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Commit 700130b4 authored by Myron Stowe's avatar Myron Stowe Committed by Len Brown
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ACPI APEI: Convert atomicio routines 

APEI needs memory access in interrupt context.  The obvious choice is
acpi_read(), but originally it couldn't be used in interrupt context
because it makes temporary mappings with ioremap().  Therefore, we added
drivers/acpi/atomicio.c, which provides:
    acpi_pre_map_gar()     -- ioremap in process context
	acpi_atomic_read()     -- memory access in interrupt context
	acpi_post_unmap_gar()  -- iounmap

Later we added acpi_os_map_generic_address() (29718521) and enhanced
acpi_read() so it works in interrupt context as long as the address has
been previously mapped (620242ae).  Now this sequence:
    acpi_os_map_generic_address()    -- ioremap in process context
    acpi_read()/apei_read()          -- now OK in interrupt context
    acpi_os_unmap_generic_address()
is equivalent to what atomicio.c provides.

This patch introduces apei_read() and apei_write(), which currently are
functional equivalents of acpi_read() and acpi_write().  This is mainly
proactive, to prevent APEI breakages if acpi_read() and acpi_write()
are ever augmented to support the 'bit_offset' field of GAS, as APEI's
__apei_exec_write_register() precludes splitting up functionality
related to 'bit_offset' and APEI's 'mask' (see its
APEI_EXEC_PRESERVE_REGISTER block).

With apei_read() and apei_write() in place, usages of atomicio routines
are converted to apei_read()/apei_write() and existing calls within
osl.c and the CA, based on the re-factoring that was done in an earlier
patch series - http://marc.info/?l=linux-acpi&m=128769263327206&w=2

:
    acpi_pre_map_gar()     -->  acpi_os_map_generic_address()
    acpi_post_unmap_gar()  -->  acpi_os_unmap_generic_address()
    acpi_atomic_read()     -->  apei_read()
    acpi_atomic_write()    -->  apei_write()

Note that acpi_read() and acpi_write() currently use 'bit_width'
for accessing GARs which seems incorrect.  'bit_width' is the size of
the register, while 'access_width' is the size of the access the
processor must generate on the bus.  The 'access_width' may be larger,
for example, if the hardware only supports 32-bit or 64-bit reads.  I
wanted to minimize any possible impacts with this patch series so I
did *not* change this behavior.

Signed-off-by: default avatarMyron Stowe <myron.stowe@redhat.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 6f68c91c

drivers/acpi/apei/apei-base.c

+96 −6
Original line number Diff line number Diff line
@@ -34,13 +34,13 @@ 
#include <linux/module.h>

#include <linux/init.h>

#include <linux/acpi.h>

#include <linux/acpi_io.h>

#include <linux/slab.h>

#include <linux/io.h>

#include <linux/kref.h>

#include <linux/rculist.h>

#include <linux/interrupt.h>

#include <linux/debugfs.h>

#include <acpi/atomicio.h>



#include "apei-internal.h"
@@ -70,7 +70,7 @@ int __apei_exec_read_register(struct acpi_whea_header *entry, u64 *val) 
{

	int rc;



	rc = acpi_atomic_read(val, &entry->register_region);

	rc = apei_read(val, &entry->register_region);

	if (rc)

		return rc;

	*val >>= entry->register_region.bit_offset;
@@ -116,13 +116,13 @@ int __apei_exec_write_register(struct acpi_whea_header *entry, u64 val) 
	val <<= entry->register_region.bit_offset;

	if (entry->flags & APEI_EXEC_PRESERVE_REGISTER) {

		u64 valr = 0;

		rc = acpi_atomic_read(&valr, &entry->register_region);

		rc = apei_read(&valr, &entry->register_region);

		if (rc)

			return rc;

		valr &= ~(entry->mask << entry->register_region.bit_offset);

		val |= valr;

	}

	rc = acpi_atomic_write(val, &entry->register_region);

	rc = apei_write(val, &entry->register_region);



	return rc;

}
@@ -243,7 +243,7 @@ static int pre_map_gar_callback(struct apei_exec_context *ctx, 
	u8 ins = entry->instruction;



	if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)

		return acpi_pre_map_gar(&entry->register_region);

		return acpi_os_map_generic_address(&entry->register_region);



	return 0;

}
@@ -276,7 +276,7 @@ static int post_unmap_gar_callback(struct apei_exec_context *ctx, 
	u8 ins = entry->instruction;



	if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)

		acpi_post_unmap_gar(&entry->register_region);

		acpi_os_unmap_generic_address(&entry->register_region);



	return 0;

}
@@ -591,6 +591,96 @@ static int apei_check_gar(struct acpi_generic_address *reg, u64 *paddr) 
	return 0;

}



/* read GAR in interrupt (including NMI) or process context */

int apei_read(u64 *val, struct acpi_generic_address *reg)

{

	int rc;

	u64 address;

	u32 tmp, width = reg->bit_width;

	acpi_status status;



	rc = apei_check_gar(reg, &address);

	if (rc)

		return rc;



	if (width == 64)

		width = 32;	/* Break into two 32-bit transfers */



	*val = 0;

	switch(reg->space_id) {

	case ACPI_ADR_SPACE_SYSTEM_MEMORY:

		status = acpi_os_read_memory((acpi_physical_address)

					     address, &tmp, width);

		if (ACPI_FAILURE(status))

			return -EIO;

		*val = tmp;



		if (reg->bit_width == 64) {

			/* Read the top 32 bits */

			status = acpi_os_read_memory((acpi_physical_address)

						     (address + 4), &tmp, 32);

			if (ACPI_FAILURE(status))

				return -EIO;

			*val |= ((u64)tmp << 32);

		}

		break;

	case ACPI_ADR_SPACE_SYSTEM_IO:

		status = acpi_os_read_port(address, (u32 *)val, reg->bit_width);

		if (ACPI_FAILURE(status))

			return -EIO;

		break;

	default:

		return -EINVAL;

	}



	return 0;

}

EXPORT_SYMBOL_GPL(apei_read);



/* write GAR in interrupt (including NMI) or process context */

int apei_write(u64 val, struct acpi_generic_address *reg)

{

	int rc;

	u64 address;

	u32 width = reg->bit_width;

	acpi_status status;



	rc = apei_check_gar(reg, &address);

	if (rc)

		return rc;



	if (width == 64)

		width = 32;	/* Break into two 32-bit transfers */



	switch (reg->space_id) {

	case ACPI_ADR_SPACE_SYSTEM_MEMORY:

		status = acpi_os_write_memory((acpi_physical_address)

					      address, ACPI_LODWORD(val),

					      width);

		if (ACPI_FAILURE(status))

			return -EIO;



		if (reg->bit_width == 64) {

			status = acpi_os_write_memory((acpi_physical_address)

						      (address + 4),

						      ACPI_HIDWORD(val), 32);

			if (ACPI_FAILURE(status))

				return -EIO;

		}

		break;

	case ACPI_ADR_SPACE_SYSTEM_IO:

		status = acpi_os_write_port(address, val, reg->bit_width);

		if (ACPI_FAILURE(status))

			return -EIO;

		break;

	default:

		return -EINVAL;

	}



	return 0;

}

EXPORT_SYMBOL_GPL(apei_write);



static int collect_res_callback(struct apei_exec_context *ctx,

				struct acpi_whea_header *entry,

				void *data)

drivers/acpi/apei/apei-internal.h

+3 −0
Original line number Diff line number Diff line
@@ -68,6 +68,9 @@ static inline int apei_exec_run_optional(struct apei_exec_context *ctx, u8 actio 
/* IP has been set in instruction function */

#define APEI_EXEC_SET_IP	1



int apei_read(u64 *val, struct acpi_generic_address *reg);

int apei_write(u64 val, struct acpi_generic_address *reg);



int __apei_exec_read_register(struct acpi_whea_header *entry, u64 *val);

int __apei_exec_write_register(struct acpi_whea_header *entry, u64 val);

int apei_exec_read_register(struct apei_exec_context *ctx,

drivers/acpi/apei/ghes.c

+5 −5
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <linux/module.h>

#include <linux/init.h>

#include <linux/acpi.h>

#include <linux/acpi_io.h>

#include <linux/io.h>

#include <linux/interrupt.h>

#include <linux/timer.h>
@@ -48,7 +49,6 @@ 
#include <linux/pci.h>

#include <linux/aer.h>

#include <acpi/apei.h>

#include <acpi/atomicio.h>

#include <acpi/hed.h>

#include <asm/mce.h>

#include <asm/tlbflush.h>
@@ -301,7 +301,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic) 
	if (!ghes)

		return ERR_PTR(-ENOMEM);

	ghes->generic = generic;

	rc = acpi_pre_map_gar(&generic->error_status_address);

	rc = acpi_os_map_generic_address(&generic->error_status_address);

	if (rc)

		goto err_free;

	error_block_length = generic->error_block_length;
@@ -321,7 +321,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic) 
	return ghes;



err_unmap:

	acpi_post_unmap_gar(&generic->error_status_address);

	acpi_os_unmap_generic_address(&generic->error_status_address);

err_free:

	kfree(ghes);

	return ERR_PTR(rc);
@@ -330,7 +330,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic) 
static void ghes_fini(struct ghes *ghes)

{

	kfree(ghes->estatus);

	acpi_post_unmap_gar(&ghes->generic->error_status_address);

	acpi_os_unmap_generic_address(&ghes->generic->error_status_address);

}



enum {
@@ -401,7 +401,7 @@ static int ghes_read_estatus(struct ghes *ghes, int silent) 
	u32 len;

	int rc;



	rc = acpi_atomic_read(&buf_paddr, &g->error_status_address);

	rc = apei_read(&buf_paddr, &g->error_status_address);

	if (rc) {

		if (!silent && printk_ratelimit())

			pr_warning(FW_WARN GHES_PFX