qemu/hw/xics.c
David Gibson d07fee7e8a pseries: Add support for level interrupts to XICS
The pseries "xics" interrupt controller, like most interrupt
controllers can support both message (i.e. edge sensitive) interrupts
and level sensitive interrupts, but it needs to know which are which.

When I implemented the xics emulation for qemu, the only devices we
supported were the PAPR virtual IO devices.  These devices only use
message interrupts, so they were the only ones I implemented in xics.

Since then, however, we have added support for PCI devices, which use
level sensitive interrupts.  It turns out the message interrupt logic
still actually works most of the time for these, but there are
circumstances where we can lost interrupts due to the incorrect
interrupt logic.

This patch, therefore, implements the correct xics level-sensitive
interrupt logic.  The type of the interrupt is set when a device
allocates a new xics interrupt.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-03-15 13:12:12 +01:00

555 lines
14 KiB
C

/*
* QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator
*
* PAPR Virtualized Interrupt System, aka ICS/ICP aka xics
*
* Copyright (c) 2010,2011 David Gibson, IBM Corporation.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
*/
#include "hw.h"
#include "hw/spapr.h"
#include "hw/xics.h"
/*
* ICP: Presentation layer
*/
struct icp_server_state {
uint32_t xirr;
uint8_t pending_priority;
uint8_t mfrr;
qemu_irq output;
};
#define XISR_MASK 0x00ffffff
#define CPPR_MASK 0xff000000
#define XISR(ss) (((ss)->xirr) & XISR_MASK)
#define CPPR(ss) (((ss)->xirr) >> 24)
struct ics_state;
struct icp_state {
long nr_servers;
struct icp_server_state *ss;
struct ics_state *ics;
};
static void ics_reject(struct ics_state *ics, int nr);
static void ics_resend(struct ics_state *ics);
static void ics_eoi(struct ics_state *ics, int nr);
static void icp_check_ipi(struct icp_state *icp, int server)
{
struct icp_server_state *ss = icp->ss + server;
if (XISR(ss) && (ss->pending_priority <= ss->mfrr)) {
return;
}
if (XISR(ss)) {
ics_reject(icp->ics, XISR(ss));
}
ss->xirr = (ss->xirr & ~XISR_MASK) | XICS_IPI;
ss->pending_priority = ss->mfrr;
qemu_irq_raise(ss->output);
}
static void icp_resend(struct icp_state *icp, int server)
{
struct icp_server_state *ss = icp->ss + server;
if (ss->mfrr < CPPR(ss)) {
icp_check_ipi(icp, server);
}
ics_resend(icp->ics);
}
static void icp_set_cppr(struct icp_state *icp, int server, uint8_t cppr)
{
struct icp_server_state *ss = icp->ss + server;
uint8_t old_cppr;
uint32_t old_xisr;
old_cppr = CPPR(ss);
ss->xirr = (ss->xirr & ~CPPR_MASK) | (cppr << 24);
if (cppr < old_cppr) {
if (XISR(ss) && (cppr <= ss->pending_priority)) {
old_xisr = XISR(ss);
ss->xirr &= ~XISR_MASK; /* Clear XISR */
qemu_irq_lower(ss->output);
ics_reject(icp->ics, old_xisr);
}
} else {
if (!XISR(ss)) {
icp_resend(icp, server);
}
}
}
static void icp_set_mfrr(struct icp_state *icp, int nr, uint8_t mfrr)
{
struct icp_server_state *ss = icp->ss + nr;
ss->mfrr = mfrr;
if (mfrr < CPPR(ss)) {
icp_check_ipi(icp, nr);
}
}
static uint32_t icp_accept(struct icp_server_state *ss)
{
uint32_t xirr;
qemu_irq_lower(ss->output);
xirr = ss->xirr;
ss->xirr = ss->pending_priority << 24;
return xirr;
}
static void icp_eoi(struct icp_state *icp, int server, uint32_t xirr)
{
struct icp_server_state *ss = icp->ss + server;
/* Send EOI -> ICS */
ss->xirr = (ss->xirr & ~CPPR_MASK) | (xirr & CPPR_MASK);
ics_eoi(icp->ics, xirr & XISR_MASK);
if (!XISR(ss)) {
icp_resend(icp, server);
}
}
static void icp_irq(struct icp_state *icp, int server, int nr, uint8_t priority)
{
struct icp_server_state *ss = icp->ss + server;
if ((priority >= CPPR(ss))
|| (XISR(ss) && (ss->pending_priority <= priority))) {
ics_reject(icp->ics, nr);
} else {
if (XISR(ss)) {
ics_reject(icp->ics, XISR(ss));
}
ss->xirr = (ss->xirr & ~XISR_MASK) | (nr & XISR_MASK);
ss->pending_priority = priority;
qemu_irq_raise(ss->output);
}
}
/*
* ICS: Source layer
*/
struct ics_irq_state {
int server;
uint8_t priority;
uint8_t saved_priority;
enum xics_irq_type type;
int asserted:1;
int sent:1;
int rejected:1;
int masked_pending:1;
};
struct ics_state {
int nr_irqs;
int offset;
qemu_irq *qirqs;
struct ics_irq_state *irqs;
struct icp_state *icp;
};
static int ics_valid_irq(struct ics_state *ics, uint32_t nr)
{
return (nr >= ics->offset)
&& (nr < (ics->offset + ics->nr_irqs));
}
static void resend_msi(struct ics_state *ics, int srcno)
{
struct ics_irq_state *irq = ics->irqs + srcno;
/* FIXME: filter by server#? */
if (irq->rejected) {
irq->rejected = 0;
if (irq->priority != 0xff) {
icp_irq(ics->icp, irq->server, srcno + ics->offset,
irq->priority);
}
}
}
static void resend_lsi(struct ics_state *ics, int srcno)
{
struct ics_irq_state *irq = ics->irqs + srcno;
if ((irq->priority != 0xff) && irq->asserted && !irq->sent) {
irq->sent = 1;
icp_irq(ics->icp, irq->server, srcno + ics->offset, irq->priority);
}
}
static void set_irq_msi(struct ics_state *ics, int srcno, int val)
{
struct ics_irq_state *irq = ics->irqs + srcno;
if (val) {
if (irq->priority == 0xff) {
irq->masked_pending = 1;
/* masked pending */ ;
} else {
icp_irq(ics->icp, irq->server, srcno + ics->offset, irq->priority);
}
}
}
static void set_irq_lsi(struct ics_state *ics, int srcno, int val)
{
struct ics_irq_state *irq = ics->irqs + srcno;
irq->asserted = val;
resend_lsi(ics, srcno);
}
static void ics_set_irq(void *opaque, int srcno, int val)
{
struct ics_state *ics = (struct ics_state *)opaque;
struct ics_irq_state *irq = ics->irqs + srcno;
if (irq->type == XICS_LSI) {
set_irq_lsi(ics, srcno, val);
} else {
set_irq_msi(ics, srcno, val);
}
}
static void write_xive_msi(struct ics_state *ics, int srcno)
{
struct ics_irq_state *irq = ics->irqs + srcno;
if (!irq->masked_pending || (irq->priority == 0xff)) {
return;
}
irq->masked_pending = 0;
icp_irq(ics->icp, irq->server, srcno + ics->offset, irq->priority);
}
static void write_xive_lsi(struct ics_state *ics, int srcno)
{
resend_lsi(ics, srcno);
}
static void ics_write_xive(struct ics_state *ics, int nr, int server,
uint8_t priority)
{
int srcno = nr - ics->offset;
struct ics_irq_state *irq = ics->irqs + srcno;
irq->server = server;
irq->priority = priority;
if (irq->type == XICS_LSI) {
write_xive_lsi(ics, srcno);
} else {
write_xive_msi(ics, srcno);
}
}
static void ics_reject(struct ics_state *ics, int nr)
{
struct ics_irq_state *irq = ics->irqs + nr - ics->offset;
irq->rejected = 1; /* Irrelevant but harmless for LSI */
irq->sent = 0; /* Irrelevant but harmless for MSI */
}
static void ics_resend(struct ics_state *ics)
{
int i;
for (i = 0; i < ics->nr_irqs; i++) {
struct ics_irq_state *irq = ics->irqs + i;
/* FIXME: filter by server#? */
if (irq->type == XICS_LSI) {
resend_lsi(ics, i);
} else {
resend_msi(ics, i);
}
}
}
static void ics_eoi(struct ics_state *ics, int nr)
{
int srcno = nr - ics->offset;
struct ics_irq_state *irq = ics->irqs + srcno;
if (irq->type == XICS_LSI) {
irq->sent = 0;
}
}
/*
* Exported functions
*/
qemu_irq xics_assign_irq(struct icp_state *icp, int irq,
enum xics_irq_type type)
{
if ((irq < icp->ics->offset)
|| (irq >= (icp->ics->offset + icp->ics->nr_irqs))) {
return NULL;
}
assert((type == XICS_MSI) || (type == XICS_LSI));
icp->ics->irqs[irq - icp->ics->offset].type = type;
return icp->ics->qirqs[irq - icp->ics->offset];
}
static target_ulong h_cppr(CPUPPCState *env, sPAPREnvironment *spapr,
target_ulong opcode, target_ulong *args)
{
target_ulong cppr = args[0];
icp_set_cppr(spapr->icp, env->cpu_index, cppr);
return H_SUCCESS;
}
static target_ulong h_ipi(CPUPPCState *env, sPAPREnvironment *spapr,
target_ulong opcode, target_ulong *args)
{
target_ulong server = args[0];
target_ulong mfrr = args[1];
if (server >= spapr->icp->nr_servers) {
return H_PARAMETER;
}
icp_set_mfrr(spapr->icp, server, mfrr);
return H_SUCCESS;
}
static target_ulong h_xirr(CPUPPCState *env, sPAPREnvironment *spapr,
target_ulong opcode, target_ulong *args)
{
uint32_t xirr = icp_accept(spapr->icp->ss + env->cpu_index);
args[0] = xirr;
return H_SUCCESS;
}
static target_ulong h_eoi(CPUPPCState *env, sPAPREnvironment *spapr,
target_ulong opcode, target_ulong *args)
{
target_ulong xirr = args[0];
icp_eoi(spapr->icp, env->cpu_index, xirr);
return H_SUCCESS;
}
static void rtas_set_xive(sPAPREnvironment *spapr, uint32_t token,
uint32_t nargs, target_ulong args,
uint32_t nret, target_ulong rets)
{
struct ics_state *ics = spapr->icp->ics;
uint32_t nr, server, priority;
if ((nargs != 3) || (nret != 1)) {
rtas_st(rets, 0, -3);
return;
}
nr = rtas_ld(args, 0);
server = rtas_ld(args, 1);
priority = rtas_ld(args, 2);
if (!ics_valid_irq(ics, nr) || (server >= ics->icp->nr_servers)
|| (priority > 0xff)) {
rtas_st(rets, 0, -3);
return;
}
ics_write_xive(ics, nr, server, priority);
rtas_st(rets, 0, 0); /* Success */
}
static void rtas_get_xive(sPAPREnvironment *spapr, uint32_t token,
uint32_t nargs, target_ulong args,
uint32_t nret, target_ulong rets)
{
struct ics_state *ics = spapr->icp->ics;
uint32_t nr;
if ((nargs != 1) || (nret != 3)) {
rtas_st(rets, 0, -3);
return;
}
nr = rtas_ld(args, 0);
if (!ics_valid_irq(ics, nr)) {
rtas_st(rets, 0, -3);
return;
}
rtas_st(rets, 0, 0); /* Success */
rtas_st(rets, 1, ics->irqs[nr - ics->offset].server);
rtas_st(rets, 2, ics->irqs[nr - ics->offset].priority);
}
static void rtas_int_off(sPAPREnvironment *spapr, uint32_t token,
uint32_t nargs, target_ulong args,
uint32_t nret, target_ulong rets)
{
struct ics_state *ics = spapr->icp->ics;
uint32_t nr;
if ((nargs != 1) || (nret != 1)) {
rtas_st(rets, 0, -3);
return;
}
nr = rtas_ld(args, 0);
if (!ics_valid_irq(ics, nr)) {
rtas_st(rets, 0, -3);
return;
}
/* This is a NOP for now, since the described PAPR semantics don't
* seem to gel with what Linux does */
#if 0
struct ics_irq_state *irq = xics->irqs + (nr - xics->offset);
irq->saved_priority = irq->priority;
ics_write_xive_msi(xics, nr, irq->server, 0xff);
#endif
rtas_st(rets, 0, 0); /* Success */
}
static void rtas_int_on(sPAPREnvironment *spapr, uint32_t token,
uint32_t nargs, target_ulong args,
uint32_t nret, target_ulong rets)
{
struct ics_state *ics = spapr->icp->ics;
uint32_t nr;
if ((nargs != 1) || (nret != 1)) {
rtas_st(rets, 0, -3);
return;
}
nr = rtas_ld(args, 0);
if (!ics_valid_irq(ics, nr)) {
rtas_st(rets, 0, -3);
return;
}
/* This is a NOP for now, since the described PAPR semantics don't
* seem to gel with what Linux does */
#if 0
struct ics_irq_state *irq = xics->irqs + (nr - xics->offset);
ics_write_xive_msi(xics, nr, irq->server, irq->saved_priority);
#endif
rtas_st(rets, 0, 0); /* Success */
}
struct icp_state *xics_system_init(int nr_irqs)
{
CPUPPCState *env;
int max_server_num;
int i;
struct icp_state *icp;
struct ics_state *ics;
max_server_num = -1;
for (env = first_cpu; env != NULL; env = env->next_cpu) {
if (env->cpu_index > max_server_num) {
max_server_num = env->cpu_index;
}
}
icp = g_malloc0(sizeof(*icp));
icp->nr_servers = max_server_num + 1;
icp->ss = g_malloc0(icp->nr_servers*sizeof(struct icp_server_state));
for (i = 0; i < icp->nr_servers; i++) {
icp->ss[i].mfrr = 0xff;
}
for (env = first_cpu; env != NULL; env = env->next_cpu) {
struct icp_server_state *ss = &icp->ss[env->cpu_index];
switch (PPC_INPUT(env)) {
case PPC_FLAGS_INPUT_POWER7:
ss->output = env->irq_inputs[POWER7_INPUT_INT];
break;
case PPC_FLAGS_INPUT_970:
ss->output = env->irq_inputs[PPC970_INPUT_INT];
break;
default:
hw_error("XICS interrupt model does not support this CPU bus "
"model\n");
exit(1);
}
}
ics = g_malloc0(sizeof(*ics));
ics->nr_irqs = nr_irqs;
ics->offset = 16;
ics->irqs = g_malloc0(nr_irqs * sizeof(struct ics_irq_state));
icp->ics = ics;
ics->icp = icp;
for (i = 0; i < nr_irqs; i++) {
ics->irqs[i].priority = 0xff;
ics->irqs[i].saved_priority = 0xff;
}
ics->qirqs = qemu_allocate_irqs(ics_set_irq, ics, nr_irqs);
spapr_register_hypercall(H_CPPR, h_cppr);
spapr_register_hypercall(H_IPI, h_ipi);
spapr_register_hypercall(H_XIRR, h_xirr);
spapr_register_hypercall(H_EOI, h_eoi);
spapr_rtas_register("ibm,set-xive", rtas_set_xive);
spapr_rtas_register("ibm,get-xive", rtas_get_xive);
spapr_rtas_register("ibm,int-off", rtas_int_off);
spapr_rtas_register("ibm,int-on", rtas_int_on);
return icp;
}