// SPDX-License-Identifier: GPL-2.0-only
/*
* ARM Specific GTDT table Support
*
* Copyright (C) 2016, Linaro Ltd.
* Author: Daniel Lezcano <[email protected]>
* Fu Wei <[email protected]>
* Hanjun Guo <[email protected]>
*/
#include <linux/acpi.h>
#include <linux/init.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <clocksource/arm_arch_timer.h>
#undef pr_fmt
#define pr_fmt(fmt) "ACPI GTDT: " fmt
/**
* struct acpi_gtdt_descriptor - Store the key info of GTDT for all functions
* @gtdt: The pointer to the struct acpi_table_gtdt of GTDT table.
* @gtdt_end: The pointer to the end of GTDT table.
* @platform_timer: The pointer to the start of Platform Timer Structure
*
* The struct store the key info of GTDT table, it should be initialized by
* acpi_gtdt_init.
*/
struct acpi_gtdt_descriptor {
struct acpi_table_gtdt *gtdt;
void *gtdt_end;
void *platform_timer;
};
static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata;
static inline __init 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 inline bool is_non_secure_watchdog(void *platform_timer)
{
struct acpi_gtdt_header *gh = platform_timer;
struct acpi_gtdt_watchdog *wd = platform_timer;
if (gh->type != ACPI_GTDT_TYPE_WATCHDOG)
return false;
return !(wd->timer_flags & ACPI_GTDT_WATCHDOG_SECURE);
}
static int __init map_gt_gsi(u32 interrupt, u32 flags)
{
int trigger, polarity;
trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
: ACPI_LEVEL_SENSITIVE;
polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
: ACPI_ACTIVE_HIGH;
return acpi_register_gsi(NULL, interrupt, trigger, polarity);
}
/**
* acpi_gtdt_map_ppi() - Map the PPIs of per-cpu arch_timer.
* @type: the type of PPI.
*
* Note: Secure state is not managed by the kernel on ARM64 systems.
* So we only handle the non-secure timer PPIs,
* ARCH_TIMER_PHYS_SECURE_PPI is treated as invalid type.
*
* Return: the mapped PPI value, 0 if error.
*/
int __init acpi_gtdt_map_ppi(int type)
{
struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;
switch (type) {
case ARCH_TIMER_PHYS_NONSECURE_PPI:
return map_gt_gsi(gtdt->non_secure_el1_interrupt,
gtdt->non_secure_el1_flags);
case ARCH_TIMER_VIRT_PPI:
return map_gt_gsi(gtdt->virtual_timer_interrupt,
gtdt->virtual_timer_flags);
case ARCH_TIMER_HYP_PPI:
return map_gt_gsi(gtdt->non_secure_el2_interrupt,
gtdt->non_secure_el2_flags);
default:
pr_err("Failed to map timer interrupt: invalid type.\n");
}
return 0;
}
/**
* acpi_gtdt_c3stop() - Got c3stop info from GTDT according to the type of PPI.
* @type: the type of PPI.
*
* Return: true if the timer HW state is lost when a CPU enters an idle state,
* false otherwise
*/
bool __init acpi_gtdt_c3stop(int type)
{
struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;
switch (type) {
case ARCH_TIMER_PHYS_NONSECURE_PPI:
return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
case ARCH_TIMER_VIRT_PPI:
return !(gtdt->virtual_timer_flags & ACPI_GTDT_ALWAYS_ON);
case ARCH_TIMER_HYP_PPI:
return !(gtdt->non_secure_el2_flags & ACPI_GTDT_ALWAYS_ON);
default:
pr_err("Failed to get c3stop info: invalid type.\n");
}
return false;
}
/**
* acpi_gtdt_init() - Get the info of GTDT table to prepare for further init.
* @table: The pointer to GTDT table.
* @platform_timer_count: It points to a integer variable which is used
* for storing the number of platform timers.
* This pointer could be NULL, if the caller
* doesn't need this info.
*
* Return: 0 if success, -EINVAL if error.
*/
int __init acpi_gtdt_init(struct acpi_table_header *table,
int *platform_timer_count)
{
void *platform_timer;
struct acpi_table_gtdt *gtdt;
gtdt = container_of(table, struct acpi_table_gtdt, header);
acpi_gtdt_desc.gtdt = gtdt;
acpi_gtdt_desc.gtdt_end = (void *)table + table->length;
acpi_gtdt_desc.platform_timer = NULL;
if (platform_timer_count)
*platform_timer_count = 0;
if (table->revision < 2) {
pr_warn("Revision:%d doesn't support Platform Timers.\n",
table->revision);
return 0;
}
if (!gtdt->platform_timer_count) {
pr_debug("No Platform Timer.\n");
return 0;
}
platform_timer = (void *)gtdt + gtdt->platform_timer_offset;
if (platform_timer < (void *)table + sizeof(struct acpi_table_gtdt)) {
pr_err(FW_BUG "invalid timer data.\n");
return -EINVAL;
}
acpi_gtdt_desc.platform_timer = platform_timer;
if (platform_timer_count)
*platform_timer_count = gtdt->platform_timer_count;
return 0;
}
static int __init gtdt_parse_timer_block(struct acpi_gtdt_timer_block *block,
struct arch_timer_mem *timer_mem)
{
int i;
struct arch_timer_mem_frame *frame;
struct acpi_gtdt_timer_entry *gtdt_frame;
if (!block->timer_count) {
pr_err(FW_BUG "GT block present, but frame count is zero.\n");
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; i < block->timer_count; i++, gtdt_frame++) {
if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER)
continue;
if (gtdt_frame->frame_number >= ARCH_TIMER_MEM_MAX_FRAMES ||
!gtdt_frame->base_address || !gtdt_frame->timer_interrupt)
goto error;
frame = &timer_mem->frame[gtdt_frame->frame_number];
/* duplicate frame */
if (frame->valid)
goto error;
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",
gtdt_frame->frame_number);
goto error;
}
if (gtdt_frame->virtual_timer_interrupt) {
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",
gtdt_frame->frame_number);
goto error;
}
} else {
pr_debug("virtual timer in frame %d not implemented.\n",
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;
frame->valid = true;
}
return 0;
error:
do {
if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER ||
gtdt_frame->frame_number >= ARCH_TIMER_MEM_MAX_FRAMES)
continue;
frame = &timer_mem->frame[gtdt_frame->frame_number];
if (frame->phys_irq > 0)
acpi_unregister_gsi(gtdt_frame->timer_interrupt);
frame->phys_irq = 0;
if (frame->virt_irq > 0)
acpi_unregister_gsi(gtdt_frame->virtual_timer_interrupt);
frame->virt_irq = 0;
} while (i-- >= 0 && gtdt_frame--);
return -EINVAL;
}
/**
* 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).
* @timer_count: It points to a integer variable which is used for storing the
* number of GT blocks we have parsed.
*
* 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;
timer_mem++;
(*timer_count)++;
}
}
if (*timer_count)
pr_info("found %d memory-mapped timer block(s).\n",
*timer_count);
return 0;
}
/*
* Initialize a SBSA generic Watchdog platform device info from GTDT
*/
static int __init gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd,
int index)
{
struct platform_device *pdev;
int irq;
/*
* According to SBSA specification the size of refresh and control
* frames of SBSA Generic Watchdog is SZ_4K(Offset 0x000 – 0xFFF).
*/
struct resource res[] = {
DEFINE_RES_MEM(wd->control_frame_address, SZ_4K),
DEFINE_RES_MEM(wd->refresh_frame_address, SZ_4K),
{},
};
int nr_res = ARRAY_SIZE(res);
pr_debug("found a Watchdog (0x%llx/0x%llx gsi:%u flags:0x%x).\n",
wd->refresh_frame_address, wd->control_frame_address,
wd->timer_interrupt, wd->timer_flags);
if (!(wd->refresh_frame_address && wd->control_frame_address)) {
pr_err(FW_BUG "failed to get the Watchdog base address.\n");
return -EINVAL;
}
irq = map_gt_gsi(wd->timer_interrupt, wd->timer_flags);
res[2] = (struct resource)DEFINE_RES_IRQ(irq);
if (irq <= 0) {
pr_warn("failed to map the Watchdog interrupt.\n");
nr_res--;
}
/*
* Add a platform device named "sbsa-gwdt" to match the platform driver.
* "sbsa-gwdt": SBSA(Server Base System Architecture) Generic Watchdog
* The platform driver can get device info below by matching this name.
*/
pdev = platform_device_register_simple("sbsa-gwdt", index, res, nr_res);
if (IS_ERR(pdev)) {
if (irq > 0)
acpi_unregister_gsi(wd->timer_interrupt);
return PTR_ERR(pdev);
}
return 0;
}
static int __init gtdt_sbsa_gwdt_init(void)
{
void *platform_timer;
struct acpi_table_header *table;
int ret, timer_count, gwdt_count = 0;
if (acpi_disabled)
return 0;
if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_GTDT, 0, &table)))
return -EINVAL;
/*
* Note: Even though the global variable acpi_gtdt_desc has been
* initialized by acpi_gtdt_init() while initializing the arch timers,
* when we call this function to get SBSA watchdogs info from GTDT, the
* pointers stashed in it are stale (since they are early temporary
* mappings carried out before acpi_permanent_mmap is set) and we need
* to re-initialize them with permanent mapped pointer values to let the
* GTDT parsing possible.
*/
ret = acpi_gtdt_init(table, &timer_count);
if (ret || !timer_count)
goto out_put_gtdt;
for_each_platform_timer(platform_timer) {
if (is_non_secure_watchdog(platform_timer)) {
ret = gtdt_import_sbsa_gwdt(platform_timer, gwdt_count);
if (ret)
break;
gwdt_count++;
}
}
if (gwdt_count)
pr_info("found %d SBSA generic Watchdog(s).\n", gwdt_count);
out_put_gtdt:
acpi_put_table(table);
return ret;
}
device_initcall(gtdt_sbsa_gwdt_init);
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