Hi Lorenzo,
On 30 March 2017 at 00:47, Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> wrote:
> On Wed, Mar 22, 2017 at 12:31:20AM +0800, fu.wei@xxxxxxxxxx wrote:
>> From: Fu Wei <fu.wei@xxxxxxxxxx>
>>
>> On platforms booting with ACPI, architected memory-mapped timers'
>> configuration data is provided by firmware through the ACPI GTDT
>> static table.
>>
>> The clocksource architected timer kernel driver requires a firmware
>> interface to collect timer configuration and configure its driver.
>> this infrastructure is present for device tree systems, but it is
>> missing on systems booting with ACPI.
>>
>> Implement the kernel infrastructure required to parse the static
>> ACPI GTDT table so that the architected timer clocksource driver can
>> make use of it on systems booting with ACPI, therefore enabling
>> the corresponding timers configuration.
>>
>> Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx>
>> Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
>> ---
>> drivers/acpi/arm64/gtdt.c | 130 ++++++++++++++++++++++++++++++++++++++++++++++
>> include/linux/acpi.h | 1 +
>> 2 files changed, 131 insertions(+)
>>
>> diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c
>> index 8a03b4b..f471873 100644
>> --- a/drivers/acpi/arm64/gtdt.c
>> +++ b/drivers/acpi/arm64/gtdt.c
>> @@ -37,6 +37,28 @@ struct acpi_gtdt_descriptor {
>>
>> static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata;
>>
>> +static inline void *next_platform_timer(void *platform_timer)
>> +{
>> + struct acpi_gtdt_header *gh = platform_timer;
>> +
>> + platform_timer += gh->length;
>> + if (platform_timer < acpi_gtdt_desc.gtdt_end)
>> + return platform_timer;
>> +
>> + return NULL;
>> +}
>> +
>> +#define for_each_platform_timer(_g) \
>> + for (_g = acpi_gtdt_desc.platform_timer; _g; \
>> + _g = next_platform_timer(_g))
>> +
>> +static inline bool is_timer_block(void *platform_timer)
>> +{
>> + struct acpi_gtdt_header *gh = platform_timer;
>> +
>> + return gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK;
>> +}
>> +
>> static int __init map_gt_gsi(u32 interrupt, u32 flags)
>> {
>> int trigger, polarity;
>> @@ -155,3 +177,111 @@ int __init acpi_gtdt_init(struct acpi_table_header *table,
>>
>> return ret;
>> }
>> +
>> +static int __init gtdt_parse_timer_block(struct acpi_gtdt_timer_block *block,
>> + struct arch_timer_mem *timer_mem)
>> +{
>> + int i, j;
>> + struct acpi_gtdt_timer_entry *gtdt_frame;
>> +
>> + if (!block->timer_count) {
>> + pr_err(FW_BUG "GT block present, but frame count is zero.");
>> + return -ENODEV;
>> + }
>> +
>> + if (block->timer_count > ARCH_TIMER_MEM_MAX_FRAMES) {
>> + pr_err(FW_BUG "GT block lists %d frames, ACPI spec only allows 8\n",
>> + block->timer_count);
>> + return -EINVAL;
>> + }
>> +
>> + timer_mem->cntctlbase = (phys_addr_t)block->block_address;
>> + /*
>> + * The CNTCTLBase frame is 4KB (register offsets 0x000 - 0xFFC).
>> + * See ARM DDI 0487A.k_iss10775, page I1-5129, Table I1-3
>> + * "CNTCTLBase memory map".
>> + */
>> + timer_mem->size = SZ_4K;
>> +
>> + gtdt_frame = (void *)block + block->timer_offset;
>> + if (gtdt_frame + block->timer_count != (void *)block + block->header.length)
>> + return -EINVAL;
>> +
>> + /*
>> + * Get the GT timer Frame data for every GT Block Timer
>> + */
>> + for (i = 0, j = 0; i < block->timer_count; i++, gtdt_frame++) {
>> + struct arch_timer_mem_frame *frame = &timer_mem->frame[j];
>> +
>> + if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER)
>> + continue;
>> +
>> + if (!gtdt_frame->base_address || !gtdt_frame->timer_interrupt)
>> + return -EINVAL;
>> +
>> + frame->phys_irq = map_gt_gsi(gtdt_frame->timer_interrupt,
>> + gtdt_frame->timer_flags);
>> + if (frame->phys_irq <= 0) {
>> + pr_warn("failed to map physical timer irq in frame %d.\n",
>> + i);
>> + return -EINVAL;
>> + }
>> +
>> + frame->virt_irq =
>> + map_gt_gsi(gtdt_frame->virtual_timer_interrupt,
>> + gtdt_frame->virtual_timer_flags);
>> + if (frame->virt_irq <= 0) {
>> + pr_warn("failed to map virtual timer irq in frame %d.\n",
>> + i);
>> + acpi_unregister_gsi(gtdt_frame->timer_interrupt);
>> + return -EINVAL;
>> + }
>> +
>> + frame->frame_nr = gtdt_frame->frame_number;
>> + frame->cntbase = gtdt_frame->base_address;
>> + /*
>> + * The CNTBaseN frame is 4KB (register offsets 0x000 - 0xFFC).
>> + * See ARM DDI 0487A.k_iss10775, page I1-5130, Table I1-4
>> + * "CNTBaseN memory map".
>> + */
>> + frame->size = SZ_4K;
>> + j++;
>> + }
>> + timer_mem->num_frames = j;
>> +
>> + return 0;
>> +}
>> +
>> +/**
>> + * acpi_arch_timer_mem_init() - Get the info of all GT blocks in GTDT table.
>> + * @timer_mem: the pointer to the array of struct arch_timer_mem for returning
>> + * the result of parsing. The element number of this array should
>> + * be platform_timer_count(the total number of platform timers).
>> + * @count: The pointer of int variate for returning the number of GT
>> + * blocks we have parsed.
>
> Nit: this comment was wrong on all the patches I reviewed :) must be
> some copy and paste.
Thanks ,
* @timer_count: It points to a integer variable which is used for storing the
* number of GT blocks we have parsed.
Is that OK for you?
>
>> + *
>> + * Return: 0 if success, -EINVAL/-ENODEV if error.
>> + */
>> +int __init acpi_arch_timer_mem_init(struct arch_timer_mem *timer_mem,
>> + int *timer_count)
>> +{
>> + int ret;
>> + void *platform_timer;
>> +
>> + *timer_count = 0;
>> + for_each_platform_timer(platform_timer) {
>> + if (is_timer_block(platform_timer)) {
>> + ret = gtdt_parse_timer_block(platform_timer, timer_mem);
>> + if (ret)
>> + return ret;
>
> Isn't there some unwinding to carry out here (eg GSI) ?
Thanks for your reminding,
it should be in gtdt_parse_timer_block, will do
>
> Otherwise it looks fine (minus Mark's request for using frame numbers
> as indexes that you should change).
>
> Lorenzo
>
>> + timer_mem++;
>> + (*timer_count)++;
>> + }
>> + }
>> +
>> + if (*timer_count)
>> + pr_info("found %d memory-mapped timer block(s).\n",
>> + *timer_count);
>> +
>> + return 0;
>> +}
>> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
>> index 4b5c146..3193724 100644
>> --- a/include/linux/acpi.h
>> +++ b/include/linux/acpi.h
>> @@ -599,6 +599,7 @@ int acpi_reconfig_notifier_unregister(struct notifier_block *nb);
>> int acpi_gtdt_init(struct acpi_table_header *table, int *platform_timer_count);
>> int acpi_gtdt_map_ppi(int type);
>> bool acpi_gtdt_c3stop(int type);
>> +int acpi_arch_timer_mem_init(struct arch_timer_mem *timer_mem, int *timer_count);
>> #endif
>>
>> #else /* !CONFIG_ACPI */
>> --
>> 2.9.3
>>
--
Best regards,
Fu Wei
Software Engineer
Red Hat
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
