[RFC PATCH 01/33] irqchip/gic-v3: Add redistributor iterator
Shanker Donthineni
shankerd at codeaurora.org
Mon Feb 13 13:12:17 PST 2017
Hi Marc,
On 01/17/2017 04:20 AM, Marc Zyngier wrote:
> In order to discover the VLPI properties, we need to iterate over
> the redistributor regions. As we already have code that does this,
> let's factor it out and make it slightly more generic.
>
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
> ---
> drivers/irqchip/irq-gic-v3.c | 77
> ++++++++++++++++++++++++++++++++------------
> 1 file changed, 56 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
> index c132f29..5cadec0 100644
> --- a/drivers/irqchip/irq-gic-v3.c
> +++ b/drivers/irqchip/irq-gic-v3.c
> @@ -421,24 +421,15 @@ static void __init gic_dist_init(void)
> gic_write_irouter(affinity, base + GICD_IROUTER + i * 8);
> }
>
> -static int gic_populate_rdist(void)
> +static int gic_scan_rdist_properties(int (*fn)(struct redist_region *,
> + void __iomem *))
I don't see this function is parsing GICR properties, may be it makes
readable on changing name to gic_redist_iterator().
> {
> - unsigned long mpidr = cpu_logical_map(smp_processor_id());
> - u64 typer;
> - u32 aff;
> + int ret = 0;
For readability purpose set ret = ENODEV, to cover error case where
gic_data.nr_redist_regions == 0.
> int i;
>
> - /*
> - * Convert affinity to a 32bit value that can be matched to
> - * GICR_TYPER bits [63:32].
> - */
> - aff = (MPIDR_AFFINITY_LEVEL(mpidr, 3) << 24 |
> - MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 |
> - MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8 |
> - MPIDR_AFFINITY_LEVEL(mpidr, 0));
> -
> for (i = 0; i < gic_data.nr_redist_regions; i++) {
> void __iomem *ptr =
> gic_data.redist_regions[i].redist_base;
> + u64 typer;
> u32 reg;
>
> reg = readl_relaxed(ptr + GICR_PIDR2) &
> GIC_PIDR2_ARCH_MASK;
> @@ -450,14 +441,14 @@ static int gic_populate_rdist(void)
>
> do {
> typer = gic_read_typer(ptr + GICR_TYPER);
> - if ((typer >> 32) == aff) {
> - u64 offset = ptr -
> gic_data.redist_regions[i].redist_base;
> - gic_data_rdist_rd_base() = ptr;
> - gic_data_rdist()->phys_base =
> gic_data.redist_regions[i].phys_base + offset;
> - pr_info("CPU%d: found redistributor %lx
> region %d:%pa\n",
> - smp_processor_id(), mpidr, i,
> - &gic_data_rdist()->phys_base);
> + ret = fn(gic_data.redist_regions + i, ptr);
> + switch (ret) {
> + case 0:
> return 0;
> + case -1:
> + break;
> + default:
> + ret = 0;
> }
>
> if (gic_data.redist_regions[i].single_redist)
> @@ -473,9 +464,53 @@ static int gic_populate_rdist(void)
> } while (!(typer & GICR_TYPER_LAST));
>
>
> + if (ret == -1)
> + ret = -ENODEV;
> +
__gic_populate_rdist() returns 1 to try next entry in the list. We
should not return value 0 here if no matching entry is found otherwise
the gic_populate_rdist() assumes that it found the corresponding GICR.
+ return 0;
+}
+
+static int __gic_populate_rdist(struct redist_region *region, void
__iomem *ptr)
+{
+ unsigned long mpidr = cpu_logical_map(smp_processor_id());
+ u64 typer;
+ u32 aff;
+
+ /*
+ * Convert affinity to a 32bit value that can be matched to
+ * GICR_TYPER bits [63:32].
+ */
+ aff = (MPIDR_AFFINITY_LEVEL(mpidr, 3) << 24 |
+ MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 |
+ MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8 |
+ MPIDR_AFFINITY_LEVEL(mpidr, 0));
+
+ typer = gic_read_typer(ptr + GICR_TYPER);
+ if ((typer >> 32) == aff) {
+ u64 offset = ptr - region->redist_base;
+ gic_data_rdist_rd_base() = ptr;
+ gic_data_rdist()->phys_base = region->phys_base + offset;
+
+ pr_info("CPU%d: found redistributor %lx region %d:%pa\n",
+ smp_processor_id(), mpidr,
+ (int)(region - gic_data.redist_regions),
+ &gic_data_rdist()->phys_base);
+ return 0;
+ }
+
+ /* Try next one */
+ return 1;
+}
+
+static int gic_populate_rdist(void)
+{
+ if (gic_scan_rdist_properties(__gic_populate_rdist) == 0)
what about 'if (!gic_scan_rdist_properties(__gic_populate_rdist))'?
> + return 0;
> +
> /* We couldn't even deal with ourselves... */
> WARN(true, "CPU%d: mpidr %lx has no re-distributor!\n",
> - smp_processor_id(), mpidr);
> + smp_processor_id(),
> + (unsigned long)cpu_logical_map(smp_processor_id()));
> return -ENODEV;
> }
>
--
Shanker Donthineni
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
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