For LS1046a and LS1043a v1.1, the MSI controller has 4 MSIRs and 4
CPUs. A GIC SPI interrupt of MSIR can be associated with a CPU.
When changing MSI interrupt affinity, this MSI will be moved to the
corresponding MSIR and MSI message data will be changed according to
MSIR. when requesting a MSI, the bits of all 4 MSIR will be reserved.
The parameter 'msi_affinity_flag' is provide to change this mode.
"lsmsi=no-affinity" will disable affinity, all MSI can only be
associated with CPU 0.

Signed-off-by: Minghuan Lian <minghuan.l...@nxp.com>
---
v2-v1:
- None

 drivers/irqchip/irq-ls-scfg-msi.c | 75 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 70 insertions(+), 5 deletions(-)

diff --git a/drivers/irqchip/irq-ls-scfg-msi.c 
b/drivers/irqchip/irq-ls-scfg-msi.c
index dc19569..753fe39 100644
--- a/drivers/irqchip/irq-ls-scfg-msi.c
+++ b/drivers/irqchip/irq-ls-scfg-msi.c
@@ -40,6 +40,7 @@ struct ls_scfg_msir {
        unsigned int gic_irq;
        unsigned int bit_start;
        unsigned int bit_end;
+       unsigned int srs; /* Shared interrupt register select */
        void __iomem *reg;
 };
 
@@ -70,6 +71,19 @@ struct ls_scfg_msi {
        .chip   = &ls_scfg_msi_irq_chip,
 };
 
+static int msi_affinity_flag = 1;
+
+static int __init early_parse_ls_scfg_msi(char *p)
+{
+       if (p && strncmp(p, "no-affinity", 11) == 0)
+               msi_affinity_flag = 0;
+       else
+               msi_affinity_flag = 1;
+
+       return 0;
+}
+early_param("lsmsi", early_parse_ls_scfg_msi);
+
 static void ls_scfg_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
 {
        struct ls_scfg_msi *msi_data = irq_data_get_irq_chip_data(data);
@@ -77,12 +91,43 @@ static void ls_scfg_msi_compose_msg(struct irq_data *data, 
struct msi_msg *msg)
        msg->address_hi = upper_32_bits(msi_data->msiir_addr);
        msg->address_lo = lower_32_bits(msi_data->msiir_addr);
        msg->data = data->hwirq;
+
+       if (msi_affinity_flag) {
+               u32 msir_index;
+
+               msir_index = cpumask_first(data->common->affinity);
+               if (msir_index >= msi_data->msir_num)
+                       msir_index = 0;
+
+               msg->data |= msir_index;
+       }
 }
 
 static int ls_scfg_msi_set_affinity(struct irq_data *irq_data,
                                    const struct cpumask *mask, bool force)
 {
-       return -EINVAL;
+       struct ls_scfg_msi *msi_data = irq_data_get_irq_chip_data(irq_data);
+       u32 cpu;
+
+       if (!msi_affinity_flag)
+               return -EINVAL;
+
+       if (!force)
+               cpu = cpumask_any_and(mask, cpu_online_mask);
+       else
+               cpu = cpumask_first(mask);
+
+       if (cpu >= msi_data->msir_num)
+               return -EINVAL;
+
+       if (msi_data->msir[cpu].gic_irq <= 0) {
+               pr_warn("cannot bind the irq to cpu%d\n", cpu);
+               return -EINVAL;
+       }
+
+       cpumask_copy(irq_data->common->affinity, mask);
+
+       return IRQ_SET_MASK_OK;
 }
 
 static struct irq_chip ls_scfg_msi_parent_chip = {
@@ -158,7 +203,7 @@ static void ls_scfg_msi_irq_handler(struct irq_desc *desc)
 
        for_each_set_bit_from(pos, &val, size) {
                hwirq = ((msir->bit_end - pos) << msi_data->cfg->ibs_shift) |
-                       msir->index;
+                       msir->srs;
                virq = irq_find_mapping(msi_data->parent, hwirq);
                if (virq)
                        generic_handle_irq(virq);
@@ -221,10 +266,19 @@ static int ls_scfg_msi_setup_hwirq(struct ls_scfg_msi 
*msi_data, int index)
                                         ls_scfg_msi_irq_handler,
                                         msir);
 
+       if (msi_affinity_flag) {
+               /* Associate MSIR interrupt to the cpu */
+               irq_set_affinity(msir->gic_irq, get_cpu_mask(index));
+               msir->srs = 0; /* This value is determined by the CPU */
+       } else
+               msir->srs = index;
+
        /* Release the hwirqs corresponding to this MSIR */
-       for (i = 0; i < msi_data->cfg->msir_irqs; i++) {
-               hwirq = i << msi_data->cfg->ibs_shift | msir->index;
-               bitmap_clear(msi_data->used, hwirq, 1);
+       if (!msi_affinity_flag || msir->index == 0) {
+               for (i = 0; i < msi_data->cfg->msir_irqs; i++) {
+                       hwirq = i << msi_data->cfg->ibs_shift | msir->index;
+                       bitmap_clear(msi_data->used, hwirq, 1);
+               }
        }
 
        return 0;
@@ -316,6 +370,17 @@ static int ls_scfg_msi_probe(struct platform_device *pdev)
        bitmap_set(msi_data->used, 0, msi_data->irqs_num);
 
        msi_data->msir_num = of_irq_count(pdev->dev.of_node);
+
+       if (msi_affinity_flag) {
+               u32 cpu_num;
+
+               cpu_num = num_possible_cpus();
+               if (msi_data->msir_num >= cpu_num)
+                       msi_data->msir_num = cpu_num;
+               else
+                       msi_affinity_flag = 0;
+       }
+
        msi_data->msir = devm_kcalloc(&pdev->dev, msi_data->msir_num,
                                      sizeof(*msi_data->msir),
                                      GFP_KERNEL);
-- 
1.9.1

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