linux/drivers/acpi/acpica/exregion.c
Rafael J. Wysocki b8fcd0e588 ACPICA: Preserve memory opregion mappings
The ACPICA's strategy with respect to the handling of memory mappings
associated with memory operation regions is to avoid mapping the
entire region at once which may be problematic at least in principle
(for example, it may lead to conflicts with overlapping mappings
having different attributes created by drivers).  It may also be
wasteful, because memory opregions on some systems take up vast
chunks of address space while the fields in those regions actually
accessed by AML are sparsely distributed.

For this reason, a one-page "window" is mapped for a given opregion
on the first memory access through it and if that "window" does not
cover an address range accessed through that opregion subsequently,
it is unmapped and a new "window" is mapped to replace it.  Next,
if the new "window" is not sufficient to acess memory through the
opregion in question in the future, it will be replaced with yet
another "window" and so on.  That may lead to a suboptimal sequence
of memory mapping and unmapping operations, for example if two fields
in one opregion separated from each other by a sufficiently wide
chunk of unused address space are accessed in an alternating pattern.

The situation may still be suboptimal if the deferred unmapping
introduced previously is supported by the OS layer.  For instance,
the alternating memory access pattern mentioned above may produce
a relatively long list of mappings to release with substantial
duplication among the entries in it, which could be avoided if
acpi_ex_system_memory_space_handler() did not release the mapping
used by it previously as soon as the current access was not covered
by it.

In order to improve that, modify acpi_ex_system_memory_space_handler()
to preserve all of the memory mappings created by it until the memory
regions associated with them go away.

Accordingly, update acpi_ev_system_memory_region_setup() to unmap all
memory associated with memory opregions that go away.

Reported-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Xiang Li <xiang.z.li@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-27 12:29:02 +02:00

538 lines
14 KiB
C

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: exregion - ACPI default op_region (address space) handlers
*
* Copyright (C) 2000 - 2020, Intel Corp.
*
*****************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acinterp.h"
#define _COMPONENT ACPI_EXECUTER
ACPI_MODULE_NAME("exregion")
/*******************************************************************************
*
* FUNCTION: acpi_ex_system_memory_space_handler
*
* PARAMETERS: function - Read or Write operation
* address - Where in the space to read or write
* bit_width - Field width in bits (8, 16, or 32)
* value - Pointer to in or out value
* handler_context - Pointer to Handler's context
* region_context - Pointer to context specific to the
* accessed region
*
* RETURN: Status
*
* DESCRIPTION: Handler for the System Memory address space (Op Region)
*
******************************************************************************/
acpi_status
acpi_ex_system_memory_space_handler(u32 function,
acpi_physical_address address,
u32 bit_width,
u64 *value,
void *handler_context, void *region_context)
{
acpi_status status = AE_OK;
void *logical_addr_ptr = NULL;
struct acpi_mem_space_context *mem_info = region_context;
struct acpi_mem_mapping *mm = mem_info->cur_mm;
u32 length;
acpi_size map_length;
acpi_size page_boundary_map_length;
#ifdef ACPI_MISALIGNMENT_NOT_SUPPORTED
u32 remainder;
#endif
ACPI_FUNCTION_TRACE(ex_system_memory_space_handler);
/* Validate and translate the bit width */
switch (bit_width) {
case 8:
length = 1;
break;
case 16:
length = 2;
break;
case 32:
length = 4;
break;
case 64:
length = 8;
break;
default:
ACPI_ERROR((AE_INFO, "Invalid SystemMemory width %u",
bit_width));
return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
}
#ifdef ACPI_MISALIGNMENT_NOT_SUPPORTED
/*
* Hardware does not support non-aligned data transfers, we must verify
* the request.
*/
(void)acpi_ut_short_divide((u64) address, length, NULL, &remainder);
if (remainder != 0) {
return_ACPI_STATUS(AE_AML_ALIGNMENT);
}
#endif
/*
* Does the request fit into the cached memory mapping?
* Is 1) Address below the current mapping? OR
* 2) Address beyond the current mapping?
*/
if (!mm || (address < mm->physical_address) ||
((u64) address + length > (u64) mm->physical_address + mm->length)) {
/*
* The request cannot be resolved by the current memory mapping.
*
* Look for an existing saved mapping covering the address range
* at hand. If found, save it as the current one and carry out
* the access.
*/
for (mm = mem_info->first_mm; mm; mm = mm->next_mm) {
if (mm == mem_info->cur_mm)
continue;
if (address < mm->physical_address)
continue;
if ((u64) address + length >
(u64) mm->physical_address + mm->length)
continue;
mem_info->cur_mm = mm;
goto access;
}
/* Create a new mappings list entry */
mm = ACPI_ALLOCATE_ZEROED(sizeof(*mm));
if (!mm) {
ACPI_ERROR((AE_INFO,
"Unable to save memory mapping at 0x%8.8X%8.8X, size %u",
ACPI_FORMAT_UINT64(address), length));
return_ACPI_STATUS(AE_NO_MEMORY);
}
/*
* October 2009: Attempt to map from the requested address to the
* end of the region. However, we will never map more than one
* page, nor will we cross a page boundary.
*/
map_length = (acpi_size)
((mem_info->address + mem_info->length) - address);
/*
* If mapping the entire remaining portion of the region will cross
* a page boundary, just map up to the page boundary, do not cross.
* On some systems, crossing a page boundary while mapping regions
* can cause warnings if the pages have different attributes
* due to resource management.
*
* This has the added benefit of constraining a single mapping to
* one page, which is similar to the original code that used a 4k
* maximum window.
*/
page_boundary_map_length = (acpi_size)
(ACPI_ROUND_UP(address, ACPI_DEFAULT_PAGE_SIZE) - address);
if (page_boundary_map_length == 0) {
page_boundary_map_length = ACPI_DEFAULT_PAGE_SIZE;
}
if (map_length > page_boundary_map_length) {
map_length = page_boundary_map_length;
}
/* Create a new mapping starting at the address given */
logical_addr_ptr = acpi_os_map_memory(address, map_length);
if (!logical_addr_ptr) {
ACPI_ERROR((AE_INFO,
"Could not map memory at 0x%8.8X%8.8X, size %u",
ACPI_FORMAT_UINT64(address),
(u32)map_length));
ACPI_FREE(mm);
return_ACPI_STATUS(AE_NO_MEMORY);
}
/* Save the physical address and mapping size */
mm->logical_address = logical_addr_ptr;
mm->physical_address = address;
mm->length = map_length;
/*
* Add the new entry to the mappigs list and save it as the
* current mapping.
*/
mm->next_mm = mem_info->first_mm;
mem_info->first_mm = mm;
mem_info->cur_mm = mm;
}
access:
/*
* Generate a logical pointer corresponding to the address we want to
* access
*/
logical_addr_ptr = mm->logical_address +
((u64) address - (u64) mm->physical_address);
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"System-Memory (width %u) R/W %u Address=%8.8X%8.8X\n",
bit_width, function, ACPI_FORMAT_UINT64(address)));
/*
* Perform the memory read or write
*
* Note: For machines that do not support non-aligned transfers, the target
* address was checked for alignment above. We do not attempt to break the
* transfer up into smaller (byte-size) chunks because the AML specifically
* asked for a transfer width that the hardware may require.
*/
switch (function) {
case ACPI_READ:
*value = 0;
switch (bit_width) {
case 8:
*value = (u64)ACPI_GET8(logical_addr_ptr);
break;
case 16:
*value = (u64)ACPI_GET16(logical_addr_ptr);
break;
case 32:
*value = (u64)ACPI_GET32(logical_addr_ptr);
break;
case 64:
*value = (u64)ACPI_GET64(logical_addr_ptr);
break;
default:
/* bit_width was already validated */
break;
}
break;
case ACPI_WRITE:
switch (bit_width) {
case 8:
ACPI_SET8(logical_addr_ptr, *value);
break;
case 16:
ACPI_SET16(logical_addr_ptr, *value);
break;
case 32:
ACPI_SET32(logical_addr_ptr, *value);
break;
case 64:
ACPI_SET64(logical_addr_ptr, *value);
break;
default:
/* bit_width was already validated */
break;
}
break;
default:
status = AE_BAD_PARAMETER;
break;
}
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_system_io_space_handler
*
* PARAMETERS: function - Read or Write operation
* address - Where in the space to read or write
* bit_width - Field width in bits (8, 16, or 32)
* value - Pointer to in or out value
* handler_context - Pointer to Handler's context
* region_context - Pointer to context specific to the
* accessed region
*
* RETURN: Status
*
* DESCRIPTION: Handler for the System IO address space (Op Region)
*
******************************************************************************/
acpi_status
acpi_ex_system_io_space_handler(u32 function,
acpi_physical_address address,
u32 bit_width,
u64 *value,
void *handler_context, void *region_context)
{
acpi_status status = AE_OK;
u32 value32;
ACPI_FUNCTION_TRACE(ex_system_io_space_handler);
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"System-IO (width %u) R/W %u Address=%8.8X%8.8X\n",
bit_width, function, ACPI_FORMAT_UINT64(address)));
/* Decode the function parameter */
switch (function) {
case ACPI_READ:
status = acpi_hw_read_port((acpi_io_address)address,
&value32, bit_width);
*value = value32;
break;
case ACPI_WRITE:
status = acpi_hw_write_port((acpi_io_address)address,
(u32)*value, bit_width);
break;
default:
status = AE_BAD_PARAMETER;
break;
}
return_ACPI_STATUS(status);
}
#ifdef ACPI_PCI_CONFIGURED
/*******************************************************************************
*
* FUNCTION: acpi_ex_pci_config_space_handler
*
* PARAMETERS: function - Read or Write operation
* address - Where in the space to read or write
* bit_width - Field width in bits (8, 16, or 32)
* value - Pointer to in or out value
* handler_context - Pointer to Handler's context
* region_context - Pointer to context specific to the
* accessed region
*
* RETURN: Status
*
* DESCRIPTION: Handler for the PCI Config address space (Op Region)
*
******************************************************************************/
acpi_status
acpi_ex_pci_config_space_handler(u32 function,
acpi_physical_address address,
u32 bit_width,
u64 *value,
void *handler_context, void *region_context)
{
acpi_status status = AE_OK;
struct acpi_pci_id *pci_id;
u16 pci_register;
ACPI_FUNCTION_TRACE(ex_pci_config_space_handler);
/*
* The arguments to acpi_os(Read|Write)pci_configuration are:
*
* pci_segment is the PCI bus segment range 0-31
* pci_bus is the PCI bus number range 0-255
* pci_device is the PCI device number range 0-31
* pci_function is the PCI device function number
* pci_register is the Config space register range 0-255 bytes
*
* value - input value for write, output address for read
*
*/
pci_id = (struct acpi_pci_id *)region_context;
pci_register = (u16) (u32) address;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Pci-Config %u (%u) Seg(%04x) Bus(%04x) "
"Dev(%04x) Func(%04x) Reg(%04x)\n",
function, bit_width, pci_id->segment, pci_id->bus,
pci_id->device, pci_id->function, pci_register));
switch (function) {
case ACPI_READ:
*value = 0;
status =
acpi_os_read_pci_configuration(pci_id, pci_register, value,
bit_width);
break;
case ACPI_WRITE:
status =
acpi_os_write_pci_configuration(pci_id, pci_register,
*value, bit_width);
break;
default:
status = AE_BAD_PARAMETER;
break;
}
return_ACPI_STATUS(status);
}
#endif
/*******************************************************************************
*
* FUNCTION: acpi_ex_cmos_space_handler
*
* PARAMETERS: function - Read or Write operation
* address - Where in the space to read or write
* bit_width - Field width in bits (8, 16, or 32)
* value - Pointer to in or out value
* handler_context - Pointer to Handler's context
* region_context - Pointer to context specific to the
* accessed region
*
* RETURN: Status
*
* DESCRIPTION: Handler for the CMOS address space (Op Region)
*
******************************************************************************/
acpi_status
acpi_ex_cmos_space_handler(u32 function,
acpi_physical_address address,
u32 bit_width,
u64 *value,
void *handler_context, void *region_context)
{
acpi_status status = AE_OK;
ACPI_FUNCTION_TRACE(ex_cmos_space_handler);
return_ACPI_STATUS(status);
}
#ifdef ACPI_PCI_CONFIGURED
/*******************************************************************************
*
* FUNCTION: acpi_ex_pci_bar_space_handler
*
* PARAMETERS: function - Read or Write operation
* address - Where in the space to read or write
* bit_width - Field width in bits (8, 16, or 32)
* value - Pointer to in or out value
* handler_context - Pointer to Handler's context
* region_context - Pointer to context specific to the
* accessed region
*
* RETURN: Status
*
* DESCRIPTION: Handler for the PCI bar_target address space (Op Region)
*
******************************************************************************/
acpi_status
acpi_ex_pci_bar_space_handler(u32 function,
acpi_physical_address address,
u32 bit_width,
u64 *value,
void *handler_context, void *region_context)
{
acpi_status status = AE_OK;
ACPI_FUNCTION_TRACE(ex_pci_bar_space_handler);
return_ACPI_STATUS(status);
}
#endif
/*******************************************************************************
*
* FUNCTION: acpi_ex_data_table_space_handler
*
* PARAMETERS: function - Read or Write operation
* address - Where in the space to read or write
* bit_width - Field width in bits (8, 16, or 32)
* value - Pointer to in or out value
* handler_context - Pointer to Handler's context
* region_context - Pointer to context specific to the
* accessed region
*
* RETURN: Status
*
* DESCRIPTION: Handler for the Data Table address space (Op Region)
*
******************************************************************************/
acpi_status
acpi_ex_data_table_space_handler(u32 function,
acpi_physical_address address,
u32 bit_width,
u64 *value,
void *handler_context, void *region_context)
{
ACPI_FUNCTION_TRACE(ex_data_table_space_handler);
/*
* Perform the memory read or write. The bit_width was already
* validated.
*/
switch (function) {
case ACPI_READ:
memcpy(ACPI_CAST_PTR(char, value),
ACPI_PHYSADDR_TO_PTR(address), ACPI_DIV_8(bit_width));
break;
case ACPI_WRITE:
memcpy(ACPI_PHYSADDR_TO_PTR(address),
ACPI_CAST_PTR(char, value), ACPI_DIV_8(bit_width));
break;
default:
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
return_ACPI_STATUS(AE_OK);
}