Hi Petr,
On 13/7/23 17:23, Petr Tesarik wrote:
From: Petr Tesarik <petr.tesarik.ext@xxxxxxxxxx>
SWIOTLB implementation details should not be exposed to the rest of the
kernel. This will allow to make changes to the implementation without
modifying non-swiotlb code.
To avoid breaking existing users, provide helper functions for the few
required fields.
As a bonus, using a helper function to initialize struct device allows to
get rid of an #ifdef in driver core.
Signed-off-by: Petr Tesarik <petr.tesarik.ext@xxxxxxxxxx>
---
arch/arm/xen/mm.c | 2 +-
arch/mips/pci/pci-octeon.c | 2 +-
arch/x86/kernel/pci-dma.c | 2 +-
drivers/base/core.c | 4 +---
drivers/xen/swiotlb-xen.c | 2 +-
include/linux/swiotlb.h | 25 +++++++++++++++++++++++-
kernel/dma/swiotlb.c | 39 +++++++++++++++++++++++++++++++++++++-
7 files changed, 67 insertions(+), 9 deletions(-)
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 4e52cd5e0bdc..07216af59e93 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -110,7 +110,6 @@ struct io_tlb_mem {
atomic_long_t used_hiwater;
#endif
};
-extern struct io_tlb_mem io_tlb_default_mem;
static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
{
@@ -128,13 +127,22 @@ static inline bool is_swiotlb_force_bounce(struct device *dev)
void swiotlb_init(bool addressing_limited, unsigned int flags);
void __init swiotlb_exit(void);
+void swiotlb_dev_init(struct device *dev);
size_t swiotlb_max_mapping_size(struct device *dev);
+bool is_swiotlb_allocated(void);
bool is_swiotlb_active(struct device *dev);
void __init swiotlb_adjust_size(unsigned long size);
+phys_addr_t default_swiotlb_start(void);
+phys_addr_t default_swiotlb_limit(void);
Usually we use start/end, base/limit, low[est]/high[est] tuples.
Possibly clearer to rename, regardless:
Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 2b83e3ad9dca..873b077d7e37 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -958,6 +975,26 @@ bool is_swiotlb_active(struct device *dev)
}
EXPORT_SYMBOL_GPL(is_swiotlb_active);
+/**
+ * default_swiotlb_start() - get the start of the default SWIOTLB
+ *
+ * Get the lowest physical address used by the default software IO TLB pool.
+ */
+phys_addr_t default_swiotlb_start(void)
+{
+ return io_tlb_default_mem.start;
+}
+
+/**
+ * default_swiotlb_limit() - get the highest address in the default SWIOTLB
+ *
+ * Get the highest physical address used by the default software IO TLB pool.
(note you describe lowest/highest).
+ */
+phys_addr_t default_swiotlb_limit(void)
+{
+ return io_tlb_default_mem.end - 1;
+}
+
#ifdef CONFIG_DEBUG_FS
static int io_tlb_used_get(void *data, u64 *val)
