associating a unique wq_ctx with a struct completion variable for easy
lookup.
Signed-off-by: Guru Das Srinagesh <quic_gurus@xxxxxxxxxxx>
---
This series is based on the tip of linux-next because a couple of SCM
driver-related patches are still in-flight in Bjorn's tree.
---
drivers/firmware/qcom/qcom_scm-smc.c | 7 ++-
drivers/firmware/qcom/qcom_scm.c | 90 +++++++++++++++++++++++++++---------
drivers/firmware/qcom/qcom_scm.h | 3 +-
3 files changed, 77 insertions(+), 23 deletions(-)
diff --git a/drivers/firmware/qcom/qcom_scm-smc.c b/drivers/firmware/qcom/qcom_scm-smc.c
index 16cf88acfa8e..80083e3615b1 100644
--- a/drivers/firmware/qcom/qcom_scm-smc.c
+++ b/drivers/firmware/qcom/qcom_scm-smc.c
@@ -103,7 +103,12 @@ static int __scm_smc_do_quirk_handle_waitq(struct device *dev, struct arm_smccc_
wq_ctx = res->a1;
smc_call_ctx = res->a2;
- ret = qcom_scm_wait_for_wq_completion(wq_ctx);
+ if (!dev) {
+ /* Protect the dev_get_drvdata() call that follows */
+ return -EPROBE_DEFER;
+ }
+
+ ret = qcom_scm_wait_for_wq_completion(dev_get_drvdata(dev), wq_ctx);
if (ret)
return ret;
diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index 520de9b5633a..70f0c35beb16 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -10,6 +10,7 @@
#include <linux/dma-mapping.h>
#include <linux/export.h>
#include <linux/firmware/qcom/qcom_scm.h>
+#include <linux/idr.h>
#include <linux/init.h>
#include <linux/interconnect.h>
#include <linux/interrupt.h>
@@ -27,13 +28,18 @@
static bool download_mode = IS_ENABLED(CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT);
module_param(download_mode, bool, 0);
+struct qcom_scm_waitq {
+ struct idr idr;
+ spinlock_t idr_lock;
+};
+
struct qcom_scm {
struct device *dev;
struct clk *core_clk;
struct clk *iface_clk;
struct clk *bus_clk;
struct icc_path *path;
- struct completion waitq_comp;
+ struct qcom_scm_waitq waitq;
struct reset_controller_dev reset;
/* control access to the interconnect path */
@@ -1742,42 +1748,76 @@ bool qcom_scm_is_available(void)
}
EXPORT_SYMBOL_GPL(qcom_scm_is_available);
-static int qcom_scm_assert_valid_wq_ctx(u32 wq_ctx)
+static struct completion *qcom_scm_get_completion(struct qcom_scm *scm, u32 wq_ctx)
{
- /* FW currently only supports a single wq_ctx (zero).
- * TODO: Update this logic to include dynamic allocation and lookup of
- * completion structs when FW supports more wq_ctx values.
+ struct completion *wq;
+ unsigned long flags;
+ int err;
+
+ spin_lock_irqsave(&scm->waitq.idr_lock, flags);
+ wq = idr_find(&scm->waitq.idr, wq_ctx);
+ if (wq) {
+ /*
+ * Valid struct completion *wq found corresponding to
+ * given wq_ctx. We're done here.
+ */
+ goto out;
+ }
+
+ /*
+ * If a struct completion *wq does not exist for wq_ctx, create it. FW
+ * only uses a finite number of wq_ctx values, so we will be reaching
+ * here only a few times right at the beginning of the device's uptime
+ * and then early-exit from idr_find() above subsequently.
*/
- if (wq_ctx != 0) {
- dev_err(__scm->dev, "Firmware unexpectedly passed non-zero wq_ctx\n");
- return -EINVAL;
+ wq = devm_kzalloc(scm->dev, sizeof(*wq), GFP_ATOMIC);
+ if (!wq) {
+ wq = ERR_PTR(-ENOMEM);
+ goto out;
}
- return 0;
+ init_completion(wq);
+
+ err = idr_alloc_u32(&scm->waitq.idr, wq, &wq_ctx, wq_ctx, GFP_ATOMIC);
+ if (err < 0) {
+ /* Don't wait for driver to be unloaded to free wq */
+ devm_kfree(scm->dev, wq);
+ wq = ERR_PTR(err);
+ }
+
+out:
+ spin_unlock_irqrestore(&scm->waitq.idr_lock, flags);
+ return wq;
}
-int qcom_scm_wait_for_wq_completion(u32 wq_ctx)
+int qcom_scm_wait_for_wq_completion(struct qcom_scm *scm, u32 wq_ctx)
{
- int ret;
+ struct completion *wq;
- ret = qcom_scm_assert_valid_wq_ctx(wq_ctx);
- if (ret)
- return ret;
+ wq = qcom_scm_get_completion(scm, wq_ctx);
+ if (IS_ERR(wq)) {
+ pr_err("Unable to wait on invalid waitqueue for wq_ctx %d: %ld\n",
+ wq_ctx, PTR_ERR(wq));
+ return PTR_ERR(wq);
+ }
- wait_for_completion(&__scm->waitq_comp);
+ wait_for_completion(wq);
return 0;
}
static int qcom_scm_waitq_wakeup(struct qcom_scm *scm, unsigned int wq_ctx)
{
- int ret;
+ struct completion *wq;
- ret = qcom_scm_assert_valid_wq_ctx(wq_ctx);
- if (ret)
- return ret;
+ wq = qcom_scm_get_completion(scm, wq_ctx);
+ if (IS_ERR(wq)) {
+ pr_err("Unable to wake up invalid waitqueue for wq_ctx %d: %ld\n",
+ wq_ctx, PTR_ERR(wq));
+ return PTR_ERR(wq);
+ }
- complete(&__scm->waitq_comp);
+ complete(wq);
return 0;
}
@@ -1854,10 +1894,13 @@ static int qcom_scm_probe(struct platform_device *pdev)
if (ret)
return ret;
+ platform_set_drvdata(pdev, scm);
+
__scm = scm;
__scm->dev = &pdev->dev;
- init_completion(&__scm->waitq_comp);
+ spin_lock_init(&__scm->waitq.idr_lock);
+ idr_init(&__scm->waitq.idr);
irq = platform_get_irq_optional(pdev, 0);
if (irq < 0) {
@@ -1905,8 +1948,13 @@ static int qcom_scm_probe(struct platform_device *pdev)
static void qcom_scm_shutdown(struct platform_device *pdev)
{
+ struct qcom_scm *scm;
+
+ scm = platform_get_drvdata(pdev);
+
/* Clean shutdown, disable download mode to allow normal restart */
qcom_scm_set_download_mode(false);
+ idr_destroy(&scm->waitq.idr);
}
static const struct of_device_id qcom_scm_dt_match[] = {
diff --git a/drivers/firmware/qcom/qcom_scm.h b/drivers/firmware/qcom/qcom_scm.h
index 4532907e8489..d54df5a2b690 100644
--- a/drivers/firmware/qcom/qcom_scm.h
+++ b/drivers/firmware/qcom/qcom_scm.h
@@ -62,7 +62,8 @@ struct qcom_scm_res {
u64 result[MAX_QCOM_SCM_RETS];
};
-int qcom_scm_wait_for_wq_completion(u32 wq_ctx);
+struct qcom_scm;
+int qcom_scm_wait_for_wq_completion(struct qcom_scm *scm, u32 wq_ctx);
int scm_get_wq_ctx(u32 *wq_ctx, u32 *flags, u32 *more_pending);
#define SCM_SMC_FNID(s, c) ((((s) & 0xFF) << 8) | ((c) & 0xFF))
---
base-commit: 2ef7141596eed0b4b45ef18b3626f428a6b0a822
change-id: 20231027-multi-wqs-8b87fc0d3b53
Best regards,
