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Date: Fri, 06 Jun 2008 14:17:07 -0700
From: Keith Packard <keithp@...thp.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, airlied@...ux.ie,
Keith Packard <keith@...thp.com>
Subject: Re: [intel-agp] Rewrite GTT on resume
On Fri, 2008-06-06 at 13:50 -0700, Andrew Morton wrote:
> Please send a signed-off-by:?
See below.
> Is it safe to use this without locking?
I don't know. There is a mutex in the agp frontend exposed to user mode,
but that is not used by the internal kernel interfaces used by drm. This
scares me a bit, but the agp code doesn't appear to have any kind of
internal data structures that might be messed up, so it 'should' be OK.
This version adds a spinlock around all of the mapped_list manipulation.
From 26b58f13ecbe95a7eaca7434aeb885def057b835 Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@...thp.com>
Date: Tue, 3 Jun 2008 20:34:54 -0700
Subject: [PATCH] [INTEL-AGP] Re-write GATT on resume
Keep a list of current GATT mappings. At resume time, rewrite them into the
GATT. This is needed on Intel (at least) as the entire GATT is cleared
across suspend/resume. The list is protected by a spinlock.
Signed-off-by: Keith Packard <keithp@...thp.com>
diff --git a/drivers/char/agp/agp.h b/drivers/char/agp/agp.h
index c69f795..5fdbbd7 100644
--- a/drivers/char/agp/agp.h
+++ b/drivers/char/agp/agp.h
@@ -148,6 +148,9 @@ struct agp_bridge_data {
char minor_version;
struct list_head list;
u32 apbase_config;
+ /* list of agp_memory mapped to the aperture */
+ struct list_head mapped_list;
+ spinlock_t mapped_lock;
};
#define KB(x) ((x) * 1024)
diff --git a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c
index b1bdd01..463f04b 100644
--- a/drivers/char/agp/backend.c
+++ b/drivers/char/agp/backend.c
@@ -183,6 +183,8 @@ static int agp_backend_initialize(struct agp_bridge_data *bridge)
rc = -EINVAL;
goto err_out;
}
+ INIT_LIST_HEAD(&bridge->mapped_list);
+ spin_lock_init(&bridge->mapped_lock);
return 0;
diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index 7fc0c99..4741438 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -426,6 +426,10 @@ int agp_bind_memory(struct agp_memory *curr, off_t pg_start)
curr->is_bound = TRUE;
curr->pg_start = pg_start;
+ spin_lock(&agp_bridge->mapped_lock);
+ list_add (&curr->mapped_list, &agp_bridge->mapped_list);
+ spin_unlock(&agp_bridge->mapped_lock);
+
return 0;
}
EXPORT_SYMBOL(agp_bind_memory);
@@ -458,10 +462,34 @@ int agp_unbind_memory(struct agp_memory *curr)
curr->is_bound = FALSE;
curr->pg_start = 0;
+ spin_lock(&curr->bridge->mapped_lock);
+ list_del (&curr->mapped_list);
+ spin_unlock(&curr->bridge->mapped_lock);
return 0;
}
EXPORT_SYMBOL(agp_unbind_memory);
+/**
+ * agp_rebind_emmory - Rewrite the entire GATT, useful on resume
+ */
+int agp_rebind_memory (void)
+{
+ struct agp_memory *curr;
+ int ret_val;
+
+ spin_lock(&agp_bridge->mapped_lock);
+ list_for_each_entry(curr, &agp_bridge->mapped_list, mapped_list) {
+ ret_val = curr->bridge->driver->insert_memory(curr,
+ curr->pg_start,
+ curr->type);
+ if (ret_val != 0)
+ return ret_val;
+ }
+ spin_unlock(&agp_bridge->mapped_lock);
+ return 0;
+}
+EXPORT_SYMBOL(agp_rebind_memory);
+
/* End - Routines for handling swapping of agp_memory into the GATT */
diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index eeea50a..7f1a96e 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -2176,6 +2176,7 @@ static void __devexit agp_intel_remove(struct pci_dev *pdev)
static int agp_intel_resume(struct pci_dev *pdev)
{
struct agp_bridge_data *bridge = pci_get_drvdata(pdev);
+ int ret_val;
pci_restore_state(pdev);
@@ -2203,6 +2204,10 @@ static int agp_intel_resume(struct pci_dev *pdev)
else if (bridge->driver == &intel_i965_driver)
intel_i915_configure();
+ ret_val = agp_rebind_memory();
+ if (ret_val != 0)
+ return ret_val;
+
return 0;
}
#endif
diff --git a/include/linux/agp_backend.h b/include/linux/agp_backend.h
index 03e3454..2fbfe4d 100644
--- a/include/linux/agp_backend.h
+++ b/include/linux/agp_backend.h
@@ -32,6 +32,8 @@
#ifdef __KERNEL__
+#include <linux/list.h>
+
#ifndef TRUE
#define TRUE 1
#endif
@@ -88,6 +90,8 @@ struct agp_memory {
u8 is_bound;
u8 is_flushed;
u8 vmalloc_flag;
+ /* list of agp_memory mapped to the aperture */
+ struct list_head mapped_list;
};
#define AGP_NORMAL_MEMORY 0
@@ -106,6 +110,7 @@ extern struct agp_memory *agp_allocate_memory(struct agp_bridge_data *, size_t,
extern int agp_copy_info(struct agp_bridge_data *, struct agp_kern_info *);
extern int agp_bind_memory(struct agp_memory *, off_t);
extern int agp_unbind_memory(struct agp_memory *);
+extern int agp_rebind_memory (void);
extern void agp_enable(struct agp_bridge_data *, u32);
extern struct agp_bridge_data *agp_backend_acquire(struct pci_dev *);
extern void agp_backend_release(struct agp_bridge_data *);
--
keith.packard@...el.com
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