Re: [PATCH v2 11/16] irqchip/irq-mvebu-icu: add support for System Error Interrupts (SEI)

Marc Zyngier
2018-05-23T14:23:59Z

On 22/05/18 10:40, Miquel Raynal wrote:
> An SEI driver provides an MSI domain through which it is possible to
> raise SEIs.
>
> Handle the NSR probe function in a more generic way to support other
> type of interrupts (ie. the SEIs).
>
> For clarity we do not use tree IRQ domains for now but linear ones
> instead, allocating the 207 ICU lines for each interrupt group.

What's the rational for not using trees? Because that's effectively a
100% overhead...

> Reallocating an ICU slot is prevented by the use of an ICU-wide bitmap.
>
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
> drivers/irqchip/irq-mvebu-icu.c | 126 ++++++++++++++++++++++++++++++++++------
> 1 file changed, 108 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/irqchip/irq-mvebu-icu.c b/drivers/irqchip/irq-mvebu-icu.c
> index 977e47b2716f..6ad6236d6ff1 100644
> --- a/drivers/irqchip/irq-mvebu-icu.c
> +++ b/drivers/irqchip/irq-mvebu-icu.c
> @@ -28,6 +28,10 @@
> #define ICU_SETSPI_NSR_AH 0x14
> #define ICU_CLRSPI_NSR_AL 0x18
> #define ICU_CLRSPI_NSR_AH 0x1c
> +#define ICU_SET_SEI_AL 0x50
> +#define ICU_SET_SEI_AH 0x54
> +#define ICU_CLR_SEI_AL 0x58
> +#define ICU_CLR_SEI_AH 0x5C
> #define ICU_INT_CFG(x) (0x100 + 4 * (x))
> #define ICU_INT_ENABLE BIT(24)
> #define ICU_IS_EDGE BIT(28)
> @@ -38,12 +42,28 @@
> #define ICU_SATA0_ICU_ID 109
> #define ICU_SATA1_ICU_ID 107
>
> +struct mvebu_icu_subset_data {
> + unsigned int icu_group;
> + unsigned int offset_set_ah;
> + unsigned int offset_set_al;
> + unsigned int offset_clr_ah;
> + unsigned int offset_clr_al;
> +};
> +
> struct mvebu_icu {
> struct irq_chip irq_chip;
> struct regmap *regmap;
> struct device *dev;
> - atomic_t initialized;
> bool legacy_bindings;
> + /* Lock on interrupt allocations/releases */
> + spinlock_t msi_lock;
> + DECLARE_BITMAP(msi_bitmap, ICU_MAX_IRQS);
> +};
> +
> +struct mvebu_icu_msi_data {
> + struct mvebu_icu *icu;
> + atomic_t initialized;
> + const struct mvebu_icu_subset_data *subset_data;
> };
>
> struct mvebu_icu_irq_data {
> @@ -76,16 +96,25 @@ static struct mvebu_icu *mvebu_icu_dev_get_drvdata(struct platform_device *pdev)
> return icu;
> }
>
> -static void mvebu_icu_init(struct mvebu_icu *icu, struct msi_msg *msg)
> +static void mvebu_icu_init(struct mvebu_icu *icu, struct irq_domain *d,
> + struct msi_msg *msg)
> {
> - if (atomic_cmpxchg(&icu->initialized, false, true))
> + struct mvebu_icu_msi_data *msi_data = platform_msi_get_host_data(d);
> + const struct mvebu_icu_subset_data *subset = msi_data->subset_data;
> +
> + if (atomic_cmpxchg(&msi_data->initialized, false, true))
> + return;
> +
> + /* Set 'SET' ICU SPI message address in AP */
> + regmap_write(icu->regmap, subset->offset_set_ah, msg[0].address_hi);
> + regmap_write(icu->regmap, subset->offset_set_al, msg[0].address_lo);
> +
> + if (subset->icu_group != ICU_GRP_NSR)
> return;
>
> - /* Set Clear/Set ICU SPI message address in AP */
> - regmap_write(icu->regmap, ICU_SETSPI_NSR_AH, msg[0].address_hi);
> - regmap_write(icu->regmap, ICU_SETSPI_NSR_AL, msg[0].address_lo);
> - regmap_write(icu->regmap, ICU_CLRSPI_NSR_AH, msg[1].address_hi);
> - regmap_write(icu->regmap, ICU_CLRSPI_NSR_AL, msg[1].address_lo);
> + /* Set 'CLEAR' ICU SPI message address in AP (level-MSI only) */
> + regmap_write(icu->regmap, subset->offset_clr_ah, msg[1].address_hi);
> + regmap_write(icu->regmap, subset->offset_clr_al, msg[1].address_lo);
> }
>
> static void mvebu_icu_write_msg(struct msi_desc *desc, struct msi_msg *msg)
> @@ -96,8 +125,8 @@ static void mvebu_icu_write_msg(struct msi_desc *desc, struct msi_msg *msg)
> unsigned int icu_int;
>
> if (msg->address_lo || msg->address_hi) {
> - /* One off initialization */
> - mvebu_icu_init(icu, msg);
> + /* One off initialization per domain */
> + mvebu_icu_init(icu, d->domain, msg);
> /* Configure the ICU with irq number & type */
> icu_int = msg->data | ICU_INT_ENABLE;
> if (icu_irqd->type & IRQ_TYPE_EDGE_RISING)
> @@ -131,7 +160,8 @@ static int
> mvebu_icu_irq_domain_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
> unsigned long *hwirq, unsigned int *type)
> {
> - struct mvebu_icu *icu = platform_msi_get_host_data(d);
> + struct mvebu_icu_msi_data *msi_data = platform_msi_get_host_data(d);
> + struct mvebu_icu *icu = msi_data->icu;
> unsigned int param_count = icu->legacy_bindings ? 3 : 2;
>
> /* Check the count of the parameters in dt */
> @@ -172,7 +202,9 @@ mvebu_icu_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
> int err;
> unsigned long hwirq;
> struct irq_fwspec *fwspec = args;
> - struct mvebu_icu *icu = platform_msi_get_host_data(domain);
> + struct mvebu_icu_msi_data *msi_data =
> + platform_msi_get_host_data(domain);
> + struct mvebu_icu *icu = msi_data->icu;
> struct mvebu_icu_irq_data *icu_irqd;
>
> icu_irqd = kmalloc(sizeof(*icu_irqd), GFP_KERNEL);
> @@ -186,16 +218,22 @@ mvebu_icu_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
> goto free_irqd;
> }
>
> + spin_lock(&icu->msi_lock);
> + err = bitmap_allocate_region(icu->msi_bitmap, hwirq, 0);
> + spin_unlock(&icu->msi_lock);

This (and the freeing counterpart) could deserve a couple of helpers.

> + if (err < 0)
> + goto free_irqd;
> +
> if (icu->legacy_bindings)
> icu_irqd->icu_group = fwspec->param[0];
> else
> - icu_irqd->icu_group = ICU_GRP_NSR;
> + icu_irqd->icu_group = msi_data->subset_data->icu_group;
> icu_irqd->icu = icu;
>
> err = platform_msi_domain_alloc(domain, virq, nr_irqs);
> if (err) {
> dev_err(icu->dev, "failed to allocate ICU interrupt in parent domain\n");
> - goto free_irqd;
> + goto free_bitmap;
> }
>
> /* Make sure there is no interrupt left pending by the firmware */
> @@ -214,6 +252,10 @@ mvebu_icu_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
>
> free_msi:
> platform_msi_domain_free(domain, virq, nr_irqs);
> +free_bitmap:
> + spin_lock(&icu->msi_lock);
> + bitmap_release_region(icu->msi_bitmap, hwirq, 0);
> + spin_unlock(&icu->msi_lock);
> free_irqd:
> kfree(icu_irqd);
> return err;
> @@ -223,12 +265,19 @@ static void
> mvebu_icu_irq_domain_free(struct irq_domain *domain, unsigned int virq,
> unsigned int nr_irqs)
> {
> + struct mvebu_icu_msi_data *msi_data =
> + platform_msi_get_host_data(domain);
> + struct mvebu_icu *icu = msi_data->icu;
> struct irq_data *d = irq_get_irq_data(virq);
> struct mvebu_icu_irq_data *icu_irqd = d->chip_data;
>
> kfree(icu_irqd);
>
> platform_msi_domain_free(domain, virq, nr_irqs);
> +
> + spin_lock(&icu->msi_lock);
> + bitmap_release_region(icu->msi_bitmap, d->hwirq, 0);
> + spin_unlock(&icu->msi_lock);
> }
>
> static const struct irq_domain_ops mvebu_icu_domain_ops = {
> @@ -239,14 +288,29 @@ static const struct irq_domain_ops mvebu_icu_domain_ops = {
>
> static int mvebu_icu_subset_probe(struct platform_device *pdev)
> {
> + const struct mvebu_icu_subset_data *subset;
> + struct mvebu_icu_msi_data *msi_data;
> struct device_node *msi_parent_dn;
> struct irq_domain *irq_domain;
> struct mvebu_icu *icu;
>
> + msi_data = devm_kzalloc(&pdev->dev, sizeof(*msi_data), GFP_KERNEL);
> + if (!msi_data)
> + return -ENOMEM;
> +
> icu = mvebu_icu_dev_get_drvdata(pdev);
> if (IS_ERR(icu))
> return PTR_ERR(icu);
>
> + subset = of_device_get_match_data(&pdev->dev);
> + if (!subset) {
> + dev_err(&pdev->dev, "Could not retrieve subset data\n");
> + return -EINVAL;
> + }
> +
> + msi_data->icu = icu;
> + msi_data->subset_data = subset;
> +
> pdev->dev.msi_domain = of_msi_get_domain(&pdev->dev, pdev->dev.of_node,
> DOMAIN_BUS_PLATFORM_MSI);
> if (!pdev->dev.msi_domain)
> @@ -259,7 +323,7 @@ static int mvebu_icu_subset_probe(struct platform_device *pdev)
> irq_domain = platform_msi_create_device_domain(&pdev->dev, ICU_MAX_IRQS,
> mvebu_icu_write_msg,
> &mvebu_icu_domain_ops,
> - icu);
> + msi_data);
> if (!irq_domain) {
> dev_err(&pdev->dev, "Failed to create ICU MSI domain\n");
> return -ENOMEM;
> @@ -268,9 +332,30 @@ static int mvebu_icu_subset_probe(struct platform_device *pdev)
> return 0;
> }
>
> +static const struct mvebu_icu_subset_data mvebu_icu_nsr_subset_data = {
> + .icu_group = ICU_GRP_NSR,
> + .offset_set_ah = ICU_SETSPI_NSR_AH,
> + .offset_set_al = ICU_SETSPI_NSR_AL,
> + .offset_clr_ah = ICU_CLRSPI_NSR_AH,
> + .offset_clr_al = ICU_CLRSPI_NSR_AL,
> +};
> +
> +static const struct mvebu_icu_subset_data mvebu_icu_sei_subset_data = {
> + .icu_group = ICU_GRP_SEI,
> + .offset_set_ah = ICU_SET_SEI_AH,
> + .offset_set_al = ICU_SET_SEI_AL,
> + .offset_clr_ah = ICU_CLR_SEI_AH,
> + .offset_clr_al = ICU_CLR_SEI_AL,

I thought SEI was edge only, given what you do in mvebu_icu_init.
Confused...

> +};
> +
> static const struct of_device_id mvebu_icu_subset_of_match[] = {
> {
> .compatible = "marvell,cp110-icu-nsr",
> + .data = &mvebu_icu_nsr_subset_data,
> + },
> + {
> + .compatible = "marvell,cp110-icu-sei",
> + .data = &mvebu_icu_sei_subset_data,
> },
> {},
> };
> @@ -317,6 +402,8 @@ static int mvebu_icu_probe(struct platform_device *pdev)
> if (IS_ERR(icu->regmap))
> return PTR_ERR(icu->regmap);
>
> + spin_lock_init(&icu->msi_lock);
> +
> icu->irq_chip.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
> "ICU.%x",
> (unsigned int)res->start);
> @@ -341,7 +428,7 @@ static int mvebu_icu_probe(struct platform_device *pdev)
> #endif
>
> /*
> - * Clean all ICU interrupts with type SPI_NSR, required to
> + * Clean all ICU interrupts of type NSR and SEI, required to
> * avoid unpredictable SPI assignments done by firmware.
> */
> for (i = 0 ; i < ICU_MAX_IRQS ; i++) {
> @@ -350,7 +437,8 @@ static int mvebu_icu_probe(struct platform_device *pdev)
> regmap_read(icu->regmap, ICU_INT_CFG(i), &icu_int);
> icu_grp = icu_int >> ICU_GROUP_SHIFT;
>
> - if (icu_grp == ICU_GRP_NSR)
> + if (icu_grp == ICU_GRP_NSR ||
> + (icu_grp == ICU_GRP_SEI && !icu->legacy_bindings))
> regmap_write(icu->regmap, ICU_INT_CFG(i), 0);
> }
>
> @@ -363,7 +451,9 @@ static int mvebu_icu_probe(struct platform_device *pdev)
> }
>
> static const struct of_device_id mvebu_icu_of_match[] = {
> - { .compatible = "marvell,cp110-icu", },
> + {
> + .compatible = "marvell,cp110-icu",
> + },
> {},
> };
>
>

Thanks,

M.
--
Jazz is not dead. It just smells funny...