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