Orange Pi5 kernel

// 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_reentrant(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_reentrant(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_reentrant(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_reentrant(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_reentrant(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_reentrant(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_reentrant(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_reentrant(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;
}