/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright 2014 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
* Copyright (c) 2014 by Delphix. All rights reserved.
*/
#include <sys/cpuvar.h>
#include <sys/psm.h>
#include <sys/archsystm.h>
#include <sys/apic.h>
#include <sys/sunddi.h>
#include <sys/ddi_impldefs.h>
#include <sys/mach_intr.h>
#include <sys/sysmacros.h>
#include <sys/trap.h>
#include <sys/x86_archext.h>
#include <sys/privregs.h>
#include <sys/psm_common.h>
/* Function prototypes of local apic and X2APIC */
static uint64_t local_apic_read(uint32_t reg);
static void local_apic_write(uint32_t reg, uint64_t value);
static int get_local_apic_pri(void);
static void local_apic_write_task_reg(uint64_t value);
static void local_apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1);
static uint64_t local_x2apic_read(uint32_t msr);
static void local_x2apic_write(uint32_t msr, uint64_t value);
static int get_local_x2apic_pri(void);
static void local_x2apic_write_task_reg(uint64_t value);
static void local_x2apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1);
/*
* According to the X2APIC specification:
*
* xAPIC global enable X2APIC enable Description
* (IA32_APIC_BASE[11]) (IA32_APIC_BASE[10])
* -----------------------------------------------------------
* 0 0 APIC is disabled
* 0 1 Invalid
* 1 0 APIC is enabled in xAPIC mode
* 1 1 APIC is enabled in X2APIC mode
* -----------------------------------------------------------
*/
int x2apic_enable = 1;
apic_mode_t apic_mode = LOCAL_APIC; /* Default mode is Local APIC */
/* See apic_directed_EOI_supported(). Currently 3-state variable. */
volatile int apic_directed_eoi_state = 2;
/* Uses MMIO (Memory Mapped IO) */
static apic_reg_ops_t local_apic_regs_ops = {
local_apic_read,
local_apic_write,
get_local_apic_pri,
local_apic_write_task_reg,
local_apic_write_int_cmd,
apic_send_EOI,
};
/* X2APIC : Uses RDMSR/WRMSR instructions to access APIC registers */
static apic_reg_ops_t x2apic_regs_ops = {
local_x2apic_read,
local_x2apic_write,
get_local_x2apic_pri,
local_x2apic_write_task_reg,
local_x2apic_write_int_cmd,
apic_send_EOI,
};
int apic_have_32bit_cr8 = 0;
/* The default ops is local APIC (Memory Mapped IO) */
apic_reg_ops_t *apic_reg_ops = &local_apic_regs_ops;
/*
* APIC register ops related data sturctures and functions.
*/
void apic_send_EOI();
void apic_send_directed_EOI(uint32_t irq);
#define X2APIC_ENABLE_BIT 10
/*
* Local APIC Implementation
*/
static uint64_t
local_apic_read(uint32_t reg)
{
return ((uint32_t)apicadr[reg]);
}
static void
local_apic_write(uint32_t reg, uint64_t value)
{
apicadr[reg] = (uint32_t)value;
}
static int
get_local_apic_pri(void)
{
#if defined(__amd64)
return ((int)getcr8());
#else
if (apic_have_32bit_cr8)
return ((int)getcr8());
return (apicadr[APIC_TASK_REG]);
#endif
}
static void
local_apic_write_task_reg(uint64_t value)
{
#if defined(__amd64)
setcr8((ulong_t)(value >> APIC_IPL_SHIFT));
#else
if (apic_have_32bit_cr8)
setcr8((ulong_t)(value >> APIC_IPL_SHIFT));
else
apicadr[APIC_TASK_REG] = (uint32_t)value;
#endif
}
static void
local_apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1)
{
apicadr[APIC_INT_CMD2] = cpu_id << APIC_ICR_ID_BIT_OFFSET;
apicadr[APIC_INT_CMD1] = cmd1;
}
/*
* X2APIC Implementation.
*/
static uint64_t
local_x2apic_read(uint32_t msr)
{
uint64_t i;
i = (uint64_t)(rdmsr(REG_X2APIC_BASE_MSR + (msr >> 2)) & 0xffffffff);
return (i);
}
static void
local_x2apic_write(uint32_t msr, uint64_t value)
{
uint64_t tmp;
if (msr != APIC_EOI_REG) {
tmp = rdmsr(REG_X2APIC_BASE_MSR + (msr >> 2));
tmp = (tmp & 0xffffffff00000000) | value;
} else {
tmp = 0;
}
wrmsr((REG_X2APIC_BASE_MSR + (msr >> 2)), tmp);
}
static int
get_local_x2apic_pri(void)
{
return (rdmsr(REG_X2APIC_BASE_MSR + (APIC_TASK_REG >> 2)));
}
static void
local_x2apic_write_task_reg(uint64_t value)
{
X2APIC_WRITE(APIC_TASK_REG, value);
}
static void
local_x2apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1)
{
wrmsr((REG_X2APIC_BASE_MSR + (APIC_INT_CMD1 >> 2)),
(((uint64_t)cpu_id << 32) | cmd1));
}
/*ARGSUSED*/
void
apic_send_EOI(uint32_t irq)
{
apic_reg_ops->apic_write(APIC_EOI_REG, 0);
}
/*
* Support for Directed EOI capability is available in both the xAPIC
* and x2APIC mode.
*/
void
apic_send_directed_EOI(uint32_t irq)
{
uchar_t ioapicindex;
uchar_t vector;
apic_irq_t *apic_irq;
short intr_index;
/*
* Following the EOI to the local APIC unit, perform a directed
* EOI to the IOxAPIC generating the interrupt by writing to its
* EOI register.
*
* A broadcast EOI is not generated.
*/
apic_reg_ops->apic_write(APIC_EOI_REG, 0);
apic_irq = apic_irq_table[irq];
while (apic_irq) {
intr_index = apic_irq->airq_mps_intr_index;
if (intr_index == ACPI_INDEX || intr_index >= 0) {
ioapicindex = apic_irq->airq_ioapicindex;
vector = apic_irq->airq_vector;
ioapic_write_eoi(ioapicindex, vector);
}
apic_irq = apic_irq->airq_next;
}
}
int
apic_detect_x2apic(void)
{
if (x2apic_enable == 0)
return (0);
return (is_x86_feature(x86_featureset, X86FSET_X2APIC));
}
void
apic_enable_x2apic(void)
{
uint64_t apic_base_msr;
if (apic_local_mode() == LOCAL_X2APIC) {
/* BIOS apparently has enabled X2APIC */
if (apic_mode != LOCAL_X2APIC)
x2apic_update_psm();
return;
}
/*
* This is the first time we are enabling X2APIC on this CPU
*/
apic_base_msr = rdmsr(REG_APIC_BASE_MSR);
apic_base_msr = apic_base_msr | (0x1 << X2APIC_ENABLE_BIT);
wrmsr(REG_APIC_BASE_MSR, apic_base_msr);
if (apic_mode != LOCAL_X2APIC)
x2apic_update_psm();
}
/*
* Determine which mode the current CPU is in. See the table above.
* (IA32_APIC_BASE[11]) (IA32_APIC_BASE[10])
*/
int
apic_local_mode(void)
{
uint64_t apic_base_msr;
int bit = ((0x1 << (X2APIC_ENABLE_BIT + 1)) |
(0x1 << X2APIC_ENABLE_BIT));
apic_base_msr = rdmsr(REG_APIC_BASE_MSR);
if ((apic_base_msr & bit) == bit)
return (LOCAL_X2APIC);
else
return (LOCAL_APIC);
}
void
apic_set_directed_EOI_handler()
{
apic_reg_ops->apic_send_eoi = apic_send_directed_EOI;
}
int
apic_directed_EOI_supported()
{
uint32_t ver;
/*
* There are some known issues with some versions of Linux KVM and QEMU
* where by directed EOIs do not properly function and instead get
* coalesced at the hypervisor, causing the host not to see interrupts.
* Thus, when the platform is KVM, we would like to disable it by
* default, but keep it available otherwise.
*
* We use a three-state variable (apic_directed_eoi_state) to determine
* how we handle directed EOI.
*
* 0 --> Don't do directed EOI at all.
* 1 --> Do directed EOI if available, no matter the HW environment.
* 2 --> Don't do directed EOI on KVM, but do it otherwise if available.
*
* If some grinning weirdo put something else in there, treat it as '2'
* (i.e. the current default).
*
* Note, at this time illumos KVM does not identify as KVM. If it does,
* we'll need to do some work to determine if it should be caught by
* this or if it should show up as its own value of platform_type.
*/
switch (apic_directed_eoi_state) {
case 0:
/* Don't do it at all. */
return (0);
case 1:
break;
case 2:
default:
/* Only do it if we aren't on KVM. */
if (get_hwenv() == HW_KVM)
return (0);
/* FALLTHRU */
}
ver = apic_reg_ops->apic_read(APIC_VERS_REG);
if (ver & APIC_DIRECTED_EOI_BIT)
return (1);
return (0);
}
/*
* Change apic_reg_ops depending upon the apic_mode.
*/
void
apic_change_ops()
{
if (apic_mode == LOCAL_APIC)
apic_reg_ops = &local_apic_regs_ops;
else if (apic_mode == LOCAL_X2APIC)
apic_reg_ops = &x2apic_regs_ops;
}
/*
* Generates an interprocessor interrupt to another CPU when X2APIC mode is
* enabled.
*/
void
x2apic_send_ipi(int cpun, int ipl)
{
int vector;
ulong_t flag;
ASSERT(apic_mode == LOCAL_X2APIC);
/*
* With X2APIC, Intel relaxed the semantics of the
* WRMSR instruction such that references to the X2APIC
* MSR registers are no longer serializing instructions.
* The code that initiates IPIs assumes that some sort
* of memory serialization occurs. The old APIC code
* did a write to uncachable memory mapped registers.
* Any reference to uncached memory is a serializing
* operation. To mimic those semantics here, we do an
* atomic operation, which translates to a LOCK OR instruction,
* which is serializing.
*/
atomic_or_ulong(&flag, 1);
vector = apic_resv_vector[ipl];
flag = intr_clear();
/*
* According to X2APIC specification in section '2.3.5.1' of
* Interrupt Command Register Semantics, the semantics of
* programming Interrupt Command Register to dispatch an interrupt
* is simplified. A single MSR write to the 64-bit ICR is required
* for dispatching an interrupt. Specifically with the 64-bit MSR
* interface to ICR, system software is not required to check the
* status of the delivery status bit prior to writing to the ICR
* to send an IPI. With the removal of the Delivery Status bit,
* system software no longer has a reason to read the ICR. It remains
* readable only to aid in debugging.
*/
#ifdef DEBUG
APIC_AV_PENDING_SET();
#endif /* DEBUG */
if ((cpun == psm_get_cpu_id())) {
X2APIC_WRITE(X2APIC_SELF_IPI, vector);
} else {
apic_reg_ops->apic_write_int_cmd(
apic_cpus[cpun].aci_local_id, vector);
}
intr_restore(flag);
}
/*
* Generates IPI to another CPU depending on the local APIC mode.
* apic_send_ipi() and x2apic_send_ipi() depends on the configured
* mode of the local APIC, but that may not match the actual mode
* early in CPU startup.
*
* Any changes made to this routine must be accompanied by similar
* changes to apic_send_ipi().
*/
void
apic_common_send_ipi(int cpun, int ipl)
{
int vector;
ulong_t flag;
int mode = apic_local_mode();
if (mode == LOCAL_X2APIC) {
x2apic_send_ipi(cpun, ipl);
return;
}
ASSERT(mode == LOCAL_APIC);
vector = apic_resv_vector[ipl];
ASSERT((vector >= APIC_BASE_VECT) && (vector <= APIC_SPUR_INTR));
flag = intr_clear();
while (local_apic_regs_ops.apic_read(APIC_INT_CMD1) & AV_PENDING)
apic_ret();
local_apic_regs_ops.apic_write_int_cmd(apic_cpus[cpun].aci_local_id,
vector);
intr_restore(flag);
}