One trivial comment:
On Thu, Jan 25, 2018 at 11:38:32PM -0800, Derek Basehore wrote:
> Some platforms power off GIC logic in suspend, so we need to
> save/restore state. The distributor and redistributor registers need
> to be handled in platform code due to access permissions on those
> registers, but the ITS registers can be restored in the kernel.
>
> Signed-off-by: Derek Basehore <[email protected]>
> ---
> drivers/irqchip/irq-gic-v3-its.c | 86
> ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 86 insertions(+)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c
> b/drivers/irqchip/irq-gic-v3-its.c
> index 06f025fd5726..4727b447610f 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
...
> @@ -3042,6 +3054,75 @@ static void its_enable_quirks(struct its_node *its)
> gic_enable_quirks(iidr, its_quirks, its);
> }
>
> +int its_save_disable(void)
This (and its_restore_enable()) should be static, now that you're only
using them in this file.
Brian
> +{
> + struct its_node *its;
> + int err = 0;
> +
> + spin_lock(&its_lock);
> + list_for_each_entry(its, &its_nodes, entry) {
> + if (its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE) {
> + struct its_ctx *ctx = &its->its_ctx;
> + void __iomem *base = its->base;
> +
> + ctx->ctlr = readl_relaxed(base + GITS_CTLR);
> + err = its_force_quiescent(base);
> + if (err) {
> + writel_relaxed(ctx->ctlr, base + GITS_CTLR);
> + goto err;
> + }
> +
> + ctx->cbaser = gits_read_cbaser(base + GITS_CBASER);
> + }
> + }
> +
> +err:
> + if (err) {
> + list_for_each_entry_continue_reverse(its, &its_nodes, entry) {
> + if (its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE) {
> + struct its_ctx *ctx = &its->its_ctx;
> + void __iomem *base = its->base;
> +
> + writel_relaxed(ctx->ctlr, base + GITS_CTLR);
> + }
> + }
> + }
> +
> + spin_unlock(&its_lock);
> +
> + return err;
> +}
> +
> +void its_restore_enable(void)
> +{
> + struct its_node *its;
> +
> + spin_lock(&its_lock);
> + list_for_each_entry(its, &its_nodes, entry) {
> + struct its_ctx *ctx = &its->its_ctx;
> + struct its_baser *baser;
> + void __iomem *base;
> + int i;
> +
> + if (its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE) {
> + base = its->base;
> + gits_write_cbaser(ctx->cbaser, base + GITS_CBASER);
> + /* Restore GITS_BASER from the value cache. */
> + for (i = 0; i < GITS_BASER_NR_REGS; i++) {
> + baser = &its->tables[i];
> + its_write_baser(its, baser, baser->val);
> + }
> + writel_relaxed(ctx->ctlr, base + GITS_CTLR);
> + }
> + }
> + spin_unlock(&its_lock);
> +}
> +
> +static struct syscore_ops its_syscore_ops = {
> + .suspend = its_save_disable,
> + .resume = its_restore_enable,
> +};
> +
> static int its_init_domain(struct fwnode_handle *handle, struct its_node
> *its)
> {
> struct irq_domain *inner_domain;
