arch/powerpc/sysdev/xics/ics-rtas.c

   1 #include <linux/types.h>
   2 #include <linux/kernel.h>
   3 #include <linux/irq.h>
   4 #include <linux/smp.h>
   5 #include <linux/interrupt.h>
   6 #include <linux/init.h>
   7 #include <linux/cpu.h>
   8 #include <linux/of.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/msi.h>
  11
  12 #include <asm/prom.h>
  13 #include <asm/smp.h>
  14 #include <asm/machdep.h>
  15 #include <asm/irq.h>
  16 #include <asm/errno.h>
  17 #include <asm/xics.h>
  18 #include <asm/rtas.h>
  19
  20 /* RTAS service tokens */
  21 static int ibm_get_xive;
  22 static int ibm_set_xive;
  23 static int ibm_int_on;
  24 static int ibm_int_off;
  25
  26 static int ics_rtas_map(struct ics *ics, unsigned int virq);
  27 static void ics_rtas_mask_unknown(struct ics *ics, unsigned long vec);
  28 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 /* Only one global & state struct ics */
  32 static struct ics ics_rtas = {
  33         .map            = ics_rtas_map,
  34         .mask_unknown   = ics_rtas_mask_unknown,
  35         .get_server     = ics_rtas_get_server,
  36         .host_match     = ics_rtas_host_match,
  37 };
  38
  39 static void ics_rtas_unmask_irq(struct irq_data *d)
  40 {
  41         unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
  42         int call_status;
  43         int server;
  44
  45         pr_devel("xics: unmask virq %d [hw 0x%x]\n", d->irq, hw_irq);
  46
  47         if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
  48                 return;
  49
  50         server = xics_get_irq_server(d->irq, irq_data_get_affinity_mask(d), 0);
  51
  52         call_status = rtas_call(ibm_set_xive, 3, 1, NULL, hw_irq, server,
  53                                 DEFAULT_PRIORITY);
  54         if (call_status != 0) {
  55                 printk(KERN_ERR
  56                         "%s: ibm_set_xive irq %u server %x returned %d\n",
  57                         __func__, hw_irq, server, call_status);
  58                 return;
  59         }
  60
  61         /* Now unmask the interrupt (often a no-op) */
  62         call_status = rtas_call(ibm_int_on, 1, 1, NULL, hw_irq);
  63         if (call_status != 0) {
  64                 printk(KERN_ERR "%s: ibm_int_on irq=%u returned %d\n",
  65                         __func__, hw_irq, call_status);
  66                 return;
  67         }
  68 }
  69
  70 static unsigned int ics_rtas_startup(struct irq_data *d)
  71 {
  72 #ifdef CONFIG_PCI_MSI
  73         /*
  74          * The generic MSI code returns with the interrupt disabled on the
  75          * card, using the MSI mask bits. Firmware doesn't appear to unmask
  76          * at that level, so we do it here by hand.
  77          */
  78         if (irq_data_get_msi_desc(d))
  79                 pci_msi_unmask_irq(d);
  80 #endif
  81         /* unmask it */
  82         ics_rtas_unmask_irq(d);
  83         return 0;
  84 }
  85
  86 static void ics_rtas_mask_real_irq(unsigned int hw_irq)
  87 {
  88         int call_status;
  89
  90         if (hw_irq == XICS_IPI)
  91                 return;
  92
  93         call_status = rtas_call(ibm_int_off, 1, 1, NULL, hw_irq);
  94         if (call_status != 0) {
  95                 printk(KERN_ERR "%s: ibm_int_off irq=%u returned %d\n",
  96                         __func__, hw_irq, call_status);
  97                 return;
  98         }
  99
 100         /* Have to set XIVE to 0xff to be able to remove a slot */
 101         call_status = rtas_call(ibm_set_xive, 3, 1, NULL, hw_irq,
 102                                 xics_default_server, 0xff);
 103         if (call_status != 0) {
 104                 printk(KERN_ERR "%s: ibm_set_xive(0xff) irq=%u returned %d\n",
 105                         __func__, hw_irq, call_status);
 106                 return;
 107         }
 108 }
 109
 110 static void ics_rtas_mask_irq(struct irq_data *d)
 111 {
 112         unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
 113
 114         pr_devel("xics: mask virq %d [hw 0x%x]\n", d->irq, hw_irq);
 115
 116         if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
 117                 return;
 118         ics_rtas_mask_real_irq(hw_irq);
 119 }
 120
 121 static int ics_rtas_set_affinity(struct irq_data *d,
 122                                  const struct cpumask *cpumask,
 123                                  bool force)
 124 {
 125         unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
 126         int status;
 127         int xics_status[2];
 128         int irq_server;
 129
 130         if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
 131                 return -1;
 132
 133         status = rtas_call(ibm_get_xive, 1, 3, xics_status, hw_irq);
 134
 135         if (status) {
 136                 printk(KERN_ERR "%s: ibm,get-xive irq=%u returns %d\n",
 137                         __func__, hw_irq, status);
 138                 return -1;
 139         }
 140
 141         irq_server = xics_get_irq_server(d->irq, cpumask, 1);
 142         if (irq_server == -1) {
 143                 pr_warning("%s: No online cpus in the mask %*pb for irq %d\n",
 144                            __func__, cpumask_pr_args(cpumask), d->irq);
 145                 return -1;
 146         }
 147
 148         status = rtas_call(ibm_set_xive, 3, 1, NULL,
 149                            hw_irq, irq_server, xics_status[1]);
 150
 151         if (status) {
 152                 printk(KERN_ERR "%s: ibm,set-xive irq=%u returns %d\n",
 153                         __func__, hw_irq, status);
 154                 return -1;
 155         }
 156
 157         return IRQ_SET_MASK_OK;
 158 }
 159
 160 static struct irq_chip ics_rtas_irq_chip = {
 161         .name = "XICS",
 162         .irq_startup = ics_rtas_startup,
 163         .irq_mask = ics_rtas_mask_irq,
 164         .irq_unmask = ics_rtas_unmask_irq,
 165         .irq_eoi = NULL, /* Patched at init time */
 166         .irq_set_affinity = ics_rtas_set_affinity
 167 };
 168
 169 static int ics_rtas_map(struct ics *ics, unsigned int virq)
 170 {
 171         unsigned int hw_irq = (unsigned int)virq_to_hw(virq);
 172         int status[2];
 173         int rc;
 174
 175         if (WARN_ON(hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS))
 176                 return -EINVAL;
 177
 178         /* Check if RTAS knows about this interrupt */
 179         rc = rtas_call(ibm_get_xive, 1, 3, status, hw_irq);
 180         if (rc)
 181                 return -ENXIO;
 182
 183         irq_set_chip_and_handler(virq, &ics_rtas_irq_chip, handle_fasteoi_irq);
 184         irq_set_chip_data(virq, &ics_rtas);
 185
 186         return 0;
 187 }
 188
 189 static void ics_rtas_mask_unknown(struct ics *ics, unsigned long vec)
 190 {
 191         ics_rtas_mask_real_irq(vec);
 192 }
 193
 194 static long ics_rtas_get_server(struct ics *ics, unsigned long vec)
 195 {
 196         int rc, status[2];
 197
 198         rc = rtas_call(ibm_get_xive, 1, 3, status, vec);
 199         if (rc)
 200                 return -1;
 201         return status[0];
 202 }
 203
 204 static int ics_rtas_host_match(struct ics *ics, struct device_node *node)
 205 {
 206         /* IBM machines have interrupt parents of various funky types for things
 207          * like vdevices, events, etc... The trick we use here is to match
 208          * everything here except the legacy 8259 which is compatible "chrp,iic"
 209          */
 210         return !of_device_is_compatible(node, "chrp,iic");
 211 }
 212
 213 __init int ics_rtas_init(void)
 214 {
 215         ibm_get_xive = rtas_token("ibm,get-xive");
 216         ibm_set_xive = rtas_token("ibm,set-xive");
 217         ibm_int_on  = rtas_token("ibm,int-on");
 218         ibm_int_off = rtas_token("ibm,int-off");
 219
 220         /* We enable the RTAS "ICS" if RTAS is present with the
 221          * appropriate tokens
 222          */
 223         if (ibm_get_xive == RTAS_UNKNOWN_SERVICE ||
 224             ibm_set_xive == RTAS_UNKNOWN_SERVICE)
 225                 return -ENODEV;
 226
 227         /* We need to patch our irq chip's EOI to point to the
 228          * right ICP
 229          */
 230         ics_rtas_irq_chip.irq_eoi = icp_ops->eoi;
 231
 232         /* Register ourselves */
 233         xics_register_ics(&ics_rtas);
 234
 235         return 0;
 236 }
 237