On 5/7/20 11:50 am, Damien Zammit wrote:
> One thing that is missing from this patch is the "vm_allocate_contiguous" RPC.
> It is required for DMA. How should I proceed with it? Do I make it an RPC
> on the
> "mem" device only?
See attached for first attempt at reworking this RPC.
Thanks,
Damien
>From d487e6393191f29361f76fcb89ea02f561fea82a Mon Sep 17 00:00:00 2001
From: Damien Zammit <dam...@zamaudio.com>
Date: Sun, 5 Jul 2020 16:42:28 +1000
Subject: [PATCH] Add ds_device_vm_allocate_contiguous RPC
---
device/ds_routines.c | 17 +++++++++++++++++
include/device/device.defs | 31 +++++++++++++++++++++++++++++++
include/mach/mach.defs | 33 +--------------------------------
vm/vm_user.c | 6 +-----
vm/vm_user.h | 2 ++
5 files changed, 52 insertions(+), 37 deletions(-)
diff --git a/device/ds_routines.c b/device/ds_routines.c
index 69e963bd..28100da1 100644
--- a/device/ds_routines.c
+++ b/device/ds_routines.c
@@ -1848,6 +1848,23 @@ ds_device_intr_ack (device_t dev, ipc_port_t receive_port)
return irq_acknowledge(receive_port);
}
+kern_return_t
+ds_device_allocate_contiguous (device_t dev, vm_address_t *vaddr,
+ vm_address_t *paddr, vm_size_t size)
+{
+ mach_device_t mdev = dev->emul_data;
+
+ /* Refuse if device is dead or not completely open. */
+ if (dev == DEVICE_NULL)
+ return D_NO_SUCH_DEVICE;
+
+ /* Must be called on the mem device only */
+ if (! name_equal(mdev->dev_ops->d_name, 3, "mem"))
+ return D_INVALID_OPERATION;
+
+ return vm_allocate_contiguous (kernel_map, vaddr, paddr, size);
+}
+
struct device_emulation_ops mach_device_emulation_ops =
{
(void*) mach_device_reference,
diff --git a/include/device/device.defs b/include/device/device.defs
index ec4b5bf8..bf81b9ae 100644
--- a/include/device/device.defs
+++ b/include/device/device.defs
@@ -160,3 +160,34 @@ routine device_intr_ack(
device : device_t;
in receive_port : mach_port_send_t);
+/*
+ * This routine is created for allocating DMA buffers.
+ * We are going to get contiguous physical memory
+ * and its physical address in addition to the virtual address.
+ * It only works on the mem device.
+ */
+ /* XXX
+ This RPC lacks a few additional constraints like boundaries, alignment
+and maybe phase. We may not use them now, but they're important for
+portability (e.g. if GNU Mach supports PAE, drivers that can't use
+physical memory beyond the 4 GiB limit must be able to express it).
+
+> What do you mean by "phase"?
+
+Offset from the alignment. But I don't think it's useful at all in this
+case. Minimum and maximum addresses and alignment should do. Maybe
+boundary crossing but usually, specifying the right alignment and size
+is enough.
+
+For upstream
+inclusion, we need to do it properly: the RPC should return a special
+memory object (similar to device_map() ), which can then be mapped into
+the process address space with vm_map() like any other memory object.
+
+phys_address_t?
+ */
+routine device_allocate_contiguous(
+ device : device_t;
+ out vaddr : vm_address_t;
+ out paddr : vm_address_t;
+ size : vm_size_t);
diff --git a/include/mach/mach.defs b/include/mach/mach.defs
index 77cc7d49..20f425fa 100644
--- a/include/mach/mach.defs
+++ b/include/mach/mach.defs
@@ -719,38 +719,7 @@ skip; /* old host_fpa_counters_reset */
#endif /* ! KERNEL_USER */
-/*
- * This routine is created for allocating DMA buffers.
- * We are going to get a contiguous physical memory
- * and its physical address in addition to the virtual address.
- */
-
- /* XXX
- This RPC lacks a few additional constraints like boundaries, alignment
-and maybe phase. We may not use them now, but they're important for
-portability (e.g. if GNU Mach supports PAE, drivers that can't use
-physical memory beyond the 4 GiB limit must be able to express it).
-
-> What do you mean by "phase"?
-
-Offset from the alignment. But I don't think it's useful at all in this
-case. Minimum and maximum addresses and alignment should do. Maybe
-boundary crossing but usually, specifying the right alignment and size
-is enough.
-
-For upstream
-inclusion, we need to do it properly: the RPC should return a special
-memory object (similar to device_map() ), which can then be mapped into
-the process address space with vm_map() like any other memory object.
-
-phys_address_t?
- */
-routine vm_allocate_contiguous(
- host_priv : host_priv_t;
- target_task : vm_task_t;
- out vaddr : vm_address_t;
- out paddr : vm_address_t;
- size : vm_size_t);
+skip; /* old vm_allocate_contiguous */
/*
* There is no more room in this interface for additional calls.
diff --git a/vm/vm_user.c b/vm/vm_user.c
index 1789dbfa..44a3e578 100644
--- a/vm/vm_user.c
+++ b/vm/vm_user.c
@@ -532,8 +532,7 @@ kern_return_t vm_msync(
return vm_map_msync(map, (vm_offset_t) address, size, sync_flags);
}
-kern_return_t vm_allocate_contiguous(host_priv, map, result_vaddr, result_paddr, size)
- host_t host_priv;
+kern_return_t vm_allocate_contiguous(map, result_vaddr, result_paddr, size)
vm_map_t map;
vm_address_t *result_vaddr;
vm_address_t *result_paddr;
@@ -548,9 +547,6 @@ kern_return_t vm_allocate_contiguous(host_priv, map, result_vaddr, result_paddr,
kern_return_t kr;
vm_address_t vaddr;
- if (host_priv == HOST_NULL)
- return KERN_INVALID_HOST;
-
if (map == VM_MAP_NULL)
return KERN_INVALID_TASK;
diff --git a/vm/vm_user.h b/vm/vm_user.h
index c6f20a82..85918417 100644
--- a/vm/vm_user.h
+++ b/vm/vm_user.h
@@ -56,5 +56,7 @@ extern kern_return_t vm_copy(vm_map_t, vm_address_t, vm_size_t,
extern kern_return_t vm_map(vm_map_t, vm_offset_t *, vm_size_t, vm_offset_t,
boolean_t, ipc_port_t, vm_offset_t, boolean_t,
vm_prot_t, vm_prot_t, vm_inherit_t);
+extern kern_return_t vm_allocate_contiguous(vm_map_t, vm_address_t *,
+ vm_address_t *, vm_size_t);
#endif /* _VM_VM_USER_H_ */
--
2.25.1
