Commit b054d4f9 authored by Alex Elder's avatar Alex Elder Committed by Jakub Kicinski
Browse files

net: ipa: only enable GSI channel control IRQs when needed 



A GSI channel causes a channel control interrupt to fire whenever
its state changes (between NOT_ALLOCATED, ALLOCATED, STARTED, etc.).
We do not support inter-EE channel commands (initiated by other EEs),
so no channel should ever change state except when we request it to.

Currently, we permit *all* channels to generate channel control
interrupts--even those that are never used.  And we enable channel
control interrupts essentially at all times, from setup to teardown.

Instead, disable all channel control interrupts initially in
gsi_irq_setup(), and only enable the channel control interrupt
type for the duration of a channel command.  When doing so, only
allow the channel being operated upon to cause the interrupt to
fire.

Because a channel's interrupt is now enabled only when needed (one
channel at a time), there is no longer any need to zero the channel
mask in gsi_irq_disable().

Add new gsi_irq_type_enable() and gsi_irq_type_disable() as helper
functions to control whether a given GSI interrupt type is enabled.

Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 3ca97ffd

drivers/net/ipa/gsi.c

+32 −7
Original line number Diff line number Diff line
@@ -237,11 +237,25 @@ static void gsi_irq_type_update(struct gsi *gsi) 
		  gsi->virt + GSI_CNTXT_TYPE_IRQ_MSK_OFFSET);

}



static void gsi_irq_type_enable(struct gsi *gsi, enum gsi_irq_type_id type_id)

{

	gsi->type_enabled_bitmap |= BIT(type_id);

	gsi_irq_type_update(gsi);

}



static void gsi_irq_type_disable(struct gsi *gsi, enum gsi_irq_type_id type_id)

{

	gsi->type_enabled_bitmap &= ~BIT(type_id);

	gsi_irq_type_update(gsi);

}



/* Turn off all GSI interrupts initially */

static void gsi_irq_setup(struct gsi *gsi)

{

	gsi->type_enabled_bitmap = 0;

	gsi_irq_type_update(gsi);



	iowrite32(0, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_MSK_OFFSET);

}



/* Turn off all GSI interrupts when we're all done */
@@ -274,10 +288,6 @@ static void gsi_irq_enable(struct gsi *gsi) 
{

	u32 val;



	val = GENMASK(gsi->channel_count - 1, 0);

	iowrite32(val, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_MSK_OFFSET);

	gsi->type_enabled_bitmap |= BIT(GSI_CH_CTRL);



	val = GENMASK(gsi->evt_ring_count - 1, 0);

	iowrite32(val, gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_MSK_OFFSET);

	gsi->type_enabled_bitmap |= BIT(GSI_EV_CTRL);
@@ -311,7 +321,6 @@ static void gsi_irq_disable(struct gsi *gsi) 
	iowrite32(0, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);

	iowrite32(0, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_MSK_OFFSET);

	iowrite32(0, gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_MSK_OFFSET);

	iowrite32(0, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_MSK_OFFSET);

}



/* Return the virtual address associated with a ring index */
@@ -461,13 +470,29 @@ gsi_channel_command(struct gsi_channel *channel, enum gsi_ch_cmd_opcode opcode) 
	u32 channel_id = gsi_channel_id(channel);

	struct gsi *gsi = channel->gsi;

	struct device *dev = gsi->dev;

	bool success;

	u32 val;



	/* We only perform one channel command at a time, and channel

	 * control interrupts should only occur when such a command is

	 * issued here.  So we only permit *this* channel to trigger

	 * an interrupt and only enable the channel control IRQ type

	 * when we expect it to occur.

	 */

	val = BIT(channel_id);

	iowrite32(val, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_MSK_OFFSET);

	gsi_irq_type_enable(gsi, GSI_CH_CTRL);



	val = u32_encode_bits(channel_id, CH_CHID_FMASK);

	val |= u32_encode_bits(opcode, CH_OPCODE_FMASK);

	success = gsi_command(gsi, GSI_CH_CMD_OFFSET, val, completion);



	if (gsi_command(gsi, GSI_CH_CMD_OFFSET, val, completion))

		return 0;	/* Success! */

	/* Disable the interrupt again */

	gsi_irq_type_disable(gsi, GSI_CH_CTRL);

	iowrite32(0, gsi->virt + GSI_CNTXT_SRC_CH_IRQ_MSK_OFFSET);



	if (success)

		return 0;



	dev_err(dev, "GSI command %u for channel %u timed out, state %u\n",

		opcode, channel_id, gsi_channel_state(channel));

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