///////////////////////////////////////////////////////////////////////////////////
// File       : ioc_driver.c
// Date       : 23/05/2013
// Author     : alain greiner
// Maintainer : cesar fuguet
// Copyright (c) UPMC-LIP6
///////////////////////////////////////////////////////////////////////////////////
// The ioc_driver.c and ioc_driver.h files are part ot the GIET-VM kernel.
//
// This abstact driver define a generic API, supporting various physical
// block device controlers, including:
// - vci_block_device : single channel)                    => bdv_driver
// - vci_ahci         : multi channels                     => hba_driver
// - sd_card          : single channel                     => sdc_driver
// - ramdisk (single channel meory mapped virtual disk)    => rdk_driver
//
// It can exist only one block-device type in the architecture, that must be
// defined by one of the following configuration variables in hard_config.h file:
// USE_IOC_BDV, USE_IOC_SDC, USE_IOC_HBA, USE_IOC_RDK.
//
// Any physical driver xxx must provide the following API:
// - _xxx_init()
// - _xxx_read()
// - _xxx_write()
// - _xxx_get_status()
// - _xxx_get_block_size()
// The "channel" parameter is no transmited to single channel devices.
//
// The _ioc_read() and _ioc_write() functions are always blocking for
// the calling user program.
//
// These functions compute the physical address of the memory buffer before 
// calling the proper physical device. They can be called in 3 modes:
//
// - In BOOT mode, these functions use the buffer virtual address
//   as a physical address if the MMU is not activated.
//   They make a V2P translation if the MMU is activated.
//   This mode is used to load the map.bin file (before memory activation),
//   or to load the various .elf files (after MMU activation).
//
// - In KERNEL mode, these functions make a V2P translation to
//   compute the buffer physical address.
//   There is no checking of user access right to the memory buffer.  
//   This mode must be used for an "open" system call.
//
// - In USER mode, these functions make a V2P translation to
//   compute the buffer physical address. 
//   The user access right to the memory buffer are checked.  
//   This mode must be used for a "read" or "write" system call.
//
// The IOMMU can be activated or not:
// 
// 1) When the IOMMU is used, a fixed size 2Mbytes vseg is allocated to 
// the IOC peripheral, in the I/O virtual space, and the user buffer is
// dynamically remapped in the IOMMU page table. The corresponding entry 
// in the IOMMU PT1 is defined by the kernel _ioc_iommu_ix1 variable.
// The number of pages to be unmapped is stored in the _ioc_npages variable.
// The number of PT2 entries is dynamically computed and stored in the
// kernel _ioc_iommu_npages variable. It cannot be larger than 512.
// The user buffer is unmapped by the _ioc_completed() function when 
// the transfer is completed.
//
// 2/ If the IOMMU is not used, we check that  the user buffer is mapped to a
// contiguous physical buffer (this is generally true because the user space
// page tables are statically constructed to use contiguous physical memory).
//
// Finally, the memory buffer must fulfill the following conditions:
// - The buffer must be word aligned, 
// - The buffer must be mapped in user space for an user access, 
// - The buffer must be writable in case of (to_mem) access,
// - The total number of physical pages occupied by the user buffer cannot
//   be larger than 512 pages if the IOMMU is activated,
// - All physical pages occupied by the user buffer must be contiguous
//   if the IOMMU is not activated.
// An error code is returned if these conditions are not verified.
//
// The SEG_IOC_BASE virtual base address must be defined in hard_config.h,
// as it is used by the BDV, HBA and SPI drivers.
//
// If the RAMDISK is used, an extra memory segment with virtual base address
// SEG_RDK_BASE, used by RDK driver, must be defined in hard_config.h.
///////////////////////////////////////////////////////////////////////////////////
// Implementation note:
// In order to share the code, the two _ioc_read() and _ioc_write() functions
// call the same _ioc_access() function.
///////////////////////////////////////////////////////////////////////////////////

#include <giet_config.h>
#include <ioc_driver.h>
#include <bdv_driver.h>
#include <hba_driver.h>
#include <sdc_driver.h>
#include <rdk_driver.h>
#include <utils.h>
#include <tty_driver.h>
#include <iob_driver.h>
#include <ctx_handler.h>
#include <mmc_driver.h>
#include <vmem.h>

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

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

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

#if (USE_IOC_BDV + USE_IOC_SPI + USE_IOC_HBA + USE_IOC_RDK) != 1
# error: You must use only one IOC controller type (BDV or SPI or HBA or RDK)
#endif

#if USE_IOC_BDV
# include <bdv_driver.h>
#endif

#if USE_IOC_SPI
# include <sdc_driver.h>
#endif

#if USE_IOC_HBA
# include <hba_driver.h>
#endif

#if USE_IOC_RDK
# include <rdk_driver.h>
#endif

///////////////////////////////////////////////////////////////////////////////
// IOC global variables
///////////////////////////////////////////////////////////////////////////////

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

in_unckdata volatile unsigned int _ioc_iommu_ix1 = 0;
in_unckdata volatile unsigned int _ioc_iommu_npages; 

///////////////////////////////////////////////////////////////////////////////
// This function transfer data between a memory buffer and the block device.
// The buffer lentgth is (count*block_size) bytes.
// Arguments are:
// - to_mem     : from external storage to memory when non 0.
// - mode       : BOOT_PA / BOOT_VA / KERNEL / USER 
// - lba        : first block index on the external storage.
// - buf_vaddr  : virtual base address of the memory buffer.
// - count      : number of blocks to be transfered.
// Returns 0 if success, > 0 if error.
///////////////////////////////////////////////////////////////////////////////
static unsigned int _ioc_access( unsigned int to_mem,
                                 unsigned int channel,
                                 unsigned int mode,
                                 unsigned int lba,
                                 unsigned int buf_vaddr,
                                 unsigned int count) 
{

#if GIET_DEBUG_IOC_DRIVER
unsigned int procid  = _get_procid();
unsigned int cid     = procid / NB_PROCS_MAX;
unsigned int lpid    = procid % NB_PROCS_MAX;
unsigned int x       = cid >> Y_WIDTH;
unsigned int y       = cid & ((1<<Y_WIDTH) - 1);

_printf("\n[IOC DEBUG] Processor[%d,%d,%d] enters _ioc_access() at cycle %d\n"
        " - channel  = %d\n"
        " - mode     = %d\n"
        " - vaddr    = %x\n"
        " - sectors  = %d\n"
        " - lba      = %x\n",
        x, y, lpid, _get_proctime(), channel, mode, buf_vaddr, count, lba );
#endif

    unsigned int error;            // return value
    unsigned int pt_vbase;         // page table vbase address
    unsigned int vpn_min;          // first virtuel page index covering buffer
    unsigned int vpn_max;          // last virtual page index covering buffer
    unsigned int vpn;              // current virtual page index
    unsigned int ppn;              // physical page number
    unsigned int flags;            // page protection flags
    unsigned int ix2;              // page index in IOMMU PT1 page table
    unsigned int ppn_first;        // first physical page number for user buffer
    unsigned int buf_xaddr = 0;    // user buffer virtual address in IO space (if IOMMU)
    paddr_t      buf_paddr = 0;    // user buffer physical address (if no IOMMU),

    // check buffer alignment
    if ((unsigned int) buf_vaddr & 0x3)
    {
        _printf("\n[GIET ERROR] in _ioc_access() : buffer not word aligned\n");
        _exit(); 
    }

    // check channel 
    if ( (USE_IOC_HBA == 0) && (channel > 0) )
    {
        _printf("\n[GIET ERROR] in _ioc_access() : channel must be 0 when HBA not used\n");
        _exit(); 
    }

    unsigned int length = count << 9;  // count * 512 bytes

    // computing memory buffer physical address
    if ( (mode == IOC_BOOT_MODE) && ((_get_mmu_mode() & 0x4) == 0) ) // identity mapping
    {
        buf_paddr = (paddr_t)buf_vaddr;
    }
    else                                                    // V2P translation required
    {
        // get page table virtual address
        pt_vbase = _get_context_slot(CTX_PTAB_ID);
        vpn_min  = buf_vaddr >> 12;
        vpn_max  = (buf_vaddr + length - 1) >> 12;

        // loop on all virtual pages covering the user buffer
        for (vpn = vpn_min, ix2 = 0 ; vpn <= vpn_max ; vpn++, ix2++ ) 
        {
            // get ppn and flags for each vpn
            unsigned int ko = _v2p_translate( (page_table_t*)pt_vbase,
                                              vpn,
                                              &ppn,
                                              &flags);
            // check access rights
            if ( ko )
            {
                _printf("\n[GIET ERROR] in _ioc_access() : buffer unmapped\n");
                return 1; 
            }

            if ( (mode == IOC_USER_MODE) && ((flags & PTE_U) == 0) )
            {
                _printf("\n[GIET ERROR] in _ioc_access() : buffer not user accessible\n");
                return 1; 
            }

            if ( ((flags & PTE_W) == 0 ) && to_mem )
            {
                _printf("\n[GIET ERROR] in _ioc_access() : buffer not writable\n");
                return 1; 
            }

            // save first ppn value
            if (ix2 == 0) ppn_first = ppn;

#if GIET_USE_IOMMU 
 
            // check buffer length < 2 Mbytes
            if (ix2 > 511) // check buffer length < 2 Mbytes
            {
                _printf("\n[GIET ERROR] in _ioc_access() : user buffer > 2 Mbytes\n");
                return 1; 
            }
            // map the physical page in IOMMU page table
            _iommu_add_pte2( _ioc_iommu_ix1,    // PT1 index
                             ix2,               // PT2 index
                             ppn,               // Physical page number    
                             flags );           // Protection flags

            // compute user buffer virtual adress in IO space
            buf_xaddr = (_ioc_iommu_ix1) << 21 | (buf_vaddr & 0xFFF);

#else

            // check that physical pages are contiguous
            if ((ppn - ppn_first) != ix2) 
            {
                _printf("[GIET ERROR] in _ioc_access() : split physical buffer\n");
                return 1; 
            }

            // compute user buffer physical adress
            buf_paddr = (((paddr_t)ppn_first) << 12) | (buf_vaddr & 0xFFF);
#endif            

        } // end for vpn
    }

#if GIET_USE_IOMMU 

    // register the number of pages to be unmapped in IOMMU
    _ioc_iommu_npages = (vpn_max - vpn_min) + 1;

#endif

    if ( to_mem ) // memory write : invalidate data caches 
    {
        // L1 cache
        if ( GIET_NO_HARD_CC ) _dcache_buf_invalidate((void *) buf_vaddr, length);

        // L2 cache (only if IOB used)
        if ( USE_IOB ) _mmc_inval( buf_paddr, length );
    }
    else         // memory read : update data caches
    {
        // L1 cache : nothing to do for L1 write-through

        // L2 cache (only if IOB used)
        if ( USE_IOB ) _mmc_sync( buf_paddr, length );
    }

    if ( GIET_USE_IOMMU ) buf_paddr = (paddr_t) buf_xaddr;

    ///////////////////////////////////////////
    // select the proper physical device 
    ///////////////////////////////////////////

#if       ( USE_IOC_BDV )

#if GIET_DEBUG_IOC_DRIVER
_printf("\n[IOC DEBUG] Calling BDV driver\n");
#endif
        if (to_mem) error = _bdv_read ( mode, lba, buf_paddr, count);
        else        error = _bdv_write( mode, lba, buf_paddr, count);

#elif ( USE_IOC_SPI )

#if GIET_DEBUG_IOC_DRIVER
_printf("\n[IOC DEBUG] Calling SPI driver\n");
#endif
        if (to_mem) error = _sdc_read (mode, lba, buf_paddr, count);
        else        error = _sdc_write(mode, lba, buf_paddr, count);

#elif ( USE_IOC_HBA )

#if GIET_DEBUG_IOC_DRIVER
_printf("\n[IOC DEBUG] Calling HBA driver\n");
#endif
        if (to_mem) error = _hba_read (channel, mode, lba, buf_paddr, count);
        else        error = _hba_write(channel, mode, lba, buf_paddr, count);

#elif ( USE_IOC_RDK )

#if GIET_DEBUG_IOC_DRIVER
_printf("\n[IOC DEBUG] Calling RDK driver\n");
#endif
        if (to_mem) error = _rdk_read (lba, buf_vaddr, count);
        else        error = _rdk_write(lba, buf_vaddr, count);

#endif

    return error;
} // end _ioc_access()

///////////////////////////////////////////////////////////////////////////////
// This function cheks block size, and desactivates the IOC interrupts.
// Return 0 for success.
///////////////////////////////////////////////////////////////////////////////
unsigned int _ioc_init( unsigned int channel )
{

#if   ( USE_IOC_BDV ) 

    return _bdv_init();

#elif ( USE_IOC_SPI ) 

    return _sdc_init();
    
#elif ( USE_IOC_HBA ) 

    return _hba_init( channel );
    
#elif ( USE_IOC_RDK ) 

    return _rdk_init();
    
#endif
    
}

///////////////////////////////////////////////////////////////////////////////
// Transfer data from the block device to a memory buffer. 
// - mode     : BOOT_PA / BOOT_VA / KERNEL / USER 
// - lba      : first block index on the block device
// - buffer   : base address of the memory buffer (must be word aligned)
// - count    : number of blocks to be transfered.
// Returns 0 if success, > 0 if error.
///////////////////////////////////////////////////////////////////////////////
unsigned int _ioc_read( unsigned int channel,
                        unsigned int mode,  
                        unsigned int lba, 
                        void*        buffer, 
                        unsigned int count) 
{
    return _ioc_access( 1,        // read access
                        channel,
                        mode,  
                        lba,
                        (unsigned int) buffer,
                        count );
}

///////////////////////////////////////////////////////////////////////////////
// Transfer data from a memory buffer to the block device. 
// - mode     : BOOT_PA / BOOT_VA / KERNEL / USER 
// - lba      : first block index on the block device
// - buffer   : base address of the memory buffer (must be word aligned)
// - count    : number of blocks to be transfered.
// Returns 0 if success, > 0 if error.
///////////////////////////////////////////////////////////////////////////////
unsigned int _ioc_write( unsigned int channel,
                         unsigned int mode,  
                         unsigned int lba, 
                         const void*  buffer, 
                         unsigned int count ) 
{
    return _ioc_access( 0,        // write access
                        channel,
                        mode,  
                        lba,
                        (unsigned int) buffer,
                        count );
}

///////////////////////////////////////////////////////////////////////////////
// This function returns in the status variable, the transfert status, and
// acknowledge the IRQ if the IOC controler is not busy.
// Returns 0 if success, > 0 if error
///////////////////////////////////////////////////////////////////////////////
unsigned int _ioc_get_status( unsigned int  channel )
{

#if   ( USE_IOC_BDV ) 

    return _bdv_get_status( );

#elif ( USE_IOC_SPI ) 

    return _sdc_get_status( );

#elif ( USE_IOC_HBA ) 

    return _hba_get_status( channel );

#elif ( USE_IOC_RDK )

    _printf("[GIET ERROR] _ioc_get_status() should not be called");
    _printf(" when RAMDISK  is used...\n");
    _exit();

    return 0;

#endif

}

///////////////////////////////////////////////////////////////////////////////
// This function returns the block_size with which the IOC has been configured.
///////////////////////////////////////////////////////////////////////////////
unsigned int _ioc_get_block_size() 
{

#if   ( USE_IOC_BDV ) 

    return _bdv_get_block_size();
    
#elif ( USE_IOC_SPI ) 

    return _sdc_get_block_size();
    
#elif ( USE_IOC_HBA ) 

    return _hba_get_block_size();
    
#elif ( USE_IOC_RDK ) 

    return 512;

#endif

}


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