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[Xen-devel] [RFC PATCH v2 04/22] xen/arm: its: Import GICv3 ITS driver from linux



From: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx>

This is actual GICv3 ITS driver from linux (4.0_rc4)
with latest commit id: 4559fbb3a9b1bde46afc739fa6c300826acdc19c

No xen related changes are made and is not compiled.
This helps to import any issues found in linux

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx>
---
v2: Import GIC ITS driver from linux 4.0_rc4
---
 xen/arch/arm/gic-v3-its.c | 1524 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 1524 insertions(+)

diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c
new file mode 100644
index 0000000..596b0a9
--- /dev/null
+++ b/xen/arch/arm/gic-v3-its.c
@@ -0,0 +1,1524 @@
+/*
+ * Copyright (C) 2013, 2014 ARM Limited, All Rights Reserved.
+ * Author: Marc Zyngier <marc.zyngier@xxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/log2.h>
+#include <linux/mm.h>
+#include <linux/msi.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/percpu.h>
+#include <linux/slab.h>
+
+#include <linux/irqchip/arm-gic-v3.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cputype.h>
+#include <asm/exception.h>
+
+#include "irqchip.h"
+
+#define ITS_FLAGS_CMDQ_NEEDS_FLUSHING          (1 << 0)
+
+#define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING    (1 << 0)
+
+/*
+ * Collection structure - just an ID, and a redistributor address to
+ * ping. We use one per CPU as a bag of interrupts assigned to this
+ * CPU.
+ */
+struct its_collection {
+       u64                     target_address;
+       u16                     col_id;
+};
+
+/*
+ * The ITS structure - contains most of the infrastructure, with the
+ * msi_controller, the command queue, the collections, and the list of
+ * devices writing to it.
+ */
+struct its_node {
+       raw_spinlock_t          lock;
+       struct list_head        entry;
+       struct msi_controller   msi_chip;
+       struct irq_domain       *domain;
+       void __iomem            *base;
+       unsigned long           phys_base;
+       struct its_cmd_block    *cmd_base;
+       struct its_cmd_block    *cmd_write;
+       void                    *tables[GITS_BASER_NR_REGS];
+       struct its_collection   *collections;
+       struct list_head        its_device_list;
+       u64                     flags;
+       u32                     ite_size;
+};
+
+#define ITS_ITT_ALIGN          SZ_256
+
+/*
+ * The ITS view of a device - belongs to an ITS, a collection, owns an
+ * interrupt translation table, and a list of interrupts.
+ */
+struct its_device {
+       struct list_head        entry;
+       struct its_node         *its;
+       struct its_collection   *collection;
+       void                    *itt;
+       unsigned long           *lpi_map;
+       irq_hw_number_t         lpi_base;
+       int                     nr_lpis;
+       u32                     nr_ites;
+       u32                     device_id;
+};
+
+static LIST_HEAD(its_nodes);
+static DEFINE_SPINLOCK(its_lock);
+static struct device_node *gic_root_node;
+static struct rdists *gic_rdists;
+
+#define gic_data_rdist()               (raw_cpu_ptr(gic_rdists->rdist))
+#define gic_data_rdist_rd_base()       (gic_data_rdist()->rd_base)
+
+/*
+ * ITS command descriptors - parameters to be encoded in a command
+ * block.
+ */
+struct its_cmd_desc {
+       union {
+               struct {
+                       struct its_device *dev;
+                       u32 event_id;
+               } its_inv_cmd;
+
+               struct {
+                       struct its_device *dev;
+                       u32 event_id;
+               } its_int_cmd;
+
+               struct {
+                       struct its_device *dev;
+                       int valid;
+               } its_mapd_cmd;
+
+               struct {
+                       struct its_collection *col;
+                       int valid;
+               } its_mapc_cmd;
+
+               struct {
+                       struct its_device *dev;
+                       u32 phys_id;
+                       u32 event_id;
+               } its_mapvi_cmd;
+
+               struct {
+                       struct its_device *dev;
+                       struct its_collection *col;
+                       u32 id;
+               } its_movi_cmd;
+
+               struct {
+                       struct its_device *dev;
+                       u32 event_id;
+               } its_discard_cmd;
+
+               struct {
+                       struct its_collection *col;
+               } its_invall_cmd;
+       };
+};
+
+/*
+ * The ITS command block, which is what the ITS actually parses.
+ */
+struct its_cmd_block {
+       u64     raw_cmd[4];
+};
+
+#define ITS_CMD_QUEUE_SZ               SZ_64K
+#define ITS_CMD_QUEUE_NR_ENTRIES       (ITS_CMD_QUEUE_SZ / sizeof(struct 
its_cmd_block))
+
+typedef struct its_collection *(*its_cmd_builder_t)(struct its_cmd_block *,
+                                                   struct its_cmd_desc *);
+
+static void its_encode_cmd(struct its_cmd_block *cmd, u8 cmd_nr)
+{
+       cmd->raw_cmd[0] &= ~0xffUL;
+       cmd->raw_cmd[0] |= cmd_nr;
+}
+
+static void its_encode_devid(struct its_cmd_block *cmd, u32 devid)
+{
+       cmd->raw_cmd[0] &= ~(0xffffUL << 32);
+       cmd->raw_cmd[0] |= ((u64)devid) << 32;
+}
+
+static void its_encode_event_id(struct its_cmd_block *cmd, u32 id)
+{
+       cmd->raw_cmd[1] &= ~0xffffffffUL;
+       cmd->raw_cmd[1] |= id;
+}
+
+static void its_encode_phys_id(struct its_cmd_block *cmd, u32 phys_id)
+{
+       cmd->raw_cmd[1] &= 0xffffffffUL;
+       cmd->raw_cmd[1] |= ((u64)phys_id) << 32;
+}
+
+static void its_encode_size(struct its_cmd_block *cmd, u8 size)
+{
+       cmd->raw_cmd[1] &= ~0x1fUL;
+       cmd->raw_cmd[1] |= size & 0x1f;
+}
+
+static void its_encode_itt(struct its_cmd_block *cmd, u64 itt_addr)
+{
+       cmd->raw_cmd[2] &= ~0xffffffffffffUL;
+       cmd->raw_cmd[2] |= itt_addr & 0xffffffffff00UL;
+}
+
+static void its_encode_valid(struct its_cmd_block *cmd, int valid)
+{
+       cmd->raw_cmd[2] &= ~(1UL << 63);
+       cmd->raw_cmd[2] |= ((u64)!!valid) << 63;
+}
+
+static void its_encode_target(struct its_cmd_block *cmd, u64 target_addr)
+{
+       cmd->raw_cmd[2] &= ~(0xffffffffUL << 16);
+       cmd->raw_cmd[2] |= (target_addr & (0xffffffffUL << 16));
+}
+
+static void its_encode_collection(struct its_cmd_block *cmd, u16 col)
+{
+       cmd->raw_cmd[2] &= ~0xffffUL;
+       cmd->raw_cmd[2] |= col;
+}
+
+static inline void its_fixup_cmd(struct its_cmd_block *cmd)
+{
+       /* Let's fixup BE commands */
+       cmd->raw_cmd[0] = cpu_to_le64(cmd->raw_cmd[0]);
+       cmd->raw_cmd[1] = cpu_to_le64(cmd->raw_cmd[1]);
+       cmd->raw_cmd[2] = cpu_to_le64(cmd->raw_cmd[2]);
+       cmd->raw_cmd[3] = cpu_to_le64(cmd->raw_cmd[3]);
+}
+
+static struct its_collection *its_build_mapd_cmd(struct its_cmd_block *cmd,
+                                                struct its_cmd_desc *desc)
+{
+       unsigned long itt_addr;
+       u8 size = ilog2(desc->its_mapd_cmd.dev->nr_ites);
+
+       itt_addr = virt_to_phys(desc->its_mapd_cmd.dev->itt);
+       itt_addr = ALIGN(itt_addr, ITS_ITT_ALIGN);
+
+       its_encode_cmd(cmd, GITS_CMD_MAPD);
+       its_encode_devid(cmd, desc->its_mapd_cmd.dev->device_id);
+       its_encode_size(cmd, size - 1);
+       its_encode_itt(cmd, itt_addr);
+       its_encode_valid(cmd, desc->its_mapd_cmd.valid);
+
+       its_fixup_cmd(cmd);
+
+       return desc->its_mapd_cmd.dev->collection;
+}
+
+static struct its_collection *its_build_mapc_cmd(struct its_cmd_block *cmd,
+                                                struct its_cmd_desc *desc)
+{
+       its_encode_cmd(cmd, GITS_CMD_MAPC);
+       its_encode_collection(cmd, desc->its_mapc_cmd.col->col_id);
+       its_encode_target(cmd, desc->its_mapc_cmd.col->target_address);
+       its_encode_valid(cmd, desc->its_mapc_cmd.valid);
+
+       its_fixup_cmd(cmd);
+
+       return desc->its_mapc_cmd.col;
+}
+
+static struct its_collection *its_build_mapvi_cmd(struct its_cmd_block *cmd,
+                                                 struct its_cmd_desc *desc)
+{
+       its_encode_cmd(cmd, GITS_CMD_MAPVI);
+       its_encode_devid(cmd, desc->its_mapvi_cmd.dev->device_id);
+       its_encode_event_id(cmd, desc->its_mapvi_cmd.event_id);
+       its_encode_phys_id(cmd, desc->its_mapvi_cmd.phys_id);
+       its_encode_collection(cmd, desc->its_mapvi_cmd.dev->collection->col_id);
+
+       its_fixup_cmd(cmd);
+
+       return desc->its_mapvi_cmd.dev->collection;
+}
+
+static struct its_collection *its_build_movi_cmd(struct its_cmd_block *cmd,
+                                                struct its_cmd_desc *desc)
+{
+       its_encode_cmd(cmd, GITS_CMD_MOVI);
+       its_encode_devid(cmd, desc->its_movi_cmd.dev->device_id);
+       its_encode_event_id(cmd, desc->its_movi_cmd.id);
+       its_encode_collection(cmd, desc->its_movi_cmd.col->col_id);
+
+       its_fixup_cmd(cmd);
+
+       return desc->its_movi_cmd.dev->collection;
+}
+
+static struct its_collection *its_build_discard_cmd(struct its_cmd_block *cmd,
+                                                   struct its_cmd_desc *desc)
+{
+       its_encode_cmd(cmd, GITS_CMD_DISCARD);
+       its_encode_devid(cmd, desc->its_discard_cmd.dev->device_id);
+       its_encode_event_id(cmd, desc->its_discard_cmd.event_id);
+
+       its_fixup_cmd(cmd);
+
+       return desc->its_discard_cmd.dev->collection;
+}
+
+static struct its_collection *its_build_inv_cmd(struct its_cmd_block *cmd,
+                                               struct its_cmd_desc *desc)
+{
+       its_encode_cmd(cmd, GITS_CMD_INV);
+       its_encode_devid(cmd, desc->its_inv_cmd.dev->device_id);
+       its_encode_event_id(cmd, desc->its_inv_cmd.event_id);
+
+       its_fixup_cmd(cmd);
+
+       return desc->its_inv_cmd.dev->collection;
+}
+
+static struct its_collection *its_build_invall_cmd(struct its_cmd_block *cmd,
+                                                  struct its_cmd_desc *desc)
+{
+       its_encode_cmd(cmd, GITS_CMD_INVALL);
+       its_encode_collection(cmd, desc->its_mapc_cmd.col->col_id);
+
+       its_fixup_cmd(cmd);
+
+       return NULL;
+}
+
+static u64 its_cmd_ptr_to_offset(struct its_node *its,
+                                struct its_cmd_block *ptr)
+{
+       return (ptr - its->cmd_base) * sizeof(*ptr);
+}
+
+static int its_queue_full(struct its_node *its)
+{
+       int widx;
+       int ridx;
+
+       widx = its->cmd_write - its->cmd_base;
+       ridx = readl_relaxed(its->base + GITS_CREADR) / sizeof(struct 
its_cmd_block);
+
+       /* This is incredibly unlikely to happen, unless the ITS locks up. */
+       if (((widx + 1) % ITS_CMD_QUEUE_NR_ENTRIES) == ridx)
+               return 1;
+
+       return 0;
+}
+
+static struct its_cmd_block *its_allocate_entry(struct its_node *its)
+{
+       struct its_cmd_block *cmd;
+       u32 count = 1000000;    /* 1s! */
+
+       while (its_queue_full(its)) {
+               count--;
+               if (!count) {
+                       pr_err_ratelimited("ITS queue not draining\n");
+                       return NULL;
+               }
+               cpu_relax();
+               udelay(1);
+       }
+
+       cmd = its->cmd_write++;
+
+       /* Handle queue wrapping */
+       if (its->cmd_write == (its->cmd_base + ITS_CMD_QUEUE_NR_ENTRIES))
+               its->cmd_write = its->cmd_base;
+
+       return cmd;
+}
+
+static struct its_cmd_block *its_post_commands(struct its_node *its)
+{
+       u64 wr = its_cmd_ptr_to_offset(its, its->cmd_write);
+
+       writel_relaxed(wr, its->base + GITS_CWRITER);
+
+       return its->cmd_write;
+}
+
+static void its_flush_cmd(struct its_node *its, struct its_cmd_block *cmd)
+{
+       /*
+        * Make sure the commands written to memory are observable by
+        * the ITS.
+        */
+       if (its->flags & ITS_FLAGS_CMDQ_NEEDS_FLUSHING)
+               __flush_dcache_area(cmd, sizeof(*cmd));
+       else
+               dsb(ishst);
+}
+
+static void its_wait_for_range_completion(struct its_node *its,
+                                         struct its_cmd_block *from,
+                                         struct its_cmd_block *to)
+{
+       u64 rd_idx, from_idx, to_idx;
+       u32 count = 1000000;    /* 1s! */
+
+       from_idx = its_cmd_ptr_to_offset(its, from);
+       to_idx = its_cmd_ptr_to_offset(its, to);
+
+       while (1) {
+               rd_idx = readl_relaxed(its->base + GITS_CREADR);
+               if (rd_idx >= to_idx || rd_idx < from_idx)
+                       break;
+
+               count--;
+               if (!count) {
+                       pr_err_ratelimited("ITS queue timeout\n");
+                       return;
+               }
+               cpu_relax();
+               udelay(1);
+       }
+}
+
+static void its_send_single_command(struct its_node *its,
+                                   its_cmd_builder_t builder,
+                                   struct its_cmd_desc *desc)
+{
+       struct its_cmd_block *cmd, *sync_cmd, *next_cmd;
+       struct its_collection *sync_col;
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&its->lock, flags);
+
+       cmd = its_allocate_entry(its);
+       if (!cmd) {             /* We're soooooo screewed... */
+               pr_err_ratelimited("ITS can't allocate, dropping command\n");
+               raw_spin_unlock_irqrestore(&its->lock, flags);
+               return;
+       }
+       sync_col = builder(cmd, desc);
+       its_flush_cmd(its, cmd);
+
+       if (sync_col) {
+               sync_cmd = its_allocate_entry(its);
+               if (!sync_cmd) {
+                       pr_err_ratelimited("ITS can't SYNC, skipping\n");
+                       goto post;
+               }
+               its_encode_cmd(sync_cmd, GITS_CMD_SYNC);
+               its_encode_target(sync_cmd, sync_col->target_address);
+               its_fixup_cmd(sync_cmd);
+               its_flush_cmd(its, sync_cmd);
+       }
+
+post:
+       next_cmd = its_post_commands(its);
+       raw_spin_unlock_irqrestore(&its->lock, flags);
+
+       its_wait_for_range_completion(its, cmd, next_cmd);
+}
+
+static void its_send_inv(struct its_device *dev, u32 event_id)
+{
+       struct its_cmd_desc desc;
+
+       desc.its_inv_cmd.dev = dev;
+       desc.its_inv_cmd.event_id = event_id;
+
+       its_send_single_command(dev->its, its_build_inv_cmd, &desc);
+}
+
+static void its_send_mapd(struct its_device *dev, int valid)
+{
+       struct its_cmd_desc desc;
+
+       desc.its_mapd_cmd.dev = dev;
+       desc.its_mapd_cmd.valid = !!valid;
+
+       its_send_single_command(dev->its, its_build_mapd_cmd, &desc);
+}
+
+static void its_send_mapc(struct its_node *its, struct its_collection *col,
+                         int valid)
+{
+       struct its_cmd_desc desc;
+
+       desc.its_mapc_cmd.col = col;
+       desc.its_mapc_cmd.valid = !!valid;
+
+       its_send_single_command(its, its_build_mapc_cmd, &desc);
+}
+
+static void its_send_mapvi(struct its_device *dev, u32 irq_id, u32 id)
+{
+       struct its_cmd_desc desc;
+
+       desc.its_mapvi_cmd.dev = dev;
+       desc.its_mapvi_cmd.phys_id = irq_id;
+       desc.its_mapvi_cmd.event_id = id;
+
+       its_send_single_command(dev->its, its_build_mapvi_cmd, &desc);
+}
+
+static void its_send_movi(struct its_device *dev,
+                         struct its_collection *col, u32 id)
+{
+       struct its_cmd_desc desc;
+
+       desc.its_movi_cmd.dev = dev;
+       desc.its_movi_cmd.col = col;
+       desc.its_movi_cmd.id = id;
+
+       its_send_single_command(dev->its, its_build_movi_cmd, &desc);
+}
+
+static void its_send_discard(struct its_device *dev, u32 id)
+{
+       struct its_cmd_desc desc;
+
+       desc.its_discard_cmd.dev = dev;
+       desc.its_discard_cmd.event_id = id;
+
+       its_send_single_command(dev->its, its_build_discard_cmd, &desc);
+}
+
+static void its_send_invall(struct its_node *its, struct its_collection *col)
+{
+       struct its_cmd_desc desc;
+
+       desc.its_invall_cmd.col = col;
+
+       its_send_single_command(its, its_build_invall_cmd, &desc);
+}
+
+/*
+ * irqchip functions - assumes MSI, mostly.
+ */
+
+static inline u32 its_get_event_id(struct irq_data *d)
+{
+       struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+       return d->hwirq - its_dev->lpi_base;
+}
+
+static void lpi_set_config(struct irq_data *d, bool enable)
+{
+       struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+       irq_hw_number_t hwirq = d->hwirq;
+       u32 id = its_get_event_id(d);
+       u8 *cfg = page_address(gic_rdists->prop_page) + hwirq - 8192;
+
+       if (enable)
+               *cfg |= LPI_PROP_ENABLED;
+       else
+               *cfg &= ~LPI_PROP_ENABLED;
+
+       /*
+        * Make the above write visible to the redistributors.
+        * And yes, we're flushing exactly: One. Single. Byte.
+        * Humpf...
+        */
+       if (gic_rdists->flags & RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING)
+               __flush_dcache_area(cfg, sizeof(*cfg));
+       else
+               dsb(ishst);
+       its_send_inv(its_dev, id);
+}
+
+static void its_mask_irq(struct irq_data *d)
+{
+       lpi_set_config(d, false);
+}
+
+static void its_unmask_irq(struct irq_data *d)
+{
+       lpi_set_config(d, true);
+}
+
+static void its_eoi_irq(struct irq_data *d)
+{
+       gic_write_eoir(d->hwirq);
+}
+
+static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
+                           bool force)
+{
+       unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
+       struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+       struct its_collection *target_col;
+       u32 id = its_get_event_id(d);
+
+       if (cpu >= nr_cpu_ids)
+               return -EINVAL;
+
+       target_col = &its_dev->its->collections[cpu];
+       its_send_movi(its_dev, target_col, id);
+       its_dev->collection = target_col;
+
+       return IRQ_SET_MASK_OK_DONE;
+}
+
+static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)
+{
+       struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+       struct its_node *its;
+       u64 addr;
+
+       its = its_dev->its;
+       addr = its->phys_base + GITS_TRANSLATER;
+
+       msg->address_lo         = addr & ((1UL << 32) - 1);
+       msg->address_hi         = addr >> 32;
+       msg->data               = its_get_event_id(d);
+}
+
+static struct irq_chip its_irq_chip = {
+       .name                   = "ITS",
+       .irq_mask               = its_mask_irq,
+       .irq_unmask             = its_unmask_irq,
+       .irq_eoi                = its_eoi_irq,
+       .irq_set_affinity       = its_set_affinity,
+       .irq_compose_msi_msg    = its_irq_compose_msi_msg,
+};
+
+static void its_mask_msi_irq(struct irq_data *d)
+{
+       pci_msi_mask_irq(d);
+       irq_chip_mask_parent(d);
+}
+
+static void its_unmask_msi_irq(struct irq_data *d)
+{
+       pci_msi_unmask_irq(d);
+       irq_chip_unmask_parent(d);
+}
+
+static struct irq_chip its_msi_irq_chip = {
+       .name                   = "ITS-MSI",
+       .irq_unmask             = its_unmask_msi_irq,
+       .irq_mask               = its_mask_msi_irq,
+       .irq_eoi                = irq_chip_eoi_parent,
+       .irq_write_msi_msg      = pci_msi_domain_write_msg,
+};
+
+/*
+ * How we allocate LPIs:
+ *
+ * The GIC has id_bits bits for interrupt identifiers. From there, we
+ * must subtract 8192 which are reserved for SGIs/PPIs/SPIs. Then, as
+ * we allocate LPIs by chunks of 32, we can shift the whole thing by 5
+ * bits to the right.
+ *
+ * This gives us (((1UL << id_bits) - 8192) >> 5) possible allocations.
+ */
+#define IRQS_PER_CHUNK_SHIFT   5
+#define IRQS_PER_CHUNK         (1 << IRQS_PER_CHUNK_SHIFT)
+
+static unsigned long *lpi_bitmap;
+static u32 lpi_chunks;
+static DEFINE_SPINLOCK(lpi_lock);
+
+static int its_lpi_to_chunk(int lpi)
+{
+       return (lpi - 8192) >> IRQS_PER_CHUNK_SHIFT;
+}
+
+static int its_chunk_to_lpi(int chunk)
+{
+       return (chunk << IRQS_PER_CHUNK_SHIFT) + 8192;
+}
+
+static int its_lpi_init(u32 id_bits)
+{
+       lpi_chunks = its_lpi_to_chunk(1UL << id_bits);
+
+       lpi_bitmap = kzalloc(BITS_TO_LONGS(lpi_chunks) * sizeof(long),
+                            GFP_KERNEL);
+       if (!lpi_bitmap) {
+               lpi_chunks = 0;
+               return -ENOMEM;
+       }
+
+       pr_info("ITS: Allocated %d chunks for LPIs\n", (int)lpi_chunks);
+       return 0;
+}
+
+static unsigned long *its_lpi_alloc_chunks(int nr_irqs, int *base, int *nr_ids)
+{
+       unsigned long *bitmap = NULL;
+       int chunk_id;
+       int nr_chunks;
+       int i;
+
+       nr_chunks = DIV_ROUND_UP(nr_irqs, IRQS_PER_CHUNK);
+
+       spin_lock(&lpi_lock);
+
+       do {
+               chunk_id = bitmap_find_next_zero_area(lpi_bitmap, lpi_chunks,
+                                                     0, nr_chunks, 0);
+               if (chunk_id < lpi_chunks)
+                       break;
+
+               nr_chunks--;
+       } while (nr_chunks > 0);
+
+       if (!nr_chunks)
+               goto out;
+
+       bitmap = kzalloc(BITS_TO_LONGS(nr_chunks * IRQS_PER_CHUNK) * sizeof 
(long),
+                        GFP_ATOMIC);
+       if (!bitmap)
+               goto out;
+
+       for (i = 0; i < nr_chunks; i++)
+               set_bit(chunk_id + i, lpi_bitmap);
+
+       *base = its_chunk_to_lpi(chunk_id);
+       *nr_ids = nr_chunks * IRQS_PER_CHUNK;
+
+out:
+       spin_unlock(&lpi_lock);
+
+       return bitmap;
+}
+
+static void its_lpi_free(unsigned long *bitmap, int base, int nr_ids)
+{
+       int lpi;
+
+       spin_lock(&lpi_lock);
+
+       for (lpi = base; lpi < (base + nr_ids); lpi += IRQS_PER_CHUNK) {
+               int chunk = its_lpi_to_chunk(lpi);
+               BUG_ON(chunk > lpi_chunks);
+               if (test_bit(chunk, lpi_bitmap)) {
+                       clear_bit(chunk, lpi_bitmap);
+               } else {
+                       pr_err("Bad LPI chunk %d\n", chunk);
+               }
+       }
+
+       spin_unlock(&lpi_lock);
+
+       kfree(bitmap);
+}
+
+/*
+ * We allocate 64kB for PROPBASE. That gives us at most 64K LPIs to
+ * deal with (one configuration byte per interrupt). PENDBASE has to
+ * be 64kB aligned (one bit per LPI, plus 8192 bits for SPI/PPI/SGI).
+ */
+#define LPI_PROPBASE_SZ                SZ_64K
+#define LPI_PENDBASE_SZ                (LPI_PROPBASE_SZ / 8 + SZ_1K)
+
+/*
+ * This is how many bits of ID we need, including the useless ones.
+ */
+#define LPI_NRBITS             ilog2(LPI_PROPBASE_SZ + SZ_8K)
+
+#define LPI_PROP_DEFAULT_PRIO  0xa0
+
+static int __init its_alloc_lpi_tables(void)
+{
+       phys_addr_t paddr;
+
+       gic_rdists->prop_page = alloc_pages(GFP_NOWAIT,
+                                          get_order(LPI_PROPBASE_SZ));
+       if (!gic_rdists->prop_page) {
+               pr_err("Failed to allocate PROPBASE\n");
+               return -ENOMEM;
+       }
+
+       paddr = page_to_phys(gic_rdists->prop_page);
+       pr_info("GIC: using LPI property table @%pa\n", &paddr);
+
+       /* Priority 0xa0, Group-1, disabled */
+       memset(page_address(gic_rdists->prop_page),
+              LPI_PROP_DEFAULT_PRIO | LPI_PROP_GROUP1,
+              LPI_PROPBASE_SZ);
+
+       /* Make sure the GIC will observe the written configuration */
+       __flush_dcache_area(page_address(gic_rdists->prop_page), 
LPI_PROPBASE_SZ);
+
+       return 0;
+}
+
+static const char *its_base_type_string[] = {
+       [GITS_BASER_TYPE_DEVICE]        = "Devices",
+       [GITS_BASER_TYPE_VCPU]          = "Virtual CPUs",
+       [GITS_BASER_TYPE_CPU]           = "Physical CPUs",
+       [GITS_BASER_TYPE_COLLECTION]    = "Interrupt Collections",
+       [GITS_BASER_TYPE_RESERVED5]     = "Reserved (5)",
+       [GITS_BASER_TYPE_RESERVED6]     = "Reserved (6)",
+       [GITS_BASER_TYPE_RESERVED7]     = "Reserved (7)",
+};
+
+static void its_free_tables(struct its_node *its)
+{
+       int i;
+
+       for (i = 0; i < GITS_BASER_NR_REGS; i++) {
+               if (its->tables[i]) {
+                       free_page((unsigned long)its->tables[i]);
+                       its->tables[i] = NULL;
+               }
+       }
+}
+
+static int its_alloc_tables(struct its_node *its)
+{
+       int err;
+       int i;
+       int psz = SZ_64K;
+       u64 shr = GITS_BASER_InnerShareable;
+
+       for (i = 0; i < GITS_BASER_NR_REGS; i++) {
+               u64 val = readq_relaxed(its->base + GITS_BASER + i * 8);
+               u64 type = GITS_BASER_TYPE(val);
+               u64 entry_size = GITS_BASER_ENTRY_SIZE(val);
+               int order = get_order(psz);
+               int alloc_size;
+               u64 tmp;
+               void *base;
+
+               if (type == GITS_BASER_TYPE_NONE)
+                       continue;
+
+               /*
+                * Allocate as many entries as required to fit the
+                * range of device IDs that the ITS can grok... The ID
+                * space being incredibly sparse, this results in a
+                * massive waste of memory.
+                *
+                * For other tables, only allocate a single page.
+                */
+               if (type == GITS_BASER_TYPE_DEVICE) {
+                       u64 typer = readq_relaxed(its->base + GITS_TYPER);
+                       u32 ids = GITS_TYPER_DEVBITS(typer);
+
+                       order = get_order((1UL << ids) * entry_size);
+                       if (order >= MAX_ORDER) {
+                               order = MAX_ORDER - 1;
+                               pr_warn("%s: Device Table too large, reduce its 
page order to %u\n",
+                                       its->msi_chip.of_node->full_name, 
order);
+                       }
+               }
+
+               alloc_size = (1 << order) * PAGE_SIZE;
+               base = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
+               if (!base) {
+                       err = -ENOMEM;
+                       goto out_free;
+               }
+
+               its->tables[i] = base;
+
+retry_baser:
+               val = (virt_to_phys(base)                                |
+                      (type << GITS_BASER_TYPE_SHIFT)                   |
+                      ((entry_size - 1) << GITS_BASER_ENTRY_SIZE_SHIFT) |
+                      GITS_BASER_WaWb                                   |
+                      shr                                               |
+                      GITS_BASER_VALID);
+
+               switch (psz) {
+               case SZ_4K:
+                       val |= GITS_BASER_PAGE_SIZE_4K;
+                       break;
+               case SZ_16K:
+                       val |= GITS_BASER_PAGE_SIZE_16K;
+                       break;
+               case SZ_64K:
+                       val |= GITS_BASER_PAGE_SIZE_64K;
+                       break;
+               }
+
+               val |= (alloc_size / psz) - 1;
+
+               writeq_relaxed(val, its->base + GITS_BASER + i * 8);
+               tmp = readq_relaxed(its->base + GITS_BASER + i * 8);
+
+               if ((val ^ tmp) & GITS_BASER_SHAREABILITY_MASK) {
+                       /*
+                        * Shareability didn't stick. Just use
+                        * whatever the read reported, which is likely
+                        * to be the only thing this redistributor
+                        * supports.
+                        */
+                       shr = tmp & GITS_BASER_SHAREABILITY_MASK;
+                       goto retry_baser;
+               }
+
+               if ((val ^ tmp) & GITS_BASER_PAGE_SIZE_MASK) {
+                       /*
+                        * Page size didn't stick. Let's try a smaller
+                        * size and retry. If we reach 4K, then
+                        * something is horribly wrong...
+                        */
+                       switch (psz) {
+                       case SZ_16K:
+                               psz = SZ_4K;
+                               goto retry_baser;
+                       case SZ_64K:
+                               psz = SZ_16K;
+                               goto retry_baser;
+                       }
+               }
+
+               if (val != tmp) {
+                       pr_err("ITS: %s: GITS_BASER%d doesn't stick: %lx %lx\n",
+                              its->msi_chip.of_node->full_name, i,
+                              (unsigned long) val, (unsigned long) tmp);
+                       err = -ENXIO;
+                       goto out_free;
+               }
+
+               pr_info("ITS: allocated %d %s @%lx (psz %dK, shr %d)\n",
+                       (int)(alloc_size / entry_size),
+                       its_base_type_string[type],
+                       (unsigned long)virt_to_phys(base),
+                       psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT);
+       }
+
+       return 0;
+
+out_free:
+       its_free_tables(its);
+
+       return err;
+}
+
+static int its_alloc_collections(struct its_node *its)
+{
+       its->collections = kzalloc(nr_cpu_ids * sizeof(*its->collections),
+                                  GFP_KERNEL);
+       if (!its->collections)
+               return -ENOMEM;
+
+       return 0;
+}
+
+static void its_cpu_init_lpis(void)
+{
+       void __iomem *rbase = gic_data_rdist_rd_base();
+       struct page *pend_page;
+       u64 val, tmp;
+
+       /* If we didn't allocate the pending table yet, do it now */
+       pend_page = gic_data_rdist()->pend_page;
+       if (!pend_page) {
+               phys_addr_t paddr;
+               /*
+                * The pending pages have to be at least 64kB aligned,
+                * hence the 'max(LPI_PENDBASE_SZ, SZ_64K)' below.
+                */
+               pend_page = alloc_pages(GFP_NOWAIT | __GFP_ZERO,
+                                       get_order(max(LPI_PENDBASE_SZ, 
SZ_64K)));
+               if (!pend_page) {
+                       pr_err("Failed to allocate PENDBASE for CPU%d\n",
+                              smp_processor_id());
+                       return;
+               }
+
+               /* Make sure the GIC will observe the zero-ed page */
+               __flush_dcache_area(page_address(pend_page), LPI_PENDBASE_SZ);
+
+               paddr = page_to_phys(pend_page);
+               pr_info("CPU%d: using LPI pending table @%pa\n",
+                       smp_processor_id(), &paddr);
+               gic_data_rdist()->pend_page = pend_page;
+       }
+
+       /* Disable LPIs */
+       val = readl_relaxed(rbase + GICR_CTLR);
+       val &= ~GICR_CTLR_ENABLE_LPIS;
+       writel_relaxed(val, rbase + GICR_CTLR);
+
+       /*
+        * Make sure any change to the table is observable by the GIC.
+        */
+       dsb(sy);
+
+       /* set PROPBASE */
+       val = (page_to_phys(gic_rdists->prop_page) |
+              GICR_PROPBASER_InnerShareable |
+              GICR_PROPBASER_WaWb |
+              ((LPI_NRBITS - 1) & GICR_PROPBASER_IDBITS_MASK));
+
+       writeq_relaxed(val, rbase + GICR_PROPBASER);
+       tmp = readq_relaxed(rbase + GICR_PROPBASER);
+
+       if ((tmp ^ val) & GICR_PROPBASER_SHAREABILITY_MASK) {
+               pr_info_once("GIC: using cache flushing for LPI property 
table\n");
+               gic_rdists->flags |= RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING;
+       }
+
+       /* set PENDBASE */
+       val = (page_to_phys(pend_page) |
+              GICR_PROPBASER_InnerShareable |
+              GICR_PROPBASER_WaWb);
+
+       writeq_relaxed(val, rbase + GICR_PENDBASER);
+
+       /* Enable LPIs */
+       val = readl_relaxed(rbase + GICR_CTLR);
+       val |= GICR_CTLR_ENABLE_LPIS;
+       writel_relaxed(val, rbase + GICR_CTLR);
+
+       /* Make sure the GIC has seen the above */
+       dsb(sy);
+}
+
+static void its_cpu_init_collection(void)
+{
+       struct its_node *its;
+       int cpu;
+
+       spin_lock(&its_lock);
+       cpu = smp_processor_id();
+
+       list_for_each_entry(its, &its_nodes, entry) {
+               u64 target;
+
+               /*
+                * We now have to bind each collection to its target
+                * redistributor.
+                */
+               if (readq_relaxed(its->base + GITS_TYPER) & GITS_TYPER_PTA) {
+                       /*
+                        * This ITS wants the physical address of the
+                        * redistributor.
+                        */
+                       target = gic_data_rdist()->phys_base;
+               } else {
+                       /*
+                        * This ITS wants a linear CPU number.
+                        */
+                       target = readq_relaxed(gic_data_rdist_rd_base() + 
GICR_TYPER);
+                       target = GICR_TYPER_CPU_NUMBER(target);
+               }
+
+               /* Perform collection mapping */
+               its->collections[cpu].target_address = target;
+               its->collections[cpu].col_id = cpu;
+
+               its_send_mapc(its, &its->collections[cpu], 1);
+               its_send_invall(its, &its->collections[cpu]);
+       }
+
+       spin_unlock(&its_lock);
+}
+
+static struct its_device *its_find_device(struct its_node *its, u32 dev_id)
+{
+       struct its_device *its_dev = NULL, *tmp;
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&its->lock, flags);
+
+       list_for_each_entry(tmp, &its->its_device_list, entry) {
+               if (tmp->device_id == dev_id) {
+                       its_dev = tmp;
+                       break;
+               }
+       }
+
+       raw_spin_unlock_irqrestore(&its->lock, flags);
+
+       return its_dev;
+}
+
+static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
+                                           int nvecs)
+{
+       struct its_device *dev;
+       unsigned long *lpi_map;
+       unsigned long flags;
+       void *itt;
+       int lpi_base;
+       int nr_lpis;
+       int nr_ites;
+       int cpu;
+       int sz;
+
+       dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+       /*
+        * At least one bit of EventID is being used, hence a minimum
+        * of two entries. No, the architecture doesn't let you
+        * express an ITT with a single entry.
+        */
+       nr_ites = max(2UL, roundup_pow_of_two(nvecs));
+       sz = nr_ites * its->ite_size;
+       sz = max(sz, ITS_ITT_ALIGN) + ITS_ITT_ALIGN - 1;
+       itt = kzalloc(sz, GFP_KERNEL);
+       lpi_map = its_lpi_alloc_chunks(nvecs, &lpi_base, &nr_lpis);
+
+       if (!dev || !itt || !lpi_map) {
+               kfree(dev);
+               kfree(itt);
+               kfree(lpi_map);
+               return NULL;
+       }
+
+       dev->its = its;
+       dev->itt = itt;
+       dev->nr_ites = nr_ites;
+       dev->lpi_map = lpi_map;
+       dev->lpi_base = lpi_base;
+       dev->nr_lpis = nr_lpis;
+       dev->device_id = dev_id;
+       INIT_LIST_HEAD(&dev->entry);
+
+       raw_spin_lock_irqsave(&its->lock, flags);
+       list_add(&dev->entry, &its->its_device_list);
+       raw_spin_unlock_irqrestore(&its->lock, flags);
+
+       /* Bind the device to the first possible CPU */
+       cpu = cpumask_first(cpu_online_mask);
+       dev->collection = &its->collections[cpu];
+
+       /* Map device to its ITT */
+       its_send_mapd(dev, 1);
+
+       return dev;
+}
+
+static void its_free_device(struct its_device *its_dev)
+{
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&its_dev->its->lock, flags);
+       list_del(&its_dev->entry);
+       raw_spin_unlock_irqrestore(&its_dev->its->lock, flags);
+       kfree(its_dev->itt);
+       kfree(its_dev);
+}
+
+static int its_alloc_device_irq(struct its_device *dev, irq_hw_number_t *hwirq)
+{
+       int idx;
+
+       idx = find_first_zero_bit(dev->lpi_map, dev->nr_lpis);
+       if (idx == dev->nr_lpis)
+               return -ENOSPC;
+
+       *hwirq = dev->lpi_base + idx;
+       set_bit(idx, dev->lpi_map);
+
+       return 0;
+}
+
+struct its_pci_alias {
+       struct pci_dev  *pdev;
+       u32             dev_id;
+       u32             count;
+};
+
+static int its_pci_msi_vec_count(struct pci_dev *pdev)
+{
+       int msi, msix;
+
+       msi = max(pci_msi_vec_count(pdev), 0);
+       msix = max(pci_msix_vec_count(pdev), 0);
+
+       return max(msi, msix);
+}
+
+static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data)
+{
+       struct its_pci_alias *dev_alias = data;
+
+       dev_alias->dev_id = alias;
+       if (pdev != dev_alias->pdev)
+               dev_alias->count += its_pci_msi_vec_count(dev_alias->pdev);
+
+       return 0;
+}
+
+static int its_msi_prepare(struct irq_domain *domain, struct device *dev,
+                          int nvec, msi_alloc_info_t *info)
+{
+       struct pci_dev *pdev;
+       struct its_node *its;
+       struct its_device *its_dev;
+       struct its_pci_alias dev_alias;
+
+       if (!dev_is_pci(dev))
+               return -EINVAL;
+
+       pdev = to_pci_dev(dev);
+       dev_alias.pdev = pdev;
+       dev_alias.count = nvec;
+
+       pci_for_each_dma_alias(pdev, its_get_pci_alias, &dev_alias);
+       its = domain->parent->host_data;
+
+       its_dev = its_find_device(its, dev_alias.dev_id);
+       if (its_dev) {
+               /*
+                * We already have seen this ID, probably through
+                * another alias (PCI bridge of some sort). No need to
+                * create the device.
+                */
+               dev_dbg(dev, "Reusing ITT for devID %x\n", dev_alias.dev_id);
+               goto out;
+       }
+
+       its_dev = its_create_device(its, dev_alias.dev_id, dev_alias.count);
+       if (!its_dev)
+               return -ENOMEM;
+
+       dev_dbg(&pdev->dev, "ITT %d entries, %d bits\n",
+               dev_alias.count, ilog2(dev_alias.count));
+out:
+       info->scratchpad[0].ptr = its_dev;
+       info->scratchpad[1].ptr = dev;
+       return 0;
+}
+
+static struct msi_domain_ops its_pci_msi_ops = {
+       .msi_prepare    = its_msi_prepare,
+};
+
+static struct msi_domain_info its_pci_msi_domain_info = {
+       .flags  = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+                  MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX),
+       .ops    = &its_pci_msi_ops,
+       .chip   = &its_msi_irq_chip,
+};
+
+static int its_irq_gic_domain_alloc(struct irq_domain *domain,
+                                   unsigned int virq,
+                                   irq_hw_number_t hwirq)
+{
+       struct of_phandle_args args;
+
+       args.np = domain->parent->of_node;
+       args.args_count = 3;
+       args.args[0] = GIC_IRQ_TYPE_LPI;
+       args.args[1] = hwirq;
+       args.args[2] = IRQ_TYPE_EDGE_RISING;
+
+       return irq_domain_alloc_irqs_parent(domain, virq, 1, &args);
+}
+
+static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+                               unsigned int nr_irqs, void *args)
+{
+       msi_alloc_info_t *info = args;
+       struct its_device *its_dev = info->scratchpad[0].ptr;
+       irq_hw_number_t hwirq;
+       int err;
+       int i;
+
+       for (i = 0; i < nr_irqs; i++) {
+               err = its_alloc_device_irq(its_dev, &hwirq);
+               if (err)
+                       return err;
+
+               err = its_irq_gic_domain_alloc(domain, virq + i, hwirq);
+               if (err)
+                       return err;
+
+               irq_domain_set_hwirq_and_chip(domain, virq + i,
+                                             hwirq, &its_irq_chip, its_dev);
+               dev_dbg(info->scratchpad[1].ptr, "ID:%d pID:%d vID:%d\n",
+                       (int)(hwirq - its_dev->lpi_base), (int)hwirq, virq + i);
+       }
+
+       return 0;
+}
+
+static void its_irq_domain_activate(struct irq_domain *domain,
+                                   struct irq_data *d)
+{
+       struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+       u32 event = its_get_event_id(d);
+
+       /* Map the GIC IRQ and event to the device */
+       its_send_mapvi(its_dev, d->hwirq, event);
+}
+
+static void its_irq_domain_deactivate(struct irq_domain *domain,
+                                     struct irq_data *d)
+{
+       struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+       u32 event = its_get_event_id(d);
+
+       /* Stop the delivery of interrupts */
+       its_send_discard(its_dev, event);
+}
+
+static void its_irq_domain_free(struct irq_domain *domain, unsigned int virq,
+                               unsigned int nr_irqs)
+{
+       struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+       struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+       int i;
+
+       for (i = 0; i < nr_irqs; i++) {
+               struct irq_data *data = irq_domain_get_irq_data(domain,
+                                                               virq + i);
+               u32 event = its_get_event_id(data);
+
+               /* Mark interrupt index as unused */
+               clear_bit(event, its_dev->lpi_map);
+
+               /* Nuke the entry in the domain */
+               irq_domain_reset_irq_data(data);
+       }
+
+       /* If all interrupts have been freed, start mopping the floor */
+       if (bitmap_empty(its_dev->lpi_map, its_dev->nr_lpis)) {
+               its_lpi_free(its_dev->lpi_map,
+                            its_dev->lpi_base,
+                            its_dev->nr_lpis);
+
+               /* Unmap device/itt */
+               its_send_mapd(its_dev, 0);
+               its_free_device(its_dev);
+       }
+
+       irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops its_domain_ops = {
+       .alloc                  = its_irq_domain_alloc,
+       .free                   = its_irq_domain_free,
+       .activate               = its_irq_domain_activate,
+       .deactivate             = its_irq_domain_deactivate,
+};
+
+static int its_force_quiescent(void __iomem *base)
+{
+       u32 count = 1000000;    /* 1s */
+       u32 val;
+
+       val = readl_relaxed(base + GITS_CTLR);
+       if (val & GITS_CTLR_QUIESCENT)
+               return 0;
+
+       /* Disable the generation of all interrupts to this ITS */
+       val &= ~GITS_CTLR_ENABLE;
+       writel_relaxed(val, base + GITS_CTLR);
+
+       /* Poll GITS_CTLR and wait until ITS becomes quiescent */
+       while (1) {
+               val = readl_relaxed(base + GITS_CTLR);
+               if (val & GITS_CTLR_QUIESCENT)
+                       return 0;
+
+               count--;
+               if (!count)
+                       return -EBUSY;
+
+               cpu_relax();
+               udelay(1);
+       }
+}
+
+static int its_probe(struct device_node *node, struct irq_domain *parent)
+{
+       struct resource res;
+       struct its_node *its;
+       void __iomem *its_base;
+       u32 val;
+       u64 baser, tmp;
+       int err;
+
+       err = of_address_to_resource(node, 0, &res);
+       if (err) {
+               pr_warn("%s: no regs?\n", node->full_name);
+               return -ENXIO;
+       }
+
+       its_base = ioremap(res.start, resource_size(&res));
+       if (!its_base) {
+               pr_warn("%s: unable to map registers\n", node->full_name);
+               return -ENOMEM;
+       }
+
+       val = readl_relaxed(its_base + GITS_PIDR2) & GIC_PIDR2_ARCH_MASK;
+       if (val != 0x30 && val != 0x40) {
+               pr_warn("%s: no ITS detected, giving up\n", node->full_name);
+               err = -ENODEV;
+               goto out_unmap;
+       }
+
+       err = its_force_quiescent(its_base);
+       if (err) {
+               pr_warn("%s: failed to quiesce, giving up\n",
+                       node->full_name);
+               goto out_unmap;
+       }
+
+       pr_info("ITS: %s\n", node->full_name);
+
+       its = kzalloc(sizeof(*its), GFP_KERNEL);
+       if (!its) {
+               err = -ENOMEM;
+               goto out_unmap;
+       }
+
+       raw_spin_lock_init(&its->lock);
+       INIT_LIST_HEAD(&its->entry);
+       INIT_LIST_HEAD(&its->its_device_list);
+       its->base = its_base;
+       its->phys_base = res.start;
+       its->msi_chip.of_node = node;
+       its->ite_size = ((readl_relaxed(its_base + GITS_TYPER) >> 4) & 0xf) + 1;
+
+       its->cmd_base = kzalloc(ITS_CMD_QUEUE_SZ, GFP_KERNEL);
+       if (!its->cmd_base) {
+               err = -ENOMEM;
+               goto out_free_its;
+       }
+       its->cmd_write = its->cmd_base;
+
+       err = its_alloc_tables(its);
+       if (err)
+               goto out_free_cmd;
+
+       err = its_alloc_collections(its);
+       if (err)
+               goto out_free_tables;
+
+       baser = (virt_to_phys(its->cmd_base)    |
+                GITS_CBASER_WaWb               |
+                GITS_CBASER_InnerShareable     |
+                (ITS_CMD_QUEUE_SZ / SZ_4K - 1) |
+                GITS_CBASER_VALID);
+
+       writeq_relaxed(baser, its->base + GITS_CBASER);
+       tmp = readq_relaxed(its->base + GITS_CBASER);
+       writeq_relaxed(0, its->base + GITS_CWRITER);
+       writel_relaxed(GITS_CTLR_ENABLE, its->base + GITS_CTLR);
+
+       if ((tmp ^ baser) & GITS_BASER_SHAREABILITY_MASK) {
+               pr_info("ITS: using cache flushing for cmd queue\n");
+               its->flags |= ITS_FLAGS_CMDQ_NEEDS_FLUSHING;
+       }
+
+       if (of_property_read_bool(its->msi_chip.of_node, "msi-controller")) {
+               its->domain = irq_domain_add_tree(NULL, &its_domain_ops, its);
+               if (!its->domain) {
+                       err = -ENOMEM;
+                       goto out_free_tables;
+               }
+
+               its->domain->parent = parent;
+
+               its->msi_chip.domain = pci_msi_create_irq_domain(node,
+                                                                
&its_pci_msi_domain_info,
+                                                                its->domain);
+               if (!its->msi_chip.domain) {
+                       err = -ENOMEM;
+                       goto out_free_domains;
+               }
+
+               err = of_pci_msi_chip_add(&its->msi_chip);
+               if (err)
+                       goto out_free_domains;
+       }
+
+       spin_lock(&its_lock);
+       list_add(&its->entry, &its_nodes);
+       spin_unlock(&its_lock);
+
+       return 0;
+
+out_free_domains:
+       if (its->msi_chip.domain)
+               irq_domain_remove(its->msi_chip.domain);
+       if (its->domain)
+               irq_domain_remove(its->domain);
+out_free_tables:
+       its_free_tables(its);
+out_free_cmd:
+       kfree(its->cmd_base);
+out_free_its:
+       kfree(its);
+out_unmap:
+       iounmap(its_base);
+       pr_err("ITS: failed probing %s (%d)\n", node->full_name, err);
+       return err;
+}
+
+static bool gic_rdists_supports_plpis(void)
+{
+       return !!(readl_relaxed(gic_data_rdist_rd_base() + GICR_TYPER) & 
GICR_TYPER_PLPIS);
+}
+
+int its_cpu_init(void)
+{
+       if (!list_empty(&its_nodes)) {
+               if (!gic_rdists_supports_plpis()) {
+                       pr_info("CPU%d: LPIs not supported\n", 
smp_processor_id());
+                       return -ENXIO;
+               }
+               its_cpu_init_lpis();
+               its_cpu_init_collection();
+       }
+
+       return 0;
+}
+
+static struct of_device_id its_device_id[] = {
+       {       .compatible     = "arm,gic-v3-its",     },
+       {},
+};
+
+int its_init(struct device_node *node, struct rdists *rdists,
+            struct irq_domain *parent_domain)
+{
+       struct device_node *np;
+
+       for (np = of_find_matching_node(node, its_device_id); np;
+            np = of_find_matching_node(np, its_device_id)) {
+               its_probe(np, parent_domain);
+       }
+
+       if (list_empty(&its_nodes)) {
+               pr_warn("ITS: No ITS available, not enabling LPIs\n");
+               return -ENXIO;
+       }
+
+       gic_rdists = rdists;
+       gic_root_node = node;
+
+       its_alloc_lpi_tables();
+       its_lpi_init(rdists->id_bits);
+
+       return 0;
+}
-- 
1.7.9.5


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