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// SPDX-License-Identifier: GPL-2.0
#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/rtas.h>
/* RTAS service tokens */
static int ibm_get_xive;
static int ibm_set_xive;
static int ibm_int_on;
static int ibm_int_off;
static int ics_rtas_map(struct ics *ics, unsigned int virq);
static void ics_rtas_mask_unknown(struct ics *ics, unsigned long vec);
static long ics_rtas_get_server(struct ics *ics, unsigned long vec);
static int ics_rtas_host_match(struct ics *ics, struct device_node *node);
/* Only one global & state struct ics */
static struct ics ics_rtas = {
.map = ics_rtas_map,
.mask_unknown = ics_rtas_mask_unknown,
.get_server = ics_rtas_get_server,
.host_match = ics_rtas_host_match,
};
static void ics_rtas_unmask_irq(struct irq_data *d)
{
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
int call_status;
int server;
pr_devel("xics: 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, irq_data_get_affinity_mask(d), 0);
call_status = rtas_call(ibm_set_xive, 3, 1, NULL, hw_irq, server,
DEFAULT_PRIORITY);
if (call_status != 0) {
printk(KERN_ERR
"%s: ibm_set_xive irq %u server %x returned %d\n",
__func__, hw_irq, server, call_status);
return;
}
/* Now unmask the interrupt (often a no-op) */
call_status = rtas_call(ibm_int_on, 1, 1, NULL, hw_irq);
if (call_status != 0) {
printk(KERN_ERR "%s: ibm_int_on irq=%u returned %d\n",
__func__, hw_irq, call_status);
return;
}
}
static unsigned int ics_rtas_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 (irq_data_get_msi_desc(d))
pci_msi_unmask_irq(d);
#endif
/* unmask it */
ics_rtas_unmask_irq(d);
return 0;
}
static void ics_rtas_mask_real_irq(unsigned int hw_irq)
{
int call_status;
if (hw_irq == XICS_IPI)
return;
call_status = rtas_call(ibm_int_off, 1, 1, NULL, hw_irq);
if (call_status != 0) {
printk(KERN_ERR "%s: ibm_int_off irq=%u returned %d\n",
__func__, hw_irq, call_status);
return;
}
/* Have to set XIVE to 0xff to be able to remove a slot */
call_status = rtas_call(ibm_set_xive, 3, 1, NULL, hw_irq,
xics_default_server, 0xff);
if (call_status != 0) {
printk(KERN_ERR "%s: ibm_set_xive(0xff) irq=%u returned %d\n",
__func__, hw_irq, call_status);
return;
}
}
static void ics_rtas_mask_irq(struct irq_data *d)
{
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
pr_devel("xics: mask virq %d [hw 0x%x]\n", d->irq, hw_irq);
if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
return;
ics_rtas_mask_real_irq(hw_irq);
}
static int ics_rtas_set_affinity(struct irq_data *d,
const struct cpumask *cpumask,
bool force)
{
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
int status;
int xics_status[2];
int irq_server;
if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
return -1;
status = rtas_call(ibm_get_xive, 1, 3, xics_status, hw_irq);
if (status) {
printk(KERN_ERR "%s: ibm,get-xive irq=%u returns %d\n",
__func__, hw_irq, status);
return -1;
}
irq_server = xics_get_irq_server(d->irq, cpumask, 1);
if (irq_server == -1) {
pr_warn("%s: No online cpus in the mask %*pb for irq %d\n",
__func__, cpumask_pr_args(cpumask), d->irq);
return -1;
}
status = rtas_call(ibm_set_xive, 3, 1, NULL,
hw_irq, irq_server, xics_status[1]);
if (status) {
printk(KERN_ERR "%s: ibm,set-xive irq=%u returns %d\n",
__func__, hw_irq, status);
return -1;
}
return IRQ_SET_MASK_OK;
}
static struct irq_chip ics_rtas_irq_chip = {
.name = "XICS",
.irq_startup = ics_rtas_startup,
.irq_mask = ics_rtas_mask_irq,
.irq_unmask = ics_rtas_unmask_irq,
.irq_eoi = NULL, /* Patched at init time */
.irq_set_affinity = ics_rtas_set_affinity,
.irq_set_type = xics_set_irq_type,
.irq_retrigger = xics_retrigger,
};
static int ics_rtas_map(struct ics *ics, unsigned int virq)
{
unsigned int hw_irq = (unsigned int)virq_to_hw(virq);
int status[2];
int rc;
if (WARN_ON(hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS))
return -EINVAL;
/* Check if RTAS knows about this interrupt */
rc = rtas_call(ibm_get_xive, 1, 3, status, hw_irq);
if (rc)
return -ENXIO;
irq_set_chip_and_handler(virq, &ics_rtas_irq_chip, handle_fasteoi_irq);
irq_set_chip_data(virq, &ics_rtas);
return 0;
}
static void ics_rtas_mask_unknown(struct ics *ics, unsigned long vec)
{
ics_rtas_mask_real_irq(vec);
}
static long ics_rtas_get_server(struct ics *ics, unsigned long vec)
{
int rc, status[2];
rc = rtas_call(ibm_get_xive, 1, 3, status, vec);
if (rc)
return -1;
return status[0];
}
static int ics_rtas_host_match(struct ics *ics, struct device_node *node)
{
/* IBM machines have interrupt parents of various funky types for things
* like vdevices, events, etc... The trick we use here is to match
* everything here except the legacy 8259 which is compatible "chrp,iic"
*/
return !of_device_is_compatible(node, "chrp,iic");
}
__init int ics_rtas_init(void)
{
ibm_get_xive = rtas_token("ibm,get-xive");
ibm_set_xive = rtas_token("ibm,set-xive");
ibm_int_on = rtas_token("ibm,int-on");
ibm_int_off = rtas_token("ibm,int-off");
/* We enable the RTAS "ICS" if RTAS is present with the
* appropriate tokens
*/
if (ibm_get_xive == RTAS_UNKNOWN_SERVICE ||
ibm_set_xive == RTAS_UNKNOWN_SERVICE)
return -ENODEV;
/* We need to patch our irq chip's EOI to point to the
* right ICP
*/
ics_rtas_irq_chip.irq_eoi = icp_ops->eoi;
/* Register ourselves */
xics_register_ics(&ics_rtas);
return 0;
}
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