Hi Andy,
On 2017-01-25 19:44, Andy Shevchenko wrote:
On Fri, Jan 20, 2017 at 4:34 AM, Agustin Vega-Frias
<agustinv@xxxxxxxxxxxxxx> wrote:
Driver for interrupt combiners in the Top-level Control and Status
Registers (TCSR) hardware block in Qualcomm Technologies chips.
An interrupt combiner in this block combines a set of interrupts by
OR'ing the individual interrupt signals into a summary interrupt
signal routed to a parent interrupt controller, and provides read-
only, 32-bit registers to query the status of individual interrupts.
The status bit for IRQ n is bit (n % 32) within register (n / 32)
of the given combiner. Thus, each combiner can be described as a set
of register offsets and the number of IRQs managed.
+static inline u32 irq_register(int irq)
+{
+ return irq / REG_SIZE;
+}
+
+static inline u32 irq_bit(int irq)
+{
+ return irq % REG_SIZE;
+
+}
Besides extra line I do not see a benefit of those helpers. On first
glance they even increase characters to type.
Will remove these.
+static inline int irq_nr(u32 reg, u32 bit)
+{
+ return reg * REG_SIZE + bit;
+}
This one might make sense.
+static void combiner_handle_irq(struct irq_desc *desc)
+{
+ struct combiner *combiner = irq_desc_get_handler_data(desc);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ u32 reg;
+
+ chained_irq_enter(chip, desc);
+
+ for (reg = 0; reg < combiner->nregs; reg++) {
+ int virq;
+ int hwirq;
+ u32 bit;
+ u32 status;
+
+ bit = readl_relaxed(combiner->regs[reg].addr);
+ status = bit & combiner->regs[reg].enabled;
+ if (!status)
+ pr_warn_ratelimited("Unexpected IRQ on CPU%d:
(%08x %08lx %p)\n",
+ smp_processor_id(), bit,
+
combiner->regs[reg].enabled,
+ combiner->regs[reg].addr);
+
+ while (status) {
+ bit = __ffs(status);
+ status &= ~(1 << bit);
Interesting way of for_each_set_bit() ?
I'm leaving this as-is since in arm64 using __ffs can be optimized
better by using the bic instruction.
+ hwirq = irq_nr(reg, bit);
+ virq = irq_find_mapping(combiner->domain,
hwirq);
+ if (virq > 0)
+ generic_handle_irq(virq);
+
+ }
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+/*
+ * irqchip callbacks
+ */
Useless.
Will remove
+/*
+ * irq_domain_ops callbacks
+ */
Ditto.
Will remove
+/*
+ * Device probing
+ */
Ditto.
Will remove
+static acpi_status count_registers_cb(struct acpi_resource *ares,
void *context)
+{
+ int *count = context;
I would consider to define a struct. It would be easy to extend if
needed and...
The intent here is always to get the count so I don't see value
in adding the struct.
+
+ if (ares->type == ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
+ ++(*count);
...allows not to use such of constructions. (I think above is
equivalent to ++*count).
IMHO having the parentheses makes the code clearer.
+ return AE_OK;
+}
+
+static int count_registers(struct platform_device *pdev)
+{
+ struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
You don't use adev, so, ACPI_HANDLE() ?
Will change
+ acpi_status status;
+ int count = 0;
+
+ if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
+ return -EINVAL;
+
+ status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
+ count_registers_cb, &count);
+ if (ACPI_FAILURE(status))
+ return -EINVAL;
+ return count;
+}
Oh, since you are using this just as a helper to get count first, why
not to combine this in one callback?
What's the benefit of separation?
This is because we do an allocation based on the count first.
+
+struct get_registers_context {
+ struct device *dev;
+ struct combiner *combiner;
+ int err;
+};
+
+static acpi_status get_registers_cb(struct acpi_resource *ares, void
*context)
+{
+ struct get_registers_context *ctx = context;
+ struct acpi_resource_generic_register *reg;
+ phys_addr_t paddr;
+ void __iomem *vaddr;
+
+ if (ares->type != ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
+ return AE_OK;
+
+ reg = &ares->data.generic_reg;
+ paddr = reg->address;
+ if ((reg->space_id != ACPI_SPACE_MEM) ||
+ (reg->bit_offset != 0) ||
+ (reg->bit_width > REG_SIZE)) {
+ dev_err(ctx->dev, "Bad register resource @%pa\n",
&paddr);
+ ctx->err = -EINVAL;
+ return AE_ERROR;
+ }
+
+ vaddr = devm_ioremap(ctx->dev, reg->address, REG_SIZE);
+ if (IS_ERR(vaddr)) {
+ dev_err(ctx->dev, "Can't map register @%pa\n",
&paddr);
+ ctx->err = PTR_ERR(vaddr);
+ return AE_ERROR;
+ }
This all sounds to me like an OperationalRegion. But I'm not sure it's
suitable here.
Do you have ACPI table carved in stone?
I decided to go with registers because in some cases these might be non-
contiguous.
+
+ ctx->combiner->regs[ctx->combiner->nregs].addr = vaddr;
+ ctx->combiner->nirqs += reg->bit_width;
+ ctx->combiner->nregs++;
+ return AE_OK;
+}
+
+static int get_registers(struct platform_device *pdev, struct
combiner *comb)
+{
+ struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+ acpi_status status;
+ struct get_registers_context ctx;
+
+ if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
+ return -EINVAL;
+
+ ctx.dev = &pdev->dev;
+ ctx.combiner = comb;
+ ctx.err = 0;
+
+ status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
+ get_registers_cb, &ctx);
+ if (ACPI_FAILURE(status))
+ return ctx.err;
+ return 0;
+}
+
+static int __init combiner_probe(struct platform_device *pdev)
+{
+ struct combiner *combiner;
+ size_t alloc_sz;
+ u32 nregs;
+ int err;
+
+ nregs = count_registers(pdev);
+ if (nregs <= 0) {
+ dev_err(&pdev->dev, "Error reading register
resources\n");
+ return -EINVAL;
+ }
+
+ alloc_sz = sizeof(*combiner) + sizeof(struct combiner_reg) *
nregs;
+ combiner = devm_kzalloc(&pdev->dev, alloc_sz, GFP_KERNEL);
+ if (!combiner)
+ return -ENOMEM;
+
+ err = get_registers(pdev, combiner);
+ if (err < 0)
+ return err;
+
+ combiner->parent_irq = platform_get_irq(pdev, 0);
+ if (combiner->parent_irq <= 0) {
+ dev_err(&pdev->dev, "Error getting IRQ resource\n");
+ return -EPROBE_DEFER;
+ }
+
+ combiner->domain = irq_domain_create_linear(pdev->dev.fwnode,
combiner->nirqs,
+ &domain_ops,
combiner);
+ if (!combiner->domain)
+ /* Errors printed by irq_domain_create_linear */
+ return -ENODEV;
+
+ irq_set_chained_handler_and_data(combiner->parent_irq,
+ combiner_handle_irq,
combiner);
+
+ dev_info(&pdev->dev, "Initialized with [p=%d,n=%d,r=%p]\n",
+ combiner->parent_irq, combiner->nirqs,
combiner->regs[0].addr);
+ return 0;
+}
+
+static const struct acpi_device_id qcom_irq_combiner_ids[]
__dsdt_irqchip = {
+ { "QCOM80B1", },
+ { }
+};
+
+static struct platform_driver qcom_irq_combiner_probe = {
+ .driver = {
+ .name = "qcom-irq-combiner",
+ .owner = THIS_MODULE,
Do you still need this?
Will remove
Thanks,
Agustin
+ .acpi_match_table = ACPI_PTR(qcom_irq_combiner_ids),
+ },
--
With Best Regards,
Andy Shevchenko
--
Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm
Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a
Linux Foundation Collaborative Project.
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