Add preliminary support for the interrupt controller

4 files changed, 90 insertions, 4 deletions

diff --git a/machine/configstring.c b/machine/configstring.c
index 2805c21..b47d067 100644
--- a/machine/configstring.c
+++ b/machine/configstring.c
@@ -20,6 +20,43 @@ static void query_rtc(const char* config_string)
   mtime = (void*)(uintptr_t)get_uint(res);
 }
 
+static void query_plic(const char* config_string)
+{
+  query_result res = query_config_string(config_string, "plic{priority");
+  if (!res.start)
+    return;
+  plic_priorities = (uint16_t*)(uintptr_t)get_uint(res);
+
+  res = query_config_string(config_string, "plic{ndevs");
+  if (!res.start)
+    return;
+  plic_ndevs = get_uint(res);
+}
+
+static void query_hart_plic(const char* config_string, hls_t* hls, int core, int hart)
+{
+  char buf[32];
+  snprintf(buf, sizeof buf, "core{%d{%d{plic{m{ie", core, hart);
+  query_result res = query_config_string(config_string, buf);
+  if (res.start)
+    hls->plic_m_ie = (void*)(uintptr_t)get_uint(res);
+
+  snprintf(buf, sizeof buf, "core{%d{%d{plic{m{thresh", core, hart);
+  res = query_config_string(config_string, buf);
+  if (res.start)
+    hls->plic_m_thresh = (void*)(uintptr_t)get_uint(res);
+
+  snprintf(buf, sizeof buf, "core{%d{%d{plic{s{ie", core, hart);
+  res = query_config_string(config_string, buf);
+  if (res.start)
+    hls->plic_s_ie = (void*)(uintptr_t)get_uint(res);
+
+  snprintf(buf, sizeof buf, "core{%d{%d{plic{s{thresh", core, hart);
+  res = query_config_string(config_string, buf);
+  if (res.start)
+    hls->plic_s_thresh = (void*)(uintptr_t)get_uint(res);
+}
+
 static void query_harts(const char* config_string)
 {
   for (int core = 0, hart; ; core++) {
@@ -32,6 +69,8 @@ static void query_harts(const char* config_string)
       hls_t* hls = hls_init(num_harts);
       hls->ipi = (void*)(uintptr_t)get_uint(res);
 
+      query_hart_plic(config_string, hls, core, hart);
+
       snprintf(buf, sizeof buf, "core{%d{%d{timecmp", core, hart);
       res = query_config_string(config_string, buf);
       assert(res.start);
@@ -51,6 +90,7 @@ void parse_config_string()
   uint32_t addr = *(uint32_t*)CONFIG_STRING_ADDR;
   const char* s = (const char*)(uintptr_t)addr;
   query_mem(s);
+  query_plic(s);
   query_rtc(s);
   query_harts(s);
 }
diff --git a/machine/encoding.h b/machine/encoding.h
index 5405148..bdba5f2 100644
--- a/machine/encoding.h
+++ b/machine/encoding.h
@@ -39,6 +39,9 @@
 #define MIP_STIP            (1 << IRQ_S_TIMER)
 #define MIP_HTIP            (1 << IRQ_H_TIMER)
 #define MIP_MTIP            (1 << IRQ_M_TIMER)
+#define MIP_SEIP            (1 << IRQ_S_EXT)
+#define MIP_HEIP            (1 << IRQ_H_EXT)
+#define MIP_MEIP            (1 << IRQ_M_EXT)
 
 #define SIP_SSIP MIP_SSIP
 #define SIP_STIP MIP_STIP
@@ -61,9 +64,9 @@
 #define IRQ_S_TIMER  5
 #define IRQ_H_TIMER  6
 #define IRQ_M_TIMER  7
-#define IRQ_S_DEV    9
-#define IRQ_H_DEV    10
-#define IRQ_M_DEV    11
+#define IRQ_S_EXT    9
+#define IRQ_H_EXT    10
+#define IRQ_M_EXT    11
 #define IRQ_COP      12
 #define IRQ_HOST     13
 
diff --git a/machine/minit.c b/machine/minit.c
index b8a67c0..661a20a 100644
--- a/machine/minit.c
+++ b/machine/minit.c
@@ -3,12 +3,15 @@
 #include "vm.h"
 #include "fp_emulation.h"
 #include <string.h>
+#include <limits.h>
 
 pte_t* root_page_table;
 uintptr_t first_free_paddr;
 uintptr_t mem_size;
 uintptr_t num_harts;
 volatile uint64_t* mtime;
+volatile uint16_t* plic_priorities;
+size_t plic_ndevs;
 
 static void mstatus_init()
 {
@@ -31,7 +34,7 @@ static void mstatus_init()
 // send S-mode interrupts and most exceptions straight to S-mode
 static void delegate_traps()
 {
-  uintptr_t interrupts = MIP_SSIP | MIP_STIP;
+  uintptr_t interrupts = MIP_SSIP | MIP_STIP | MIP_SEIP;
   uintptr_t exceptions =
     (1U << CAUSE_MISALIGNED_FETCH) |
     (1U << CAUSE_FAULT_FETCH) |
@@ -89,11 +92,42 @@ static void hart_init()
   delegate_traps();
 }
 
+static void plic_init()
+{
+  for (size_t i = 1; i <= plic_ndevs; i++)
+    plic_priorities[i] = 1;
+}
+
+static void hart_plic_init()
+{
+  if (!plic_ndevs)
+    return;
+
+  size_t ie_words = plic_ndevs / sizeof(uintptr_t) + 1;
+  for (size_t i = 0; i < ie_words; i++)
+    HLS()->plic_s_ie[i] = ULONG_MAX;
+  *HLS()->plic_m_thresh = 1;
+  *HLS()->plic_s_thresh = 0;
+
+  int x;
+  while ((x = HLS()->plic_s_thresh[1]))
+    printm("%d\n", x);
+  HLS()->plic_s_thresh[1] = 1;
+  HLS()->plic_s_thresh[1] = 3;
+  *((char*)plic_priorities + 0x805) = 1;
+  while ((x = HLS()->plic_s_thresh[1])) {
+    printm("%d\n", x);
+    *HLS()->plic_s_thresh = 1;
+  }
+}
+
 void init_first_hart()
 {
   hart_init();
   hls_init(0); // this might get called again from parse_config_string
   parse_config_string();
+  plic_init();
+  hart_plic_init();
   memory_init();
   boot_loader();
 }
@@ -106,6 +140,7 @@ void init_other_hart()
   while (*(uint64_t * volatile *)&HLS()->timecmp == NULL)
     ;
 
+  hart_plic_init();
   boot_other_hart();
 }
 
diff --git a/machine/mtrap.h b/machine/mtrap.h
index b859a63..3a6fb22 100644
--- a/machine/mtrap.h
+++ b/machine/mtrap.h
@@ -13,6 +13,7 @@
 
 #include "sbi.h"
 #include <stdint.h>
+#include <stddef.h>
 
 #define read_const_csr(reg) ({ unsigned long __tmp; \
   asm ("csrr %0, " #reg : "=r"(__tmp)); \
@@ -32,6 +33,8 @@ extern uintptr_t first_free_paddr;
 extern uintptr_t mem_size;
 extern uintptr_t num_harts;
 extern volatile uint64_t* mtime;
+extern volatile uint16_t* plic_priorities;
+extern size_t plic_ndevs;
 
 typedef struct {
   uint64_t* timecmp;
@@ -46,6 +49,11 @@ typedef struct {
   uint64_t stime_delta;
   uint64_t scycle_delta;
   uint64_t sinstret_delta;
+
+  volatile uint16_t* plic_m_thresh;
+  volatile uintptr_t* plic_m_ie;
+  volatile uint16_t* plic_s_thresh;
+  volatile uintptr_t* plic_s_ie;
 } hls_t;
 
 #define IPI_SOFT      0x1