On Tue 05 Oct 09:13 PDT 2021, Deepak Kumar Singh wrote:
> From: Chris Lew <clew@xxxxxxxxxxxxxx>
>
> This patch adds feature negotiation and ssr ack feature between
> local host and remote processor. Local host can negotiate on common
> features supported with remote processor.
>
> When ssr ack feature bit is set, the remote processor will tell local
> host when it is reinitialized. All clients registered for falling edge
> interrupts will be notified when the smp2p entries are cleared for ssr.
>
> Signed-off-by: Chris Lew <clew@xxxxxxxxxxxxxx>
> Signed-off-by: Deepak Kumar Singh <deesin@xxxxxxxxxxxxxx>
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Regards,
Bjorn
> ---
> drivers/soc/qcom/smp2p.c | 121 +++++++++++++++++++++++++++++++++++++----------
> 1 file changed, 96 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/soc/qcom/smp2p.c b/drivers/soc/qcom/smp2p.c
> index 38585a7..11b9511 100644
> --- a/drivers/soc/qcom/smp2p.c
> +++ b/drivers/soc/qcom/smp2p.c
> @@ -41,8 +41,11 @@
> #define SMP2P_MAX_ENTRY_NAME 16
>
> #define SMP2P_FEATURE_SSR_ACK 0x1
> +#define SMP2P_FLAGS_RESTART_DONE_BIT 0
> +#define SMP2P_FLAGS_RESTART_ACK_BIT 1
>
> #define SMP2P_MAGIC 0x504d5324
> +#define SMP2P_ALL_FEATURES SMP2P_FEATURE_SSR_ACK
>
> /**
> * struct smp2p_smem_item - in memory communication structure
> @@ -136,6 +139,10 @@ struct qcom_smp2p {
>
> unsigned valid_entries;
>
> + bool ssr_ack_enabled;
> + bool ssr_ack;
> + bool negotiation_done;
> +
> unsigned local_pid;
> unsigned remote_pid;
>
> @@ -163,22 +170,53 @@ static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)
> }
> }
>
> -/**
> - * qcom_smp2p_intr() - interrupt handler for incoming notifications
> - * @irq: unused
> - * @data: smp2p driver context
> - *
> - * Handle notifications from the remote side to handle newly allocated entries
> - * or any changes to the state bits of existing entries.
> - */
> -static irqreturn_t qcom_smp2p_intr(int irq, void *data)
> +static bool qcom_smp2p_check_ssr(struct qcom_smp2p *smp2p)
> +{
> + struct smp2p_smem_item *in = smp2p->in;
> + bool restart;
> +
> + if (!smp2p->ssr_ack_enabled)
> + return false;
> +
> + restart = in->flags & BIT(SMP2P_FLAGS_RESTART_DONE_BIT);
> +
> + return restart != smp2p->ssr_ack;
> +}
> +
> +static void qcom_smp2p_do_ssr_ack(struct qcom_smp2p *smp2p)
> +{
> + struct smp2p_smem_item *out = smp2p->out;
> + u32 val;
> +
> + smp2p->ssr_ack = !smp2p->ssr_ack;
> +
> + val = out->flags & ~BIT(SMP2P_FLAGS_RESTART_ACK_BIT);
> + if (smp2p->ssr_ack)
> + val |= BIT(SMP2P_FLAGS_RESTART_ACK_BIT);
> + out->flags = val;
> +
> + qcom_smp2p_kick(smp2p);
> +}
> +
> +static void qcom_smp2p_negotiate(struct qcom_smp2p *smp2p)
> +{
> + struct smp2p_smem_item *out = smp2p->out;
> + struct smp2p_smem_item *in = smp2p->in;
> +
> + if (in->version == out->version) {
> + out->features &= in->features;
> +
> + if (out->features & SMP2P_FEATURE_SSR_ACK)
> + smp2p->ssr_ack_enabled = true;
> +
> + smp2p->negotiation_done = true;
> + }
> +}
> +
> +static void qcom_smp2p_notify_in(struct qcom_smp2p *smp2p)
> {
> struct smp2p_smem_item *in;
> struct smp2p_entry *entry;
> - struct qcom_smp2p *smp2p = data;
> - unsigned smem_id = smp2p->smem_items[SMP2P_INBOUND];
> - unsigned pid = smp2p->remote_pid;
> - size_t size;
> int irq_pin;
> u32 status;
> char buf[SMP2P_MAX_ENTRY_NAME];
> @@ -187,18 +225,6 @@ static irqreturn_t qcom_smp2p_intr(int irq, void *data)
>
> in = smp2p->in;
>
> - /* Acquire smem item, if not already found */
> - if (!in) {
> - in = qcom_smem_get(pid, smem_id, &size);
> - if (IS_ERR(in)) {
> - dev_err(smp2p->dev,
> - "Unable to acquire remote smp2p item\n");
> - return IRQ_HANDLED;
> - }
> -
> - smp2p->in = in;
> - }
> -
> /* Match newly created entries */
> for (i = smp2p->valid_entries; i < in->valid_entries; i++) {
> list_for_each_entry(entry, &smp2p->inbound, node) {
> @@ -237,7 +263,51 @@ static irqreturn_t qcom_smp2p_intr(int irq, void *data)
> }
> }
> }
> +}
> +
> +/**
> + * qcom_smp2p_intr() - interrupt handler for incoming notifications
> + * @irq: unused
> + * @data: smp2p driver context
> + *
> + * Handle notifications from the remote side to handle newly allocated entries
> + * or any changes to the state bits of existing entries.
> + */
> +static irqreturn_t qcom_smp2p_intr(int irq, void *data)
> +{
> + struct smp2p_smem_item *in;
> + struct qcom_smp2p *smp2p = data;
> + unsigned int smem_id = smp2p->smem_items[SMP2P_INBOUND];
> + unsigned int pid = smp2p->remote_pid;
> + bool ack_restart;
> + size_t size;
> +
> + in = smp2p->in;
> +
> + /* Acquire smem item, if not already found */
> + if (!in) {
> + in = qcom_smem_get(pid, smem_id, &size);
> + if (IS_ERR(in)) {
> + dev_err(smp2p->dev,
> + "Unable to acquire remote smp2p item\n");
> + goto out;
> + }
> +
> + smp2p->in = in;
> + }
> +
> + if (!smp2p->negotiation_done)
> + qcom_smp2p_negotiate(smp2p);
> +
> + if (smp2p->negotiation_done) {
> + ack_restart = qcom_smp2p_check_ssr(smp2p);
> + qcom_smp2p_notify_in(smp2p);
> +
> + if (ack_restart)
> + qcom_smp2p_do_ssr_ack(smp2p);
> + }
>
> +out:
> return IRQ_HANDLED;
> }
>
> @@ -393,6 +463,7 @@ static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)
> out->remote_pid = smp2p->remote_pid;
> out->total_entries = SMP2P_MAX_ENTRY;
> out->valid_entries = 0;
> + out->features = SMP2P_ALL_FEATURES;
>
> /*
> * Make sure the rest of the header is written before we validate the
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
