[src/trunk]: src/sys/dev/fdt Rewrite interrupt-map support based on ePAPR spec.

[jmcneill <jmcneill%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e164609f023a
branches:  trunk
changeset: 824332:e164609f023a
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Fri Jun 02 00:55:26 2017 +0000

description:
Rewrite interrupt-map support based on ePAPR spec.

diffstat:

 sys/dev/fdt/fdt_intr.c |  266 ++++++++++++++++++++++--------------------------
 1 files changed, 122 insertions(+), 144 deletions(-)

diffs (truncated from 364 to 300 lines):

diff -r 7b93435b60d5 -r e164609f023a sys/dev/fdt/fdt_intr.c
--- a/sys/dev/fdt/fdt_intr.c    Fri Jun 02 00:32:12 2017 +0000
+++ b/sys/dev/fdt/fdt_intr.c    Fri Jun 02 00:55:26 2017 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: fdt_intr.c,v 1.8 2016/05/25 12:43:08 jmcneill Exp $ */
+/* $NetBSD: fdt_intr.c,v 1.9 2017/06/02 00:55:26 jmcneill Exp $ */
 
 /*-
  * Copyright (c) 2015 Jared D. McNeill <jmcneill%invisible.ca@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fdt_intr.c,v 1.8 2016/05/25 12:43:08 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fdt_intr.c,v 1.9 2017/06/02 00:55:26 jmcneill Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -47,8 +47,8 @@
 static struct fdtbus_interrupt_controller *fdtbus_ic = NULL;
 
 static bool has_interrupt_map(int phandle);
-static u_int *get_entry_from_map(int phandle, int pindex, u_int *spec);
 static u_int *get_specifier_by_index(int phandle, int pindex, u_int *spec);
+static u_int *get_specifier_from_map(int phandle, u_int *spec, u_int spec_len, int *piphandle);
 
 static int
 fdtbus_get_interrupt_parent(int phandle)
@@ -122,41 +122,22 @@
 fdtbus_intr_establish(int phandle, u_int index, int ipl, int flags,
     int (*func)(void *), void *arg)
 {
-       void * result = NULL;
+       struct fdtbus_interrupt_controller *ic;
+       int ihandle = phandle;
        u_int *specifier;
        u_int spec_length;
-       int ihandle;
-       struct fdtbus_interrupt_controller *ic;
+
+       specifier = get_specifier_by_index(phandle, index, &spec_length);
+       if (has_interrupt_map(phandle))
+               specifier = get_specifier_from_map(phandle, specifier,
+                   spec_length, &ihandle);
 
-       if (has_interrupt_map(phandle)) {
-               specifier = get_entry_from_map(phandle, index, &spec_length);
-               ihandle = be32toh(specifier[1]);
-               ihandle = fdtbus_get_phandle_from_native(ihandle);
-               specifier += 2;
-       } else {
-               specifier = get_specifier_by_index(phandle, index,
-                                                  &spec_length);
-               ihandle = phandle;
-       }
-       if (specifier == NULL) {
-               printf("%s: Unable to get specifier %d for phandle %d\n",
-                      __func__, index, phandle);
-               goto done;
-       }
        ic = fdtbus_get_interrupt_controller(ihandle);
-       if (ic == NULL) {
-               printf("%s: Unable to get interrupt controller for %d\n",
-                      __func__, ihandle);
-               goto done;
-       }
-       result = ic->ic_funcs->establish(ic->ic_dev, specifier,
-                                              ipl, flags, func, arg);
-done:
-       if (has_interrupt_map(phandle))
-           specifier -= 2;
-       if (specifier && spec_length > 0)
-               kmem_free(specifier, spec_length);
-       return result;
+       if (ic == NULL)
+               return NULL;
+
+       return ic->ic_funcs->establish(ic->ic_dev, specifier,
+           ipl, flags, func, arg);
 }
 
 void
@@ -173,166 +154,163 @@
 bool
 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
 {
-       bool result = false;
        struct fdtbus_interrupt_controller *ic;
-       int ihandle;
+       int ihandle = phandle;
        u_int *specifier;
        u_int spec_length;
-       if (has_interrupt_map(phandle)) {
-               specifier = get_entry_from_map(phandle, index,
-                       &spec_length);
-               ihandle = be32toh(specifier[1]);
-               ihandle = fdtbus_get_phandle_from_native(ihandle);
-               specifier += 2;
-       } else {
-               ihandle = phandle;
-               specifier = get_specifier_by_index(phandle, index,
-                                                  &spec_length);
+
+       specifier = get_specifier_by_index(phandle, index, &spec_length);
+       if (has_interrupt_map(phandle))
+               specifier = get_specifier_from_map(phandle, specifier,
+                   spec_length, &ihandle);
+
+       ic = fdtbus_get_interrupt_controller(ihandle);
+       if (ic == NULL)
+               return false;
+
+       return ic->ic_funcs->intrstr(ic->ic_dev, specifier, buf, buflen);
+}
+
+static int
+find_interrupt_map(int phandle)
+{
+       while (phandle > 0) {
+               if (of_hasprop(phandle, "interrupt-map"))
+                       return phandle;
+               phandle = OF_parent(phandle);
        }
-       if (specifier == NULL) {
-               printf("%s: Unable to get specifier %d for phandle %d\n",
-                      __func__, index, phandle);
-               goto done;
-       }
-       ic = fdtbus_get_interrupt_controller(ihandle);
-       if (ic == NULL) {
-               printf("%s: Unable to get interrupt controller for %d\n",
-                      __func__, ihandle);
-               goto done;
-       }
-       result = ic->ic_funcs->intrstr(ic->ic_dev, specifier, buf, buflen);
-done:
-       if (has_interrupt_map(phandle))
-           specifier -= 2;
-       if (specifier && spec_length > 0)
-               kmem_free(specifier, spec_length);
-       return result;
+       return -1;
 }
 
-/*
- * Devices that have multiple interrupts, connected to two or more
- * interrupt sources use an interrupt map rather than a simple
- * interrupt parent to indicate which interrupt controller goes with
- * which map.  The interrupt map is contained in the node describing
- * the first level parent and contains one entry per interrupt:
- *   index -- the index of the entry in the map
- *   &parent -- pointer to the node containing the actual interrupt parent
- *              for the specific interrupt
- *  [specifier 0 - specifier N-1] The N (usually 2 or 3) 32 bit words
- *              that make up the specifier.
- *
- * returns true if the device phandle has an interrupt-parent that
- * contains an interrupt-map.
- */
+static int
+find_address_cells(int phandle)
+{
+       uint32_t cells;
+
+       if (of_getprop_uint32(phandle, "#address-cells", &cells) != 0)
+               cells = 2;
+
+       return cells;
+}
+
+static int
+find_interrupt_cells(int phandle)
+{
+       uint32_t cells;
+
+       while (phandle > 0) {
+               if (of_getprop_uint32(phandle, "#interrupt-cells", &cells) == 0)
+                       return cells;
+               phandle = OF_parent(phandle);
+       }
+       return 0;
+}
+
 static bool
 has_interrupt_map(int phandle)
 {
-       int ic_phandle;
-       of_getprop_uint32(phandle, "interrupt-parent", &ic_phandle);
-       ic_phandle = fdtbus_get_phandle_from_native(ic_phandle);
-       if (ic_phandle <= 0)
-               return false;
-       int len = OF_getproplen(ic_phandle, "interrupt-map");
-       if (len > 0)
-               return true;
-       return false;
+       return find_interrupt_map(OF_parent(phandle)) != -1;
 }
 
-/*
- * Walk the specifier map and return a pointer to the map entry
- * associated with pindex.  Return null if there is no entry.
- *
- * Because the length of the specifier depends on the interrupt
- * controller, we need to repeatedly obtain interrupt-celss for
- * the controller for the current index.
- *
- */
 static u_int *
-get_entry_from_map(int phandle, int pindex, u_int *spec_length)
+get_specifier_from_map(int phandle, u_int *specifier, u_int spec_length, int *piphandle)
 {
-       int intr_cells;
-       int intr_parent;
        u_int *result = NULL;
 
-       of_getprop_uint32(phandle, "#interrupt-cells", &intr_cells);
-       of_getprop_uint32(phandle, "interrupt-parent", &intr_parent);
+       const int nexus_phandle = find_interrupt_map(phandle);
 
-       intr_parent = fdtbus_get_phandle_from_native(intr_parent);
-       int len = OF_getproplen(intr_parent, "interrupt-map");
+       int len = OF_getproplen(nexus_phandle, "interrupt-map");
        if (len <= 0) {
                printf("%s: no interrupt-map.\n", __func__);
                return NULL;
        }
-       uint resid = len;
+       int resid = len;
        char *data = kmem_alloc(len, KM_SLEEP);
-       len = OF_getprop(intr_parent, "interrupt-map", data, len);
+       len = OF_getprop(nexus_phandle, "interrupt-map", data, len);
        if (len <= 0) {
-               printf("%s:  can't get property interrupt-map.\n", __func__);
+               printf("%s: can't get property interrupt-map.\n", __func__);
                goto done;
        }
+
+       /* child unit address: #address-cells prop of child bus node */
+       const int cua_cells = find_address_cells(nexus_phandle);
+       /* child interrupt specifier: #interrupt-cells of the nexus node */
+       const int cis_cells = find_interrupt_cells(nexus_phandle);
+
+       /* Offset (in cells) from map entry to child unit address specifier */
+       const u_int cua_off = 0;
+       /* Offset (in cells) from map entry to child interrupt specifier */
+       const u_int cis_off = cua_off + cua_cells;
+       /* Offset (in cells) from map entry to interrupt parent phandle */
+       const u_int ip_off = cis_off + cis_cells;
+       /* Offset (in cells) from map entry to parent unit specifier */
+       const u_int pus_off = ip_off + 1;
+
+#ifdef FDT_INTR_DEBUG
+       printf("cua_cells: %d, cis_cells: %d, ip_off = %d\n", cua_cells, cis_cells, ip_off);
+       printf("searching for interrupt in map:");
+       for (int i = 0; i < spec_length; i++)
+               printf(" %08x", specifier[i]);
+       printf("\n");
+#endif
+
        u_int *p = (u_int *)data;
-
        while (resid > 0) {
-               u_int index = be32toh(p[0]);
-               const u_int parent = fdtbus_get_phandle_from_native(be32toh(p[intr_cells]));
-               u_int pintr_cells;
-               of_getprop_uint32(parent, "#interrupt-cells", &pintr_cells);
-               if (index == pindex) {
-                       result = kmem_alloc((pintr_cells + 2) * sizeof(u_int),
-                                           KM_SLEEP);
-                       *spec_length = (pintr_cells + 2) * sizeof (u_int);
-                       for (int i = 0; i < pintr_cells + 2; i++)
-                               result[i] =  p[i];
+               /* Interrupt parent phandle */
+               const u_int iparent = fdtbus_get_phandle_from_native(be32toh(p[ip_off]));
+
+               /* parent unit specifier: #address-cells of the interrupt parent */
+               const u_int pus_cells = find_address_cells(iparent);
+               /* parent interrupt specifier: #interrupt-cells of the interrupt parent */
+               const u_int pis_cells = find_interrupt_cells(iparent);
+
+               /* Offset (in cells) from map entry to parent interrupt specifier */
+               const u_int pis_off = pus_off + pus_cells;
+
+               if (cis_cells == spec_length && memcmp(&p[cis_off], specifier, spec_length * 4) == 0) {
+                       const int slen = pus_cells + pis_cells;
+#ifdef FDT_INTR_DEBUG
+                       printf(" intr map match iparent %08x slen %d:", iparent, slen);
+                       for (int i = 0; i < slen; i++)
+                               printf(" %08x", p[pus_off + i]);
+                       printf("\n");
+#endif
+                       result = kmem_alloc(slen, KM_SLEEP);
+                       memcpy(result, &p[pus_off], slen * 4);
+                       *piphandle = iparent;
                        goto done;
-                                                                       
                }
                /* Determine the length of the entry and skip that many
                 * 32 bit words
                 */