Re: [PATCH] ACPI / scan: Support multiple dma windows with different offsets
From: Jianmin Lv
Date: Fri Aug 05 2022 - 03:18:02 EST
On 2022/8/5 上午2:26, Robin Murphy wrote:
On 04/08/2022 2:27 pm, Lorenzo Pieralisi wrote:
[+Robin]
On Thu, Aug 04, 2022 at 05:59:23PM +0800, Jianmin Lv wrote:
Hi, all
Can anybody help to review the patch, or I missed somebody else?
I will review the patch - added Robin since it affects the DMA
ranges handling.
Thanks Lorenzo!
Lorenzo
Thanks!
On 2022/7/31 下午4:17, Jianmin Lv wrote:
For DT, of_dma_get_range returns bus_dma_region typed dma regions,
which makes multiple dma windows with different offset available
for translation between dma address and cpu address.
But for ACPI, acpi_dma_get_range doesn't return similar dma regions,
causing no path for setting dev->dma_range_map conveniently. So the
patch changes acpi_dma_get_range and returns bus_dma_region typed
dma regions according to of_dma_get_range.
After changing acpi_dma_get_range, original part of internal code
only available for ARM is moved to acpi_arch_dma_setup for remaining
unchanged.
This seems a bit silly. If we've finally done the work to parse a proper
dma_range_map, we can use it; no need to artificially maintain the old
dma_pfn_offset limitation. TBH I wouldn't even preserve the dmaaddr and
size calculations as they are either, just set dev->bus_dma_limit based
on the highest entry in the map, and pass 0 and U64_MAX to
arch_setup_dma_ops() since those are basically meaningless now (I plan
to remove them entirely once I unpick the IOMMU setup).
Thanks,
Robin.
Ok, thanks, I'll change the patch as your suggestion in next revision.
Signed-off-by: Jianmin Lv <lvjianmin@xxxxxxxxxxx>
diff --git a/drivers/acpi/arm64/dma.c b/drivers/acpi/arm64/dma.c
index f16739a..840f918 100644
--- a/drivers/acpi/arm64/dma.c
+++ b/drivers/acpi/arm64/dma.c
@@ -9,6 +9,7 @@ void acpi_arch_dma_setup(struct device *dev, u64
*dma_addr, u64 *dma_size)
int ret;
u64 end, mask;
u64 dmaaddr = 0, size = 0, offset = 0;
+ const struct bus_dma_region *map = NULL;
/*
* If @dev is expected to be DMA-capable then the bus code
that created
@@ -26,10 +27,37 @@ void acpi_arch_dma_setup(struct device *dev, u64
*dma_addr, u64 *dma_size)
else
size = 1ULL << 32;
- ret = acpi_dma_get_range(dev, &dmaaddr, &offset, &size);
+ ret = acpi_dma_get_range(dev, &map);
if (ret == -ENODEV)
ret = iort_dma_get_ranges(dev, &size);
if (!ret) {
+ const struct bus_dma_region *r = map;
+ u64 len, dma_start, dma_end = 0;
+
+ /* determine the overall bounds of all dma regions */
+ for (dma_start = U64_MAX; r->size; r++) {
+ if (offset && r->offset != offset) {
+ dev_warn(dev, "Can't handle multiple windows with
different offsets\n");
+ return;
+ }
+ offset = r->offset;
+
+ /* Take lower and upper limits */
+ if (r->dma_start < dma_start)
+ dma_start = r->dma_start;
+ if (r->dma_start + r->size - 1 > dma_end)
+ dma_end = r->dma_start + r->size - 1;
+ }
+
+ if (dma_start >= dma_end) {
+ dev_dbg(dev, "Invalid DMA regions configuration\n");
+ return;
+ }
+
+ dmaaddr = dma_start;
+ len = dma_end - dma_start;
+ size = max(len, len + 1);
+
/*
* Limit coherent and dma mask based on size retrieved from
* firmware.
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 762b61f..8961b51 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -20,6 +20,7 @@
#include <linux/platform_data/x86/apple.h>
#include <linux/pgtable.h>
#include <linux/crc32.h>
+#include <linux/dma-direct.h>
#include "internal.h"
@@ -1492,15 +1493,15 @@ enum dev_dma_attr acpi_get_dma_attr(struct
acpi_device *adev)
*
* Return 0 on success, < 0 on failure.
*/
-int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
- u64 *size)
+int acpi_dma_get_range(struct device *dev, const struct
bus_dma_region **map)
{
struct acpi_device *adev;
LIST_HEAD(list);
struct resource_entry *rentry;
int ret;
struct device *dma_dev = dev;
- u64 len, dma_start = U64_MAX, dma_end = 0, dma_offset = 0;
+ int num_ranges = 0;
+ struct bus_dma_region *r;
/*
* Walk the device tree chasing an ACPI companion with a _DMA
@@ -1525,31 +1526,31 @@ int acpi_dma_get_range(struct device *dev,
u64 *dma_addr, u64 *offset,
ret = acpi_dev_get_dma_resources(adev, &list);
if (ret > 0) {
+ list_for_each_entry(rentry, &list, node)
+ num_ranges++;
+
+ r = kcalloc(num_ranges + 1, sizeof(*r), GFP_KERNEL);
+ if (!r) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ *map = r;
+
list_for_each_entry(rentry, &list, node) {
- if (dma_offset && rentry->offset != dma_offset) {
+ if (rentry->res->start >= rentry->res->end) {
ret = -EINVAL;
- dev_warn(dma_dev, "Can't handle multiple windows
with different offsets\n");
+ dev_dbg(dma_dev, "Invalid DMA regions
configuration\n");
goto out;
}
- dma_offset = rentry->offset;
-
- /* Take lower and upper limits */
- if (rentry->res->start < dma_start)
- dma_start = rentry->res->start;
- if (rentry->res->end > dma_end)
- dma_end = rentry->res->end;
- }
- if (dma_start >= dma_end) {
- ret = -EINVAL;
- dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
- goto out;
+ r->cpu_start = rentry->res->start;
+ r->dma_start = rentry->res->start - rentry->offset;
+ r->size = rentry->res->end - rentry->res->start + 1;
+ r->offset = rentry->offset;
+ r++;
}
- *dma_addr = dma_start - dma_offset;
- len = dma_end - dma_start;
- *size = max(len, len + 1);
- *offset = dma_offset;
}
out:
acpi_dev_free_resource_list(&list);
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 0dc1ea0b..e106073 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -611,8 +611,7 @@ struct acpi_pci_root {
int acpi_iommu_fwspec_init(struct device *dev, u32 id,
struct fwnode_handle *fwnode,
const struct iommu_ops *ops);
-int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
- u64 *size);
+int acpi_dma_get_range(struct device *dev, const struct
bus_dma_region **map);
int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr
attr,
const u32 *input_id);
static inline int acpi_dma_configure(struct device *dev,
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 44975c1..f806092 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -974,8 +974,7 @@ static inline enum dev_dma_attr
acpi_get_dma_attr(struct acpi_device *adev)
return DEV_DMA_NOT_SUPPORTED;
}
-static inline int acpi_dma_get_range(struct device *dev, u64
*dma_addr,
- u64 *offset, u64 *size)
+static inline int acpi_dma_get_range(struct device *dev, const
struct bus_dma_region **map)
{
return -ENODEV;
}