--- /dev/null
+/*
+ * Meta External interrupt code.
+ *
+ * Copyright (C) 2005-2012 Imagination Technologies Ltd.
+ *
+ * External interrupts on Meta are configured at two-levels, in the CPU core and
+ * in the external trigger block. Interrupts from SoC peripherals are
+ * multiplexed onto a single Meta CPU "trigger" - traditionally it has always
+ * been trigger 2 (TR2). For info on how de-multiplexing happens check out
+ * meta_intc_irq_demux().
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irqchip/metag-ext.h>
+#include <linux/irqdomain.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/syscore_ops.h>
+
+#include <asm/irq.h>
+#include <asm/hwthread.h>
+
+#define HWSTAT_STRIDE 8
+#define HWVEC_BLK_STRIDE 0x1000
+
+/**
+ * struct meta_intc_priv - private meta external interrupt data
+ * @nr_banks: Number of interrupt banks
+ * @domain: IRQ domain for all banks of external IRQs
+ * @unmasked: Record of unmasked IRQs
+ * @levels_altered: Record of altered level bits
+ */
+struct meta_intc_priv {
+ unsigned int nr_banks;
+ struct irq_domain *domain;
+
+ unsigned long unmasked[4];
+
+#ifdef CONFIG_METAG_SUSPEND_MEM
+ unsigned long levels_altered[4];
+#endif
+};
+
+/* Private data for the one and only external interrupt controller */
+static struct meta_intc_priv meta_intc_priv;
+
+/**
+ * meta_intc_offset() - Get the offset into the bank of a hardware IRQ number
+ * @hw: Hardware IRQ number (within external trigger block)
+ *
+ * Returns: Bit offset into the IRQ's bank registers
+ */
+static unsigned int meta_intc_offset(irq_hw_number_t hw)
+{
+ return hw & 0x1f;
+}
+
+/**
+ * meta_intc_bank() - Get the bank number of a hardware IRQ number
+ * @hw: Hardware IRQ number (within external trigger block)
+ *
+ * Returns: Bank number indicating which register the IRQ's bits are
+ */
+static unsigned int meta_intc_bank(irq_hw_number_t hw)
+{
+ return hw >> 5;
+}
+
+/**
+ * meta_intc_stat_addr() - Get the address of a HWSTATEXT register
+ * @hw: Hardware IRQ number (within external trigger block)
+ *
+ * Returns: Address of a HWSTATEXT register containing the status bit for
+ * the specified hardware IRQ number
+ */
+static void __iomem *meta_intc_stat_addr(irq_hw_number_t hw)
+{
+ return (void __iomem *)(HWSTATEXT +
+ HWSTAT_STRIDE * meta_intc_bank(hw));
+}
+
+/**
+ * meta_intc_level_addr() - Get the address of a HWLEVELEXT register
+ * @hw: Hardware IRQ number (within external trigger block)
+ *
+ * Returns: Address of a HWLEVELEXT register containing the sense bit for
+ * the specified hardware IRQ number
+ */
+static void __iomem *meta_intc_level_addr(irq_hw_number_t hw)
+{
+ return (void __iomem *)(HWLEVELEXT +
+ HWSTAT_STRIDE * meta_intc_bank(hw));
+}
+
+/**
+ * meta_intc_mask_addr() - Get the address of a HWMASKEXT register
+ * @hw: Hardware IRQ number (within external trigger block)
+ *
+ * Returns: Address of a HWMASKEXT register containing the mask bit for the
+ * specified hardware IRQ number
+ */
+static void __iomem *meta_intc_mask_addr(irq_hw_number_t hw)
+{
+ return (void __iomem *)(HWMASKEXT +
+ HWSTAT_STRIDE * meta_intc_bank(hw));
+}
+
+/**
+ * meta_intc_vec_addr() - Get the vector address of a hardware interrupt
+ * @hw: Hardware IRQ number (within external trigger block)
+ *
+ * Returns: Address of a HWVECEXT register controlling the core trigger to
+ * vector the IRQ onto
+ */
+static inline void __iomem *meta_intc_vec_addr(irq_hw_number_t hw)
+{
+ return (void __iomem *)(HWVEC0EXT +
+ HWVEC_BLK_STRIDE * meta_intc_bank(hw) +
+ HWVECnEXT_STRIDE * meta_intc_offset(hw));
+}
+
+/**
+ * meta_intc_startup_irq() - set up an external irq
+ * @data: data for the external irq to start up
+ *
+ * Multiplex interrupts for irq onto TR2. Clear any pending interrupts and
+ * unmask irq, both using the appropriate callbacks.
+ */
+static unsigned int meta_intc_startup_irq(struct irq_data *data)
+{
+ irq_hw_number_t hw = data->hwirq;
+ void __iomem *vec_addr = meta_intc_vec_addr(hw);
+ int thread = hard_processor_id();
+
+ /* Perform any necessary acking. */
+ if (data->chip->irq_ack)
+ data->chip->irq_ack(data);
+
+ /* Wire up this interrupt to the core with HWVECxEXT. */
+ metag_out32(TBI_TRIG_VEC(TBID_SIGNUM_TR2(thread)), vec_addr);
+
+ /* Perform any necessary unmasking. */
+ data->chip->irq_unmask(data);
+
+ return 0;
+}
+
+/**
+ * meta_intc_shutdown_irq() - turn off an external irq
+ * @data: data for the external irq to turn off
+ *
+ * Mask irq using the appropriate callback and stop muxing it onto TR2.
+ */
+static void meta_intc_shutdown_irq(struct irq_data *data)
+{
+ irq_hw_number_t hw = data->hwirq;
+ void __iomem *vec_addr = meta_intc_vec_addr(hw);
+
+ /* Mask the IRQ */
+ data->chip->irq_mask(data);
+
+ /*
+ * Disable the IRQ at the core by removing the interrupt from
+ * the HW vector mapping.
+ */
+ metag_out32(0, vec_addr);
+}
+
+/**
+ * meta_intc_ack_irq() - acknowledge an external irq
+ * @data: data for the external irq to ack
+ *
+ * Clear down an edge interrupt in the status register.
+ */
+static void meta_intc_ack_irq(struct irq_data *data)
+{
+ irq_hw_number_t hw = data->hwirq;
+ unsigned int bit = 1 << meta_intc_offset(hw);
+ void __iomem *stat_addr = meta_intc_stat_addr(hw);
+
+ /* Ack the int, if it is still 'on'.
+ * NOTE - this only works for edge triggered interrupts.
+ */
+ if (metag_in32(stat_addr) & bit)
+ metag_out32(bit, stat_addr);
+}
+
+/**
+ * record_irq_is_masked() - record the IRQ masked so it doesn't get handled
+ * @data: data for the external irq to record
+ *
+ * This should get called whenever an external IRQ is masked (by whichever
+ * callback is used). It records the IRQ masked so that it doesn't get handled
+ * if it still shows up in the status register.
+ */
+static void record_irq_is_masked(struct irq_data *data)
+{
+ struct meta_intc_priv *priv = &meta_intc_priv;
+ irq_hw_number_t hw = data->hwirq;
+
+ clear_bit(meta_intc_offset(hw), &priv->unmasked[meta_intc_bank(hw)]);
+}
+
+/**
+ * record_irq_is_unmasked() - record the IRQ unmasked so it can be handled
+ * @data: data for the external irq to record
+ *
+ * This should get called whenever an external IRQ is unmasked (by whichever
+ * callback is used). It records the IRQ unmasked so that it gets handled if it
+ * shows up in the status register.
+ */
+static void record_irq_is_unmasked(struct irq_data *data)
+{
+ struct meta_intc_priv *priv = &meta_intc_priv;
+ irq_hw_number_t hw = data->hwirq;
+
+ set_bit(meta_intc_offset(hw), &priv->unmasked[meta_intc_bank(hw)]);
+}
+
+/*
+ * For use by wrapper IRQ drivers
+ */
+
+/**
+ * meta_intc_mask_irq_simple() - minimal mask used by wrapper IRQ drivers
+ * @data: data for the external irq being masked
+ *
+ * This should be called by any wrapper IRQ driver mask functions. it doesn't do
+ * any masking but records the IRQ as masked so that the core code knows the
+ * mask has taken place. It is the callers responsibility to ensure that the IRQ
+ * won't trigger an interrupt to the core.
+ */
+void meta_intc_mask_irq_simple(struct irq_data *data)
+{
+ record_irq_is_masked(data);
+}
+
+/**
+ * meta_intc_unmask_irq_simple() - minimal unmask used by wrapper IRQ drivers
+ * @data: data for the external irq being unmasked
+ *
+ * This should be called by any wrapper IRQ driver unmask functions. it doesn't
+ * do any unmasking but records the IRQ as unmasked so that the core code knows
+ * the unmask has taken place. It is the callers responsibility to ensure that
+ * the IRQ can now trigger an interrupt to the core.
+ */
+void meta_intc_unmask_irq_simple(struct irq_data *data)
+{
+ record_irq_is_unmasked(data);
+}
+
+
+/**
+ * meta_intc_mask_irq() - mask an external irq using HWMASKEXT
+ * @data: data for the external irq to mask
+ *
+ * This is a default implementation of a mask function which makes use of the
+ * HWMASKEXT registers available in newer versions.
+ *
+ * Earlier versions without these registers should use SoC level IRQ masking
+ * which call the meta_intc_*_simple() functions above, or if that isn't
+ * available should use the fallback meta_intc_*_nomask() functions below.
+ */
+static void meta_intc_mask_irq(struct irq_data *data)
+{
+ irq_hw_number_t hw = data->hwirq;
+ unsigned int bit = 1 << meta_intc_offset(hw);
+ void __iomem *mask_addr = meta_intc_mask_addr(hw);
+ unsigned long flags;
+
+ record_irq_is_masked(data);
+
+ /* update the interrupt mask */
+ __global_lock2(flags);
+ metag_out32(metag_in32(mask_addr) & ~bit, mask_addr);
+ __global_unlock2(flags);
+}
+
+/**
+ * meta_intc_unmask_irq() - unmask an external irq using HWMASKEXT
+ * @data: data for the external irq to unmask
+ *
+ * This is a default implementation of an unmask function which makes use of the
+ * HWMASKEXT registers available on new versions. It should be paired with
+ * meta_intc_mask_irq() above.
+ */
+static void meta_intc_unmask_irq(struct irq_data *data)
+{
+ irq_hw_number_t hw = data->hwirq;
+ unsigned int bit = 1 << meta_intc_offset(hw);
+ void __iomem *mask_addr = meta_intc_mask_addr(hw);
+ unsigned long flags;
+
+ record_irq_is_unmasked(data);
+
+ /* update the interrupt mask */
+ __global_lock2(flags);
+ metag_out32(metag_in32(mask_addr) | bit, mask_addr);
+ __global_unlock2(flags);
+}
+
+/**
+ * meta_intc_mask_irq_nomask() - mask an external irq by unvectoring
+ * @data: data for the external irq to mask
+ *
+ * This is the version of the mask function for older versions which don't have
+ * HWMASKEXT registers, or a SoC level means of masking IRQs. Instead the IRQ is
+ * unvectored from the core and retriggered if necessary later.
+ */
+static void meta_intc_mask_irq_nomask(struct irq_data *data)
+{
+ irq_hw_number_t hw = data->hwirq;
+ void __iomem *vec_addr = meta_intc_vec_addr(hw);
+
+ record_irq_is_masked(data);
+
+ /* there is no interrupt mask, so unvector the interrupt */
+ metag_out32(0, vec_addr);
+}
+
+/**
+ * meta_intc_unmask_edge_irq_nomask() - unmask an edge irq by revectoring
+ * @data: data for the external irq to unmask
+ *
+ * This is the version of the unmask function for older versions which don't
+ * have HWMASKEXT registers, or a SoC level means of masking IRQs. Instead the
+ * IRQ is revectored back to the core and retriggered if necessary.
+ *
+ * The retriggering done by this function is specific to edge interrupts.
+ */
+static void meta_intc_unmask_edge_irq_nomask(struct irq_data *data)
+{
+ irq_hw_number_t hw = data->hwirq;
+ unsigned int bit = 1 << meta_intc_offset(hw);
+ void __iomem *stat_addr = meta_intc_stat_addr(hw);
+ void __iomem *vec_addr = meta_intc_vec_addr(hw);
+ unsigned int thread = hard_processor_id();
+
+ record_irq_is_unmasked(data);
+
+ /* there is no interrupt mask, so revector the interrupt */
+ metag_out32(TBI_TRIG_VEC(TBID_SIGNUM_TR2(thread)), vec_addr);
+
+ /*
+ * Re-trigger interrupt
+ *
+ * Writing a 1 toggles, and a 0->1 transition triggers. We only
+ * retrigger if the status bit is already set, which means we
+ * need to clear it first. Retriggering is fundamentally racy
+ * because if the interrupt fires again after we clear it we
+ * could end up clearing it again and the interrupt handler
+ * thinking it hasn't fired. Therefore we need to keep trying to
+ * retrigger until the bit is set.
+ */
+ if (metag_in32(stat_addr) & bit) {
+ metag_out32(bit, stat_addr);
+ while (!(metag_in32(stat_addr) & bit))
+ metag_out32(bit, stat_addr);
+ }
+}
+
+/**
+ * meta_intc_unmask_level_irq_nomask() - unmask a level irq by revectoring
+ * @data: data for the external irq to unmask
+ *
+ * This is the version of the unmask function for older versions which don't
+ * have HWMASKEXT registers, or a SoC level means of masking IRQs. Instead the
+ * IRQ is revectored back to the core and retriggered if necessary.
+ *
+ * The retriggering done by this function is specific to level interrupts.
+ */
+static void meta_intc_unmask_level_irq_nomask(struct irq_data *data)
+{
+ irq_hw_number_t hw = data->hwirq;
+ unsigned int bit = 1 << meta_intc_offset(hw);
+ void __iomem *stat_addr = meta_intc_stat_addr(hw);
+ void __iomem *vec_addr = meta_intc_vec_addr(hw);
+ unsigned int thread = hard_processor_id();
+
+ record_irq_is_unmasked(data);
+
+ /* there is no interrupt mask, so revector the interrupt */
+ metag_out32(TBI_TRIG_VEC(TBID_SIGNUM_TR2(thread)), vec_addr);
+
+ /* Re-trigger interrupt */
+ /* Writing a 1 triggers interrupt */
+ if (metag_in32(stat_addr) & bit)
+ metag_out32(bit, stat_addr);
+}
+
+/**
+ * meta_intc_irq_set_type() - set the type of an external irq
+ * @data: data for the external irq to set the type of
+ * @flow_type: new irq flow type
+ *
+ * Set the flow type of an external interrupt. This updates the irq chip and irq
+ * handler depending on whether the irq is edge or level sensitive (the polarity
+ * is ignored), and also sets up the bit in HWLEVELEXT so the hardware knows
+ * when to trigger.
+ */
+static int meta_intc_irq_set_type(struct irq_data *data, unsigned int flow_type)
+{
+#ifdef CONFIG_METAG_SUSPEND_MEM
+ struct meta_intc_priv *priv = &meta_intc_priv;
+#endif
+ unsigned int irq = data->irq;
+ irq_hw_number_t hw = data->hwirq;
+ unsigned int bit = 1 << meta_intc_offset(hw);
+ void __iomem *level_addr = meta_intc_level_addr(hw);
+ unsigned long flags;
+ unsigned int level;
+
+ /* update the chip/handler */
+ if (flow_type & IRQ_TYPE_LEVEL_MASK)
+ __irq_set_chip_handler_name_locked(irq, &meta_intc_level_chip,
+ handle_level_irq, NULL);
+ else
+ __irq_set_chip_handler_name_locked(irq, &meta_intc_edge_chip,
+ handle_edge_irq, NULL);
+
+ /* and clear/set the bit in HWLEVELEXT */
+ __global_lock2(flags);
+ level = metag_in32(level_addr);
+ if (flow_type & IRQ_TYPE_LEVEL_MASK)
+ level |= bit;
+ else
+ level &= ~bit;
+ metag_out32(level, level_addr);
+#ifdef CONFIG_METAG_SUSPEND_MEM
+ priv->levels_altered[meta_intc_bank(hw)] |= bit;
+#endif
+ __global_unlock2(flags);
+
+ return 0;
+}
+
+/**
+ * meta_intc_irq_demux() - external irq de-multiplexer
+ * @irq: the virtual interrupt number
+ * @desc: the interrupt description structure for this irq
+ *
+ * The cpu receives an interrupt on TR2 when a SoC interrupt has occurred. It is
+ * this function's job to demux this irq and figure out exactly which external
+ * irq needs servicing.
+ *
+ * Whilst using TR2 to detect external interrupts is a software convention it is
+ * (hopefully) unlikely to change.
+ */
+static void meta_intc_irq_demux(unsigned int irq, struct irq_desc *desc)
+{
+ struct meta_intc_priv *priv = &meta_intc_priv;
+ irq_hw_number_t hw;
+ unsigned int bank, irq_no, status;
+ void __iomem *stat_addr = meta_intc_stat_addr(0);
+
+ /*
+ * Locate which interrupt has caused our handler to run.
+ */
+ for (bank = 0; bank < priv->nr_banks; ++bank) {
+ /* Which interrupts are currently pending in this bank? */
+recalculate:
+ status = metag_in32(stat_addr) & priv->unmasked[bank];
+
+ for (hw = bank*32; status; status >>= 1, ++hw) {
+ if (status & 0x1) {
+ /*
+ * Map the hardware IRQ number to a virtual
+ * Linux IRQ number.
+ */
+ irq_no = irq_linear_revmap(priv->domain, hw);
+
+ /*
+ * Only fire off external interrupts that are
+ * registered to be handled by the kernel.
+ * Other external interrupts are probably being
+ * handled by other Meta hardware threads.
+ */
+ generic_handle_irq(irq_no);
+
+ /*
+ * The handler may have re-enabled interrupts
+ * which could have caused a nested invocation
+ * of this code and make the copy of the
+ * status register we are using invalid.
+ */
+ goto recalculate;
+ }
+ }
+ stat_addr += HWSTAT_STRIDE;
+ }
+}
+
+#ifdef CONFIG_SMP
+/**
+ * meta_intc_set_affinity() - set the affinity for an interrupt
+ * @data: data for the external irq to set the affinity of
+ * @cpumask: cpu mask representing cpus which can handle the interrupt
+ * @force: whether to force (ignored)
+ *
+ * Revector the specified external irq onto a specific cpu's TR2 trigger, so
+ * that that cpu tends to be the one who handles it.
+ */
+static int meta_intc_set_affinity(struct irq_data *data,
+ const struct cpumask *cpumask, bool force)
+{
+ irq_hw_number_t hw = data->hwirq;
+ void __iomem *vec_addr = meta_intc_vec_addr(hw);
+ unsigned int cpu, thread;
+
+ /*
+ * Wire up this interrupt from HWVECxEXT to the Meta core.
+ *
+ * Note that we can't wire up HWVECxEXT to interrupt more than
+ * one cpu (the interrupt code doesn't support it), so we just
+ * pick the first cpu we find in 'cpumask'.
+ */
+ cpu = cpumask_any(cpumask);
+ thread = cpu_2_hwthread_id[cpu];
+
+ metag_out32(TBI_TRIG_VEC(TBID_SIGNUM_TR2(thread)), vec_addr);
+
+ return 0;
+}
+#else
+#define meta_intc_set_affinity NULL
+#endif
+
+#ifdef CONFIG_PM_SLEEP
+#define META_INTC_CHIP_FLAGS (IRQCHIP_MASK_ON_SUSPEND \
+ | IRQCHIP_SKIP_SET_WAKE)
+#else
+#define META_INTC_CHIP_FLAGS 0
+#endif
+
+/* public edge/level irq chips which SoCs can override */
+
+struct irq_chip meta_intc_edge_chip = {
+ .irq_startup = meta_intc_startup_irq,
+ .irq_shutdown = meta_intc_shutdown_irq,
+ .irq_ack = meta_intc_ack_irq,
+ .irq_mask = meta_intc_mask_irq,
+ .irq_unmask = meta_intc_unmask_irq,
+ .irq_set_type = meta_intc_irq_set_type,
+ .irq_set_affinity = meta_intc_set_affinity,
+ .flags = META_INTC_CHIP_FLAGS,
+};
+
+struct irq_chip meta_intc_level_chip = {
+ .irq_startup = meta_intc_startup_irq,
+ .irq_shutdown = meta_intc_shutdown_irq,
+ .irq_set_type = meta_intc_irq_set_type,
+ .irq_mask = meta_intc_mask_irq,
+ .irq_unmask = meta_intc_unmask_irq,
+ .irq_set_affinity = meta_intc_set_affinity,
+ .flags = META_INTC_CHIP_FLAGS,
+};
+
+/**
+ * meta_intc_map() - map an external irq
+ * @d: irq domain of external trigger block
+ * @irq: virtual irq number
+ * @hw: hardware irq number within external trigger block
+ *
+ * This sets up a virtual irq for a specified hardware interrupt. The irq chip
+ * and handler is configured, using the HWLEVELEXT registers to determine
+ * edge/level flow type. These registers will have been set when the irq type is
+ * set (or set to a default at init time).
+ */
+static int meta_intc_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hw)
+{
+ unsigned int bit = 1 << meta_intc_offset(hw);
+ void __iomem *level_addr = meta_intc_level_addr(hw);
+
+ /* Go by the current sense in the HWLEVELEXT register */
+ if (metag_in32(level_addr) & bit)
+ irq_set_chip_and_handler(irq, &meta_intc_level_chip,
+ handle_level_irq);
+ else
+ irq_set_chip_and_handler(irq, &meta_intc_edge_chip,
+ handle_edge_irq);
+ return 0;
+}
+
+static const struct irq_domain_ops meta_intc_domain_ops = {
+ .map = meta_intc_map,
+ .xlate = irq_domain_xlate_twocell,
+};
+
+#ifdef CONFIG_METAG_SUSPEND_MEM
+
+/**
+ * struct meta_intc_context - suspend context
+ * @levels: State of HWLEVELEXT registers
+ * @masks: State of HWMASKEXT registers
+ * @vectors: State of HWVECEXT registers
+ * @txvecint: State of TxVECINT registers
+ *
+ * This structure stores the IRQ state across suspend.
+ */
+struct meta_intc_context {
+ u32 levels[4];
+ u32 masks[4];
+ u8 vectors[4*32];
+
+ u8 txvecint[4][4];
+};
+
+/* suspend context */
+static struct meta_intc_context *meta_intc_context;
+
+/**
+ * meta_intc_suspend() - store irq state
+ *
+ * To avoid interfering with other threads we only save the IRQ state of IRQs in
+ * use by Linux.
+ */
+static int meta_intc_suspend(void)
+{
+ struct meta_intc_priv *priv = &meta_intc_priv;
+ int i, j;
+ irq_hw_number_t hw;
+ unsigned int bank;
+ unsigned long flags;
+ struct meta_intc_context *context;
+ void __iomem *level_addr, *mask_addr, *vec_addr;
+ u32 mask, bit;
+
+ context = kzalloc(sizeof(*context), GFP_ATOMIC);
+ if (!context)
+ return -ENOMEM;
+
+ hw = 0;
+ level_addr = meta_intc_level_addr(0);
+ mask_addr = meta_intc_mask_addr(0);
+ for (bank = 0; bank < priv->nr_banks; ++bank) {
+ vec_addr = meta_intc_vec_addr(hw);
+
+ /* create mask of interrupts in use */
+ mask = 0;
+ for (bit = 1; bit; bit <<= 1) {
+ i = irq_linear_revmap(priv->domain, hw);
+ /* save mapped irqs which are enabled or have actions */
+ if (i && (!irqd_irq_disabled(irq_get_irq_data(i)) ||
+ irq_has_action(i))) {
+ mask |= bit;
+
+ /* save trigger vector */
+ context->vectors[hw] = metag_in32(vec_addr);
+ }
+
+ ++hw;
+ vec_addr += HWVECnEXT_STRIDE;
+ }
+
+ /* save level state if any IRQ levels altered */
+ if (priv->levels_altered[bank])
+ context->levels[bank] = metag_in32(level_addr);
+ /* save mask state if any IRQs in use */
+ if (mask)
+ context->masks[bank] = metag_in32(mask_addr);
+
+ level_addr += HWSTAT_STRIDE;
+ mask_addr += HWSTAT_STRIDE;
+ }
+
+ /* save trigger matrixing */
+ __global_lock2(flags);
+ for (i = 0; i < 4; ++i)
+ for (j = 0; j < 4; ++j)
+ context->txvecint[i][j] = metag_in32(T0VECINT_BHALT +
+ TnVECINT_STRIDE*i +
+ 8*j);
+ __global_unlock2(flags);
+
+ meta_intc_context = context;
+ return 0;
+}
+
+/**
+ * meta_intc_resume() - restore saved irq state
+ *
+ * Restore the saved IRQ state and drop it.
+ */
+static void meta_intc_resume(void)
+{
+ struct meta_intc_priv *priv = &meta_intc_priv;
+ int i, j;
+ irq_hw_number_t hw;
+ unsigned int bank;
+ unsigned long flags;
+ struct meta_intc_context *context = meta_intc_context;
+ void __iomem *level_addr, *mask_addr, *vec_addr;
+ u32 mask, bit, tmp;
+
+ meta_intc_context = NULL;
+
+ hw = 0;
+ level_addr = meta_intc_level_addr(0);
+ mask_addr = meta_intc_mask_addr(0);
+ for (bank = 0; bank < priv->nr_banks; ++bank) {
+ vec_addr = meta_intc_vec_addr(hw);
+
+ /* create mask of interrupts in use */
+ mask = 0;
+ for (bit = 1; bit; bit <<= 1) {
+ i = irq_linear_revmap(priv->domain, hw);
+ /* restore mapped irqs, enabled or with actions */
+ if (i && (!irqd_irq_disabled(irq_get_irq_data(i)) ||
+ irq_has_action(i))) {
+ mask |= bit;
+
+ /* restore trigger vector */
+ metag_out32(context->vectors[hw], vec_addr);
+ }
+
+ ++hw;
+ vec_addr += HWVECnEXT_STRIDE;
+ }
+
+ if (mask) {
+ /* restore mask state */
+ __global_lock2(flags);
+ tmp = metag_in32(mask_addr);
+ tmp = (tmp & ~mask) | (context->masks[bank] & mask);
+ metag_out32(tmp, mask_addr);
+ __global_unlock2(flags);
+ }
+
+ mask = priv->levels_altered[bank];
+ if (mask) {
+ /* restore level state */
+ __global_lock2(flags);
+ tmp = metag_in32(level_addr);
+ tmp = (tmp & ~mask) | (context->levels[bank] & mask);
+ metag_out32(tmp, level_addr);
+ __global_unlock2(flags);
+ }
+
+ level_addr += HWSTAT_STRIDE;
+ mask_addr += HWSTAT_STRIDE;
+ }
+
+ /* restore trigger matrixing */
+ __global_lock2(flags);
+ for (i = 0; i < 4; ++i) {
+ for (j = 0; j < 4; ++j) {
+ metag_out32(context->txvecint[i][j],
+ T0VECINT_BHALT +
+ TnVECINT_STRIDE*i +
+ 8*j);
+ }
+ }
+ __global_unlock2(flags);
+
+ kfree(context);
+}
+
+static struct syscore_ops meta_intc_syscore_ops = {
+ .suspend = meta_intc_suspend,
+ .resume = meta_intc_resume,
+};
+
+static void __init meta_intc_init_syscore_ops(struct meta_intc_priv *priv)
+{
+ register_syscore_ops(&meta_intc_syscore_ops);
+}
+#else
+#define meta_intc_init_syscore_ops(priv) do {} while (0)
+#endif
+
+/**
+ * meta_intc_init_cpu() - register with a Meta cpu
+ * @priv: private interrupt controller data
+ * @cpu: the CPU to register on
+ *
+ * Configure @cpu's TR2 irq so that we can demux external irqs.
+ */
+static void __init meta_intc_init_cpu(struct meta_intc_priv *priv, int cpu)
+{
+ unsigned int thread = cpu_2_hwthread_id[cpu];
+ unsigned int signum = TBID_SIGNUM_TR2(thread);
+ int irq = tbisig_map(signum);
+
+ /* Register the multiplexed IRQ handler */
+ irq_set_chained_handler(irq, meta_intc_irq_demux);
+ irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
+}
+
+/**
+ * meta_intc_no_mask() - indicate lack of HWMASKEXT registers
+ *
+ * Called from SoC code (or init code below) to dynamically indicate the lack of
+ * HWMASKEXT registers (for example depending on some SoC revision register).
+ * This alters the irq mask and unmask callbacks to use the fallback
+ * unvectoring/retriggering technique instead of using HWMASKEXT registers.
+ */
+void __init meta_intc_no_mask(void)
+{
+ meta_intc_edge_chip.irq_mask = meta_intc_mask_irq_nomask;
+ meta_intc_edge_chip.irq_unmask = meta_intc_unmask_edge_irq_nomask;
+ meta_intc_level_chip.irq_mask = meta_intc_mask_irq_nomask;
+ meta_intc_level_chip.irq_unmask = meta_intc_unmask_level_irq_nomask;
+}
+
+/**
+ * init_external_IRQ() - initialise the external irq controller
+ *
+ * Set up the external irq controller using device tree properties. This is
+ * called from init_IRQ().
+ */
+int __init init_external_IRQ(void)
+{
+ struct meta_intc_priv *priv = &meta_intc_priv;
+ struct device_node *node;
+ int ret, cpu;
+ u32 val;
+ bool no_masks = false;
+
+ node = of_find_compatible_node(NULL, NULL, "img,meta-intc");
+ if (!node)
+ return -ENOENT;
+
+ /* Get number of banks */
+ ret = of_property_read_u32(node, "num-banks", &val);
+ if (ret) {
+ pr_err("meta-intc: No num-banks property found\n");
+ return ret;
+ }
+ if (val < 1 || val > 4) {
+ pr_err("meta-intc: num-banks (%u) out of range\n", val);
+ return -EINVAL;
+ }
+ priv->nr_banks = val;
+
+ /* Are any mask registers present? */
+ if (of_get_property(node, "no-mask", NULL))
+ no_masks = true;
+
+ /* No HWMASKEXT registers present? */
+ if (no_masks)
+ meta_intc_no_mask();
+
+ /* Set up an IRQ domain */
+ /*
+ * This is a legacy IRQ domain for now until all the platform setup code
+ * has been converted to devicetree.
+ */
+ priv->domain = irq_domain_add_linear(node, priv->nr_banks*32,
+ &meta_intc_domain_ops, priv);
+ if (unlikely(!priv->domain)) {
+ pr_err("meta-intc: cannot add IRQ domain\n");
+ return -ENOMEM;
+ }
+
+ /* Setup TR2 for all cpus. */
+ for_each_possible_cpu(cpu)
+ meta_intc_init_cpu(priv, cpu);
+
+ /* Set up system suspend/resume callbacks */
+ meta_intc_init_syscore_ops(priv);
+
+ pr_info("meta-intc: External IRQ controller initialised (%u IRQs)\n",
+ priv->nr_banks*32);
+
+ return 0;
+}
--- /dev/null
+/*
+ * Meta internal (HWSTATMETA) interrupt code.
+ *
+ * Copyright (C) 2011-2012 Imagination Technologies Ltd.
+ *
+ * This code is based on the code in SoC/common/irq.c and SoC/comet/irq.c
+ * The code base could be generalised/merged as a lot of the functionality is
+ * similar. Until this is done, we try to keep the code simple here.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irqdomain.h>
+
+#include <asm/irq.h>
+#include <asm/hwthread.h>
+
+#define PERF0VECINT 0x04820580
+#define PERF1VECINT 0x04820588
+#define PERF0TRIG_OFFSET 16
+#define PERF1TRIG_OFFSET 17
+
+/**
+ * struct metag_internal_irq_priv - private meta internal interrupt data
+ * @domain: IRQ domain for all internal Meta IRQs (HWSTATMETA)
+ * @unmasked: Record of unmasked IRQs
+ */
+struct metag_internal_irq_priv {
+ struct irq_domain *domain;
+
+ unsigned long unmasked;
+};
+
+/* Private data for the one and only internal interrupt controller */
+static struct metag_internal_irq_priv metag_internal_irq_priv;
+
+static unsigned int metag_internal_irq_startup(struct irq_data *data);
+static void metag_internal_irq_shutdown(struct irq_data *data);
+static void metag_internal_irq_ack(struct irq_data *data);
+static void metag_internal_irq_mask(struct irq_data *data);
+static void metag_internal_irq_unmask(struct irq_data *data);
+#ifdef CONFIG_SMP
+static int metag_internal_irq_set_affinity(struct irq_data *data,
+ const struct cpumask *cpumask, bool force);
+#endif
+
+static struct irq_chip internal_irq_edge_chip = {
+ .name = "HWSTATMETA-IRQ",
+ .irq_startup = metag_internal_irq_startup,
+ .irq_shutdown = metag_internal_irq_shutdown,
+ .irq_ack = metag_internal_irq_ack,
+ .irq_mask = metag_internal_irq_mask,
+ .irq_unmask = metag_internal_irq_unmask,
+#ifdef CONFIG_SMP
+ .irq_set_affinity = metag_internal_irq_set_affinity,
+#endif
+};
+
+/*
+ * metag_hwvec_addr - get the address of *VECINT regs of irq
+ *
+ * This function is a table of supported triggers on HWSTATMETA
+ * Could do with a structure, but better keep it simple. Changes
+ * in this code should be rare.
+ */
+static inline void __iomem *metag_hwvec_addr(irq_hw_number_t hw)
+{
+ void __iomem *addr;
+
+ switch (hw) {
+ case PERF0TRIG_OFFSET:
+ addr = (void __iomem *)PERF0VECINT;
+ break;
+ case PERF1TRIG_OFFSET:
+ addr = (void __iomem *)PERF1VECINT;
+ break;
+ default:
+ addr = NULL;
+ break;
+ }
+ return addr;
+}
+
+/*
+ * metag_internal_startup - setup an internal irq
+ * @irq: the irq to startup
+ *
+ * Multiplex interrupts for @irq onto TR1. Clear any pending
+ * interrupts.
+ */
+static unsigned int metag_internal_irq_startup(struct irq_data *data)
+{
+ /* Clear (toggle) the bit in HWSTATMETA for our interrupt. */
+ metag_internal_irq_ack(data);
+
+ /* Enable the interrupt by unmasking it */
+ metag_internal_irq_unmask(data);
+
+ return 0;
+}
+
+/*
+ * metag_internal_irq_shutdown - turn off the irq
+ * @irq: the irq number to turn off
+ *
+ * Mask @irq and clear any pending interrupts.
+ * Stop muxing @irq onto TR1.
+ */
+static void metag_internal_irq_shutdown(struct irq_data *data)
+{
+ /* Disable the IRQ at the core by masking it. */
+ metag_internal_irq_mask(data);
+
+ /* Clear (toggle) the bit in HWSTATMETA for our interrupt. */
+ metag_internal_irq_ack(data);
+}
+
+/*
+ * metag_internal_irq_ack - acknowledge irq
+ * @irq: the irq to ack
+ */
+static void metag_internal_irq_ack(struct irq_data *data)
+{
+ irq_hw_number_t hw = data->hwirq;
+ unsigned int bit = 1 << hw;
+
+ if (metag_in32(HWSTATMETA) & bit)
+ metag_out32(bit, HWSTATMETA);
+}
+
+/**
+ * metag_internal_irq_mask() - mask an internal irq by unvectoring
+ * @data: data for the internal irq to mask
+ *
+ * HWSTATMETA has no mask register. Instead the IRQ is unvectored from the core
+ * and retriggered if necessary later.
+ */
+static void metag_internal_irq_mask(struct irq_data *data)
+{
+ struct metag_internal_irq_priv *priv = &metag_internal_irq_priv;
+ irq_hw_number_t hw = data->hwirq;
+ void __iomem *vec_addr = metag_hwvec_addr(hw);
+
+ clear_bit(hw, &priv->unmasked);
+
+ /* there is no interrupt mask, so unvector the interrupt */
+ metag_out32(0, vec_addr);
+}
+
+/**
+ * meta_intc_unmask_edge_irq_nomask() - unmask an edge irq by revectoring
+ * @data: data for the internal irq to unmask
+ *
+ * HWSTATMETA has no mask register. Instead the IRQ is revectored back to the
+ * core and retriggered if necessary.
+ */
+static void metag_internal_irq_unmask(struct irq_data *data)
+{
+ struct metag_internal_irq_priv *priv = &metag_internal_irq_priv;
+ irq_hw_number_t hw = data->hwirq;
+ unsigned int bit = 1 << hw;
+ void __iomem *vec_addr = metag_hwvec_addr(hw);
+ unsigned int thread = hard_processor_id();
+
+ set_bit(hw, &priv->unmasked);
+
+ /* there is no interrupt mask, so revector the interrupt */
+ metag_out32(TBI_TRIG_VEC(TBID_SIGNUM_TR1(thread)), vec_addr);
+
+ /*
+ * Re-trigger interrupt
+ *
+ * Writing a 1 toggles, and a 0->1 transition triggers. We only
+ * retrigger if the status bit is already set, which means we
+ * need to clear it first. Retriggering is fundamentally racy
+ * because if the interrupt fires again after we clear it we
+ * could end up clearing it again and the interrupt handler
+ * thinking it hasn't fired. Therefore we need to keep trying to
+ * retrigger until the bit is set.
+ */
+ if (metag_in32(HWSTATMETA) & bit) {
+ metag_out32(bit, HWSTATMETA);
+ while (!(metag_in32(HWSTATMETA) & bit))
+ metag_out32(bit, HWSTATMETA);
+ }
+}
+
+#ifdef CONFIG_SMP
+/*
+ * metag_internal_irq_set_affinity - set the affinity for an interrupt
+ */
+static int metag_internal_irq_set_affinity(struct irq_data *data,
+ const struct cpumask *cpumask, bool force)
+{
+ unsigned int cpu, thread;
+ irq_hw_number_t hw = data->hwirq;
+ /*
+ * Wire up this interrupt from *VECINT to the Meta core.
+ *
+ * Note that we can't wire up *VECINT to interrupt more than
+ * one cpu (the interrupt code doesn't support it), so we just
+ * pick the first cpu we find in 'cpumask'.
+ */
+ cpu = cpumask_any(cpumask);
+ thread = cpu_2_hwthread_id[cpu];
+
+ metag_out32(TBI_TRIG_VEC(TBID_SIGNUM_TR1(thread)),
+ metag_hwvec_addr(hw));
+
+ return 0;
+}
+#endif
+
+/*
+ * metag_internal_irq_demux - irq de-multiplexer
+ * @irq: the interrupt number
+ * @desc: the interrupt description structure for this irq
+ *
+ * The cpu receives an interrupt on TR1 when an interrupt has
+ * occurred. It is this function's job to demux this irq and
+ * figure out exactly which trigger needs servicing.
+ */
+static void metag_internal_irq_demux(unsigned int irq, struct irq_desc *desc)
+{
+ struct metag_internal_irq_priv *priv = irq_desc_get_handler_data(desc);
+ irq_hw_number_t hw;
+ unsigned int irq_no;
+ u32 status;
+
+recalculate:
+ status = metag_in32(HWSTATMETA) & priv->unmasked;
+
+ for (hw = 0; status != 0; status >>= 1, ++hw) {
+ if (status & 0x1) {
+ /*
+ * Map the hardware IRQ number to a virtual Linux IRQ
+ * number.
+ */
+ irq_no = irq_linear_revmap(priv->domain, hw);
+
+ /*
+ * Only fire off interrupts that are
+ * registered to be handled by the kernel.
+ * Other interrupts are probably being
+ * handled by other Meta hardware threads.
+ */
+ generic_handle_irq(irq_no);
+
+ /*
+ * The handler may have re-enabled interrupts
+ * which could have caused a nested invocation
+ * of this code and make the copy of the
+ * status register we are using invalid.
+ */
+ goto recalculate;
+ }
+ }
+}
+
+/**
+ * internal_irq_map() - Map an internal meta IRQ to a virtual IRQ number.
+ * @hw: Number of the internal IRQ. Must be in range.
+ *
+ * Returns: The virtual IRQ number of the Meta internal IRQ specified by
+ * @hw.
+ */
+int internal_irq_map(unsigned int hw)
+{
+ struct metag_internal_irq_priv *priv = &metag_internal_irq_priv;
+ if (!priv->domain)
+ return -ENODEV;
+ return irq_create_mapping(priv->domain, hw);
+}
+
+/**
+ * metag_internal_irq_init_cpu - regsister with the Meta cpu
+ * @cpu: the CPU to register on
+ *
+ * Configure @cpu's TR1 irq so that we can demux irqs.
+ */
+static void metag_internal_irq_init_cpu(struct metag_internal_irq_priv *priv,
+ int cpu)
+{
+ unsigned int thread = cpu_2_hwthread_id[cpu];
+ unsigned int signum = TBID_SIGNUM_TR1(thread);
+ int irq = tbisig_map(signum);
+
+ /* Register the multiplexed IRQ handler */
+ irq_set_handler_data(irq, priv);
+ irq_set_chained_handler(irq, metag_internal_irq_demux);
+ irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
+}
+
+/**
+ * metag_internal_intc_map() - map an internal irq
+ * @d: irq domain of internal trigger block
+ * @irq: virtual irq number
+ * @hw: hardware irq number within internal trigger block
+ *
+ * This sets up a virtual irq for a specified hardware interrupt. The irq chip
+ * and handler is configured.
+ */
+static int metag_internal_intc_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hw)
+{
+ /* only register interrupt if it is mapped */
+ if (!metag_hwvec_addr(hw))
+ return -EINVAL;
+
+ irq_set_chip_and_handler(irq, &internal_irq_edge_chip,
+ handle_edge_irq);
+ return 0;
+}
+
+static const struct irq_domain_ops metag_internal_intc_domain_ops = {
+ .map = metag_internal_intc_map,
+};
+
+/**
+ * metag_internal_irq_register - register internal IRQs
+ *
+ * Register the irq chip and handler function for all internal IRQs
+ */
+int __init init_internal_IRQ(void)
+{
+ struct metag_internal_irq_priv *priv = &metag_internal_irq_priv;
+ unsigned int cpu;
+
+ /* Set up an IRQ domain */
+ priv->domain = irq_domain_add_linear(NULL, 32,
+ &metag_internal_intc_domain_ops,
+ priv);
+ if (unlikely(!priv->domain)) {
+ pr_err("meta-internal-intc: cannot add IRQ domain\n");
+ return -ENOMEM;
+ }
+
+ /* Setup TR1 for all cpus. */
+ for_each_possible_cpu(cpu)
+ metag_internal_irq_init_cpu(priv, cpu);
+
+ return 0;
+};
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