[PATCH V5 1/2] ACPI / scan: Support multiple dma windows with different offsets

From: Jianmin Lv
Date: Sun Sep 11 2022 - 05:07:01 EST


In DT systems configurations, of_dma_get_range() returns struct
bus_dma_region DMA regions; they are used to set-up devices
DMA windows with different offset available for translation between DMA
address and CPU address.

In ACPI systems configuration, acpi_dma_get_range() does not return
DMA regions yet and that precludes setting up the dev->dma_range_map
pointer and therefore DMA regions with multiple offsets.

Update acpi_dma_get_range() to return struct bus_dma_region
DMA regions like of_dma_get_range() does.

After updating acpi_dma_get_range(), acpi_arch_dma_setup() is changed for
ARM64, where the original dma_addr and size are removed as these
arguments are now redundant, and pass 0 and U64_MAX for dma_base
and size of arch_setup_dma_ops; this is a simplification consistent
with what other ACPI architectures also pass to iommu_setup_dma_ops().

Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
Signed-off-by: Jianmin Lv <lvjianmin@xxxxxxxxxxx>
---
drivers/acpi/arm64/dma.c | 28 ++++++++++++---------
drivers/acpi/scan.c | 53 +++++++++++++++++-----------------------
include/acpi/acpi_bus.h | 3 +--
include/linux/acpi.h | 7 +++---
4 files changed, 44 insertions(+), 47 deletions(-)

diff --git a/drivers/acpi/arm64/dma.c b/drivers/acpi/arm64/dma.c
index f16739ad3cc0..93d796531af3 100644
--- a/drivers/acpi/arm64/dma.c
+++ b/drivers/acpi/arm64/dma.c
@@ -4,11 +4,12 @@
#include <linux/device.h>
#include <linux/dma-direct.h>

-void acpi_arch_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
+void acpi_arch_dma_setup(struct device *dev)
{
int ret;
u64 end, mask;
- u64 dmaaddr = 0, size = 0, offset = 0;
+ u64 size = 0;
+ const struct bus_dma_region *map = NULL;

/*
* If @dev is expected to be DMA-capable then the bus code that created
@@ -26,7 +27,19 @@ 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 && map) {
+ const struct bus_dma_region *r = map;
+
+ for (end = 0; r->size; r++) {
+ if (r->dma_start + r->size - 1 > end)
+ end = r->dma_start + r->size - 1;
+ }
+
+ size = end + 1;
+ dev->dma_range_map = map;
+ }
+
if (ret == -ENODEV)
ret = iort_dma_get_ranges(dev, &size);
if (!ret) {
@@ -34,17 +47,10 @@ void acpi_arch_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
* Limit coherent and dma mask based on size retrieved from
* firmware.
*/
- end = dmaaddr + size - 1;
+ end = size - 1;
mask = DMA_BIT_MASK(ilog2(end) + 1);
dev->bus_dma_limit = end;
dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask);
*dev->dma_mask = min(*dev->dma_mask, mask);
}
-
- *dma_addr = dmaaddr;
- *dma_size = size;
-
- ret = dma_direct_set_offset(dev, dmaaddr + offset, dmaaddr, size);
-
- dev_dbg(dev, "dma_offset(%#08llx)%s\n", offset, ret ? " failed!" : "");
}
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 42cec8120f18..f96ef8536037 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"

@@ -1467,25 +1468,21 @@ enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
* acpi_dma_get_range() - Get device DMA parameters.
*
* @dev: device to configure
- * @dma_addr: pointer device DMA address result
- * @offset: pointer to the DMA offset result
- * @size: pointer to DMA range size result
+ * @map: pointer to DMA ranges result
*
- * Evaluate DMA regions and return respectively DMA region start, offset
- * and size in dma_addr, offset and size on parsing success; it does not
- * update the passed in values on failure.
+ * Evaluate DMA regions and return pointer to DMA regions on
+ * parsing success; it does not update the passed in values on failure.
*
* 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;
+ struct bus_dma_region *r;

/*
* Walk the device tree chasing an ACPI companion with a _DMA
@@ -1510,31 +1507,28 @@ int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,

ret = acpi_dev_get_dma_resources(adev, &list);
if (ret > 0) {
+ r = kcalloc(ret + 1, sizeof(*r), GFP_KERNEL);
+ if (!r) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
list_for_each_entry(rentry, &list, node) {
- if (dma_offset && rentry->offset != dma_offset) {
+ if (rentry->res->start >= rentry->res->end) {
+ kfree(r);
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 = resource_size(rentry->res);
+ r->offset = rentry->offset;
+ r++;
}

- *dma_addr = dma_start - dma_offset;
- len = dma_end - dma_start;
- *size = max(len, len + 1);
- *offset = dma_offset;
+ *map = r;
}
out:
acpi_dev_free_resource_list(&list);
@@ -1624,20 +1618,19 @@ int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
const u32 *input_id)
{
const struct iommu_ops *iommu;
- u64 dma_addr = 0, size = 0;

if (attr == DEV_DMA_NOT_SUPPORTED) {
set_dma_ops(dev, &dma_dummy_ops);
return 0;
}

- acpi_arch_dma_setup(dev, &dma_addr, &size);
+ acpi_arch_dma_setup(dev);

iommu = acpi_iommu_configure_id(dev, input_id);
if (PTR_ERR(iommu) == -EPROBE_DEFER)
return -EPROBE_DEFER;

- arch_setup_dma_ops(dev, dma_addr, size,
+ arch_setup_dma_ops(dev, 0, U64_MAX,
iommu, attr == DEV_DMA_COHERENT);

return 0;
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index e7d27373ff71..73ac4a1d6947 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -613,8 +613,7 @@ enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev);
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 6f64b2f3dc54..bb41623dab77 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -281,12 +281,12 @@ void acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa);

#ifdef CONFIG_ARM64
void acpi_numa_gicc_affinity_init(struct acpi_srat_gicc_affinity *pa);
-void acpi_arch_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size);
+void acpi_arch_dma_setup(struct device *dev);
#else
static inline void
acpi_numa_gicc_affinity_init(struct acpi_srat_gicc_affinity *pa) { }
static inline void
-acpi_arch_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size) { }
+acpi_arch_dma_setup(struct device *dev) { }
#endif

int acpi_numa_memory_affinity_init (struct acpi_srat_mem_affinity *ma);
@@ -977,8 +977,7 @@ 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;
}
--
2.31.1