ics-rtas.c 5.9 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
#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);
29
static int ics_rtas_host_match(struct ics *ics, struct device_node *node);
30 31 32 33 34 35

/* 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,
36
	.host_match	= ics_rtas_host_match,
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206
};

static void ics_rtas_unmask_irq(struct irq_data *d)
{
	unsigned int hw_irq = (unsigned int)irq_data_to_hw(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, d->affinity, 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 (d->msi_desc)
		unmask_msi_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)irq_data_to_hw(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)irq_data_to_hw(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) {
		char cpulist[128];
		cpumask_scnprintf(cpulist, sizeof(cpulist), cpumask);
		printk(KERN_WARNING
			"%s: No online cpus in the mask %s for irq %d\n",
			__func__, cpulist, 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
};

static int ics_rtas_map(struct ics *ics, unsigned int virq)
{
	unsigned int hw_irq = (unsigned int)irq_map[virq].hwirq;
	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];
}

207 208 209 210 211 212 213 214 215
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");
}

216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240
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;
}