Commit e615bf5b authored by Myron Stowe's avatar Myron Stowe Committed by Len Brown
Browse files

ACPI, APEI: Add 64-bit read/write support for APEI on i386 



Base ACPI (CA) currently does not support atomic 64-bit reads and writes
(acpi_read() and acpi_write() split 64-bit loads/stores into two
32-bit transfers) yet APEI expects 64-bit transfer capability, even
when running on 32-bit systems.

This patch implements 64-bit read and write routines for APEI usage.

This patch re-factors similar functionality introduced in commit
04c25997, bringing it into the ACPI subsystem in preparation for
removing ./drivers/acpi/atomicio.[ch].  In the implementation I have
replicated acpi_os_read_memory() and acpi_os_write_memory(), creating
64-bit versions for APEI to utilize, as opposed to something more
elegant.  My thinking is that we should attempt to see if we can get
ACPI's CA/OSL changed so that the existing acpi_read() and acpi_write()
interfaces are natively 64-bit capable and then subsequently remove the
replication.

Signed-off-by: default avatarMyron Stowe <myron.stowe@redhat.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent dcd6c922

drivers/acpi/apei/apei-base.c

+4 −31
Original line number Diff line number Diff line
@@ -596,33 +596,19 @@ 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);

		status = acpi_os_read_memory64((acpi_physical_address)

					     address, val, reg->bit_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);
@@ -642,31 +628,18 @@ 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);

		status = acpi_os_write_memory64((acpi_physical_address)

					      address, val, reg->bit_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);

drivers/acpi/osl.c

+116 −0
Original line number Diff line number Diff line
@@ -710,6 +710,67 @@ acpi_os_read_memory(acpi_physical_address phys_addr, u32 * value, u32 width) 
	return AE_OK;

}



#ifdef readq

static inline u64 read64(const volatile void __iomem *addr)

{

	return readq(addr);

}

#else

static inline u64 read64(const volatile void __iomem *addr)

{

	u64 l, h;

	l = readl(addr);

	h = readl(addr+4);

	return l | (h << 32);

}

#endif



acpi_status

acpi_os_read_memory64(acpi_physical_address phys_addr, u64 *value, u32 width)

{

	void __iomem *virt_addr;

	unsigned int size = width / 8;

	bool unmap = false;

	u64 dummy;



	rcu_read_lock();

	virt_addr = acpi_map_vaddr_lookup(phys_addr, size);

	if (!virt_addr) {

		rcu_read_unlock();

		virt_addr = acpi_os_ioremap(phys_addr, size);

		if (!virt_addr)

			return AE_BAD_ADDRESS;

		unmap = true;

	}



	if (!value)

		value = &dummy;



	switch (width) {

	case 8:

		*(u8 *) value = readb(virt_addr);

		break;

	case 16:

		*(u16 *) value = readw(virt_addr);

		break;

	case 32:

		*(u32 *) value = readl(virt_addr);

		break;

	case 64:

		*(u64 *) value = read64(virt_addr);

		break;

	default:

		BUG();

	}



	if (unmap)

		iounmap(virt_addr);

	else

		rcu_read_unlock();



	return AE_OK;

}



acpi_status

acpi_os_write_memory(acpi_physical_address phys_addr, u32 value, u32 width)

{
@@ -749,6 +810,61 @@ acpi_os_write_memory(acpi_physical_address phys_addr, u32 value, u32 width) 
	return AE_OK;

}



#ifdef writeq

static inline void write64(u64 val, volatile void __iomem *addr)

{

	writeq(val, addr);

}

#else

static inline void write64(u64 val, volatile void __iomem *addr)

{

	writel(val, addr);

	writel(val>>32, addr+4);

}

#endif



acpi_status

acpi_os_write_memory64(acpi_physical_address phys_addr, u64 value, u32 width)

{

	void __iomem *virt_addr;

	unsigned int size = width / 8;

	bool unmap = false;



	rcu_read_lock();

	virt_addr = acpi_map_vaddr_lookup(phys_addr, size);

	if (!virt_addr) {

		rcu_read_unlock();

		virt_addr = acpi_os_ioremap(phys_addr, size);

		if (!virt_addr)

			return AE_BAD_ADDRESS;

		unmap = true;

	}



	switch (width) {

	case 8:

		writeb(value, virt_addr);

		break;

	case 16:

		writew(value, virt_addr);

		break;

	case 32:

		writel(value, virt_addr);

		break;

	case 64:

		write64(value, virt_addr);

		break;

	default:

		BUG();

	}



	if (unmap)

		iounmap(virt_addr);

	else

		rcu_read_unlock();



	return AE_OK;

}



acpi_status

acpi_os_read_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,

			       u64 *value, u32 width)

include/acpi/acpiosxf.h

+4 −0
Original line number Diff line number Diff line
@@ -218,9 +218,13 @@ acpi_status acpi_os_write_port(acpi_io_address address, u32 value, u32 width); 
 */

acpi_status

acpi_os_read_memory(acpi_physical_address address, u32 * value, u32 width);

acpi_status

acpi_os_read_memory64(acpi_physical_address address, u64 *value, u32 width);



acpi_status

acpi_os_write_memory(acpi_physical_address address, u32 value, u32 width);

acpi_status

acpi_os_write_memory64(acpi_physical_address address, u64 value, u32 width);



/*

 * Platform and hardware-independent PCI configuration space access

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