powerpc/powernv: Add OPAL ICS backend

OPAL handles HW access to the various ICS or equivalent chips
for us (with the exception of p5ioc2 based HEA which uses a

different backend) similarily to what RTAS does on pSeries.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Benjamin Herrenschmidt 2011-09-19 17:45:02 +00:00
parent 628daa8d5a
commit 5c7c1e9444
4 changed files with 266 additions and 6 deletions

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@ -27,10 +27,18 @@
#define MAX_NUM_PRIORITIES 3
/* Native ICP */
#ifdef CONFIG_PPC_ICP_NATIVE
extern int icp_native_init(void);
#else
static inline int icp_native_init(void) { return -ENODEV; }
#endif
/* PAPR ICP */
#ifdef CONFIG_PPC_ICP_HV
extern int icp_hv_init(void);
#else
static inline int icp_hv_init(void) { return -ENODEV; }
#endif
/* ICP ops */
struct icp_ops {
@ -51,7 +59,18 @@ extern const struct icp_ops *icp_ops;
extern int ics_native_init(void);
/* RTAS ICS */
#ifdef CONFIG_PPC_ICS_RTAS
extern int ics_rtas_init(void);
#else
static inline int ics_rtas_init(void) { return -ENODEV; }
#endif
/* HAL ICS */
#ifdef CONFIG_PPC_POWERNV
extern int ics_opal_init(void);
#else
static inline int ics_opal_init(void) { return -ENODEV; }
#endif
/* ICS instance, hooked up to chip_data of an irq */
struct ics {

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@ -4,3 +4,4 @@ obj-y += xics-common.o
obj-$(CONFIG_PPC_ICP_NATIVE) += icp-native.o
obj-$(CONFIG_PPC_ICP_HV) += icp-hv.o
obj-$(CONFIG_PPC_ICS_RTAS) += ics-rtas.o
obj-$(CONFIG_PPC_POWERNV) += ics-opal.o

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@ -0,0 +1,244 @@
/*
* ICS backend for OPAL managed interrupts.
*
* Copyright 2011 IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#undef DEBUG
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/of.h>
#include <linux/spinlock.h>
#include <linux/msi.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/irq.h>
#include <asm/errno.h>
#include <asm/xics.h>
#include <asm/opal.h>
#include <asm/firmware.h>
static int ics_opal_mangle_server(int server)
{
/* No link for now */
return server << 2;
}
static int ics_opal_unmangle_server(int server)
{
/* No link for now */
return server >> 2;
}
static void ics_opal_unmask_irq(struct irq_data *d)
{
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
int64_t rc;
int server;
pr_devel("ics-hal: unmask virq %d [hw 0x%x]\n", d->irq, hw_irq);
if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
return;
server = xics_get_irq_server(d->irq, d->affinity, 0);
server = ics_opal_mangle_server(server);
rc = opal_set_xive(hw_irq, server, DEFAULT_PRIORITY);
if (rc != OPAL_SUCCESS)
pr_err("%s: opal_set_xive(irq=%d [hw 0x%x] server=%x)"
" error %lld\n",
__func__, d->irq, hw_irq, server, rc);
}
static unsigned int ics_opal_startup(struct irq_data *d)
{
#ifdef CONFIG_PCI_MSI
/*
* The generic MSI code returns with the interrupt disabled on the
* card, using the MSI mask bits. Firmware doesn't appear to unmask
* at that level, so we do it here by hand.
*/
if (d->msi_desc)
unmask_msi_irq(d);
#endif
/* unmask it */
ics_opal_unmask_irq(d);
return 0;
}
static void ics_opal_mask_real_irq(unsigned int hw_irq)
{
int server = ics_opal_mangle_server(xics_default_server);
int64_t rc;
if (hw_irq == XICS_IPI)
return;
/* Have to set XIVE to 0xff to be able to remove a slot */
rc = opal_set_xive(hw_irq, server, 0xff);
if (rc != OPAL_SUCCESS)
pr_err("%s: opal_set_xive(0xff) irq=%u returned %lld\n",
__func__, hw_irq, rc);
}
static void ics_opal_mask_irq(struct irq_data *d)
{
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
pr_devel("ics-hal: mask virq %d [hw 0x%x]\n", d->irq, hw_irq);
if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
return;
ics_opal_mask_real_irq(hw_irq);
}
static int ics_opal_set_affinity(struct irq_data *d,
const struct cpumask *cpumask,
bool force)
{
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
int16_t server;
int8_t priority;
int64_t rc;
int wanted_server;
if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
return -1;
rc = opal_get_xive(hw_irq, &server, &priority);
if (rc != OPAL_SUCCESS) {
pr_err("%s: opal_set_xive(irq=%d [hw 0x%x] server=%x)"
" error %lld\n",
__func__, d->irq, hw_irq, server, rc);
return -1;
}
wanted_server = xics_get_irq_server(d->irq, cpumask, 1);
if (wanted_server < 0) {
char cpulist[128];
cpumask_scnprintf(cpulist, sizeof(cpulist), cpumask);
pr_warning("%s: No online cpus in the mask %s for irq %d\n",
__func__, cpulist, d->irq);
return -1;
}
server = ics_opal_mangle_server(wanted_server);
pr_devel("ics-hal: set-affinity irq %d [hw 0x%x] server: 0x%x/0x%x\n",
d->irq, hw_irq, wanted_server, server);
rc = opal_set_xive(hw_irq, server, priority);
if (rc != OPAL_SUCCESS) {
pr_err("%s: opal_set_xive(irq=%d [hw 0x%x] server=%x)"
" error %lld\n",
__func__, d->irq, hw_irq, server, rc);
return -1;
}
return 0;
}
static struct irq_chip ics_opal_irq_chip = {
.name = "OPAL ICS",
.irq_startup = ics_opal_startup,
.irq_mask = ics_opal_mask_irq,
.irq_unmask = ics_opal_unmask_irq,
.irq_eoi = NULL, /* Patched at init time */
.irq_set_affinity = ics_opal_set_affinity
};
static int ics_opal_map(struct ics *ics, unsigned int virq);
static void ics_opal_mask_unknown(struct ics *ics, unsigned long vec);
static long ics_opal_get_server(struct ics *ics, unsigned long vec);
static int ics_opal_host_match(struct ics *ics, struct device_node *node)
{
return 1;
}
/* Only one global & state struct ics */
static struct ics ics_hal = {
.map = ics_opal_map,
.mask_unknown = ics_opal_mask_unknown,
.get_server = ics_opal_get_server,
.host_match = ics_opal_host_match,
};
static int ics_opal_map(struct ics *ics, unsigned int virq)
{
unsigned int hw_irq = (unsigned int)virq_to_hw(virq);
int64_t rc;
int16_t server;
int8_t priority;
if (WARN_ON(hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS))
return -EINVAL;
/* Check if HAL knows about this interrupt */
rc = opal_get_xive(hw_irq, &server, &priority);
if (rc != OPAL_SUCCESS)
return -ENXIO;
irq_set_chip_and_handler(virq, &ics_opal_irq_chip, handle_fasteoi_irq);
irq_set_chip_data(virq, &ics_hal);
return 0;
}
static void ics_opal_mask_unknown(struct ics *ics, unsigned long vec)
{
int64_t rc;
int16_t server;
int8_t priority;
/* Check if HAL knows about this interrupt */
rc = opal_get_xive(vec, &server, &priority);
if (rc != OPAL_SUCCESS)
return;
ics_opal_mask_real_irq(vec);
}
static long ics_opal_get_server(struct ics *ics, unsigned long vec)
{
int64_t rc;
int16_t server;
int8_t priority;
/* Check if HAL knows about this interrupt */
rc = opal_get_xive(vec, &server, &priority);
if (rc != OPAL_SUCCESS)
return -1;
return ics_opal_unmangle_server(server);
}
int __init ics_opal_init(void)
{
if (!firmware_has_feature(FW_FEATURE_OPAL))
return -ENODEV;
/* We need to patch our irq chip's EOI to point to the
* right ICP
*/
ics_opal_irq_chip.irq_eoi = icp_ops->eoi;
/* Register ourselves */
xics_register_ics(&ics_hal);
pr_info("ICS OPAL backend registered\n");
return 0;
}

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@ -409,14 +409,10 @@ void __init xics_init(void)
int rc = -1;
/* Fist locate ICP */
#ifdef CONFIG_PPC_ICP_HV
if (firmware_has_feature(FW_FEATURE_LPAR))
rc = icp_hv_init();
#endif
#ifdef CONFIG_PPC_ICP_NATIVE
if (rc < 0)
rc = icp_native_init();
#endif
if (rc < 0) {
pr_warning("XICS: Cannot find a Presentation Controller !\n");
return;
@ -429,9 +425,9 @@ void __init xics_init(void)
xics_ipi_chip.irq_eoi = icp_ops->eoi;
/* Now locate ICS */
#ifdef CONFIG_PPC_ICS_RTAS
rc = ics_rtas_init();
#endif
if (rc < 0)
rc = ics_opal_init();
if (rc < 0)
pr_warning("XICS: Cannot find a Source Controller !\n");