel/vsmp_64.c')
| -rw-r--r-- | arch/x86/kernel/vsmp_64.c | 245 |
1 files changed, 245 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..ee22c1d93 --- /dev/null +++ b/arch/x86/kernel/vsmp_64.c @@ -0,0 +1,245 @@ +/* + * vSMPowered(tm) systems specific initialization + * Copyright (C) 2005 ScaleMP Inc. + * + * Use of this code is subject to the terms and conditions of the + * GNU general public license version 2. See "COPYING" or + * http://www.gnu.org/licenses/gpl.html + * + * 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 + +/* Flag below is initialized once during vSMP PCI initialization. */ +static int irq_routing_comply = 1; + +#if defined CONFIG_PCI && defined CONFIG_PARAVIRT +/* + * Interrupt control on vSMPowered systems: + * ~AC is a shadow of IF. If IF is 'on' AC should be 'off' + * and vice versa. + */ + +asmlinkage __visible unsigned long vsmp_save_fl(void) +{ + unsigned long flags = native_save_fl(); + + if (!(flags & X86_EFLAGS_IF) || (flags & X86_EFLAGS_AC)) + flags &= ~X86_EFLAGS_IF; + return flags; +} +PV_CALLEE_SAVE_REGS_THUNK(vsmp_save_fl); + +__visible void vsmp_restore_fl(unsigned long flags) +{ + if (flags & X86_EFLAGS_IF) + flags &= ~X86_EFLAGS_AC; + else + flags |= X86_EFLAGS_AC; + native_restore_fl(flags); +} +PV_CALLEE_SAVE_REGS_THUNK(vsmp_restore_fl); + +asmlinkage __visible void vsmp_irq_disable(void) +{ + unsigned long flags = native_save_fl(); + + native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC); +} +PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_disable); + +asmlinkage __visible void vsmp_irq_enable(void) +{ + unsigned long flags = native_save_fl(); + + native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC)); +} +PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_enable); + +static unsigned __init_or_module vsmp_patch(u8 type, u16 clobbers, void *ibuf, + unsigned long addr, unsigned len) +{ + switch (type) { + case PARAVIRT_PATCH(pv_irq_ops.irq_enable): + case PARAVIRT_PATCH(pv_irq_ops.irq_disable): + case PARAVIRT_PATCH(pv_irq_ops.save_fl): + case PARAVIRT_PATCH(pv_irq_ops.restore_fl): + return paravirt_patch_default(type, clobbers, ibuf, addr, len); + default: + return native_patch(type, clobbers, ibuf, addr, len); + } + +} + +static void __init set_vsmp_pv_ops(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); + + /* Interrupt routing set to ignore */ + irq_routing_comply = 0; + +#ifdef CONFIG_PROC_FS + /* Don't let users change irq affinity via procfs */ + no_irq_affinity = 1; +#endif + } +#endif + + if (cap & ctl & (1 << 4)) { + /* Setup irq ops and turn on vSMP IRQ fastpath handling */ + pv_irq_ops.irq_disable = PV_CALLEE_SAVE(vsmp_irq_disable); + pv_irq_ops.irq_enable = PV_CALLEE_SAVE(vsmp_irq_enable); + pv_irq_ops.save_fl = PV_CALLEE_SAVE(vsmp_save_fl); + pv_irq_ops.restore_fl = PV_CALLEE_SAVE(vsmp_restore_fl); + pv_init_ops.patch = vsmp_patch; + ctl &= ~(1 << 4); + } + writel(ctl, address + 4); + ctl = readl(address + 4); + pr_info("vSMP CTL: control set to:0x%08x\n", ctl); + + early_iounmap(address, 8); +} +#else +static void __init set_vsmp_pv_ops(void) +{ +} +#endif + +#ifdef CONFIG_PCI +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; +} +#endif + +static void __init vsmp_cap_cpus(void) +{ +#if !defined(CONFIG_X86_VSMP) && defined(CONFIG_SMP) + 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; +} + +/* + * In vSMP, all cpus should be capable of handling interrupts, regardless of + * the APIC used. + */ +static void fill_vector_allocation_domain(int cpu, struct cpumask *retmask, + const struct cpumask *mask) +{ + cpumask_setall(retmask); +} + +static void vsmp_apic_post_init(void) +{ + /* need to update phys_pkg_id */ + apic->phys_pkg_id = apicid_phys_pkg_id; + + if (!irq_routing_comply) + apic->vector_allocation_domain = fill_vector_allocation_domain; +} + +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_pv_ops(); + return; +} |