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Date: Fri, 26 Jun 2020 19:33:53 +0200
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Dan Williams <dan.j.williams@...el.com>,
Erik Kaneda <erik.kaneda@...el.com>
Cc: rafael.j.wysocki@...el.com, Len Brown <lenb@...nel.org>,
Borislav Petkov <bp@...en8.de>,
Ira Weiny <ira.weiny@...el.com>,
James Morse <james.morse@....com>,
Myron Stowe <myron.stowe@...hat.com>,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
linux-kernel@...r.kernel.org, linux-acpi@...r.kernel.org,
linux-nvdimm@...ts.01.org, Bob Moore <robert.moore@...el.com>
Subject: [RFT][PATCH v3 4/4] ACPI: OSL: Implement acpi_os_map_memory_fast_path()
From: "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>
Add acpi_os_map_memory_fast_path() and set ACPI_USE_FAST_PATH_MAPPING
to allow acpi_ex_system_memory_space_handler() to avoid unnecessary
memory mapping and unmapping overhead by retaining all memory
mappings created by it until the memory opregions associated with
them go away.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
drivers/acpi/osl.c | 65 +++++++++++++++++++++++--------
include/acpi/platform/aclinux.h | 4 ++
include/acpi/platform/aclinuxex.h | 3 ++
3 files changed, 56 insertions(+), 16 deletions(-)
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 749ae3e32193..b8537ce89ea2 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -306,21 +306,8 @@ static void acpi_unmap(acpi_physical_address pg_off, void __iomem *vaddr)
iounmap(vaddr);
}
-/**
- * acpi_os_map_iomem - Get a virtual address for a given physical address range.
- * @phys: Start of the physical address range to map.
- * @size: Size of the physical address range to map.
- *
- * Look up the given physical address range in the list of existing ACPI memory
- * mappings. If found, get a reference to it and return a pointer to it (its
- * virtual address). If not found, map it, add it to that list and return a
- * pointer to it.
- *
- * During early init (when acpi_permanent_mmap has not been set yet) this
- * routine simply calls __acpi_map_table() to get the job done.
- */
-void __iomem __ref
-*acpi_os_map_iomem(acpi_physical_address phys, acpi_size size)
+static void __iomem __ref *__acpi_os_map_iomem(acpi_physical_address phys,
+ acpi_size size, bool fast_path)
{
struct acpi_ioremap *map;
void __iomem *virt;
@@ -332,8 +319,12 @@ void __iomem __ref
return NULL;
}
- if (!acpi_permanent_mmap)
+ if (!acpi_permanent_mmap) {
+ if (WARN_ON(fast_path))
+ return NULL;
+
return __acpi_map_table((unsigned long)phys, size);
+ }
mutex_lock(&acpi_ioremap_lock);
/* Check if there's a suitable mapping already. */
@@ -343,6 +334,11 @@ void __iomem __ref
goto out;
}
+ if (fast_path) {
+ mutex_unlock(&acpi_ioremap_lock);
+ return NULL;
+ }
+
map = kzalloc(sizeof(*map), GFP_KERNEL);
if (!map) {
mutex_unlock(&acpi_ioremap_lock);
@@ -370,6 +366,25 @@ void __iomem __ref
mutex_unlock(&acpi_ioremap_lock);
return map->virt + (phys - map->phys);
}
+
+/**
+ * acpi_os_map_iomem - Get a virtual address for a given physical address range.
+ * @phys: Start of the physical address range to map.
+ * @size: Size of the physical address range to map.
+ *
+ * Look up the given physical address range in the list of existing ACPI memory
+ * mappings. If found, get a reference to it and return a pointer representing
+ * its virtual address. If not found, map it, add it to that list and return a
+ * pointer representing its virtual address.
+ *
+ * During early init (when acpi_permanent_mmap has not been set yet) call
+ * __acpi_map_table() to obtain the mapping.
+ */
+void __iomem __ref *acpi_os_map_iomem(acpi_physical_address phys,
+ acpi_size size)
+{
+ return __acpi_os_map_iomem(phys, size, false);
+}
EXPORT_SYMBOL_GPL(acpi_os_map_iomem);
void *__ref acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
@@ -378,6 +393,24 @@ void *__ref acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
}
EXPORT_SYMBOL_GPL(acpi_os_map_memory);
+/**
+ * acpi_os_map_memory_fast_path - Fast-path physical-to-virtual address mapping.
+ * @phys: Start of the physical address range to map.
+ * @size: Size of the physical address range to map.
+ *
+ * Look up the given physical address range in the list of existing ACPI memory
+ * mappings. If found, get a reference to it and return a pointer representing
+ * its virtual address. If not found, return NULL.
+ *
+ * During early init (when acpi_permanent_mmap has not been set yet) log a
+ * warning and return NULL.
+ */
+void __ref *acpi_os_map_memory_fast_path(acpi_physical_address phys,
+ acpi_size size)
+{
+ return __acpi_os_map_iomem(phys, size, true);
+}
+
/* Must be called with mutex_lock(&acpi_ioremap_lock) */
static bool acpi_os_drop_map_ref(struct acpi_ioremap *map, bool defer)
{
diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
index 784e294dc74c..1a5f8037e3d5 100644
--- a/include/acpi/platform/aclinux.h
+++ b/include/acpi/platform/aclinux.h
@@ -118,6 +118,10 @@
#define USE_NATIVE_ALLOCATE_ZEROED
+/* Use fast-path memory mapping to optimize memory opregions handling */
+
+#define ACPI_USE_FAST_PATH_MAPPING
+
/*
* Overrides for in-kernel ACPICA
*/
diff --git a/include/acpi/platform/aclinuxex.h b/include/acpi/platform/aclinuxex.h
index ad6b905358c5..c64b836ba455 100644
--- a/include/acpi/platform/aclinuxex.h
+++ b/include/acpi/platform/aclinuxex.h
@@ -141,6 +141,9 @@ static inline void acpi_os_terminate_debugger(void)
* OSL interfaces added by Linux
*/
+void *acpi_os_map_memory_fast_path(acpi_physical_address where,
+ acpi_size length);
+
#endif /* __KERNEL__ */
#endif /* __ACLINUXEX_H__ */
--
2.26.2
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