[PATCH V13 06/13] irqchip/loongson-pch-pic: Add ACPI init support

From: Jianmin Lv
Date: Mon Jun 27 2022 - 07:50:41 EST

From: Huacai Chen <chenhuacai@xxxxxxxxxxx>

We are preparing to add new Loongson (based on LoongArch, not compatible
with old MIPS-based Loongson) support. LoongArch use ACPI other than DT
as its boot protocol, so add ACPI init support.

PCH-PIC/PCH-MSI stands for "Interrupt Controller" that described in
Section 5 of "Loongson 7A1000 Bridge User Manual". For more information
please refer Documentation/loongarch/irq-chip-model.rst.

For systems with two chipsets, there are two related pch irqdomains,
each of which has the same node id as its parent irqdomain. So we
defined a structure to mantain the relation of node and it's parent
irqdomain.

struct acpi_vector_group {
int node;
struct irq_domain *parent;
};

The parent irqdomain will be set for node id in parent irqdomain driver
before pch irqdomain is created.

Co-developed-by: Jianmin Lv <lvjianmin@xxxxxxxxxxx>
Signed-off-by: Jianmin Lv <lvjianmin@xxxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
arch/loongarch/include/asm/irq.h | 11 +-
arch/loongarch/kernel/irq.c | 2 +-
drivers/irqchip/irq-loongson-pch-pic.c | 200 ++++++++++++++++++++++++++++-----
3 files changed, 179 insertions(+), 34 deletions(-)

diff --git a/arch/loongarch/include/asm/irq.h b/arch/loongarch/include/asm/irq.h
index 48c0ce4..a444dc6 100644
--- a/arch/loongarch/include/asm/irq.h
+++ b/arch/loongarch/include/asm/irq.h
@@ -48,6 +48,12 @@ static inline bool on_irq_stack(int cpu, unsigned long sp)
#define MAX_IO_PICS 2
#define NR_IRQS (64 + (256 * MAX_IO_PICS))

+struct acpi_vector_group {
+ int node;
+ struct irq_domain *parent;
+};
+extern struct acpi_vector_group pch_group[MAX_IO_PICS];
+
#define CORES_PER_EIO_NODE 4

#define LOONGSON_CPU_UART0_VEC 10 /* CPU UART0 */
@@ -108,8 +114,7 @@ int pch_lpc_acpi_init(struct irq_domain *parent,
struct acpi_madt_lpc_pic *acpi_pchlpc);
struct irq_domain *pch_msi_acpi_init(struct irq_domain *parent,
struct acpi_madt_msi_pic *acpi_pchmsi);
-struct irq_domain *pch_pic_acpi_init(struct irq_domain *parent,
- struct acpi_madt_bio_pic *acpi_pchpic);
+int find_pch_pic(u32 gsi);

extern struct acpi_madt_lio_pic *acpi_liointc;
extern struct acpi_madt_eio_pic *acpi_eiointc[MAX_IO_PICS];
@@ -123,7 +128,7 @@ struct irq_domain *pch_pic_acpi_init(struct irq_domain *parent,
extern struct irq_domain *liointc_domain;
extern struct fwnode_handle *pch_lpc_handle;
extern struct irq_domain *pch_msi_domain[MAX_IO_PICS];
-extern struct irq_domain *pch_pic_domain[MAX_IO_PICS];
+extern struct fwnode_handle *pch_pic_handle[MAX_IO_PICS];

extern irqreturn_t loongson3_ipi_interrupt(int irq, void *dev);

diff --git a/arch/loongarch/kernel/irq.c b/arch/loongarch/kernel/irq.c
index 07d6059..f2115be 100644
--- a/arch/loongarch/kernel/irq.c
+++ b/arch/loongarch/kernel/irq.c
@@ -28,7 +28,7 @@
struct irq_domain *cpu_domain;
struct irq_domain *liointc_domain;
struct irq_domain *pch_msi_domain[MAX_IO_PICS];
-struct irq_domain *pch_pic_domain[MAX_IO_PICS];
+struct acpi_vector_group pch_group[MAX_IO_PICS];

/*
* 'what should we do if we get a hw irq event on an illegal vector'.
diff --git a/drivers/irqchip/irq-loongson-pch-pic.c b/drivers/irqchip/irq-loongson-pch-pic.c
index a4eb8a2..170a5b9 100644
--- a/drivers/irqchip/irq-loongson-pch-pic.c
+++ b/drivers/irqchip/irq-loongson-pch-pic.c
@@ -33,13 +33,40 @@
#define PIC_REG_IDX(irq_id) ((irq_id) / PIC_COUNT_PER_REG)
#define PIC_REG_BIT(irq_id) ((irq_id) % PIC_COUNT_PER_REG)

+static int nr_pics;
+
struct pch_pic {
void __iomem *base;
struct irq_domain *pic_domain;
+ struct fwnode_handle *domain_handle;
u32 ht_vec_base;
raw_spinlock_t pic_lock;
+ u32 gsi_end;
+ u32 gsi_base;
};

+static struct pch_pic *pch_pic_priv[2];
+struct fwnode_handle *pch_pic_handle[MAX_IO_PICS];
+
+int find_pch_pic(u32 gsi)
+{
+ int i;
+
+ /* Find the PCH_PIC that manages this GSI. */
+ for (i = 0; i < MAX_IO_PICS; i++) {
+ struct pch_pic *priv = pch_pic_priv[i];
+
+ if (!priv)
+ return -1;
+
+ if (gsi >= priv->gsi_base && gsi <= priv->gsi_end)
+ return i;
+ }
+
+ pr_err("ERROR: Unable to locate PCH_PIC for GSI %d\n", gsi);
+ return -1;
+}
+
static void pch_pic_bitset(struct pch_pic *priv, int offset, int bit)
{
u32 reg;
@@ -139,6 +166,24 @@ static void pch_pic_ack_irq(struct irq_data *d)
.irq_set_type = pch_pic_set_type,
};

+static int pch_pic_domain_translate(struct irq_domain *d,
+ struct irq_fwspec *fwspec,
+ unsigned long *hwirq,
+ unsigned int *type)
+{
+ struct pch_pic *priv = d->host_data;
+ struct device_node *of_node = to_of_node(fwspec->fwnode);
+
+ if (fwspec->param_count < 1)
+ return -EINVAL;
+ if (of_node)
+ *hwirq += priv->ht_vec_base;
+ else
+ *hwirq = fwspec->param[0] - priv->gsi_base;
+ *type = IRQ_TYPE_NONE;
+
+ return 0;
+}
static int pch_pic_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *arg)
{
@@ -149,13 +194,13 @@ static int pch_pic_alloc(struct irq_domain *domain, unsigned int virq,
struct irq_fwspec parent_fwspec;
struct pch_pic *priv = domain->host_data;

- err = irq_domain_translate_twocell(domain, fwspec, &hwirq, &type);
+ err = pch_pic_domain_translate(domain, fwspec, &hwirq, &type);
if (err)
return err;

parent_fwspec.fwnode = domain->parent->fwnode;
parent_fwspec.param_count = 1;
- parent_fwspec.param[0] = hwirq + priv->ht_vec_base;
+ parent_fwspec.param[0] = hwirq;

err = irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
if (err)
@@ -170,7 +215,7 @@ static int pch_pic_alloc(struct irq_domain *domain, unsigned int virq,
}

static const struct irq_domain_ops pch_pic_domain_ops = {
- .translate = irq_domain_translate_twocell,
+ .translate = pch_pic_domain_translate,
.alloc = pch_pic_alloc,
.free = irq_domain_free_irqs_parent,
};
@@ -180,7 +225,7 @@ static void pch_pic_reset(struct pch_pic *priv)
int i;

for (i = 0; i < PIC_COUNT; i++) {
- /* Write vectored ID */
+ /* Write vector ID */
writeb(priv->ht_vec_base + i, priv->base + PCH_INT_HTVEC(i));
/* Hardcode route to HT0 Lo */
writeb(1, priv->base + PCH_INT_ROUTE(i));
@@ -198,50 +243,41 @@ static void pch_pic_reset(struct pch_pic *priv)
}
}

-static int pch_pic_of_init(struct device_node *node,
- struct device_node *parent)
+static int pch_pic_init(phys_addr_t addr, unsigned long size, int vec_base,
+ struct irq_domain *parent_domain, struct fwnode_handle *domain_handle,
+ u32 gsi_base)
{
+ int vec_count;
struct pch_pic *priv;
- struct irq_domain *parent_domain;
- int err;

priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;

raw_spin_lock_init(&priv->pic_lock);
- priv->base = of_iomap(node, 0);
- if (!priv->base) {
- err = -ENOMEM;
+ priv->base = ioremap(addr, size);
+ if (!priv->base)
goto free_priv;
- }

- parent_domain = irq_find_host(parent);
- if (!parent_domain) {
- pr_err("Failed to find the parent domain\n");
- err = -ENXIO;
- goto iounmap_base;
- }
+ priv->domain_handle = domain_handle;

- if (of_property_read_u32(node, "loongson,pic-base-vec",
- &priv->ht_vec_base)) {
- pr_err("Failed to determine pic-base-vec\n");
- err = -EINVAL;
- goto iounmap_base;
- }
+ priv->ht_vec_base = vec_base;
+ vec_count = ((readq(priv->base) >> 48) & 0xff) + 1;
+ priv->gsi_base = gsi_base;
+ priv->gsi_end = gsi_base + vec_count - 1;

priv->pic_domain = irq_domain_create_hierarchy(parent_domain, 0,
- PIC_COUNT,
- of_node_to_fwnode(node),
- &pch_pic_domain_ops,
- priv);
+ vec_count, priv->domain_handle,
+ &pch_pic_domain_ops, priv);
+
if (!priv->pic_domain) {
pr_err("Failed to create IRQ domain\n");
- err = -ENOMEM;
goto iounmap_base;
}

pch_pic_reset(priv);
+ pch_pic_handle[nr_pics] = domain_handle;
+ pch_pic_priv[nr_pics++] = priv;

return 0;

@@ -250,7 +286,111 @@ static int pch_pic_of_init(struct device_node *node,
free_priv:
kfree(priv);

- return err;
+ return -EINVAL;
+}
+
+#ifdef CONFIG_OF
+
+static int pch_pic_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ int err, vec_base;
+ struct resource res;
+ struct irq_domain *parent_domain;
+
+ if (of_address_to_resource(node, 0, &res))
+ return -EINVAL;
+
+ parent_domain = irq_find_host(parent);
+ if (!parent_domain) {
+ pr_err("Failed to find the parent domain\n");
+ return -ENXIO;
+ }
+
+ if (of_property_read_u32(node, "loongson,pic-base-vec", &vec_base)) {
+ pr_err("Failed to determine pic-base-vec\n");
+ return -EINVAL;
+ }
+
+ err = pch_pic_init(res.start, resource_size(&res), vec_base,
+ parent_domain, of_node_to_fwnode(node), 0);
+ if (err < 0)
+ return err;
+
+ return 0;
}

IRQCHIP_DECLARE(pch_pic, "loongson,pch-pic-1.0", pch_pic_of_init);
+
+#endif
+
+#ifdef CONFIG_ACPI
+static int __init
+lpcintc_parse_madt(union acpi_subtable_headers *header,
+ const unsigned long end)
+{
+ struct acpi_madt_lpc_pic *lpcintc_entry = (struct acpi_madt_lpc_pic *)header;
+
+ return pch_lpc_acpi_init(pch_pic_priv[0]->pic_domain, lpcintc_entry);
+}
+
+static int __init acpi_cascade_irqdomain_init(void)
+{
+ acpi_table_parse_madt(ACPI_MADT_TYPE_LPC_PIC,
+ lpcintc_parse_madt, 0);
+ return 0;
+}
+int __init pch_pic_init_irqdomain(struct irq_domain *parent,
+ struct acpi_madt_bio_pic *acpi_pchpic)
+{
+ int ret, vec_base;
+ struct fwnode_handle *domain_handle;
+
+ if (!acpi_pchpic)
+ return -EINVAL;
+
+ vec_base = acpi_pchpic->gsi_base - GSI_MIN_PCH_IRQ;
+
+ domain_handle = irq_domain_alloc_fwnode((phys_addr_t *)acpi_pchpic);
+ if (!domain_handle) {
+ pr_err("Unable to allocate domain handle\n");
+ return -ENOMEM;
+ }
+
+ ret = pch_pic_init(acpi_pchpic->address, acpi_pchpic->size,
+ vec_base, parent, domain_handle, acpi_pchpic->gsi_base);
+ if (ret == 0 && acpi_pchpic->id == 0)
+ acpi_cascade_irqdomain_init();
+
+ return ret;
+}
+
+struct irq_domain *acpi_get_pch_parent(int node)
+{
+ int i;
+
+ for (i = 0; i < MAX_IO_PICS; i++) {
+ if (node == pch_group[i].node)
+ return pch_group[i].parent;
+ }
+ return NULL;
+}
+
+static int __init pchintc_parse_madt(union acpi_subtable_headers *header,
+ const unsigned long end)
+{
+ struct acpi_madt_bio_pic *pch_pic_entry = (struct acpi_madt_bio_pic *)header;
+
+ return pch_pic_init_irqdomain(acpi_get_pch_parent((pch_pic_entry->address >> 44) & 0xf),
+ pch_pic_entry);
+}
+
+static int __init pch_pic_acpi_init(void)
+{
+ acpi_table_parse_madt(ACPI_MADT_TYPE_BIO_PIC,
+ pchintc_parse_madt, 0);
+
+ return 0;
+}
+early_initcall(pch_pic_acpi_init);
+#endif
--
1.8.3.1