[PATCH net-next v2 2/7] net: ipa: replace ipa->suspend_ref with a flag bit

Alex Elder
2020-09-12T00:47:05Z

For suspend/resume, we currently take an extra clock reference to
prevent the IPA clock from being shut down until a power management
suspend request arrives. An atomic field in the IPA structure is
used to indicate whether this reference has been taken.

Instead, introduce a new flags bitmap in the IPA structure, and use
a single bit in that bitmap rather than the atomic to indicate
whether we have taken the special IPA clock reference.

Signed-off-by: Alex Elder <elder@linaro.org>
---
v2: New patch to use a bitmap bit rather than an atomic_t.

drivers/net/ipa/ipa.h | 14 ++++++++++++--
drivers/net/ipa/ipa_main.c | 14 +++++++-------
2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ipa/ipa.h b/drivers/net/ipa/ipa.h
index 407fee841a9a8..e02fe979b645b 100644
--- a/drivers/net/ipa/ipa.h
+++ b/drivers/net/ipa/ipa.h
@@ -27,15 +27,25 @@ struct ipa_clock;
struct ipa_smp2p;
struct ipa_interrupt;

+/**
+ * enum ipa_flag - IPA state flags
+ * @IPA_FLAG_CLOCK_HELD: Whether IPA clock is held to prevent suspend
+ * @IPA_FLAG_COUNT: Number of defined IPA flags
+ */
+enum ipa_flag {
+ IPA_FLAG_CLOCK_HELD,
+ IPA_FLAG_COUNT, /* Last; not a flag */
+};
+
/**
* struct ipa - IPA information
* @gsi: Embedded GSI structure
+ * @flags: Boolean state flags
* @version: IPA hardware version
* @pdev: Platform device
* @modem_rproc: Remoteproc handle for modem subsystem
* @smp2p: SMP2P information
* @clock: IPA clocking information
- * @suspend_ref: Whether clock reference preventing suspend taken
* @table_addr: DMA address of filter/route table content
* @table_virt: Virtual address of filter/route table content
* @interrupt: IPA Interrupt information
@@ -70,6 +80,7 @@ struct ipa_interrupt;
*/
struct ipa {
struct gsi gsi;
+ DECLARE_BITMAP(flags, IPA_FLAG_COUNT);
enum ipa_version version;
struct platform_device *pdev;
struct rproc *modem_rproc;
@@ -77,7 +88,6 @@ struct ipa {
void *notifier;
struct ipa_smp2p *smp2p;
struct ipa_clock *clock;
- atomic_t suspend_ref;

dma_addr_t table_addr;
__le64 *table_virt;
diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index 1fdfec41e4421..409375b96eb8f 100644
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -84,7 +84,7 @@ static void ipa_suspend_handler(struct ipa *ipa, enum ipa_irq_id irq_id)
* endpoints will be resumed as a result. This reference will
* be dropped when we get a power management suspend request.
*/
- if (!atomic_xchg(&ipa->suspend_ref, 1))
+ if (!test_and_set_bit(IPA_FLAG_CLOCK_HELD, ipa->flags))
ipa_clock_get(ipa);

/* Acknowledge/clear the suspend interrupt on all endpoints */
@@ -508,7 +508,7 @@ static int ipa_config(struct ipa *ipa, const struct ipa_data *data)
* is held after initialization completes, and won't get dropped
* unless/until a system suspend request arrives.
*/
- atomic_set(&ipa->suspend_ref, 1);
+ __set_bit(IPA_FLAG_CLOCK_HELD, ipa->flags);
ipa_clock_get(ipa);

ipa_hardware_config(ipa);
@@ -544,7 +544,7 @@ static int ipa_config(struct ipa *ipa, const struct ipa_data *data)
err_hardware_deconfig:
ipa_hardware_deconfig(ipa);
ipa_clock_put(ipa);
- atomic_set(&ipa->suspend_ref, 0);
+ __clear_bit(IPA_FLAG_CLOCK_HELD, ipa->flags);

return ret;
}
@@ -562,7 +562,7 @@ static void ipa_deconfig(struct ipa *ipa)
ipa_endpoint_deconfig(ipa);
ipa_hardware_deconfig(ipa);
ipa_clock_put(ipa);
- atomic_set(&ipa->suspend_ref, 0);
+ __clear_bit(IPA_FLAG_CLOCK_HELD, ipa->flags);
}

static int ipa_firmware_load(struct device *dev)
@@ -777,7 +777,7 @@ static int ipa_probe(struct platform_device *pdev)
dev_set_drvdata(dev, ipa);
ipa->modem_rproc = rproc;
ipa->clock = clock;
- atomic_set(&ipa->suspend_ref, 0);
+ __clear_bit(IPA_FLAG_CLOCK_HELD, ipa->flags);
ipa->wakeup_source = wakeup_source;
ipa->version = data->version;

@@ -913,7 +913,7 @@ static int ipa_suspend(struct device *dev)
struct ipa *ipa = dev_get_drvdata(dev);

ipa_clock_put(ipa);
- atomic_set(&ipa->suspend_ref, 0);
+ __clear_bit(IPA_FLAG_CLOCK_HELD, ipa->flags);

return 0;
}
@@ -933,7 +933,7 @@ static int ipa_resume(struct device *dev)
/* This clock reference will keep the IPA out of suspend
* until we get a power management suspend request.
*/
- atomic_set(&ipa->suspend_ref, 1);
+ __set_bit(IPA_FLAG_CLOCK_HELD, ipa->flags);
ipa_clock_get(ipa);

return 0;
--
2.20.1