From 2dce04618e634ff26fc395e785c85e7f87482029 Mon Sep 17 00:00:00 2001
From: Sebastian Sumpf <sebastian.sumpf@genode-labs.com>
Date: Thu, 4 Jul 2013 15:16:32 +0200
Subject: [PATCH] atapi_drv: Implement LBA48 specific block count

Use NATIVE MAX ADDRESS EXT to retrieve last block for LBA48. Also check not only
for enabled LBA48 support but for the 'host protected area' bit before using the
LBA48 version. This is because the high order byte (HOB) data retrieval is
broken in Qemu.

Fixes #761.
---
 os/src/drivers/atapi/ata_device.cc | 33 ++++++++++++++++++++----------
 os/src/drivers/atapi/ata_device.h  |  1 +
 2 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/os/src/drivers/atapi/ata_device.cc b/os/src/drivers/atapi/ata_device.cc
index 5fbf82533..7f8dfa099 100644
--- a/os/src/drivers/atapi/ata_device.cc
+++ b/os/src/drivers/atapi/ata_device.cc
@@ -27,6 +27,7 @@ static const int verbose = 0;
 using namespace Genode;
 
 Ata::Device::Device(unsigned base_cmd, unsigned base_ctrl)
+: _lba48(false), _host_protected_area(false)
 {
 	_pio = new(env()->heap()) Ata::Io_port(base_cmd, base_ctrl);
 }
@@ -77,15 +78,13 @@ void Ata::Device::probe_dma()
 	               0L,
 	               buffer,
 	               1L, 0 )) {
-		
-		
-		unsigned command_set = buffer[164] + (buffer[165] << 8) + (buffer[166] << 16) + (buffer[167] << 24);
-		_lba48 = false;
-		if  (command_set & (1 << 26) )
-			_lba48 = true;
-		Genode::printf( "LBA%d\n", _lba48 ? 48 : 28 );
 
+		/* check command set's LBA48 bit */
+		_lba48 = !!(buffer[167] & 0x4);
+		/* check for host protected area feature */
+		_host_protected_area = !!(buffer[165] & 0x4);
 
+		Genode::printf( "Adress mode is LBA%d\n", _lba48 ? 48 : 28 );
 		Genode::printf("UDMA Modes supported:\n");
 
 		for (int i = 0; i <= 5; i++) {
@@ -112,15 +111,27 @@ void Ata::Device::read_capacity()
 	_block_start = 0;
 	_block_size  = 512;
 
-	enum { CMD_NATIVE_MAX_ADDRESS = 0xf8 };
+	enum { 
+		CMD_NATIVE_MAX_ADDRESS     = 0xf8, /* LBA28 */
+		CMD_NATIVE_MAX_ADDRESS_EXT = 0x27, /* LBA48 */
+	};
 
-	if (_lba48) {
-		if (!reg_non_data_lba48(dev_num(), CMD_NATIVE_MAX_ADDRESS, 0, 1, 0UL, 0UL)) {
+	/*
+	 * If both LBA48 is enabled and host protected area feature is set, then NATIVE MAX
+	 * ADDRESS EXT becomes mandatory, use LBA28 otherwise
+	 */
+	if (_lba48 && _host_protected_area) {
+		if (!reg_non_data_lba48(dev_num(), CMD_NATIVE_MAX_ADDRESS_EXT, 0, 1, 0UL, 0UL)) {
 
 			_block_end  =  _pio->inb(CB_SN);              /* 0 - 7 */
 			_block_end |=  _pio->inb(CB_CL) << 8;         /* 8 - 15 */
 			_block_end |=  _pio->inb(CB_CH) << 16;        /* 16 - 23 */
-			_block_end |=  _pio->inb(CB_DH) << 24;        /* 24 - 31 */
+
+			/* read higher order LBA registers */
+			_pio->outb(CB_DC, CB_DC_HOB);
+			_block_end |=  _pio->inb(CB_SN) << 24;        /* 24 - 31 */
+			/* FIXME: read bits 32 - 47 */
+
 		}
 	} else {
 		if (!reg_non_data_lba28(dev_num(), CMD_NATIVE_MAX_ADDRESS, 0, 1, 0UL)) {
diff --git a/os/src/drivers/atapi/ata_device.h b/os/src/drivers/atapi/ata_device.h
index d8160ab27..2592efaf1 100644
--- a/os/src/drivers/atapi/ata_device.h
+++ b/os/src/drivers/atapi/ata_device.h
@@ -46,6 +46,7 @@ namespace Ata {
 			unsigned                 _block_size;
 			Genode::addr_t           _base_addr;
 			bool                     _lba48;
+			bool                     _host_protected_area;
 
 		protected: