Re: [PATCH V13 07/13] irqchip/loongson-pch-msi: Add ACPI init support

From: Jianmin Lv
Date: Wed Jun 29 2022 - 22:52:11 EST




On 2022/6/29 下午9:15, Marc Zyngier wrote:
On Mon, 27 Jun 2022 12:39:51 +0100,
Jianmin Lv <lvjianmin@xxxxxxxxxxx> wrote:

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.

Same rant about the content-less paragraph, which I asked you to drop
a few version ago.


Ok, I only dropped it for the patch that you reviewed in previous version, without handling other similar patches. I'll drop it for all similar patch in next version.



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 msi irqdomains,
each of which has the same node id as its parent irqdomain. So we
use a structure to mantain the relation of node and it's parent
irqdomain as pch irqdomin, and add a pci_segment field to it for
matching the pci segment of a pci device when setting msi irqdomain
for the device.

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

The field 'pci_segment' and 'node' are initialized from MCFG, and
the parent irqdomain will set field 'parent' by matching same
'node'.

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 | 7 +-
arch/loongarch/kernel/irq.c | 30 ++++++-
drivers/irqchip/irq-loongson-pch-msi.c | 147 +++++++++++++++++++++++----------
3 files changed, 138 insertions(+), 46 deletions(-)

diff --git a/arch/loongarch/include/asm/irq.h b/arch/loongarch/include/asm/irq.h
index a444dc6..367aa44 100644
--- a/arch/loongarch/include/asm/irq.h
+++ b/arch/loongarch/include/asm/irq.h
@@ -50,9 +50,11 @@ static inline bool on_irq_stack(int cpu, unsigned long sp)
struct acpi_vector_group {
int node;
+ int pci_segment;
struct irq_domain *parent;
};
extern struct acpi_vector_group pch_group[MAX_IO_PICS];
+extern struct acpi_vector_group msi_group[MAX_IO_PICS];
#define CORES_PER_EIO_NODE 4
@@ -112,9 +114,8 @@ struct irq_domain *htvec_acpi_init(struct irq_domain *parent,
struct acpi_madt_ht_pic *acpi_htvec);
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);
int find_pch_pic(u32 gsi);
+struct fwnode_handle *get_pch_msi_handle(int pci_segment);
extern struct acpi_madt_lio_pic *acpi_liointc;
extern struct acpi_madt_eio_pic *acpi_eiointc[MAX_IO_PICS];
@@ -127,7 +128,7 @@ struct irq_domain *pch_msi_acpi_init(struct irq_domain *parent,
extern struct irq_domain *cpu_domain;
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 fwnode_handle *pch_msi_handle[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 f2115be..82bc6c7 100644
--- a/arch/loongarch/kernel/irq.c
+++ b/arch/loongarch/kernel/irq.c
@@ -27,8 +27,8 @@
struct irq_domain *cpu_domain;
struct irq_domain *liointc_domain;
-struct irq_domain *pch_msi_domain[MAX_IO_PICS];
struct acpi_vector_group pch_group[MAX_IO_PICS];
+struct acpi_vector_group msi_group[MAX_IO_PICS];
/*
* 'what should we do if we get a hw irq event on an illegal vector'.
@@ -55,6 +55,33 @@ int arch_show_interrupts(struct seq_file *p, int prec)
return 0;
}
+static int early_pci_mcfg_parse(struct acpi_table_header *header)

Shouldn't this be __init as well?


Yes, thanks, it should be __init too.


+{
+ struct acpi_table_mcfg *mcfg;
+ struct acpi_mcfg_allocation *mptr;
+ int i, n;
+
+ if (header->length < sizeof(struct acpi_table_mcfg))
+ return -EINVAL;
+
+ n = (header->length - sizeof(struct acpi_table_mcfg)) /
+ sizeof(struct acpi_mcfg_allocation);
+ mcfg = (struct acpi_table_mcfg *)header;
+ mptr = (struct acpi_mcfg_allocation *) &mcfg[1];
+
+ for (i = 0; i < n; i++, mptr++) {
+ msi_group[i].pci_segment = mptr->pci_segment;
+ msi_group[i].node = (mptr->address >> 44) & 0xf;
+ }
+
+ return 0;
+}
+
+void __init init_msi_parent_group(void)
+{
+ acpi_table_parse(ACPI_SIG_MCFG, early_pci_mcfg_parse);
+}
+
void __init init_IRQ(void)
{
int i;
@@ -68,6 +95,7 @@ void __init init_IRQ(void)
clear_csr_ecfg(ECFG0_IM);
clear_csr_estat(ESTATF_IP);
+ init_msi_parent_group();

The changes in this file should be a separate patch, as it is
completely independent.


Ok, I'll put it in a separate patch.


irqchip_init();
#ifdef CONFIG_SMP
ipi_irq = EXCCODE_IPI - EXCCODE_INT_START;
diff --git a/drivers/irqchip/irq-loongson-pch-msi.c b/drivers/irqchip/irq-loongson-pch-msi.c
index e3801c4..5db4a68 100644
--- a/drivers/irqchip/irq-loongson-pch-msi.c
+++ b/drivers/irqchip/irq-loongson-pch-msi.c
@@ -15,14 +15,30 @@
#include <linux/pci.h>
#include <linux/slab.h>
+static int nr_pics;
+
struct pch_msi_data {
struct mutex msi_map_lock;
phys_addr_t doorbell;
u32 irq_first; /* The vector number that MSIs starts */
u32 num_irqs; /* The number of vectors for MSIs */
unsigned long *msi_map;
+ struct fwnode_handle *domain_handle;
};
+static struct pch_msi_data *pch_msi_priv[2];

What is this '2'?


Yes, I should use MAX_IO_PICS, thanks.


+
+struct fwnode_handle *get_pch_msi_handle(int pci_segment)
+{
+ int i;
+
+ for (i = 0; i < MAX_IO_PICS; i++) {
+ if (msi_group[i].pci_segment == pci_segment)

AFAICT, this driver is supposed to compile on MIPS too. Clearly, you
haven't bothered checking that it was still building:

drivers/irqchip/irq-loongson-pch-msi.c: In function ‘get_pch_msi_handle’:
drivers/irqchip/irq-loongson-pch-msi.c:35:18: error: ‘MAX_IO_PICS’ undeclared (first use in this function)
35 | for (i = 0; i < MAX_IO_PICS; i++) {
| ^~~~~~~~~~~
drivers/irqchip/irq-loongson-pch-msi.c:35:18: note: each undeclared identifier is reported only once for each function it appears in
drivers/irqchip/irq-loongson-pch-msi.c:36:7: error: ‘msi_group’ undeclared (first use in this function); did you mean ‘task_group’?
36 | if (msi_group[i].pci_segment == pci_segment)
| ^~~~~~~~~
| task_group

I've stopped here.


So sorry for that, I got it, I'll fix them and test on both of LoongArch and MIPS machine.


M.