diff options
Diffstat (limited to 'drivers/irqchip/irq-gic-v3-its.c')
| -rw-r--r-- | drivers/irqchip/irq-gic-v3-its.c | 1425 |
1 files changed, 1425 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c new file mode 100644 index 000000000000..86e4684adeb1 --- /dev/null +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -0,0 +1,1425 @@ +/* + * Copyright (C) 2013, 2014 ARM Limited, All Rights Reserved. + * Author: Marc Zyngier <marc.zyngier@arm.com> + * + * 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; + + 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 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 = PAGE_SIZE; + 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); + u64 tmp; + void *base; + + if (type == GITS_BASER_TYPE_NONE) + continue; + + /* We're lazy and only allocate a single page for now */ + base = (void *)get_zeroed_page(GFP_KERNEL); + 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 |= (PAGE_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)(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 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(2, roundup_pow_of_two(nvecs)); + sz = nr_ites * 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 = 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(&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, 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; +} + +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; + u32 dev_id; + struct its_device *its_dev; + + if (!dev_is_pci(dev)) + return -EINVAL; + + pdev = to_pci_dev(dev); + dev_id = PCI_DEVID(pdev->bus->number, pdev->devfn); + its = domain->parent->host_data; + + its_dev = its_find_device(its, dev_id); + if (WARN_ON(its_dev)) + return -EINVAL; + + its_dev = its_create_device(its, dev_id, nvec); + if (!its_dev) + return -ENOMEM; + + dev_dbg(&pdev->dev, "ITT %d entries, %d bits\n", nvec, ilog2(nvec)); + + 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_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; + } + + 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; + } + + 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 (!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", }, + {}, +}; + +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; +} |