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Commit 4c0619ad authored by Sachin P Sant's avatar Sachin P Sant Committed by Greg Kroah-Hartman
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[PATCH] PCI: fix up word-aligned 16-bit PCI config access through sysfs 



This patch adds the possibility to do word-aligned 16-bit atomic PCI
configuration space accesses via the sysfs PCI interface. As a result, problems
with Emulex LFPC on IBM PowerPC64 are fixed.

Patch is present in SLES 9 SP1.

Signed-off-by: default avatarVojtech Pavlik <vojtech@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent bc56b9e0

drivers/pci/pci-sysfs.c

+58 −24
Original line number Diff line number Diff line
@@ -91,6 +91,7 @@ pci_read_config(struct kobject *kobj, char *buf, loff_t off, size_t count) 
	struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));

	unsigned int size = 64;

	loff_t init_off = off;

	u8 *data = (u8*) buf;



	/* Several chips lock up trying to read undefined config space */

	if (capable(CAP_SYS_ADMIN)) {
@@ -108,30 +109,47 @@ pci_read_config(struct kobject *kobj, char *buf, loff_t off, size_t count) 
		size = count;

	}



	while (off & 3) {

		unsigned char val;

	if ((off & 1) && size) {

		u8 val;

		pci_read_config_byte(dev, off, &val);

		buf[off - init_off] = val;

		data[off - init_off] = val;

		off++;

		if (--size == 0)

			break;

		size--;

	}



	if ((off & 3) && size > 2) {

		u16 val;

		pci_read_config_word(dev, off, &val);

		data[off - init_off] = val & 0xff;

		data[off - init_off + 1] = (val >> 8) & 0xff;

		off += 2;

		size -= 2;

	}



	while (size > 3) {

		unsigned int val;

		u32 val;

		pci_read_config_dword(dev, off, &val);

		buf[off - init_off] = val & 0xff;

		buf[off - init_off + 1] = (val >> 8) & 0xff;

		buf[off - init_off + 2] = (val >> 16) & 0xff;

		buf[off - init_off + 3] = (val >> 24) & 0xff;

		data[off - init_off] = val & 0xff;

		data[off - init_off + 1] = (val >> 8) & 0xff;

		data[off - init_off + 2] = (val >> 16) & 0xff;

		data[off - init_off + 3] = (val >> 24) & 0xff;

		off += 4;

		size -= 4;

	}



	while (size > 0) {

		unsigned char val;

	if (size >= 2) {

		u16 val;

		pci_read_config_word(dev, off, &val);

		data[off - init_off] = val & 0xff;

		data[off - init_off + 1] = (val >> 8) & 0xff;

		off += 2;

		size -= 2;

	}



	if (size > 0) {

		u8 val;

		pci_read_config_byte(dev, off, &val);

		buf[off - init_off] = val;

		data[off - init_off] = val;

		off++;

		--size;

	}
@@ -145,6 +163,7 @@ pci_write_config(struct kobject *kobj, char *buf, loff_t off, size_t count) 
	struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));

	unsigned int size = count;

	loff_t init_off = off;

	u8 *data = (u8*) buf;



	if (off > dev->cfg_size)

		return 0;
@@ -153,25 +172,40 @@ pci_write_config(struct kobject *kobj, char *buf, loff_t off, size_t count) 
		count = size;

	}

	

	while (off & 3) {

		pci_write_config_byte(dev, off, buf[off - init_off]);

	if ((off & 1) && size) {

		pci_write_config_byte(dev, off, data[off - init_off]);

		off++;

		if (--size == 0)

			break;

		size--;

	}

	

	if ((off & 3) && size > 2) {

		u16 val = data[off - init_off];

		val |= (u16) data[off - init_off + 1] << 8;

                pci_write_config_word(dev, off, val);

                off += 2;

                size -= 2;

        }



	while (size > 3) {

		unsigned int val = buf[off - init_off];

		val |= (unsigned int) buf[off - init_off + 1] << 8;

		val |= (unsigned int) buf[off - init_off + 2] << 16;

		val |= (unsigned int) buf[off - init_off + 3] << 24;

		u32 val = data[off - init_off];

		val |= (u32) data[off - init_off + 1] << 8;

		val |= (u32) data[off - init_off + 2] << 16;

		val |= (u32) data[off - init_off + 3] << 24;

		pci_write_config_dword(dev, off, val);

		off += 4;

		size -= 4;

	}

	

	while (size > 0) {

		pci_write_config_byte(dev, off, buf[off - init_off]);

	if (size >= 2) {

		u16 val = data[off - init_off];

		val |= (u16) data[off - init_off + 1] << 8;

		pci_write_config_word(dev, off, val);

		off += 2;

		size -= 2;

	}



	if (size) {

		pci_write_config_byte(dev, off, data[off - init_off]);

		off++;

		--size;

	}