///////////////////////////////////////////////////////////////////////////////////
// File     : hba_driver.c
// Date     : 23/11/2013
// Author   : alain greiner
// Copyright (c) UPMC-LIP6
///////////////////////////////////////////////////////////////////////////////////
// Implementation notes:
// 1. In order to share code, the two _hba_read() and _hba_write() functions
//    call the same _hba_set_cmd() function.
// 2. All accesses to HBA registers are done by the two
//    _hba_set_register() and _hba_get_register() low-level functions,
//    that are handling virtual / physical extended addressing.
///////////////////////////////////////////////////////////////////////////////////

#include <giet_config.h>
#include <ioc_driver.h>
#include <utils.h>
#include <tty0.h>
#include <iob_driver.h>
#include <ctx_handler.h>
#include <mmc_driver.h>
#include <hba_driver.h>
#include <vmem.h>

#if !defined( NB_IOC_CHANNELS )
# error: You must define NB_IOC_CHANNELS in the hard_config.h file
#endif

#if ( NB_IOC_CHANNELS > 8 )
# error: NB_IOC_CHANNELS cannot be larger than 8
#endif

#define in_unckdata __attribute__((section (".unckdata")))

//////////////////////////////////////////////////////////////////
//               Global variables
//////////////////////////////////////////////////////////////////

// command list array (one per channel)
hba_cmd_list_t   hba_cmd_list[NB_IOC_CHANNELS] __attribute__((aligned(0x1000)));   

// command tables array (32 command tables per channel)
hba_cmd_table_t  hba_cmd_table[NB_IOC_CHANNELS][32] __attribute__((aligned(0x1000))); 

// command list physical addresses array (one per channel)
paddr_t          hba_cmd_list_paddr[NB_IOC_CHANNELS];

// command tables physical addresses array (32 command tables per channel)
paddr_t          hba_cmd_table_paddr[NB_IOC_CHANNELS][32];

// command list pointer array (one per channel)
unsigned int     hba_cmd_slot[NB_IOC_CHANNELS];

//////////////////////////////////////////////////////////////////////////////
// This low level function returns the value of register (channel / index)
//////////////////////////////////////////////////////////////////////////////
unsigned int _hba_get_register( unsigned int channel,
                                unsigned int index )
{
    unsigned int* vaddr = (unsigned int*)SEG_IOC_BASE + channel*HBA_SPAN + index;
    return _io_extended_read( vaddr );
}

//////////////////////////////////////////////////////////////////////////////
// This low level function set a new value in register (channel / index)  
//////////////////////////////////////////////////////////////////////////////
void _hba_set_register( unsigned int channel,
                        unsigned int index,
                        unsigned int value )
{
    unsigned int* vaddr = (unsigned int*)SEG_IOC_BASE + channel*HBA_SPAN + index;
    _io_extended_write( vaddr, value );
}


///////////////////////////////////////////////////////////////////////////////
// This function register a command in both the command list
// and the command table, and updates the HBA_PXCI register.
// It uses the AHCI Scatter/Gather mechanisme to split the user 
// buffer in several physical buffers, with the constraint that each physical
// buffer must be an integer number of blocks entirely contained in a single
// page frame. 
// return 0 if success, -1 if error
///////////////////////////////////////////////////////////////////////////////
unsigned int _hba_cmd_set( unsigned int  channel,     // channel index
                           unsigned int  is_read,     // to memory
                           unsigned int  lba,         // logic block address
                           paddr_t       buffer,      // buffer physical address
                           unsigned int  count )      // number of blocks
{
    unsigned int       block_size;     // defined by the block device (bytes)
    unsigned int       pxci;           // command list status
    unsigned int       cmd_id;         // command index in command list

    hba_cmd_desc_t*    cmd_desc;       // command descriptor pointer   
    hba_cmd_table_t*   cmd_table;      // command table pointer

    block_size = _hba_get_block_size();

    // check buffer alignment
    if( buffer & (block_size-1) )
    {
        _puts("\n[GIET ERROR] in _hba_set_cmd() : user buffer not block aligned\n");
        return -1;
    }

    // get command list status from PXCI register
    pxci = _hba_get_register( channel, HBA_PXCI );

    // get command index and return error if command list full
    cmd_id = hba_cmd_slot[channel];
    if( pxci & (1<<cmd_id ) ) 
    {
        _puts("\n[GIET ERROR] in _hba_set_cmd() : command list full for channel ");
        _putd( channel );
        _puts("\n");
        return -1;
    }

    // compute pointers on command descriptor and command table    
    cmd_desc  = (hba_cmd_desc_t*)(&(hba_cmd_list[channel].desc[cmd_id]));
    cmd_table = (hba_cmd_table_t*)(&(hba_cmd_table[channel][cmd_id]));

    // set  buffer descriptor in command table 
    cmd_table->entry[0].dba  = (unsigned int)(buffer);
    cmd_table->entry[0].dbau = (unsigned int)(buffer >> 32);
    cmd_table->entry[0].dbc  = count * block_size;

    // initialize command table header
    cmd_table->header.lba0 = (char)lba;
    cmd_table->header.lba1 = (char)(lba>>8);
    cmd_table->header.lba2 = (char)(lba>>16);
    cmd_table->header.lba3 = (char)(lba>>24);
    cmd_table->header.lba4 = 0;
    cmd_table->header.lba5 = 0;

    // initialise command descriptor
    cmd_desc->prdtl[0] = 1;
    cmd_desc->prdtl[1] = 0;
    cmd_desc->ctba     = (unsigned int)(hba_cmd_table_paddr[channel][cmd_id]);
    cmd_desc->ctbau    = (unsigned int)(hba_cmd_table_paddr[channel][cmd_id]>>32);
    if( is_read ) cmd_desc->flag[0] = 0x00;
    else          cmd_desc->flag[0] = 0x40;     
   
    // update PXCI register
    _hba_set_register( channel, HBA_PXCI, (1<<cmd_id) );

    // update command pointer 
    hba_cmd_slot[channel] = (cmd_id + 1)%32;

    return  0;
} 

/* This can be used for a future use with buffer in virtual space

    // get user space page table virtual address
    user_pt_vbase     = _get_context_slot(CTX_PTAB_ID);
    vpn_min           = buf_vaddr >> 12;
    vpn_max           = (buf_vaddr + (block_size*count) - 1) >> 12;
    offset            = buf_vaddr & 0xFFF;
    offset_last       = (buf_vaddr + (block_size*count) - 1) & 0xFFF;

    // initialize all buffer descriptors in command table 
    // (loop on all virtual pages covering the user buffer)
    for( vpn = vpn_min, buf_id = 0 ; vpn <= vpn_max ; vpn++ )
    {
        paddr_t      paddr;
        unsigned int count;
        unsigned int ppn;
        unsigned int flags;
        unsigned int ko;
        unsigned int buf_id = 0;

        // get ppn and flags 
        _v2p_translate( (page_table_t*)user_pt_vbase,
                        vpn,
                        &ppn,
                        &flags );

        // check access rights
        if ((flags & PTE_U) == 0)
        {
            _puts("[GIET ERROR] in _hba_set_cmd() : user buffer not in user space\n");
            return -1;
        }
        if (((flags & PTE_W) == 0 ) && (is_read == 0) )
        {
            _puts("[GIET ERROR] in _hba_set_cmd() : user buffer not writable\n");
            return -1;
        }

        // check buffer index overflow
        if( buf_id > 245 )
        {
            _puts("[GIET ERROR] in _hba_set_cmd() : max number of buffers is 248\n");
            return -1;   
        }

        // buffer allocation
        if( vpn == vpn_min )       // first page: one single buffer
        {
            paddr = (((paddr_t)ppn) << 12) + offset;
            count = 0x1000 - offset;
            cmd_table->entry[buf_id].dba  = (unsigned int)(paddr);
            cmd_table->entry[buf_id].dbau = (unsigned int)(paddr >> 32);
            cmd_table->entry[buf_id].dbc  = count;

            buf_id++;
        }
        else if( vpn == vpn_max )  // last page: one single buffer
        {
            paddr = (((paddr_t)ppn) << 12);
            count = offset_last;
            cmd_table->entry[buf_id].dba  = (unsigned int)(paddr);
            cmd_table->entry[buf_id].dbau = (unsigned int)(paddr >> 32);
            cmd_table->entry[buf_id].dbc  = count;

            buf_id++;
        }
        else if( offset )          // midle page and offset != 0: two buffers  
        {
            paddr = (((paddr_t)ppn) << 12);
            
            count = offset;
            cmd_table->entry[buf_id].dba  = (unsigned int)(paddr);
            cmd_table->entry[buf_id].dbau = (unsigned int)(paddr >> 32);
            cmd_table->entry[buf_id].dbc  = count;

            buf_id++;

            paddr = (((paddr_t)ppn) << 12) + offset;
            count = 0x1000 - offset; 
            cmd_table->entry[buf_id].dba  = (unsigned int)(paddr);
            cmd_table->entry[buf_id].dbau = (unsigned int)(paddr >> 32);
            cmd_table->entry[buf_id].dbc  = count;

            buf_id++;
        }
        else                      // middle page and offset == 0: one buffer
        {
            paddr = (((paddr_t)ppn) << 12);
            count = 0x1000; 
            cmd_table->entry[buf_id].dba  = (unsigned int)(paddr);
            cmd_table->entry[buf_id].dbau = (unsigned int)(paddr >> 32);
            cmd_table->entry[buf_id].dbc  = count;

            buf_id++;
        }
    }
*/


//////////////////////////////////////////////
unsigned int _hba_init( unsigned int channel )
{
    unsigned int ppn;
    unsigned int flags;
    unsigned int vbase;
    unsigned int c;               // c == command index

    // get page_table pointer
    unsigned int pt = _get_context_slot(CTX_PTAB_ID);

    // HBA registers TODO: ne faut_il pas un V2P pour PXCLB/PXCLBU ? (AG)
    _hba_set_register( channel, HBA_PXCLB , (unsigned int)&hba_cmd_list[channel] );
    _hba_set_register( channel, HBA_PXCLBU, 0 );
    _hba_set_register( channel, HBA_PXIE  , 0x40000001 );
    _hba_set_register( channel, HBA_PXIS  , 0 );
    _hba_set_register( channel, HBA_PXCI  , 0 );
    _hba_set_register( channel, HBA_PXCMD , 1 );

    // command list pointer       
    hba_cmd_slot[channel] = 0;

    // Command list physical addresse
    vbase = (unsigned int)(&hba_cmd_list[channel]);
    _v2p_translate( (page_table_t*)pt,
                     vbase>>12,
                     &ppn,
                     &flags );
    hba_cmd_list_paddr[channel] = ((paddr_t)ppn) | (vbase & 0xFFF);

    // Command tables physical addresses
    for( c=0 ; c<32 ; c++ )
    {
        vbase = (unsigned int)(&hba_cmd_table[channel][c]);
        _v2p_translate( (page_table_t*)pt,
                         vbase>>12,
                         &ppn,
                         &flags );
        hba_cmd_table_paddr[channel][c] = ((paddr_t)ppn) | (vbase & 0xFFF);
    }

    return 0;
}

///////////////////////////////////////////////
unsigned int _hba_write( unsigned int  channel,
                         unsigned int  mode,
                         unsigned int  lba,
                         paddr_t       buffer, 
                         unsigned int  count )
{
    return _hba_cmd_set( channel, 
                         0,         // write 
                         lba, 
                         buffer, 
                         count );
}

//////////////////////////////////////////////
unsigned int _hba_read( unsigned int  channel,
                        unsigned int  mode,
                        unsigned int  lba, 
                        paddr_t       buffer, 
                        unsigned int  count )
{
    return _hba_cmd_set( channel,
                         1,          // read
                         lba, 
                         buffer, 
                         count );
}

//////////////////////////////////
unsigned int _hba_get_block_size()
{
    // TODO The block size must be obtained from the hardware...
    return 512;
}

////////////////////////////////////////////////////
unsigned int _hba_get_status( unsigned int channel ) 
{

    if( channel >= NB_IOC_CHANNELS )
    {
        _puts("\n[GIET ERROR] in _hba_get_status() : illegal channel\n");
        _exit();
    }

    // get HBA_PXIS value
    unsigned int status = _hba_get_register( channel, HBA_PXIS );

    // reset HBA_PXIS
    _hba_set_register( channel, HBA_PXIS, 0 );

    return status;
}

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