diff mbox

[v10,01/11] irq: gic: support hip04 gic

Message ID 1404957850-13340-2-git-send-email-haojian.zhuang@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Haojian Zhuang July 10, 2014, 2:04 a.m. UTC 
There's a little difference between ARM GIC and HiP04 GIC.

* HiP04 GIC could support 16 cores at most, and ARM GIC could support
8 cores at most. So the difination on GIC_DIST_TARGET registers are
different since CPU interfaces are increased from 8-bit to 16-bit.

* HiP04 GIC could support 510 interrupts at most, and ARM GIC could
support 1020 interrupts at most.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
---
 Documentation/devicetree/bindings/arm/gic.txt |   1 +
 drivers/irqchip/irq-gic.c                     | 141 +++++++++++++++++++-------
 2 files changed, 108 insertions(+), 34 deletions(-)

Comments

Mark Rutland July 18, 2014, 9:20 a.m. UTC | #1 
On Thu, Jul 10, 2014 at 03:04:00AM +0100, Haojian Zhuang wrote:
> There's a little difference between ARM GIC and HiP04 GIC.

Given that we can't target interrupts correctly without this patch, and
that the GIC in a HiP04 system can't claim compatibility with any other
GIC, I'd call this a major difference.

>
> * HiP04 GIC could support 16 cores at most, and ARM GIC could support
> 8 cores at most. So the difination on GIC_DIST_TARGET registers are
> different since CPU interfaces are increased from 8-bit to 16-bit.
>
> * HiP04 GIC could support 510 interrupts at most, and ARM GIC could
> support 1020 interrupts at most.
>
> Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
> ---
>  Documentation/devicetree/bindings/arm/gic.txt |   1 +
>  drivers/irqchip/irq-gic.c                     | 141 +++++++++++++++++++-------
>  2 files changed, 108 insertions(+), 34 deletions(-)

[...]

> +static bool gic_is_standard(struct gic_chip_data *gic_data)
> +{
> +       return (gic_data->nr_cpu_if == 8);
> +}
> +
> +static u32 irqs_per_target_reg(struct gic_chip_data *gic_data)
> +{
> +       return (32 / gic_data->nr_cpu_if);
> +}
> +
> +static u32 irq_to_target_reg(struct gic_chip_data *gic_data, u32 irq)
> +{
> +       if (!gic_is_standard(gic_data))
> +               irq *= 2;

If the function is called gic_is_standard, then the only thing we should
know here is whether the GIC follows the GIC standard, not how it
differs from the standard.

Please rename this function to something like gicd_has_16_bit_targets or
anything else that clearly defines what you're ttrying to derive from
it.

Thanks,
Mark.
Jason Cooper July 18, 2014, 12:05 p.m. UTC | #2 
Haojian,

On Thu, Jul 10, 2014 at 10:04:00AM +0800, Haojian Zhuang wrote:
> There's a little difference between ARM GIC and HiP04 GIC.
> 
> * HiP04 GIC could support 16 cores at most, and ARM GIC could support
> 8 cores at most. So the difination on GIC_DIST_TARGET registers are
> different since CPU interfaces are increased from 8-bit to 16-bit.
> 
> * HiP04 GIC could support 510 interrupts at most, and ARM GIC could
> support 1020 interrupts at most.
> 
> Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
> ---
>  Documentation/devicetree/bindings/arm/gic.txt |   1 +
>  drivers/irqchip/irq-gic.c                     | 141 +++++++++++++++++++-------
>  2 files changed, 108 insertions(+), 34 deletions(-)

I need to apologize.  This is my first full cycle maintaining irqchip
and I'm still coming up to speed.  The tl;dr is, I'm just not
comfortable with the approach in this patch.

If irq-gic.c was only used by one SoC, it'd be different, but in the
scenario we have, I think it would be best if this were a separate
driver, say irq-gic-hip04.c.  You can link in irq-gic-common.o to get
gic_dist_config(), and you'll be able to remove a lot of the static
functions and conditionals.

I really think it's worth the extra maintenance overhead to do it this
way.

thx,

Jason.
Mark Rutland July 18, 2014, 12:44 p.m. UTC | #3 
On Fri, Jul 18, 2014 at 01:05:26PM +0100, Jason Cooper wrote:
> Haojian,
> 
> On Thu, Jul 10, 2014 at 10:04:00AM +0800, Haojian Zhuang wrote:
> > There's a little difference between ARM GIC and HiP04 GIC.
> > 
> > * HiP04 GIC could support 16 cores at most, and ARM GIC could support
> > 8 cores at most. So the difination on GIC_DIST_TARGET registers are
> > different since CPU interfaces are increased from 8-bit to 16-bit.
> > 
> > * HiP04 GIC could support 510 interrupts at most, and ARM GIC could
> > support 1020 interrupts at most.
> > 
> > Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
> > ---
> >  Documentation/devicetree/bindings/arm/gic.txt |   1 +
> >  drivers/irqchip/irq-gic.c                     | 141 +++++++++++++++++++-------
> >  2 files changed, 108 insertions(+), 34 deletions(-)
> 
> I need to apologize.  This is my first full cycle maintaining irqchip
> and I'm still coming up to speed.  The tl;dr is, I'm just not
> comfortable with the approach in this patch.
> 
> If irq-gic.c was only used by one SoC, it'd be different, but in the
> scenario we have, I think it would be best if this were a separate
> driver, say irq-gic-hip04.c.  You can link in irq-gic-common.o to get
> gic_dist_config(), and you'll be able to remove a lot of the static
> functions and conditionals.

A better approach might be to have some function pointers with each
compatible string, and then have associated with the HiP04 compatible
string, and then have those call common (inline) function variants. The
compiler can then deal with the different variants and we don't end up
with multiple GIC drivers getting out-of-sync.

Thanks,
Mark.
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
index 5573c08..150f7d6 100644
--- a/Documentation/devicetree/bindings/arm/gic.txt
+++ b/Documentation/devicetree/bindings/arm/gic.txt
@@ -16,6 +16,7 @@  Main node required properties:
 	"arm,cortex-a9-gic"
 	"arm,cortex-a7-gic"
 	"arm,arm11mp-gic"
+	"hisilicon,hip04-gic"
 - interrupt-controller : Identifies the node as an interrupt controller
 - #interrupt-cells : Specifies the number of cells needed to encode an
   interrupt source.  The type shall be a <u32> and the value shall be 3.
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 508b815..55c34fb 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -69,6 +69,9 @@  struct gic_chip_data {
 #ifdef CONFIG_GIC_NON_BANKED
 	void __iomem *(*get_base)(union gic_base *);
 #endif
+	u32 nr_cpu_if;
+	u32 nr_cpu_if_mask;
+	u32 cpu_target_shift;
 };
 
 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
@@ -77,9 +80,11 @@  static DEFINE_RAW_SPINLOCK(irq_controller_lock);
  * The GIC mapping of CPU interfaces does not necessarily match
  * the logical CPU numbering.  Let's use a mapping as returned
  * by the GIC itself.
+ *
+ * Hisilicon HiP04 extends the number of CPU interface from 8 to 16.
  */
-#define NR_GIC_CPU_IF 8
-static u8 gic_cpu_map[NR_GIC_CPU_IF] __read_mostly;
+#define NR_GIC_CPU_IF	16
+static u16 gic_cpu_map[NR_GIC_CPU_IF] __read_mostly;
 
 /*
  * Supported arch specific GIC irq extension.
@@ -218,12 +223,41 @@  static int gic_retrigger(struct irq_data *d)
 	return 0;
 }
 
+static bool gic_is_standard(struct gic_chip_data *gic_data)
+{
+	return (gic_data->nr_cpu_if == 8);
+}
+
+static u32 irqs_per_target_reg(struct gic_chip_data *gic_data)
+{
+	return (32 / gic_data->nr_cpu_if);
+}
+
+static u32 irq_to_target_reg(struct gic_chip_data *gic_data, u32 irq)
+{
+	if (!gic_is_standard(gic_data))
+		irq *= 2;
+	irq &= ~3U;
+	return (irq + GIC_DIST_TARGET);
+}
+
 #ifdef CONFIG_SMP
+static u32 irq_to_core_shift(struct irq_data *d)
+{
+	struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
+	unsigned int i = gic_irq(d);
+
+	if (gic_is_standard(gic_data))
+		return ((i % 4) << 3);
+	return ((i % 2) << 4);
+}
+
 static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
 			    bool force)
 {
-	void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + (gic_irq(d) & ~3);
-	unsigned int cpu, shift = (gic_irq(d) % 4) * 8;
+	void __iomem *reg;
+	struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
+	unsigned int cpu, shift = irq_to_core_shift(d);
 	u32 val, mask, bit;
 
 	if (!force)
@@ -231,11 +265,13 @@  static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
 	else
 		cpu = cpumask_first(mask_val);
 
-	if (cpu >= NR_GIC_CPU_IF || cpu >= nr_cpu_ids)
+	if (cpu >= gic_data->nr_cpu_if || cpu >= nr_cpu_ids)
 		return -EINVAL;
 
+	reg = gic_dist_base(d) + irq_to_target_reg(gic_data, gic_irq(d));
+
 	raw_spin_lock(&irq_controller_lock);
-	mask = 0xff << shift;
+	mask = gic_data->nr_cpu_if_mask << irq_to_core_shift(d);
 	bit = gic_cpu_map[cpu] << shift;
 	val = readl_relaxed(reg) & ~mask;
 	writel_relaxed(val | bit, reg);
@@ -335,15 +371,20 @@  void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
 	irq_set_chained_handler(irq, gic_handle_cascade_irq);
 }
 
-static u8 gic_get_cpumask(struct gic_chip_data *gic)
+static u16 gic_get_cpumask(struct gic_chip_data *gic)
 {
 	void __iomem *base = gic_data_dist_base(gic);
 	u32 mask, i;
 
-	for (i = mask = 0; i < 32; i += 4) {
-		mask = readl_relaxed(base + GIC_DIST_TARGET + i);
+	/*
+	 * ARM GIC uses 8 registers for interrupt 0-31,
+	 * HiP04 GIC uses 16 registers for interrupt 0-31.
+	 */
+	for (i = mask = 0; i < 32; i++) {
+		mask = readl_relaxed(base + irq_to_target_reg(gic, i));
 		mask |= mask >> 16;
-		mask |= mask >> 8;
+		if (gic_is_standard(gic))
+			mask |= mask >> 8;
 		if (mask)
 			break;
 	}
@@ -351,6 +392,10 @@  static u8 gic_get_cpumask(struct gic_chip_data *gic)
 	if (!mask)
 		pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");
 
+	/* ARM GIC needs 8-bit cpu mask, HiP04 GIC needs 16-bit cpu mask. */
+	if (gic_is_standard(gic))
+		mask &= 0xff;
+
 	return mask;
 }
 
@@ -367,10 +412,11 @@  static void __init gic_dist_init(struct gic_chip_data *gic)
 	 * Set all global interrupts to this CPU only.
 	 */
 	cpumask = gic_get_cpumask(gic);
-	cpumask |= cpumask << 8;
+	if (gic_is_standard(gic))
+		cpumask |= cpumask << 8;
 	cpumask |= cpumask << 16;
-	for (i = 32; i < gic_irqs; i += 4)
-		writel_relaxed(cpumask, base + GIC_DIST_TARGET + i * 4 / 4);
+	for (i = 32; i < gic_irqs; i++)
+		writel_relaxed(cpumask, base + irq_to_target_reg(gic, i));
 
 	gic_dist_config(base, gic_irqs, NULL);
 
@@ -387,7 +433,7 @@  static void gic_cpu_init(struct gic_chip_data *gic)
 	/*
 	 * Get what the GIC says our CPU mask is.
 	 */
-	BUG_ON(cpu >= NR_GIC_CPU_IF);
+	BUG_ON(cpu >= gic->nr_cpu_if);
 	cpu_mask = gic_get_cpumask(gic);
 	gic_cpu_map[cpu] = cpu_mask;
 
@@ -395,7 +441,7 @@  static void gic_cpu_init(struct gic_chip_data *gic)
 	 * Clear our mask from the other map entries in case they're
 	 * still undefined.
 	 */
-	for (i = 0; i < NR_GIC_CPU_IF; i++)
+	for (i = 0; i < gic->nr_cpu_if; i++)
 		if (i != cpu)
 			gic_cpu_map[i] &= ~cpu_mask;
 
@@ -437,9 +483,10 @@  static void gic_dist_save(unsigned int gic_nr)
 		gic_data[gic_nr].saved_spi_conf[i] =
 			readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);
 
-	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
+	for (i = 0; i < gic_irqs; i += irqs_per_target_reg(&gic_data[gic_nr]))
 		gic_data[gic_nr].saved_spi_target[i] =
-			readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
+			readl_relaxed(dist_base +
+				      irq_to_target_reg(&gic_data[gic_nr], i));
 
 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
 		gic_data[gic_nr].saved_spi_enable[i] =
@@ -478,9 +525,9 @@  static void gic_dist_restore(unsigned int gic_nr)
 		writel_relaxed(0xa0a0a0a0,
 			dist_base + GIC_DIST_PRI + i * 4);
 
-	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
+	for (i = 0; i < gic_irqs; i += irqs_per_target_reg(&gic_data[gic_nr]))
 		writel_relaxed(gic_data[gic_nr].saved_spi_target[i],
-			dist_base + GIC_DIST_TARGET + i * 4);
+			dist_base + irq_to_target_reg(&gic_data[gic_nr], i));
 
 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
 		writel_relaxed(gic_data[gic_nr].saved_spi_enable[i],
@@ -618,9 +665,16 @@  static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
 	 */
 	dmb(ishst);
 
-	/* this always happens on GIC0 */
-	writel_relaxed(map << 16 | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
-
+	/*
+	 * CPUTargetList -- bit[23:16] in GIC_DIST_SOFTINT in ARM GIC.
+	 *                  bit[23:8] in GIC_DIST_SOFTINT in HiP04 GIC.
+	 * NSATT -- bit[15] in GIC_DIST_SOFTINT in ARM GIC.
+	 *          bit[7] in GIC_DIST_SOFTINT in HiP04 GIC.
+	 * this always happens on GIC0
+	 */
+	map = map << gic_data[0].cpu_target_shift;
+	writel_relaxed(map | irq,
+		       gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
 }
 #endif
@@ -634,10 +688,12 @@  static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
  */
 void gic_send_sgi(unsigned int cpu_id, unsigned int irq)
 {
-	BUG_ON(cpu_id >= NR_GIC_CPU_IF);
+	BUG_ON(cpu_id >= gic_data[0].nr_cpu_if);
 	cpu_id = 1 << cpu_id;
 	/* this always happens on GIC0 */
-	writel_relaxed((cpu_id << 16) | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
+	cpuid = cpuid << gic_data[0].cpu_target_shift;
+	writel_relaxed(cpu_id | irq,
+		       gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
 }
 
 /*
@@ -653,7 +709,7 @@  int gic_get_cpu_id(unsigned int cpu)
 {
 	unsigned int cpu_bit;
 
-	if (cpu >= NR_GIC_CPU_IF)
+	if (cpu >= gic_data[0].nr_cpu_if)
 		return -1;
 	cpu_bit = gic_cpu_map[cpu];
 	if (cpu_bit & (cpu_bit - 1))
@@ -700,13 +756,15 @@  void gic_migrate_target(unsigned int new_cpu_id)
 	 * CPU interface and migrate them to the new CPU interface.
 	 * We skip DIST_TARGET 0 to 7 as they are read-only.
 	 */
-	for (i = 8; i < DIV_ROUND_UP(gic_irqs, 4); i++) {
-		val = readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
+	for (i = 8; i < gic_irqs; i += irqs_per_target_reg(&gic_data[gic_nr])) {
+		val = readl_relaxed(dist_base +
+				    irq_to_target_reg(&gic_data[gic_nr], i));
 		active_mask = val & cur_target_mask;
 		if (active_mask) {
 			val &= ~active_mask;
 			val |= ror32(active_mask, ror_val);
-			writel_relaxed(val, dist_base + GIC_DIST_TARGET + i*4);
+			writel_relaxed(val, dist_base +
+				       irq_to_target_reg(&gic_data[gic_nr], i));
 		}
 	}
 
@@ -884,7 +942,7 @@  void __init gic_init_bases(unsigned int gic_nr, int irq_start,
 	irq_hw_number_t hwirq_base;
 	struct gic_chip_data *gic;
 	int gic_irqs, irq_base, i;
-	int nr_routable_irqs;
+	int nr_routable_irqs, max_nr_irq;
 
 	BUG_ON(gic_nr >= MAX_GIC_NR);
 
@@ -920,12 +978,25 @@  void __init gic_init_bases(unsigned int gic_nr, int irq_start,
 		gic_set_base_accessor(gic, gic_get_common_base);
 	}
 
+	if (of_device_is_compatible(node, "hisilicon,hip04-gic")) {
+		/* HiP04 GIC supports 16 CPUs at most */
+		gic->nr_cpu_if = 16;
+		gic->cpu_target_shift = 8;
+		max_nr_irq = 510;
+	} else {
+		/* ARM/Qualcomm GIC supports 8 CPUs at most */
+		gic->nr_cpu_if = 8;
+		gic->cpu_target_shift = 16;
+		max_nr_irq = 1020;
+	}
+	gic->nr_cpu_if_mask = (1 << gic->nr_cpu_if) - 1;
+
 	/*
 	 * Initialize the CPU interface map to all CPUs.
 	 * It will be refined as each CPU probes its ID.
 	 */
-	for (i = 0; i < NR_GIC_CPU_IF; i++)
-		gic_cpu_map[i] = 0xff;
+	for (i = 0; i < gic->nr_cpu_if; i++)
+		gic_cpu_map[i] = (1 << gic->nr_cpu_if) - 1;
 
 	/*
 	 * For primary GICs, skip over SGIs.
@@ -941,12 +1012,13 @@  void __init gic_init_bases(unsigned int gic_nr, int irq_start,
 
 	/*
 	 * Find out how many interrupts are supported.
-	 * The GIC only supports up to 1020 interrupt sources.
+	 * The ARM/Qualcomm GIC only supports up to 1020 interrupt sources.
+	 * The HiP04 GIC only supports up to 510 interrupt sources.
 	 */
 	gic_irqs = readl_relaxed(gic_data_dist_base(gic) + GIC_DIST_CTR) & 0x1f;
 	gic_irqs = (gic_irqs + 1) * 32;
-	if (gic_irqs > 1020)
-		gic_irqs = 1020;
+	if (gic_irqs > max_nr_irq)
+		gic_irqs = max_nr_irq;
 	gic->gic_irqs = gic_irqs;
 
 	gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
@@ -1022,6 +1094,7 @@  gic_of_init(struct device_node *node, struct device_node *parent)
 }
 IRQCHIP_DECLARE(cortex_a15_gic, "arm,cortex-a15-gic", gic_of_init);
 IRQCHIP_DECLARE(cortex_a9_gic, "arm,cortex-a9-gic", gic_of_init);
+IRQCHIP_DECLARE(hip04_gic, "hisilicon,hip04-gic", gic_of_init);
 IRQCHIP_DECLARE(msm_8660_qgic, "qcom,msm-8660-qgic", gic_of_init);
 IRQCHIP_DECLARE(msm_qgic2, "qcom,msm-qgic2", gic_of_init);