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authorAshish Kalra <ashish.kalra@freescale.com>2011-05-19 08:54:28 -0500
committerKumar Gala <galak@kernel.crashing.org>2011-06-27 08:30:26 -0500
commit3a93261f70c7b92f84fb211b66f1d4e66c0b3dce (patch)
tree83c9ce69a93bc16621e957fcab4b54d60a1d5678 /arch/powerpc/sysdev/ehv_pic.c
parentbd497fc9782769d5bce58fbf468eabfce9e98ce0 (diff)
powerpc: introduce the ePAPR embedded hypervisor vmpic driver
The Freescale ePAPR reference hypervisor provides interrupt controller services via a hypercall interface, instead of emulating the MPIC controller. This is called the VMPIC. The ePAPR "virtual interrupt controller" provides interrupt controller services for external interrupts. External interrupts received by a partition can come from two sources: - Hardware interrupts - hardware interrupts come from external interrupt lines or on-chip I/O devices. - Virtual interrupts - virtual interrupts are generated by the hypervisor as part of some hypervisor service or hypervisor-created virtual device. Both types of interrupts are processed using the same programming model and same set of hypercalls. Signed-off-by: Ashish Kalra <ashish.kalra@freescale.com> Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/sysdev/ehv_pic.c')
-rw-r--r--arch/powerpc/sysdev/ehv_pic.c302
1 files changed, 302 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/ehv_pic.c b/arch/powerpc/sysdev/ehv_pic.c
new file mode 100644
index 00000000000..af1a5df46b3
--- /dev/null
+++ b/arch/powerpc/sysdev/ehv_pic.c
@@ -0,0 +1,302 @@
+/*
+ * Driver for ePAPR Embedded Hypervisor PIC
+ *
+ * Copyright 2008-2011 Freescale Semiconductor, Inc.
+ *
+ * Author: Ashish Kalra <ashish.kalra@freescale.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/of.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+#include <asm/ehv_pic.h>
+#include <asm/fsl_hcalls.h>
+
+#include "../../../kernel/irq/settings.h"
+
+static struct ehv_pic *global_ehv_pic;
+static DEFINE_SPINLOCK(ehv_pic_lock);
+
+static u32 hwirq_intspec[NR_EHV_PIC_INTS];
+static u32 __iomem *mpic_percpu_base_vaddr;
+
+#define IRQ_TYPE_MPIC_DIRECT 4
+#define MPIC_EOI 0x00B0
+
+/*
+ * Linux descriptor level callbacks
+ */
+
+void ehv_pic_unmask_irq(struct irq_data *d)
+{
+ unsigned int src = virq_to_hw(d->irq);
+
+ ev_int_set_mask(src, 0);
+}
+
+void ehv_pic_mask_irq(struct irq_data *d)
+{
+ unsigned int src = virq_to_hw(d->irq);
+
+ ev_int_set_mask(src, 1);
+}
+
+void ehv_pic_end_irq(struct irq_data *d)
+{
+ unsigned int src = virq_to_hw(d->irq);
+
+ ev_int_eoi(src);
+}
+
+void ehv_pic_direct_end_irq(struct irq_data *d)
+{
+ out_be32(mpic_percpu_base_vaddr + MPIC_EOI / 4, 0);
+}
+
+int ehv_pic_set_affinity(struct irq_data *d, const struct cpumask *dest,
+ bool force)
+{
+ unsigned int src = virq_to_hw(d->irq);
+ unsigned int config, prio, cpu_dest;
+ int cpuid = irq_choose_cpu(dest);
+ unsigned long flags;
+
+ spin_lock_irqsave(&ehv_pic_lock, flags);
+ ev_int_get_config(src, &config, &prio, &cpu_dest);
+ ev_int_set_config(src, config, prio, cpuid);
+ spin_unlock_irqrestore(&ehv_pic_lock, flags);
+
+ return 0;
+}
+
+static unsigned int ehv_pic_type_to_vecpri(unsigned int type)
+{
+ /* Now convert sense value */
+
+ switch (type & IRQ_TYPE_SENSE_MASK) {
+ case IRQ_TYPE_EDGE_RISING:
+ return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
+ EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);
+
+ case IRQ_TYPE_EDGE_FALLING:
+ case IRQ_TYPE_EDGE_BOTH:
+ return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
+ EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);
+
+ case IRQ_TYPE_LEVEL_HIGH:
+ return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
+ EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);
+
+ case IRQ_TYPE_LEVEL_LOW:
+ default:
+ return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
+ EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);
+ }
+}
+
+int ehv_pic_set_irq_type(struct irq_data *d, unsigned int flow_type)
+{
+ unsigned int src = virq_to_hw(d->irq);
+ struct irq_desc *desc = irq_to_desc(d->irq);
+ unsigned int vecpri, vold, vnew, prio, cpu_dest;
+ unsigned long flags;
+
+ if (flow_type == IRQ_TYPE_NONE)
+ flow_type = IRQ_TYPE_LEVEL_LOW;
+
+ irq_settings_clr_level(desc);
+ irq_settings_set_trigger_mask(desc, flow_type);
+ if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
+ irq_settings_set_level(desc);
+
+ vecpri = ehv_pic_type_to_vecpri(flow_type);
+
+ spin_lock_irqsave(&ehv_pic_lock, flags);
+ ev_int_get_config(src, &vold, &prio, &cpu_dest);
+ vnew = vold & ~(EHV_PIC_INFO(VECPRI_POLARITY_MASK) |
+ EHV_PIC_INFO(VECPRI_SENSE_MASK));
+ vnew |= vecpri;
+
+ /*
+ * TODO : Add specific interface call for platform to set
+ * individual interrupt priorities.
+ * platform currently using static/default priority for all ints
+ */
+
+ prio = 8;
+
+ ev_int_set_config(src, vecpri, prio, cpu_dest);
+
+ spin_unlock_irqrestore(&ehv_pic_lock, flags);
+ return 0;
+}
+
+static struct irq_chip ehv_pic_irq_chip = {
+ .irq_mask = ehv_pic_mask_irq,
+ .irq_unmask = ehv_pic_unmask_irq,
+ .irq_eoi = ehv_pic_end_irq,
+ .irq_set_type = ehv_pic_set_irq_type,
+};
+
+static struct irq_chip ehv_pic_direct_eoi_irq_chip = {
+ .irq_mask = ehv_pic_mask_irq,
+ .irq_unmask = ehv_pic_unmask_irq,
+ .irq_eoi = ehv_pic_direct_end_irq,
+ .irq_set_type = ehv_pic_set_irq_type,
+};
+
+/* Return an interrupt vector or NO_IRQ if no interrupt is pending. */
+unsigned int ehv_pic_get_irq(void)
+{
+ int irq;
+
+ BUG_ON(global_ehv_pic == NULL);
+
+ if (global_ehv_pic->coreint_flag)
+ irq = mfspr(SPRN_EPR); /* if core int mode */
+ else
+ ev_int_iack(0, &irq); /* legacy mode */
+
+ if (irq == 0xFFFF) /* 0xFFFF --> no irq is pending */
+ return NO_IRQ;
+
+ /*
+ * this will also setup revmap[] in the slow path for the first
+ * time, next calls will always use fast path by indexing revmap
+ */
+ return irq_linear_revmap(global_ehv_pic->irqhost, irq);
+}
+
+static int ehv_pic_host_match(struct irq_host *h, struct device_node *node)
+{
+ /* Exact match, unless ehv_pic node is NULL */
+ return h->of_node == NULL || h->of_node == node;
+}
+
+static int ehv_pic_host_map(struct irq_host *h, unsigned int virq,
+ irq_hw_number_t hw)
+{
+ struct ehv_pic *ehv_pic = h->host_data;
+ struct irq_chip *chip;
+
+ /* Default chip */
+ chip = &ehv_pic->hc_irq;
+
+ if (mpic_percpu_base_vaddr)
+ if (hwirq_intspec[hw] & IRQ_TYPE_MPIC_DIRECT)
+ chip = &ehv_pic_direct_eoi_irq_chip;
+
+ irq_set_chip_data(virq, chip);
+ /*
+ * using handle_fasteoi_irq as our irq handler, this will
+ * only call the eoi callback and suitable for the MPIC
+ * controller which set ISR/IPR automatically and clear the
+ * highest priority active interrupt in ISR/IPR when we do
+ * a specific eoi
+ */
+ irq_set_chip_and_handler(virq, chip, handle_fasteoi_irq);
+
+ /* Set default irq type */
+ irq_set_irq_type(virq, IRQ_TYPE_NONE);
+
+ return 0;
+}
+
+static int ehv_pic_host_xlate(struct irq_host *h, struct device_node *ct,
+ const u32 *intspec, unsigned int intsize,
+ irq_hw_number_t *out_hwirq, unsigned int *out_flags)
+
+{
+ /*
+ * interrupt sense values coming from the guest device tree
+ * interrupt specifiers can have four possible sense and
+ * level encoding information and they need to
+ * be translated between firmware type & linux type.
+ */
+
+ static unsigned char map_of_senses_to_linux_irqtype[4] = {
+ IRQ_TYPE_EDGE_FALLING,
+ IRQ_TYPE_EDGE_RISING,
+ IRQ_TYPE_LEVEL_LOW,
+ IRQ_TYPE_LEVEL_HIGH,
+ };
+
+ *out_hwirq = intspec[0];
+ if (intsize > 1) {
+ hwirq_intspec[intspec[0]] = intspec[1];
+ *out_flags = map_of_senses_to_linux_irqtype[intspec[1] &
+ ~IRQ_TYPE_MPIC_DIRECT];
+ } else {
+ *out_flags = IRQ_TYPE_NONE;
+ }
+
+ return 0;
+}
+
+static struct irq_host_ops ehv_pic_host_ops = {
+ .match = ehv_pic_host_match,
+ .map = ehv_pic_host_map,
+ .xlate = ehv_pic_host_xlate,
+};
+
+void __init ehv_pic_init(void)
+{
+ struct device_node *np, *np2;
+ struct ehv_pic *ehv_pic;
+ int coreint_flag = 1;
+
+ np = of_find_compatible_node(NULL, NULL, "epapr,hv-pic");
+ if (!np) {
+ pr_err("ehv_pic_init: could not find epapr,hv-pic node\n");
+ return;
+ }
+
+ if (!of_find_property(np, "has-external-proxy", NULL))
+ coreint_flag = 0;
+
+ ehv_pic = kzalloc(sizeof(struct ehv_pic), GFP_KERNEL);
+ if (!ehv_pic) {
+ of_node_put(np);
+ return;
+ }
+
+ ehv_pic->irqhost = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
+ NR_EHV_PIC_INTS, &ehv_pic_host_ops, 0);
+
+ if (!ehv_pic->irqhost) {
+ of_node_put(np);
+ return;
+ }
+
+ np2 = of_find_compatible_node(NULL, NULL, "fsl,hv-mpic-per-cpu");
+ if (np2) {
+ mpic_percpu_base_vaddr = of_iomap(np2, 0);
+ if (!mpic_percpu_base_vaddr)
+ pr_err("ehv_pic_init: of_iomap failed\n");
+
+ of_node_put(np2);
+ }
+
+ ehv_pic->irqhost->host_data = ehv_pic;
+ ehv_pic->hc_irq = ehv_pic_irq_chip;
+ ehv_pic->hc_irq.irq_set_affinity = ehv_pic_set_affinity;
+ ehv_pic->coreint_flag = coreint_flag;
+
+ global_ehv_pic = ehv_pic;
+ irq_set_default_host(global_ehv_pic->irqhost);
+}