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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/powerpc/sysdev/xics/icp-native.c
Initial import
Diffstat (limited to 'arch/powerpc/sysdev/xics/icp-native.c')
-rw-r--r--arch/powerpc/sysdev/xics/icp-native.c342
1 files changed, 342 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 000000000..2fc4cf1b7
--- /dev/null
+++ b/arch/powerpc/sysdev/xics/icp-native.c
@@ -0,0 +1,342 @@
+/*
+ * 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 <linux/module.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>
+#include <asm/kvm_ppc.h>
+#include <asm/dbell.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();
+ unsigned int xirr;
+
+ /* Handled an interrupt latched by KVM */
+ xirr = kvmppc_get_xics_latch();
+ if (xirr)
+ return xirr;
+
+ 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();
+}
+
+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_find_mapping(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)
+{
+ kvmppc_set_host_ipi(cpu, 1);
+#ifdef CONFIG_PPC_DOORBELL
+ if (cpu_has_feature(CPU_FTR_DBELL) &&
+ (cpumask_test_cpu(cpu, cpu_sibling_mask(smp_processor_id()))))
+ doorbell_cause_ipi(cpu, data);
+ else
+#endif
+ icp_native_set_qirr(cpu, IPI_PRIORITY);
+}
+
+/*
+ * Called when an interrupt is received on an off-line CPU to
+ * clear the interrupt, so that the CPU can go back to nap mode.
+ */
+void icp_native_flush_interrupt(void)
+{
+ unsigned int xirr = icp_native_get_xirr();
+ unsigned int vec = xirr & 0x00ffffff;
+
+ if (vec == XICS_IRQ_SPURIOUS)
+ return;
+ if (vec == XICS_IPI) {
+ /* Clear pending IPI */
+ int cpu = smp_processor_id();
+ kvmppc_set_host_ipi(cpu, 0);
+ icp_native_set_qirr(cpu, 0xff);
+ } else {
+ pr_err("XICS: hw interrupt 0x%x to offline cpu, disabling\n",
+ vec);
+ xics_mask_unknown_vec(vec);
+ }
+ /* EOI the interrupt */
+ icp_native_set_xirr(xirr);
+}
+
+void xics_wake_cpu(int cpu)
+{
+ icp_native_set_qirr(cpu, IPI_PRIORITY);
+}
+EXPORT_SYMBOL_GPL(xics_wake_cpu);
+
+static irqreturn_t icp_native_ipi_action(int irq, void *dev_id)
+{
+ int cpu = smp_processor_id();
+
+ kvmppc_set_host_ipi(cpu, 0);
+ 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);
+ kvmppc_set_xics_phys(cpu, addr);
+ 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 __be32 *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, resource_size(&r)))
+ 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 __init 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;
+}