arch/tile: fix hardwall for tilegx and generalize for idn and ipi

The hardwall drain code was not properly implemented for tilegx,
just tilepro, so you couldn't reliably restart an application that
made use of the udn.

In addition, the code was only applicable to the udn (user dynamic
network).  On tilegx there is a second user network that is available
(the "idn"), and there is support for having I/O shims deliver
user-level interrupts to applications ("ipi") which functions in a
very similar way to the inter-core permissions used for udn/idn.
So this change also generalizes the code from supporting just the udn
to supports udn/idn/ipi on tilegx.

By default we now use /dev/hardwall/{udn,idn,ipi} with separate
minor numbers for the three devices.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

3 files changed, 25 insertions, 20 deletions

diff --git a/arch/tile/include/asm/hardwall.h b/arch/tile/include/asm/hardwall.h
index 2ac422848c7d..47514a58d685 100644
--- a/arch/tile/include/asm/hardwall.h
+++ b/arch/tile/include/asm/hardwall.h
@@ -11,12 +11,14 @@
  *   NON INFRINGEMENT.  See the GNU General Public License for
  *   more details.
  *
- * Provide methods for the HARDWALL_FILE for accessing the UDN.
+ * Provide methods for access control of per-cpu resources like
+ * UDN, IDN, or IPI.
  */
 
 #ifndef _ASM_TILE_HARDWALL_H
 #define _ASM_TILE_HARDWALL_H
 
+#include <arch/chip.h>
 #include <linux/ioctl.h>
 
 #define HARDWALL_IOCTL_BASE 0xa2
@@ -24,8 +26,9 @@
 /*
  * The HARDWALL_CREATE() ioctl is a macro with a "size" argument.
  * The resulting ioctl value is passed to the kernel in conjunction
- * with a pointer to a little-endian bitmask of cpus, which must be
- * physically in a rectangular configuration on the chip.
+ * with a pointer to a standard kernel bitmask of cpus.
+ * For network resources (UDN or IDN) the bitmask must physically
+ * represent a rectangular configuration on the chip.
  * The "size" is the number of bytes of cpu mask data.
  */
 #define _HARDWALL_CREATE 1
@@ -44,13 +47,7 @@
 #define HARDWALL_GET_ID \
  _IO(HARDWALL_IOCTL_BASE, _HARDWALL_GET_ID)
 
-#ifndef __KERNEL__
-
-/* This is the canonical name expected by userspace. */
-#define HARDWALL_FILE "/dev/hardwall"
-
-#else
-
+#ifdef __KERNEL__
 /* /proc hooks for hardwall. */
 struct proc_dir_entry;
 #ifdef CONFIG_HARDWALL
@@ -59,7 +56,6 @@ int proc_pid_hardwall(struct task_struct *task, char *buffer);
 #else
 static inline void proc_tile_hardwall_init(struct proc_dir_entry *root) {}
 #endif
-
 #endif
 
 #endif /* _ASM_TILE_HARDWALL_H */
diff --git a/arch/tile/include/asm/processor.h b/arch/tile/include/asm/processor.h
index 34c1e01ffb5e..e85a9af12968 100644
--- a/arch/tile/include/asm/processor.h
+++ b/arch/tile/include/asm/processor.h
@@ -76,6 +76,17 @@ struct async_tlb {
 
 #ifdef CONFIG_HARDWALL
 struct hardwall_info;
+struct hardwall_task {
+	/* Which hardwall is this task tied to? (or NULL if none) */
+	struct hardwall_info *info;
+	/* Chains this task into the list at info->task_head. */
+	struct list_head list;
+};
+#ifdef __tilepro__
+#define HARDWALL_TYPES 1   /* udn */
+#else
+#define HARDWALL_TYPES 3   /* udn, idn, and ipi */
+#endif
 #endif
 
 struct thread_struct {
@@ -116,10 +127,8 @@ struct thread_struct {
 	unsigned long dstream_pf;
 #endif
 #ifdef CONFIG_HARDWALL
-	/* Is this task tied to an activated hardwall? */
-	struct hardwall_info *hardwall;
-	/* Chains this task into the list at hardwall->list. */
-	struct list_head hardwall_list;
+	/* Hardwall information for various resources. */
+	struct hardwall_task hardwall[HARDWALL_TYPES];
 #endif
 #if CHIP_HAS_TILE_DMA()
 	/* Async DMA TLB fault information */
diff --git a/arch/tile/include/asm/setup.h b/arch/tile/include/asm/setup.h
index e58613e0752f..c67eb70ea78e 100644
--- a/arch/tile/include/asm/setup.h
+++ b/arch/tile/include/asm/setup.h
@@ -41,15 +41,15 @@ void restrict_dma_mpls(void);
 #ifdef CONFIG_HARDWALL
 /* User-level network management functions */
 void reset_network_state(void);
-void grant_network_mpls(void);
-void restrict_network_mpls(void);
 struct task_struct;
-int hardwall_deactivate(struct task_struct *task);
+void hardwall_switch_tasks(struct task_struct *prev, struct task_struct *next);
+void hardwall_deactivate_all(struct task_struct *task);
+int hardwall_ipi_valid(int cpu);
 
 /* Hook hardwall code into changes in affinity. */
 #define arch_set_cpus_allowed(p, new_mask) do { \
-	if (p->thread.hardwall && !cpumask_equal(&p->cpus_allowed, new_mask)) \
-		hardwall_deactivate(p); \
+	if (!cpumask_equal(&p->cpus_allowed, new_mask)) \
+		hardwall_deactivate_all(p); \
 } while (0)
 #endif