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Commit 558b0165 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Marc Zyngier
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irqchip/gic-v3: Add workaround for Synquacer pre-ITS 



The Socionext Synquacer SoC's implementation of GICv3 has a so-called
'pre-ITS', which maps 32-bit writes targeted at a separate window of
size '4 << device_id_bits' onto writes to GITS_TRANSLATER with device
ID taken from bits [device_id_bits + 1:2] of the window offset.
Writes that target GITS_TRANSLATER directly are reported as originating
from device ID #0.

So add a workaround for this. Given that this breaks isolation, clear
the IRQ_DOMAIN_FLAG_MSI_REMAP flag as well.

Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 9d111d49

Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt

+4 −0
Original line number Diff line number Diff line
@@ -75,6 +75,10 @@ These nodes must have the following properties: 
- reg: Specifies the base physical address and size of the ITS

  registers.



Optional:

- socionext,synquacer-pre-its: (u32, u32) tuple describing the untranslated

  address and size of the pre-ITS window.



The main GIC node must contain the appropriate #address-cells,

#size-cells and ranges properties for the reg property of all ITS

nodes.

arch/arm64/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -539,6 +539,14 @@ config QCOM_QDF2400_ERRATUM_0065 


	  If unsure, say Y.



config SOCIONEXT_SYNQUACER_PREITS

	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"

	default y

	help

	  Socionext Synquacer SoCs implement a separate h/w block to generate

	  MSI doorbell writes with non-zero values for the device ID.



	  If unsure, say Y.

endmenu

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

+70 −2
Original line number Diff line number Diff line
@@ -83,6 +83,8 @@ struct its_baser { 
	u32		psz;

};



struct its_device;



/*

 * The ITS structure - contains most of the infrastructure, with the

 * top-level MSI domain, the command queue, the collections, and the
@@ -97,11 +99,15 @@ struct its_node { 
	struct its_cmd_block	*cmd_write;

	struct its_baser	tables[GITS_BASER_NR_REGS];

	struct its_collection	*collections;

	struct fwnode_handle	*fwnode_handle;

	u64			(*get_msi_base)(struct its_device *its_dev);

	struct list_head	its_device_list;

	u64			flags;

	u32			ite_size;

	u32			device_ids;

	int			numa_node;

	unsigned int		msi_domain_flags;

	u32			pre_its_base; /* for Socionext Synquacer */

	bool			is_v4;

};
@@ -1095,6 +1101,13 @@ static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val, 
	return IRQ_SET_MASK_OK_DONE;

}



static u64 its_irq_get_msi_base(struct its_device *its_dev)

{

	struct its_node *its = its_dev->its;



	return its->phys_base + GITS_TRANSLATER;

}



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);
@@ -1102,7 +1115,7 @@ static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg) 
	u64 addr;



	its = its_dev->its;

	addr = its->phys_base + GITS_TRANSLATER;

	addr = its->get_msi_base(its_dev);



	msg->address_lo		= lower_32_bits(addr);

	msg->address_hi		= upper_32_bits(addr);
@@ -2760,6 +2773,45 @@ static bool __maybe_unused its_enable_quirk_qdf2400_e0065(void *data) 
	return true;

}



static u64 its_irq_get_msi_base_pre_its(struct its_device *its_dev)

{

	struct its_node *its = its_dev->its;



	/*

	 * The Socionext Synquacer SoC has a so-called 'pre-ITS',

	 * which maps 32-bit writes targeted at a separate window of

	 * size '4 << device_id_bits' onto writes to GITS_TRANSLATER

	 * with device ID taken from bits [device_id_bits + 1:2] of

	 * the window offset.

	 */

	return its->pre_its_base + (its_dev->device_id << 2);

}



static bool __maybe_unused its_enable_quirk_socionext_synquacer(void *data)

{

	struct its_node *its = data;

	u32 pre_its_window[2];

	u32 ids;



	if (!fwnode_property_read_u32_array(its->fwnode_handle,

					   "socionext,synquacer-pre-its",

					   pre_its_window,

					   ARRAY_SIZE(pre_its_window))) {



		its->pre_its_base = pre_its_window[0];

		its->get_msi_base = its_irq_get_msi_base_pre_its;



		ids = ilog2(pre_its_window[1]) - 2;

		if (its->device_ids > ids)

			its->device_ids = ids;



		/* the pre-ITS breaks isolation, so disable MSI remapping */

		its->msi_domain_flags &= ~IRQ_DOMAIN_FLAG_MSI_REMAP;

		return true;

	}

	return false;

}



static const struct gic_quirk its_quirks[] = {

#ifdef CONFIG_CAVIUM_ERRATUM_22375

	{
@@ -2784,6 +2836,19 @@ static const struct gic_quirk its_quirks[] = { 
		.mask	= 0xffffffff,

		.init	= its_enable_quirk_qdf2400_e0065,

	},

#endif

#ifdef CONFIG_SOCIONEXT_SYNQUACER_PREITS

	{

		/*

		 * The Socionext Synquacer SoC incorporates ARM's own GIC-500

		 * implementation, but with a 'pre-ITS' added that requires

		 * special handling in software.

		 */

		.desc	= "ITS: Socionext Synquacer pre-ITS",

		.iidr	= 0x0001143b,

		.mask	= 0xffffffff,

		.init	= its_enable_quirk_socionext_synquacer,

	},

#endif

	{

	}
@@ -2813,7 +2878,7 @@ static int its_init_domain(struct fwnode_handle *handle, struct its_node *its) 


	inner_domain->parent = its_parent;

	irq_domain_update_bus_token(inner_domain, DOMAIN_BUS_NEXUS);

	inner_domain->flags |= IRQ_DOMAIN_FLAG_MSI_REMAP;

	inner_domain->flags |= its->msi_domain_flags;

	info->ops = &its_msi_domain_ops;

	info->data = its;

	inner_domain->host_data = info;
@@ -2967,6 +3032,9 @@ static int __init its_probe_one(struct resource *res, 
		goto out_free_its;

	}

	its->cmd_write = its->cmd_base;

	its->fwnode_handle = handle;

	its->get_msi_base = its_irq_get_msi_base;

	its->msi_domain_flags = IRQ_DOMAIN_FLAG_MSI_REMAP;



	its_enable_quirks(its);