Commit cc2d3216 authored by Marc Zyngier's avatar Marc Zyngier Committed by Jason Cooper
Browse files

irqchip: GICv3: ITS command queue 



The ITS is configured through a number commands that the driver
issues to the HW using a memory-based circular buffer.

This patch implements the subset of commands that are required
for Linux.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-5-git-send-email-marc.zyngier@arm.com


Signed-off-by: default avatarJason Cooper <jason@lakedaemon.net>
parent f5c1434c

drivers/irqchip/irq-gic-v3-its.c

0 → 100644
+511 −0
Original line number Diff line number Diff line 
/*

 * 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)



/*

 * 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;

};



/*

 * 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 = order_base_2(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);

}

include/linux/irqchip/arm-gic-v3.h

+102 −0
Original line number Diff line number Diff line
@@ -80,9 +80,27 @@ 
#define GICR_MOVALLR			0x0110

#define GICR_PIDR2			GICD_PIDR2



#define GICR_CTLR_ENABLE_LPIS		(1UL << 0)



#define GICR_TYPER_CPU_NUMBER(r)	(((r) >> 8) & 0xffff)



#define GICR_WAKER_ProcessorSleep	(1U << 1)

#define GICR_WAKER_ChildrenAsleep	(1U << 2)



#define GICR_PROPBASER_NonShareable	(0U << 10)

#define GICR_PROPBASER_InnerShareable	(1U << 10)

#define GICR_PROPBASER_OuterShareable	(2U << 10)

#define GICR_PROPBASER_SHAREABILITY_MASK (3UL << 10)

#define GICR_PROPBASER_nCnB		(0U << 7)

#define GICR_PROPBASER_nC		(1U << 7)

#define GICR_PROPBASER_RaWt		(2U << 7)

#define GICR_PROPBASER_RaWb		(3U << 7)

#define GICR_PROPBASER_WaWt		(4U << 7)

#define GICR_PROPBASER_WaWb		(5U << 7)

#define GICR_PROPBASER_RaWaWt		(6U << 7)

#define GICR_PROPBASER_RaWaWb		(7U << 7)

#define GICR_PROPBASER_IDBITS_MASK	(0x1f)



/*

 * Re-Distributor registers, offsets from SGI_base

 */
@@ -95,9 +113,93 @@ 
#define GICR_IPRIORITYR0		GICD_IPRIORITYR

#define GICR_ICFGR0			GICD_ICFGR



#define GICR_TYPER_PLPIS		(1U << 0)

#define GICR_TYPER_VLPIS		(1U << 1)

#define GICR_TYPER_LAST			(1U << 4)



#define LPI_PROP_GROUP1			(1 << 1)

#define LPI_PROP_ENABLED		(1 << 0)



/*

 * ITS registers, offsets from ITS_base

 */

#define GITS_CTLR			0x0000

#define GITS_IIDR			0x0004

#define GITS_TYPER			0x0008

#define GITS_CBASER			0x0080

#define GITS_CWRITER			0x0088

#define GITS_CREADR			0x0090

#define GITS_BASER			0x0100

#define GITS_PIDR2			GICR_PIDR2



#define GITS_TRANSLATER			0x10040



#define GITS_TYPER_PTA			(1UL << 19)



#define GITS_CBASER_VALID		(1UL << 63)

#define GITS_CBASER_nCnB		(0UL << 59)

#define GITS_CBASER_nC			(1UL << 59)

#define GITS_CBASER_RaWt		(2UL << 59)

#define GITS_CBASER_RaWb		(3UL << 59)

#define GITS_CBASER_WaWt		(4UL << 59)

#define GITS_CBASER_WaWb		(5UL << 59)

#define GITS_CBASER_RaWaWt		(6UL << 59)

#define GITS_CBASER_RaWaWb		(7UL << 59)

#define GITS_CBASER_NonShareable	(0UL << 10)

#define GITS_CBASER_InnerShareable	(1UL << 10)

#define GITS_CBASER_OuterShareable	(2UL << 10)

#define GITS_CBASER_SHAREABILITY_MASK	(3UL << 10)



#define GITS_BASER_NR_REGS		8



#define GITS_BASER_VALID		(1UL << 63)

#define GITS_BASER_nCnB			(0UL << 59)

#define GITS_BASER_nC			(1UL << 59)

#define GITS_BASER_RaWt			(2UL << 59)

#define GITS_BASER_RaWb			(3UL << 59)

#define GITS_BASER_WaWt			(4UL << 59)

#define GITS_BASER_WaWb			(5UL << 59)

#define GITS_BASER_RaWaWt		(6UL << 59)

#define GITS_BASER_RaWaWb		(7UL << 59)

#define GITS_BASER_TYPE_SHIFT		(56)

#define GITS_BASER_TYPE(r)		(((r) >> GITS_BASER_TYPE_SHIFT) & 7)

#define GITS_BASER_ENTRY_SIZE_SHIFT	(48)

#define GITS_BASER_ENTRY_SIZE(r)	((((r) >> GITS_BASER_ENTRY_SIZE_SHIFT) & 0xff) + 1)

#define GITS_BASER_NonShareable		(0UL << 10)

#define GITS_BASER_InnerShareable	(1UL << 10)

#define GITS_BASER_OuterShareable	(2UL << 10)

#define GITS_BASER_SHAREABILITY_SHIFT	(10)

#define GITS_BASER_SHAREABILITY_MASK	(3UL << GITS_BASER_SHAREABILITY_SHIFT)

#define GITS_BASER_PAGE_SIZE_SHIFT	(8)

#define GITS_BASER_PAGE_SIZE_4K		(0UL << GITS_BASER_PAGE_SIZE_SHIFT)

#define GITS_BASER_PAGE_SIZE_16K	(1UL << GITS_BASER_PAGE_SIZE_SHIFT)

#define GITS_BASER_PAGE_SIZE_64K	(2UL << GITS_BASER_PAGE_SIZE_SHIFT)

#define GITS_BASER_PAGE_SIZE_MASK	(3UL << GITS_BASER_PAGE_SIZE_SHIFT)



#define GITS_BASER_TYPE_NONE		0

#define GITS_BASER_TYPE_DEVICE		1

#define GITS_BASER_TYPE_VCPU		2

#define GITS_BASER_TYPE_CPU		3

#define GITS_BASER_TYPE_COLLECTION	4

#define GITS_BASER_TYPE_RESERVED5	5

#define GITS_BASER_TYPE_RESERVED6	6

#define GITS_BASER_TYPE_RESERVED7	7



/*

 * ITS commands

 */

#define GITS_CMD_MAPD			0x08

#define GITS_CMD_MAPC			0x09

#define GITS_CMD_MAPVI			0x0a

#define GITS_CMD_MOVI			0x01

#define GITS_CMD_DISCARD		0x0f

#define GITS_CMD_INV			0x0c

#define GITS_CMD_MOVALL			0x0e

#define GITS_CMD_INVALL			0x0d

#define GITS_CMD_INT			0x03

#define GITS_CMD_CLEAR			0x04

#define GITS_CMD_SYNC			0x05



/*

 * CPU interface registers

 */

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