[PATCH net-next 09/13] net: ipa: only enable generic command completion IRQ when needed

From: Alex Elder
Date: Thu Nov 05 2020 - 13:15:24 EST


The completion of a generic EE GSI command is signaled by a global
interrupt of type GP_INT1. The only other used type for a global
interrupt is a hardware error report.

First, disallow all global interrupt types in gsi_irq_setup(). We
want to know about hardware errors, so re-enable the interrupt type
in gsi_irq_enable(), to allow hardware errors to be reported.
Disable that interrupt type again in gsi_irq_disable().

We only issue generic EE commands one at a time, and there's no
reason to keep the completion interrupt enabled when no generic
EE command is pending. We furthermore have no need to enable the
GP_INT2 or GP_INT3 interrupt types (which aren't used).

The change in gsi_irq_enable() makes GSI_CNTXT_GLOB_IRQ_ALL unused,
so get rid of it. Have gsi_generic_command() enable the GP_INT1
interrupt type (in addition to the ERROR_INT type) only while a
generic command is pending.

Signed-off-by: Alex Elder <elder@xxxxxxxxxx>
---
drivers/net/ipa/gsi.c | 35 +++++++++++++++++++++++++++--------
drivers/net/ipa/gsi_reg.h | 1 -
2 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index 2c01a04e07b70..4ab1d89f642ea 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -257,6 +257,7 @@ static void gsi_irq_setup(struct gsi *gsi)

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

/* Turn off all GSI interrupts when we're all done */
@@ -289,14 +290,16 @@ static void gsi_irq_enable(struct gsi *gsi)
{
u32 val;

+ /* Global interrupts include hardware error reports. Enable
+ * that so we can at least report the error should it occur.
+ */
+ iowrite32(ERROR_INT_FMASK, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);
+ gsi->type_enabled_bitmap |= BIT(GSI_GLOB_EE);
+
/* Each IEOB interrupt is enabled (later) as needed by channels */
iowrite32(0, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_MSK_OFFSET);
gsi->type_enabled_bitmap |= BIT(GSI_IEOB);

- val = GSI_CNTXT_GLOB_IRQ_ALL;
- iowrite32(val, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);
- gsi->type_enabled_bitmap |= BIT(GSI_GLOB_EE);
-
/* We don't use inter-EE channel or event interrupts */

/* Never enable GSI_BREAK_POINT */
@@ -315,8 +318,8 @@ static void gsi_irq_disable(struct gsi *gsi)
gsi_irq_type_update(gsi);

iowrite32(0, gsi->virt + GSI_CNTXT_GSI_IRQ_EN_OFFSET);
- 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_GLOB_IRQ_EN_OFFSET);
}

/* Return the virtual address associated with a ring index */
@@ -1101,8 +1104,8 @@ static void gsi_isr_glob_err(struct gsi *gsi)
iowrite32(~0, gsi->virt + GSI_ERROR_LOG_CLR_OFFSET);

ee = u32_get_bits(val, ERR_EE_FMASK);
- which = u32_get_bits(val, ERR_VIRT_IDX_FMASK);
type = u32_get_bits(val, ERR_TYPE_FMASK);
+ which = u32_get_bits(val, ERR_VIRT_IDX_FMASK);
code = u32_get_bits(val, ERR_CODE_FMASK);

if (type == GSI_ERR_TYPE_CHAN)
@@ -1606,8 +1609,19 @@ static int gsi_generic_command(struct gsi *gsi, u32 channel_id,
enum gsi_generic_cmd_opcode opcode)
{
struct completion *completion = &gsi->completion;
+ bool success;
u32 val;

+ /* The error global interrupt type is always enabled (until we
+ * teardown), so we won't change that. A generic EE command
+ * completes with a GSI global interrupt of type GP_INT1. We
+ * only perform one generic command at a time (to allocate or
+ * halt a modem channel) and only from this function. So we
+ * enable the GP_INT1 IRQ type here while we're expecting it.
+ */
+ val = ERROR_INT_FMASK | GP_INT1_FMASK;
+ iowrite32(val, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);
+
/* First zero the result code field */
val = ioread32(gsi->virt + GSI_CNTXT_SCRATCH_0_OFFSET);
val &= ~GENERIC_EE_RESULT_FMASK;
@@ -1618,8 +1632,13 @@ static int gsi_generic_command(struct gsi *gsi, u32 channel_id,
val |= u32_encode_bits(channel_id, GENERIC_CHID_FMASK);
val |= u32_encode_bits(GSI_EE_MODEM, GENERIC_EE_FMASK);

- if (gsi_command(gsi, GSI_GENERIC_CMD_OFFSET, val, completion))
- return 0; /* Success! */
+ success = gsi_command(gsi, GSI_GENERIC_CMD_OFFSET, val, completion);
+
+ /* Disable the GP_INT1 IRQ type again */
+ iowrite32(ERROR_INT_FMASK, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);
+
+ if (success)
+ return 0;

dev_err(gsi->dev, "GSI generic command %u to channel %u timed out\n",
opcode, channel_id);
diff --git a/drivers/net/ipa/gsi_reg.h b/drivers/net/ipa/gsi_reg.h
index 1dd81cf0b46a8..ae00aff1cfa50 100644
--- a/drivers/net/ipa/gsi_reg.h
+++ b/drivers/net/ipa/gsi_reg.h
@@ -335,7 +335,6 @@ enum gsi_irq_type_id {
#define GP_INT1_FMASK GENMASK(1, 1)
#define GP_INT2_FMASK GENMASK(2, 2)
#define GP_INT3_FMASK GENMASK(3, 3)
-#define GSI_CNTXT_GLOB_IRQ_ALL GENMASK(3, 0)

#define GSI_CNTXT_GSI_IRQ_STTS_OFFSET \
GSI_EE_N_CNTXT_GSI_IRQ_STTS_OFFSET(GSI_EE_AP)
--
2.20.1