1 files changed, 293 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/xics/icp-native.c b/arch/powerpc/sysdev/xics/icp-native.c
new file mode 100644
index 000000000000..1f15ad436140
--- /dev/null
+++ b/arch/powerpc/sysdev/xics/icp-native.c
@@ -0,0 +1,293 @@
+/*
+ * Copyright 2011 IBM Corporation.
+ *
+ *  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.
+ *
+ */
+
+#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 <asm/prom.h>
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/irq.h>
+#include <asm/errno.h>
+#include <asm/xics.h>
+
+struct icp_ipl {
+        union {
+                u32 word;
+                u8 bytes[4];
+        } xirr_poll;
+        union {
+                u32 word;
+                u8 bytes[4];
+        } xirr;
+        u32 dummy;
+        union {
+                u32 word;
+                u8 bytes[4];
+        } qirr;
+        u32 link_a;
+        u32 link_b;
+        u32 link_c;
+};
+
+static struct icp_ipl __iomem *icp_native_regs[NR_CPUS];
+
+static inline unsigned int icp_native_get_xirr(void)
+{
+        int cpu = smp_processor_id();
+
+        return in_be32(&icp_native_regs[cpu]->xirr.word);
+}
+
+static inline void icp_native_set_xirr(unsigned int value)
+{
+        int cpu = smp_processor_id();
+
+        out_be32(&icp_native_regs[cpu]->xirr.word, value);
+}
+
+static inline void icp_native_set_cppr(u8 value)
+{
+        int cpu = smp_processor_id();
+
+        out_8(&icp_native_regs[cpu]->xirr.bytes[0], value);
+}
+
+static inline void icp_native_set_qirr(int n_cpu, u8 value)
+{
+        out_8(&icp_native_regs[n_cpu]->qirr.bytes[0], value);
+}
+
+static void icp_native_set_cpu_priority(unsigned char cppr)
+{
+        xics_set_base_cppr(cppr);
+        icp_native_set_cppr(cppr);
+        iosync();
+}
+
+static void icp_native_eoi(struct irq_data *d)
+{
+        unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+
+        iosync();
+        icp_native_set_xirr((xics_pop_cppr() << 24) | hw_irq);
+}
+
+static void icp_native_teardown_cpu(void)
+{
+        int cpu = smp_processor_id();
+
+        /* Clear any pending IPI */
+        icp_native_set_qirr(cpu, 0xff);
+}
+
+static void icp_native_flush_ipi(void)
+{
+        /* We take the ipi irq but and never return so we
+         * need to EOI the IPI, but want to leave our priority 0
+         *
+         * should we check all the other interrupts too?
+         * should we be flagging idle loop instead?
+         * or creating some task to be scheduled?
+         */
+
+        icp_native_set_xirr((0x00 << 24) | XICS_IPI);
+}
+
+static unsigned int icp_native_get_irq(void)
+{
+        unsigned int xirr = icp_native_get_xirr();
+        unsigned int vec = xirr & 0x00ffffff;
+        unsigned int irq;
+
+        if (vec == XICS_IRQ_SPURIOUS)
+                return NO_IRQ;
+
+        irq = irq_radix_revmap_lookup(xics_host, vec);
+        if (likely(irq != NO_IRQ)) {
+                xics_push_cppr(vec);
+                return irq;
+        }
+
+        /* We don't have a linux mapping, so have rtas mask it. */
+        xics_mask_unknown_vec(vec);
+
+        /* We might learn about it later, so EOI it */
+        icp_native_set_xirr(xirr);
+
+        return NO_IRQ;
+}
+
+#ifdef CONFIG_SMP
+
+static void icp_native_cause_ipi(int cpu, unsigned long data)
+{
+        icp_native_set_qirr(cpu, IPI_PRIORITY);
+}
+
+static irqreturn_t icp_native_ipi_action(int irq, void *dev_id)
+{
+        int cpu = smp_processor_id();
+
+        icp_native_set_qirr(cpu, 0xff);
+
+        return smp_ipi_demux();
+}
+
+#endif /* CONFIG_SMP */
+
+static int __init icp_native_map_one_cpu(int hw_id, unsigned long addr,
+                                         unsigned long size)
+{
+        char *rname;
+        int i, cpu = -1;
+
+        /* This may look gross but it's good enough for now, we don't quite
+         * have a hard -> linux processor id matching.
+         */
+        for_each_possible_cpu(i) {
+                if (!cpu_present(i))
+                        continue;
+                if (hw_id == get_hard_smp_processor_id(i)) {
+                        cpu = i;
+                        break;
+                }
+        }
+
+        /* Fail, skip that CPU. Don't print, it's normal, some XICS come up
+         * with way more entries in there than you have CPUs
+         */
+        if (cpu == -1)
+                return 0;
+
+        rname = kasprintf(GFP_KERNEL, "CPU %d [0x%x] Interrupt Presentation",
+                          cpu, hw_id);
+
+        if (!request_mem_region(addr, size, rname)) {
+                pr_warning("icp_native: Could not reserve ICP MMIO"
+                           " for CPU %d, interrupt server #0x%x\n",
+                           cpu, hw_id);
+                return -EBUSY;
+        }
+
+        icp_native_regs[cpu] = ioremap(addr, size);
+        if (!icp_native_regs[cpu]) {
+                pr_warning("icp_native: Failed ioremap for CPU %d, "
+                           "interrupt server #0x%x, addr %#lx\n",
+                           cpu, hw_id, addr);
+                release_mem_region(addr, size);
+                return -ENOMEM;
+        }
+        return 0;
+}
+
+static int __init icp_native_init_one_node(struct device_node *np,
+                                           unsigned int *indx)
+{
+        unsigned int ilen;
+        const u32 *ireg;
+        int i;
+        int reg_tuple_size;
+        int num_servers = 0;
+
+        /* This code does the theorically broken assumption that the interrupt
+         * server numbers are the same as the hard CPU numbers.
+         * This happens to be the case so far but we are playing with fire...
+         * should be fixed one of these days. -BenH.
+         */
+        ireg = of_get_property(np, "ibm,interrupt-server-ranges", &ilen);
+
+        /* Do that ever happen ? we'll know soon enough... but even good'old
+         * f80 does have that property ..
+         */
+        WARN_ON((ireg == NULL) || (ilen != 2*sizeof(u32)));
+
+        if (ireg) {
+                *indx = of_read_number(ireg, 1);
+                if (ilen >= 2*sizeof(u32))
+                        num_servers = of_read_number(ireg + 1, 1);
+        }
+
+        ireg = of_get_property(np, "reg", &ilen);
+        if (!ireg) {
+                pr_err("icp_native: Can't find interrupt reg property");
+                return -1;
+        }
+
+        reg_tuple_size = (of_n_addr_cells(np) + of_n_size_cells(np)) * 4;
+        if (((ilen % reg_tuple_size) != 0)
+            || (num_servers && (num_servers != (ilen / reg_tuple_size)))) {
+                pr_err("icp_native: ICP reg len (%d) != num servers (%d)",
+                       ilen / reg_tuple_size, num_servers);
+                return -1;
+        }
+
+        for (i = 0; i < (ilen / reg_tuple_size); i++) {
+                struct resource r;
+                int err;
+
+                err = of_address_to_resource(np, i, &r);
+                if (err) {
+                        pr_err("icp_native: Could not translate ICP MMIO"
+                               " for interrupt server 0x%x (%d)\n", *indx, err);
+                        return -1;
+                }
+
+                if (icp_native_map_one_cpu(*indx, r.start, r.end - r.start))
+                        return -1;
+
+                (*indx)++;
+        }
+        return 0;
+}
+
+static const struct icp_ops icp_native_ops = {
+        .get_irq        = icp_native_get_irq,
+        .eoi            = icp_native_eoi,
+        .set_priority   = icp_native_set_cpu_priority,
+        .teardown_cpu   = icp_native_teardown_cpu,
+        .flush_ipi      = icp_native_flush_ipi,
+#ifdef CONFIG_SMP
+        .ipi_action     = icp_native_ipi_action,
+        .cause_ipi      = icp_native_cause_ipi,
+#endif
+};
+
+int icp_native_init(void)
+{
+        struct device_node *np;
+        u32 indx = 0;
+        int found = 0;
+
+        for_each_compatible_node(np, NULL, "ibm,ppc-xicp")
+                if (icp_native_init_one_node(np, &indx) == 0)
+                        found = 1;
+        if (!found) {
+                for_each_node_by_type(np,
+                        "PowerPC-External-Interrupt-Presentation") {
+                                if (icp_native_init_one_node(np, &indx) == 0)
+                                        found = 1;
+                }
+        }
+
+        if (found == 0)
+                return -ENODEV;
+
+        icp_ops = &icp_native_ops;
+
+        return 0;
+}