acpi: support hpet timer

Added support for the HPET timer.

Signed-off-by: Daniele Ahmed <ahmeddan amazon c;0m >

arch/x86/apic.c

@@ -26,10 +26,10 @@
 #include <console.h>
 #include <drivers/pit.h>
 #include <ktf.h>
-#include <time.h>
 #include <lib.h>
 #include <percpu.h>
 #include <processor.h>
+#include <time.h>
 #include <traps.h>
 
 static apic_mode_t apic_mode = APIC_MODE_UNKNOWN;

common/setup.c

@@ -47,6 +47,7 @@
 #include <smp/mptables.h>
 #include <smp/smp.h>
 
+#include <drivers/hpet.h>
 #include <drivers/pic.h>
 #include <drivers/pit.h>
 #include <drivers/serial.h>
@@ -63,6 +64,9 @@ bool_cmd("pit", opt_pit);
 bool opt_apic_timer = false;
 bool_cmd("apic_timer", opt_apic_timer);
 
+bool opt_hpet = false;
+bool_cmd("hpet", opt_hpet);
+
 io_port_t com_ports[2] = {COM1_PORT, COM2_PORT};
 
 static unsigned bsp_cpu_id = 0;
@@ -240,7 +244,10 @@ void __noreturn __text_init kernel_start(uint32_t multiboot_magic,
     uart_input_init(get_bsp_cpu_id());
 
     /* Initialize timers */
-    if (opt_pit)
+    bool hpet_initialized = false;
+    if (opt_hpet)
+        hpet_initialized = init_hpet(get_bsp_cpu_id());
+    if (!hpet_initialized && opt_pit)
         init_pit(get_bsp_cpu_id());
     if (opt_apic_timer)
         init_apic_timer();

drivers/hpet.c

@@ -0,0 +1,92 @@
+/*
+ * Copyright © 2020 Amazon.com, Inc. or its affiliates.
+ * All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <drivers/hpet.h>
+#include <ioapic.h>
+
+bool init_hpet(uint8_t dst_cpus) {
+    acpi_hpet_t *hpet;
+    mfn_t hpet_base_mfn;
+    volatile acpi_hpet_timer_t *config;
+    volatile acpi_hpet_general_t *general;
+    volatile uint64_t *main_counter;
+
+    printk("Initializing HPET\n");
+
+    hpet = (acpi_hpet_t *) acpi_find_table(HPET_SIGNATURE);
+
+    if (!hpet) {
+        printk("HPET not initialized\n");
+        return false;
+    }
+
+    hpet_base_mfn = paddr_to_mfn(hpet->address.address);
+    vmap((uint64_t *) hpet->address.address, hpet_base_mfn, PAGE_ORDER_4K, L1_PROT);
+    config = (acpi_hpet_timer_t *) (hpet->address.address +
+                                    HPET_OFFSET_TIMER_0_CONFIG_CAP_REG);
+    general =
+        (acpi_hpet_general_t *) (hpet->address.address + HPET_OFFSET_GENERAL_CAP_REG);
+    main_counter =
+        (uint64_t *) (hpet->address.address + HPET_OFFSET_GENERAL_MAIN_COUNTER_REG);
+
+    general->enabled = 0;
+
+    if (config->cfg_int_type != HPET_CONFIG_INT_TYPE_TRIGGER_MODE) {
+        return false;
+    }
+
+    if (!config->cap_int_periodic) {
+        return false;
+    }
+
+    if (general->num_timers_cap == 0) {
+        return false;
+    }
+
+    /* Disable all timers */
+    for (int i = 0; i < general->num_timers_cap; ++i) {
+        (config + i)->cfg_int_enabled = 0;
+    }
+
+    *main_counter = 0;
+
+    /* 1 fs = 10^15s */
+    uint64_t freq_hz = 1000000000000000 / general->counter_clock_period;
+    uint64_t ticks = freq_hz / 1000; /* Interrupt every 1ms */
+
+    config->cfg_int_enabled = 1;
+    config->cfg_int_route = 0;
+    config->cfg_fsb_enable = 0;
+    config->cfg_type = 1;
+    config->cfg_value_set = 1;
+    config->comparator = ticks;
+
+    general->leg_repl_cfg = 0; /* Disable legacy route */
+    general->enabled = 1;
+
+    configure_isa_irq(HPET_IRQ, HPET_IRQ_OFFSET, IOAPIC_DEST_MODE_PHYSICAL, dst_cpus);
+    dprintk("Initialized HPET\n");
+    return true;
+}

drivers/pit.c

@@ -27,10 +27,11 @@
 #include <drivers/pic.h>
 #include <drivers/pit.h>
 #include <ioapic.h>
-#include <time.h>
 #include <lib.h>
+#include <time.h>
 
 void init_pit(uint8_t dst_cpus) {
+    printk("Initializing PIT\n");
     outb(PIT_COMMAND_PORT,
          PIT_CHANNEL_0 & PIT_ACCESS_MODE_LH & PIT_OP_MODE_RATE & PIT_BCD_MODE);
     outb(PIT_DATA_PORT_CH0, PIT_FREQUENCY & 0xFF);          /* send low byte */

include/drivers/hpet.h

@@ -0,0 +1,107 @@
+
+/*
+ * Copyright © 2020 Amazon.com, Inc. or its affiliates.
+ * All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef KTF_HPET_H
+#define KTF_HPET_H
+
+#include <acpi.h>
+#include <drivers/pit.h>
+
+#define HPET_SIGNATURE  (('H') | ('P' << 8) | ('E' << 16) | ('T' << 24))
+#define HPET_IRQ        PIT_IRQ
+#define HPET_IRQ_OFFSET PIT_IRQ0_OFFSET
+
+struct acpi_hpet {
+    acpi_table_hdr_t header;
+    uint8_t hardware_rev_id;
+    uint8_t comparator_count : 5;
+    uint8_t counter_size : 1;
+    uint8_t reserved : 1;
+    uint8_t legacy_replacement : 1;
+    uint16_t pci_vendor_id;
+    acpi_gas_t address;
+    uint8_t hpet_number;
+    uint16_t minimum_tick;
+    uint8_t page_protection;
+} __packed;
+typedef struct acpi_hpet acpi_hpet_t;
+
+struct acpi_hpet_timer {
+    uint64_t resv0 : 1;
+    uint64_t cfg_int_type : 1;
+    uint64_t cfg_int_enabled : 1;
+    uint64_t cfg_type : 1;
+    uint64_t cap_int_periodic : 1;
+    uint64_t cap_size : 1;
+    uint64_t cfg_value_set : 1;
+    uint64_t resv1 : 1;
+    uint64_t cfg_32bit_mode : 1;
+    uint64_t cfg_int_route : 5;
+    uint64_t cfg_fsb_enable : 1;
+    uint64_t cap_fsb_int_delivery : 1;
+    uint64_t resv2 : 8;
+    uint64_t cap_int_route : 32;
+    uint64_t comparator;
+    uint64_t fsb;
+    uint64_t resv3;
+};
+typedef struct acpi_hpet_timer acpi_hpet_timer_t;
+
+struct acpi_hpet_general {
+    uint64_t rev_id : 8;
+    uint64_t num_timers_cap : 5;
+    uint64_t count_size_cap : 1;
+    uint64_t resv0 : 1;
+    uint64_t leg_repl_cap : 1;
+    uint64_t vendor_id : 16;
+    uint64_t counter_clock_period : 32;
+    uint64_t _pad;
+    uint64_t enabled : 1;
+    uint64_t leg_repl_cfg : 1;
+    uint64_t resv1 : 62;
+    uint64_t _pad2;
+    uint64_t timer_n_int_status : 32; /* n^th bit for the n^th timer */
+    uint32_t resv2;
+};
+typedef struct acpi_hpet_general acpi_hpet_general_t;
+
+enum {
+    HPET_OFFSET_GENERAL_CAP_REG = 0x000,
+    HPET_OFFSET_GENERAL_CONFIG_REG = 0x010,
+    HPET_OFFSET_GENERAL_INT_STATUS_REG = 0x020,
+    HPET_OFFSET_GENERAL_MAIN_COUNTER_REG = 0x0f0,
+    HPET_OFFSET_TIMER_0_CONFIG_CAP_REG = 0x100,
+    HPET_OFFSET_TIMER_0_COMPARATOR_REG = 0x108,
+    HPET_OFFSET_TIMER_0_FSB_ROUTE_REG = 0x110,
+};
+
+#define HPET_CONFIG_INT_TYPE_TRIGGER_MODE 0
+
+/* External Declarations */
+
+extern bool init_hpet(uint8_t dst_cpus);
+
+#endif /* KTF_HPET_H */