target/linux/brcm2708/patches-4.14/950-0169-irqchip-irq-bcm2836-Remove-regmap-and-syscon-use.patch

   1 From bb79a484a01f8f3645bd9b8fc6b15ea0ba961589 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Tue, 23 Jan 2018 16:52:45 +0000
   4 Subject: [PATCH 169/454] irqchip: irq-bcm2836: Remove regmap and syscon use
   5
   6 The syscon node defines a register range that duplicates that used by
   7 the local_intc node on bcm2836/7. Since irq-bcm2835 and irq-bcm2836 are
   8 built in and always present together (both drivers are enabled by
   9 CONFIG_ARCH_BCM2835), it is possible to replace the syscon usage with a
  10 global variable that simplifies the code. Doing so does lose the
  11 locking provided by regmap, but as only one side is using the regmap
  12 interface (irq-bcm2835 uses readl and write) there is no loss of
  13 atomicity.
  14
  15 See: https://github.com/raspberrypi/firmware/issues/926
  16
  17 Signed-off-by: Phil Elwell <phil@raspberrypi.org>
  18 ---
  19  arch/arm/boot/dts/bcm2709.dtsi |  5 -----
  20  arch/arm/boot/dts/bcm2710.dtsi |  5 -----
  21  drivers/irqchip/irq-bcm2835.c  | 32 ++++++++++++--------------------
  22  drivers/irqchip/irq-bcm2836.c  |  5 +++++
  23  4 files changed, 17 insertions(+), 30 deletions(-)
  24
  25 --- a/arch/arm/boot/dts/bcm2709.dtsi
  26 +++ b/arch/arm/boot/dts/bcm2709.dtsi
  27 @@ -6,11 +6,6 @@
  28         soc {
  29                 ranges = <0x7e000000 0x3f000000 0x01000000>,
  30                          <0x40000000 0x40000000 0x00040000>;
  31 -
  32 -               syscon@40000000 {
  33 -                       compatible = "brcm,bcm2836-arm-local", "syscon";
  34 -                       reg = <0x40000000 0x100>;
  35 -               };
  36         };
  37
  38         __overrides__ {
  39 --- a/arch/arm/boot/dts/bcm2710.dtsi
  40 +++ b/arch/arm/boot/dts/bcm2710.dtsi
  41 @@ -16,11 +16,6 @@
  42                         interrupt-parent = <&local_intc>;
  43                         interrupts = <9>;
  44                 };
  45 -
  46 -               syscon@40000000 {
  47 -                       compatible = "brcm,bcm2836-arm-local", "syscon";
  48 -                       reg = <0x40000000 0x100>;
  49 -               };
  50         };
  51
  52         __overrides__ {
  53 --- a/drivers/irqchip/irq-bcm2835.c
  54 +++ b/drivers/irqchip/irq-bcm2835.c
  55 @@ -50,8 +50,6 @@
  56  #include <linux/of_irq.h>
  57  #include <linux/irqchip.h>
  58  #include <linux/irqdomain.h>
  59 -#include <linux/mfd/syscon.h>
  60 -#include <linux/regmap.h>
  61
  62  #include <asm/exception.h>
  63  #ifndef CONFIG_ARM64
  64 @@ -103,7 +101,7 @@ struct armctrl_ic {
  65         void __iomem *enable[NR_BANKS];
  66         void __iomem *disable[NR_BANKS];
  67         struct irq_domain *domain;
  68 -       struct regmap *local_regmap;
  69 +       void __iomem *local_base;
  70  };
  71
  72  static struct armctrl_ic intc __read_mostly;
  73 @@ -140,24 +138,20 @@ static void armctrl_unmask_irq(struct ir
  74         if (d->hwirq >= NUMBER_IRQS) {
  75                 if (num_online_cpus() > 1) {
  76                         unsigned int data;
  77 -                       int ret;
  78
  79 -                       if (!intc.local_regmap) {
  80 -                               pr_err("FIQ is disabled due to missing regmap\n");
  81 +                       if (!intc.local_base) {
  82 +                               pr_err("FIQ is disabled due to missing arm_local_intc\n");
  83                                 return;
  84                         }
  85
  86 -                       ret = regmap_read(intc.local_regmap,
  87 -                                         ARM_LOCAL_GPU_INT_ROUTING, &data);
  88 -                       if (ret) {
  89 -                               pr_err("Failed to read int routing %d\n", ret);
  90 -                               return;
  91 -                       }
  92 +                       data = readl_relaxed(intc.local_base +
  93 +                                            ARM_LOCAL_GPU_INT_ROUTING);
  94
  95                         data &= ~0xc;
  96                         data |= (1 << 2);
  97 -                       regmap_write(intc.local_regmap,
  98 -                                    ARM_LOCAL_GPU_INT_ROUTING, data);
  99 +                       writel_relaxed(data,
 100 +                                      intc.local_base +
 101 +                                      ARM_LOCAL_GPU_INT_ROUTING);
 102                 }
 103
 104                 writel_relaxed(REG_FIQ_ENABLE | hwirq_to_fiq(d->hwirq),
 105 @@ -256,12 +250,10 @@ static int __init armctrl_of_init(struct
 106         }
 107
 108         if (is_2836) {
 109 -               intc.local_regmap =
 110 -                       syscon_regmap_lookup_by_compatible("brcm,bcm2836-arm-local");
 111 -               if (IS_ERR(intc.local_regmap)) {
 112 -                       pr_err("Failed to get local register map. FIQ is disabled for cpus > 1\n");
 113 -                       intc.local_regmap = NULL;
 114 -               }
 115 +               extern void __iomem * __attribute__((weak)) arm_local_intc;
 116 +               intc.local_base = arm_local_intc;
 117 +               if (!intc.local_base)
 118 +                       pr_err("Failed to get local intc base. FIQ is disabled for cpus > 1\n");
 119         }
 120
 121         /* Make a duplicate irq range which is used to enable FIQ */
 122 --- a/drivers/irqchip/irq-bcm2836.c
 123 +++ b/drivers/irqchip/irq-bcm2836.c
 124 @@ -83,6 +83,9 @@ struct bcm2836_arm_irqchip_intc {
 125
 126  static struct bcm2836_arm_irqchip_intc intc  __read_mostly;
 127
 128 +void __iomem *arm_local_intc;
 129 +EXPORT_SYMBOL_GPL(arm_local_intc);
 130 +
 131  static void bcm2836_arm_irqchip_mask_per_cpu_irq(unsigned int reg_offset,
 132                                                  unsigned int bit,
 133                                                  int cpu)
 134 @@ -310,6 +313,8 @@ static int __init bcm2836_arm_irqchip_l1
 135                 panic("%pOF: unable to map local interrupt registers\n", node);
 136         }
 137
 138 +       arm_local_intc = intc.base;
 139 +
 140         bcm2835_init_local_timer_frequency();
 141
 142         intc.domain = irq_domain_add_linear(node, LAST_IRQ + 1,