[PATCH v13 7/8] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer
fu.wei at linaro.org
fu.wei at linaro.org
Wed Sep 14 13:09:40 PDT 2016
From: Fu Wei <fu.wei at linaro.org>
The patch add memory-mapped timer register support by using the information
provided by the new GTDT driver of ACPI.
Also refactor original memory-mapped timer dt support for reusing some common
code.
Signed-off-by: Fu Wei <fu.wei at linaro.org>
---
drivers/clocksource/arm_arch_timer.c | 238 +++++++++++++++++++++++++----------
1 file changed, 172 insertions(+), 66 deletions(-)
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 0197ef9..ddca6e3 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -57,6 +57,7 @@
static unsigned arch_timers_present __initdata;
static void __iomem *arch_counter_base;
+static void __iomem *cntctlbase __initdata;
struct arch_timer {
void __iomem *base;
@@ -656,15 +657,56 @@ out:
return err;
}
-static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
+static int __init arch_timer_mem_register(struct device_node *np, void *frame)
{
- int ret;
- irq_handler_t func;
+ struct device_node *frame_node = NULL;
+ struct gt_timer_data *frame_data = NULL;
struct arch_timer *t;
+ void __iomem *base;
+ irq_handler_t func;
+ unsigned int irq;
+ int ret;
+
+ if (np) {
+ frame_node = (struct device_node *)frame;
+ base = of_iomap(frame_node, 0);
+ arch_timer_detect_rate(base, np);
+ if (arch_timer_mem_use_virtual)
+ irq = irq_of_parse_and_map(frame_node, VIRT_SPI);
+ else
+ irq = irq_of_parse_and_map(frame_node, PHYS_SPI);
+ } else {
+ frame_data = (struct gt_timer_data *)frame;
+ /*
+ * According to ARMv8 Architecture Reference Manual(ARM),
+ * the size of CNTBaseN frames of memory-mapped timer
+ * is SZ_4K(Offset 0x000 – 0xFFF).
+ */
+ base = ioremap(frame_data->cntbase_phy, SZ_4K);
+ if (arch_timer_mem_use_virtual)
+ irq = frame_data->virtual_irq;
+ else
+ irq = frame_data->irq;
+ }
+
+ if (!base) {
+ pr_err("Can't map frame's registers\n");
+ return -ENXIO;
+ }
+ if (!irq) {
+ pr_err("Frame missing %s irq",
+ arch_timer_mem_use_virtual ? "virt" : "phys");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ arch_counter_base = base;
t = kzalloc(sizeof(*t), GFP_KERNEL);
- if (!t)
+ if (!t) {
return -ENOMEM;
+ goto out;
+ }
t->base = base;
t->evt.irq = irq;
@@ -676,11 +718,13 @@ static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
func = arch_timer_handler_phys_mem;
ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &t->evt);
- if (ret) {
- pr_err("Failed to request mem timer irq\n");
- kfree(t);
- }
+ if (!ret)
+ return 0;
+ pr_err("Failed to request mem timer irq\n");
+ kfree(t);
+out:
+ iounmap(base);
return ret;
}
@@ -769,7 +813,7 @@ static int __init arch_timer_init(void)
return ret;
arch_timer_kvm_info.virtual_irq = arch_timer_ppi[VIRT_PPI];
-
+
return 0;
}
@@ -803,21 +847,56 @@ static int __init arch_timer_of_init(struct device_node *np)
CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init);
CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init);
-static int __init arch_timer_mem_init(struct device_node *np)
+static int __init get_cnttidr(struct device_node *np,
+ struct gt_block_data *gt_block, u32 *cnttidr)
{
- struct device_node *frame, *best_frame = NULL;
- void __iomem *cntctlbase, *base;
- unsigned int irq, ret = -EINVAL;
- u32 cnttidr;
+ if (np)
+ cntctlbase = of_iomap(np, 0);
+ else
+ cntctlbase = ioremap(gt_block->cntctlbase_phy, SZ_4K);
+ /*
+ * According to ARMv8 Architecture Reference Manual(ARM),
+ * the size of CNTCTLBase frame of memory-mapped timer
+ * is SZ_4K(Offset 0x000 – 0xFFF).
+ */
- arch_timers_present |= ARCH_MEM_TIMER;
- cntctlbase = of_iomap(np, 0);
if (!cntctlbase) {
pr_err("Can't find CNTCTLBase\n");
return -ENXIO;
}
- cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
+ *cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
+ return 0;
+}
+
+static bool __init is_best_frame(u32 cnttidr, int n)
+{
+ u32 cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT | CNTACR_RWVT |
+ CNTACR_RVOFF | CNTACR_RVCT;
+
+ /* Try enabling everything, and see what sticks */
+ writel_relaxed(cntacr, cntctlbase + CNTACR(n));
+ cntacr = readl_relaxed(cntctlbase + CNTACR(n));
+
+ if ((cnttidr & CNTTIDR_VIRT(n)) &&
+ !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT)))
+ arch_timer_mem_use_virtual = true;
+ else if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
+ return false;
+
+ return true;
+}
+
+static int __init arch_timer_mem_init(struct device_node *np)
+{
+ struct device_node *frame, *best_frame = NULL;
+ unsigned int ret = -EINVAL;
+ u32 cnttidr;
+
+ arch_timers_present |= ARCH_MEM_TIMER;
+
+ if (get_cnttidr(np, NULL, &cnttidr))
+ return -ENXIO;
/*
* Try to find a virtual capable frame. Otherwise fall back to a
@@ -825,60 +904,22 @@ static int __init arch_timer_mem_init(struct device_node *np)
*/
for_each_available_child_of_node(np, frame) {
int n;
- u32 cntacr;
-
if (of_property_read_u32(frame, "frame-number", &n)) {
- pr_err("Missing frame-number\n");
+ pr_err("Missing frame-number.\n");
of_node_put(frame);
goto out;
}
-
- /* Try enabling everything, and see what sticks */
- cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT |
- CNTACR_RWVT | CNTACR_RVOFF | CNTACR_RVCT;
- writel_relaxed(cntacr, cntctlbase + CNTACR(n));
- cntacr = readl_relaxed(cntctlbase + CNTACR(n));
-
- if ((cnttidr & CNTTIDR_VIRT(n)) &&
- !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT))) {
+ if (is_best_frame(cnttidr, n)) {
of_node_put(best_frame);
- best_frame = frame;
- arch_timer_mem_use_virtual = true;
- break;
+ best_frame = of_node_get(frame);
+ if (arch_timer_mem_use_virtual)
+ break;
}
-
- if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
- continue;
-
- of_node_put(best_frame);
- best_frame = of_node_get(frame);
- }
-
- ret= -ENXIO;
- base = arch_counter_base = of_iomap(best_frame, 0);
- if (!base) {
- pr_err("Can't map frame's registers\n");
- goto out;
- }
-
- if (arch_timer_mem_use_virtual)
- irq = irq_of_parse_and_map(best_frame, VIRT_SPI);
- else
- irq = irq_of_parse_and_map(best_frame, PHYS_SPI);
-
- ret = -EINVAL;
- if (!irq) {
- pr_err("Frame missing %s irq",
- arch_timer_mem_use_virtual ? "virt" : "phys");
- goto out;
}
- arch_timer_detect_rate(base, np);
- ret = arch_timer_mem_register(base, irq);
- if (ret)
- goto out;
-
- return arch_timer_common_init();
+ ret = arch_timer_mem_register(np, best_frame);
+ if (!ret)
+ ret = arch_timer_common_init();
out:
iounmap(cntctlbase);
of_node_put(best_frame);
@@ -888,7 +929,72 @@ CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
arch_timer_mem_init);
#ifdef CONFIG_ACPI_GTDT
-/* Initialize per-processor generic timer */
+static struct gt_timer_data __init *arch_timer_mem_get_timer(
+ struct gt_block_data *gt_blocks)
+{
+ struct gt_block_data *gt_block = gt_blocks;
+ struct gt_timer_data *best_frame = NULL;
+ u32 cnttidr;
+ int i;
+
+ if (get_cnttidr(NULL, gt_block, &cnttidr))
+ return NULL;
+ /*
+ * Try to find a virtual capable frame. Otherwise fall back to a
+ * physical capable frame.
+ */
+ for (i = 0; i < gt_block->timer_count; i++) {
+ if (is_best_frame(cnttidr, gt_block->timer[i].frame_nr)) {
+ best_frame = >_block->timer[i];
+ if (arch_timer_mem_use_virtual)
+ break;
+ }
+ }
+ iounmap(cntctlbase);
+
+ return best_frame;
+}
+
+static int __init arch_timer_mem_acpi_init(size_t timer_count)
+{
+ struct gt_block_data *gt_blocks;
+ struct gt_timer_data *gt_timer;
+ int ret = -EINVAL;
+
+ /*
+ * If we don't have any Platform Timer Structures, just return.
+ */
+ if (!timer_count)
+ return 0;
+
+ /*
+ * before really check all the Platform Timer Structures,
+ * we assume they are GT block, and allocate memory for them.
+ * We will free these memory once we finish the initialization.
+ */
+ gt_blocks = kcalloc(timer_count, sizeof(*gt_blocks), GFP_KERNEL);
+ if (!gt_blocks)
+ return -ENOMEM;
+
+ if (gtdt_arch_timer_mem_init(gt_blocks) > 0) {
+ gt_timer = arch_timer_mem_get_timer(gt_blocks);
+ if (!gt_timer) {
+ pr_err("Failed to get mem timer info.\n");
+ goto error;
+ }
+ ret = arch_timer_mem_register(NULL, gt_timer);
+ if (ret) {
+ pr_err("Failed to register mem timer.\n");
+ goto error;
+ }
+ }
+ arch_timers_present |= ARCH_MEM_TIMER;
+error:
+ kfree(gt_blocks);
+ return ret;
+}
+
+/* Initialize per-processor generic timer and memory-mapped timer(if present) */
static int __init arch_timer_acpi_init(struct acpi_table_header *table)
{
int timer_count;
@@ -912,8 +1018,8 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table)
/* Get the frequency from CNTFRQ */
arch_timer_detect_rate(NULL, NULL);
- if (timer_count < 0)
- pr_err("Failed to get platform timer info.\n");
+ if (timer_count < 0 || arch_timer_mem_acpi_init((size_t)timer_count))
+ pr_err("Failed to initialize memory-mapped timer.\n");
return arch_timer_init();
}
--
2.7.4
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