[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] [RFC PATCH 02/19] xen/arm: its: Import GICv3 ITS driver from linux



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

This is actual GICv3 ITS driver from linux.
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>
---
 xen/arch/arm/gic-v3-its.c | 1348 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 1348 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..28b72e4
--- /dev/null
+++ b/xen/arch/arm/gic-v3-its.c
@@ -0,0 +1,1348 @@
+/*
+ * 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_chip, 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_chip       msi_chip;
+    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;
+    int                    lpi_base;
+    int                    nr_lpis;
+    u32                    nr_ites;
+    u32                    device_id;
+};
+
+static LIST_HEAD(its_nodes);
+static DEFINE_SPINLOCK(its_lock);
+static struct irq_domain  *lpi_domain;
+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] &= ~0xffULL;
+    cmd->raw_cmd[0] |= cmd_nr;
+}
+
+static void its_encode_devid(struct its_cmd_block *cmd, u32 devid)
+{
+    cmd->raw_cmd[0] &= 0xffffffffULL;
+    cmd->raw_cmd[0] |= ((u64)devid) << 32;
+}
+
+static void its_encode_event_id(struct its_cmd_block *cmd, u32 id)
+{
+    cmd->raw_cmd[1] &= ~0xffffffffULL;
+    cmd->raw_cmd[1] |= id;
+}
+
+static void its_encode_phys_id(struct its_cmd_block *cmd, u32 phys_id)
+{
+    cmd->raw_cmd[1] &= 0xffffffffULL;
+    cmd->raw_cmd[1] |= ((u64)phys_id) << 32;
+}
+
+static void its_encode_size(struct its_cmd_block *cmd, u8 size)
+{
+    cmd->raw_cmd[1] &= ~0xffULL;
+    cmd->raw_cmd[1] |= size;
+}
+
+static void its_encode_itt(struct its_cmd_block *cmd, u64 itt_addr)
+{
+    cmd->raw_cmd[2] &= ~0xffffffffffffULL;
+    cmd->raw_cmd[2] |= itt_addr & 0xffffffffff00ULL;
+}
+
+static void its_encode_valid(struct its_cmd_block *cmd, int valid)
+{
+    cmd->raw_cmd[2] &= ~(1ULL << 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] &= ~(0xffffffffULL << 16);
+    cmd->raw_cmd[2] |= (target_addr & (0xffffffffULL << 16));
+}
+
+static void its_encode_collection(struct its_cmd_block *cmd, u16 col)
+{
+    cmd->raw_cmd[2] &= ~0xffffULL;
+    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 = max(order_base_2(desc->its_mapd_cmd.dev->nr_ites), 1);
+
+    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;
+
+    raw_spin_lock(&its->lock);
+
+    cmd = its_allocate_entry(its);
+    if (!cmd) {        /* We're soooooo screewed... */
+        pr_err_ratelimited("ITS can't allocate, dropping command\n");
+        raw_spin_unlock(&its->lock);
+        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(&its->lock);
+
+    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 void lpi_set_config(struct its_device *its_dev, u32 hwirq,
+               u32 id, int enable)
+{
+    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 inline u16 its_msi_get_entry_nr(struct msi_desc *desc)
+{
+    return desc->msi_attrib.entry_nr;
+}
+
+static void its_mask_irq(struct irq_data *d)
+{
+    struct its_device *its_dev = irq_data_get_irq_handler_data(d);
+    u32 id;
+
+    /* If MSI, propagate the mask to the RC */
+    if (IS_ENABLED(CONFIG_PCI_MSI) && d->msi_desc) {
+        id = its_msi_get_entry_nr(d->msi_desc);
+        mask_msi_irq(d);
+    } else {
+        id = d->hwirq;
+    }
+
+    lpi_set_config(its_dev, d->hwirq, id, 0);
+}
+
+static void its_unmask_irq(struct irq_data *d)
+{
+    struct its_device *its_dev = irq_data_get_irq_handler_data(d);
+    u32 id;
+
+    /* If MSI, propagate the unmask to the RC */
+    if (IS_ENABLED(CONFIG_PCI_MSI) && d->msi_desc) {
+        id = its_msi_get_entry_nr(d->msi_desc);
+        unmask_msi_irq(d);
+    } else {
+        id = d->hwirq;
+    }
+
+    lpi_set_config(its_dev, d->hwirq, id, 1);
+}
+
+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_handler_data(d);
+    struct its_collection *target_col;
+    u32 id;
+
+    if (cpu >= nr_cpu_ids)
+        return -EINVAL;
+
+    target_col = &its_dev->its->collections[cpu];
+    if (IS_ENABLED(CONFIG_PCI_MSI) && d->msi_desc)
+        id = its_msi_get_entry_nr(d->msi_desc);
+    else
+        id = d->hwirq;
+    its_send_movi(its_dev, target_col, id);
+    its_dev->collection = target_col;
+
+    return IRQ_SET_MASK_OK;
+}
+
+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,
+};
+
+/*
+ * 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;
+    u64 typer = readq_relaxed(its->base + GITS_TYPER);
+    u64 max_devices, max_ittsize;
+
+    max_devices = 1ULL << (((typer >> 13) & 0x1f) + 1);
+    max_ittsize = ((typer >> 4) & 0xf) + 1;
+    max_ittsize *= max_devices;
+
+    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);
+        u64 tmp;
+        void *base;
+
+        if (type == GITS_BASER_TYPE_NONE)
+            continue;
+
+        base = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 
get_order(max_ittsize));
+        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 |= ((max_ittsize / psz) - 1) & 0xffUL;
+        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;
+            }
+        }
+
+        /* skip comparing cacheability feilds as they are implemenations
+         * defined.
+         */
+        val = val << 5;
+        tmp = tmp << 5;
+
+        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)(PAGE_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;
+
+    raw_spin_lock(&its->lock);
+
+    list_for_each_entry(tmp, &its->its_device_list, entry) {
+        if (tmp->device_id == dev_id) {
+            its_dev = tmp;
+            break;
+        }
+    }
+
+    raw_spin_unlock(&its->lock);
+
+    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;
+    void *itt;
+    int lpi_base;
+    int nr_lpis;
+    int cpu;
+    int sz;
+
+    dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+    sz = nvecs * its->ite_size;
+    sz = max(sz, ITS_ITT_ALIGN) + ITS_ITT_ALIGN - 1;
+    itt = kmalloc(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 = nvecs;
+    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(&its->lock);
+    list_add(&dev->entry, &its->its_device_list);
+    raw_spin_unlock(&its->lock);
+
+    /* 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)
+{
+    raw_spin_lock(&its_dev->its->lock);
+    list_del(&its_dev->entry);
+    raw_spin_unlock(&its_dev->its->lock);
+    kfree(its_dev->itt);
+    kfree(its_dev);
+}
+
+static int its_alloc_device_irq(struct its_device *dev, u32 id,
+                                int *hwirq, unsigned int *irq)
+{
+    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;
+    *irq = irq_create_mapping(lpi_domain, *hwirq);
+    if (!*irq)
+        return -ENOSPC;    /* Don't kill the device, though */
+
+    set_bit(idx, dev->lpi_map);
+
+    /* Map the GIC irq ID to the device */
+    its_send_mapvi(dev, *hwirq, id);
+
+    return 0;
+}
+
+
+
+static int its_msi_get_vec_count(struct pci_dev *pdev, struct msi_desc *desc)
+{
+#ifdef CONFIG_PCI_MSI
+    if (desc->msi_attrib.is_msix)
+        return pci_msix_vec_count(pdev);
+    else
+        return pci_msi_vec_count(pdev);
+#else
+    return -EINVAL;
+#endif
+}
+
+int pci_requester_id(struct pci_dev *dev);
+static int its_msi_setup_irq(struct msi_chip *chip,
+                             struct pci_dev *pdev,
+                             struct msi_desc *desc)
+{
+    struct its_node *its = container_of(chip, struct its_node, msi_chip);
+    struct its_device *its_dev;
+    struct msi_msg msg;
+    unsigned int irq;
+    u64 addr;
+    int hwirq;
+    int err;
+    u32 dev_id = pci_requester_id(pdev);
+    u32 vec_nr;
+
+    its_dev = its_find_device(its, dev_id);
+    if (!its_dev) {
+        int nvec = its_msi_get_vec_count(pdev, desc);
+        if (WARN_ON(nvec <= 0))
+            return nvec;
+        its_dev = its_create_device(its, dev_id, nvec);
+    }
+    if (!its_dev)
+        return -ENOMEM;
+    vec_nr = its_msi_get_entry_nr(desc);
+    err = its_alloc_device_irq(its_dev, vec_nr, &hwirq, &irq);
+    if (err)
+        return err;
+
+    irq_set_msi_desc(irq, desc);
+    irq_set_handler_data(irq, its_dev);
+
+    addr = its->phys_base + GITS_TRANSLATER;
+
+    msg.address_lo        = (u32)addr;
+    msg.address_hi        = (u32)(addr >> 32);
+    msg.data        = vec_nr;
+
+    write_msi_msg(irq, &msg);
+    return 0;
+}
+
+static void its_msi_teardown_irq(struct msi_chip *chip, unsigned int irq)
+{
+    struct irq_data *d = irq_get_irq_data(irq);
+    struct its_device *its_dev = irq_data_get_irq_handler_data(d);
+
+    BUG_ON(d->hwirq < its_dev->lpi_base ||        /* OMG! */
+           d->hwirq > (its_dev->lpi_base + its_dev->nr_lpis));
+
+    /* Stop the delivery of interrupts */
+    its_send_discard(its_dev, its_msi_get_entry_nr(d->msi_desc));
+
+    /* Mark interrupt index as unused, and clear the mapping */
+    clear_bit(d->hwirq - its_dev->lpi_base, its_dev->lpi_map);
+    irq_dispose_mapping(irq);
+
+    /* 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);
+    }
+}
+
+static int its_probe(struct device_node *node)
+{
+    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;
+    }
+
+    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(1, 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;
+    }
+
+    spin_lock(&its_lock);
+    list_add(&its->entry, &its_nodes);
+    spin_unlock(&its_lock);
+
+    if (IS_ENABLED(CONFIG_PCI_MSI) && /* Remove this once we have PCI... */
+        of_property_read_bool(its->msi_chip.of_node, "msi-controller")) {
+        its->msi_chip.setup_irq        = its_msi_setup_irq;
+        its->msi_chip.teardown_irq    = its_msi_teardown_irq;
+
+        err = of_pci_msi_chip_add(&its->msi_chip);
+    }
+
+    return err;
+
+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 (!gic_rdists_supports_plpis()) {
+        pr_info("CPU%d: LPIs not supported\n", smp_processor_id());
+        return -ENXIO;
+    }
+
+    if (!list_empty(&its_nodes)) {
+        its_cpu_init_lpis();
+        its_cpu_init_collection();
+    }
+
+    return 0;
+}
+
+static struct of_device_id its_device_id[] = {
+    {    .compatible    = "arm,gic-v3-its",    },
+    {},
+};
+
+struct irq_chip *its_init(struct device_node *node, struct rdists *rdists,
+                          struct irq_domain *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);
+    }
+
+    if (list_empty(&its_nodes)) {
+        pr_info("ITS: No ITS available, not enabling LPIs\n");
+        return NULL;
+    }
+
+    gic_rdists = rdists;
+    gic_root_node = node;
+    lpi_domain = domain;
+
+    its_alloc_lpi_tables();
+    its_lpi_init(rdists->id_bits);
+
+    return &its_irq_chip;
+}
-- 
1.7.9.5


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.