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-rw-r--r--src/emu/divtlb.cpp341
1 files changed, 341 insertions, 0 deletions
diff --git a/src/emu/divtlb.cpp b/src/emu/divtlb.cpp
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+++ b/src/emu/divtlb.cpp
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+// license:BSD-3-Clause
+// copyright-holders:Aaron Giles
+/***************************************************************************
+
+ divtlb.c
+
+ Device generic virtual TLB interface.
+
+***************************************************************************/
+
+#include "emu.h"
+#include "divtlb.h"
+#include "validity.h"
+
+
+
+//**************************************************************************
+// DEBUGGING
+//**************************************************************************
+
+#define PRINTF_TLB (0)
+
+
+
+//**************************************************************************
+// DEVICE VTLB INTERFACE
+//**************************************************************************
+
+//-------------------------------------------------
+// device_vtlb_interface - constructor
+//-------------------------------------------------
+
+device_vtlb_interface::device_vtlb_interface(const machine_config &mconfig, device_t &device, address_spacenum space)
+ : device_interface(device, "vtlb"),
+ m_space(space),
+ m_dynamic(0),
+ m_fixed(0),
+ m_dynindex(0),
+ m_pageshift(0),
+ m_addrwidth(0)
+{
+}
+
+
+//-------------------------------------------------
+// device_vtlb_interface - destructor
+//-------------------------------------------------
+
+device_vtlb_interface::~device_vtlb_interface()
+{
+}
+
+
+//-------------------------------------------------
+// interface_validity_check - validation for a
+// device after the configuration has been
+// constructed
+//-------------------------------------------------
+
+void device_vtlb_interface::interface_validity_check(validity_checker &valid) const
+{
+ const device_memory_interface *intf;
+ if (!device().interface(intf))
+ osd_printf_error("Device does not have memory interface\n");
+ else
+ {
+ // validate CPU information
+ const address_space_config *spaceconfig = intf->space_config(m_space);
+ if (spaceconfig == nullptr)
+ osd_printf_error("No memory address space configuration found for space %d\n", m_space);
+ else if ((1 << spaceconfig->m_page_shift) <= VTLB_FLAGS_MASK || spaceconfig->m_logaddr_width <= spaceconfig->m_page_shift)
+ osd_printf_error("Invalid page shift %d for VTLB\n", spaceconfig->m_page_shift);
+ }
+}
+
+
+//-------------------------------------------------
+// interface_pre_start - work to be done prior to
+// actually starting a device
+//-------------------------------------------------
+
+void device_vtlb_interface::interface_pre_start()
+{
+ // fill in CPU information
+ const address_space_config *spaceconfig = device().memory().space_config(m_space);
+ m_pageshift = spaceconfig->m_page_shift;
+ m_addrwidth = spaceconfig->m_logaddr_width;
+
+ // allocate the entry array
+ m_live.resize(m_fixed + m_dynamic);
+ memset(&m_live[0], 0, m_live.size()*sizeof(m_live[0]));
+
+ // allocate the lookup table
+ m_table.resize((size_t) 1 << (m_addrwidth - m_pageshift));
+ memset(&m_table[0], 0, m_table.size()*sizeof(m_table[0]));
+
+ // allocate the fixed page count array
+ if (m_fixed > 0)
+ {
+ m_fixedpages.resize(m_fixed);
+ memset(&m_fixedpages[0], 0, m_fixed*sizeof(m_fixedpages[0]));
+ }
+}
+
+
+//-------------------------------------------------
+// interface_post_start - work to be done after
+// actually starting a device
+//-------------------------------------------------
+
+void device_vtlb_interface::interface_post_start()
+{
+ device().save_item(NAME(m_live));
+ device().save_item(NAME(m_table));
+ if (m_fixed > 0)
+ device().save_item(NAME(m_fixedpages));
+}
+
+
+//-------------------------------------------------
+// interface_pre_reset - work to be done prior to
+// actually resetting a device
+//-------------------------------------------------
+
+void device_vtlb_interface::interface_pre_reset()
+{
+ vtlb_flush_dynamic();
+}
+
+
+//**************************************************************************
+// FILLING
+//**************************************************************************
+
+//-------------------------------------------------
+// vtlb_fill - called by the CPU core in
+// response to an unmapped access
+//-------------------------------------------------
+
+int device_vtlb_interface::vtlb_fill(offs_t address, int intention)
+{
+ offs_t tableindex = address >> m_pageshift;
+ vtlb_entry entry = m_table[tableindex];
+ offs_t taddress;
+
+#if PRINTF_TLB
+ osd_printf_debug("vtlb_fill: %08X(%X) ... ", address, intention);
+#endif
+
+ // should not be called here if the entry is in the table already
+// assert((entry & (1 << intention)) == 0);
+
+ // if we have no dynamic entries, we always fail
+ if (m_dynamic == 0)
+ {
+#if PRINTF_TLB
+ osd_printf_debug("failed: no dynamic entries\n");
+#endif
+ return FALSE;
+ }
+
+ // ask the CPU core to translate for us
+ taddress = address;
+ if (!device().memory().translate(m_space, intention, taddress))
+ {
+#if PRINTF_TLB
+ osd_printf_debug("failed: no translation\n");
+#endif
+ return FALSE;
+ }
+
+ // if this is the first successful translation for this address, allocate a new entry
+ if ((entry & VTLB_FLAGS_MASK) == 0)
+ {
+ int liveindex = m_dynindex++ % m_dynamic;
+
+ // if an entry already exists at this index, free it
+ if (m_live[liveindex] != 0)
+ m_table[m_live[liveindex] - 1] = 0;
+
+ // claim this new entry
+ m_live[liveindex] = tableindex + 1;
+
+ // form a new blank entry
+ entry = (taddress >> m_pageshift) << m_pageshift;
+ entry |= VTLB_FLAG_VALID;
+
+#if PRINTF_TLB
+ osd_printf_debug("success (%08X), new entry\n", taddress);
+#endif
+ }
+
+ // otherwise, ensure that different intentions do not produce different addresses
+ else
+ {
+ assert((entry >> m_pageshift) == (taddress >> m_pageshift));
+ assert(entry & VTLB_FLAG_VALID);
+
+#if PRINTF_TLB
+ osd_printf_debug("success (%08X), existing entry\n", taddress);
+#endif
+ }
+
+ // add the intention to the list of valid intentions and store
+ entry |= 1 << (intention & (TRANSLATE_TYPE_MASK | TRANSLATE_USER_MASK));
+ m_table[tableindex] = entry;
+ return TRUE;
+}
+
+
+//-------------------------------------------------
+// vtlb_load - load a fixed VTLB entry
+//-------------------------------------------------
+
+void device_vtlb_interface::vtlb_load(int entrynum, int numpages, offs_t address, vtlb_entry value)
+{
+ offs_t tableindex = address >> m_pageshift;
+ int liveindex = m_dynamic + entrynum;
+ int pagenum;
+
+ // must be in range
+ assert(entrynum >= 0 && entrynum < m_fixed);
+
+#if PRINTF_TLB
+ osd_printf_debug("vtlb_load %d for %d pages at %08X == %08X\n", entrynum, numpages, address, value);
+#endif
+
+ // if an entry already exists at this index, free it
+ if (m_live[liveindex] != 0)
+ {
+ int pagecount = m_fixedpages[entrynum];
+ int oldtableindex = m_live[liveindex] - 1;
+ for (pagenum = 0; pagenum < pagecount; pagenum++)
+ m_table[oldtableindex + pagenum] = 0;
+ }
+
+ // claim this new entry
+ m_live[liveindex] = tableindex + 1;
+
+ // store the raw value, making sure the "fixed" flag is set
+ value |= VTLB_FLAG_FIXED;
+ m_fixedpages[entrynum] = numpages;
+ for (pagenum = 0; pagenum < numpages; pagenum++)
+ m_table[tableindex + pagenum] = value + (pagenum << m_pageshift);
+}
+
+//-------------------------------------------------
+// vtlb_dynload - load a dynamic VTLB entry
+//-------------------------------------------------
+
+void device_vtlb_interface::vtlb_dynload(UINT32 index, offs_t address, vtlb_entry value)
+{
+ vtlb_entry entry = m_table[index];
+
+ if (m_dynamic == 0)
+ {
+#if PRINTF_TLB
+ osd_printf_debug("failed: no dynamic entries\n");
+#endif
+ return;
+ }
+
+ int liveindex = m_dynindex++ % m_dynamic;
+ // is entry already live?
+ if (!(entry & VTLB_FLAG_VALID))
+ {
+ // if an entry already exists at this index, free it
+ if (m_live[liveindex] != 0)
+ m_table[m_live[liveindex] - 1] = 0;
+
+ // claim this new entry
+ m_live[liveindex] = index + 1;
+ }
+ // form a new blank entry
+ entry = (address >> m_pageshift) << m_pageshift;
+ entry |= VTLB_FLAG_VALID | value;
+
+#if PRINTF_TLB
+ osd_printf_debug("success (%08X), new entry\n", address);
+#endif
+ m_table[index] = entry;
+}
+
+//**************************************************************************
+// FLUSHING
+//**************************************************************************
+
+//-------------------------------------------------
+// vtlb_flush_dynamic - flush all knowledge
+// from the dynamic part of the VTLB
+//-------------------------------------------------
+
+void device_vtlb_interface::vtlb_flush_dynamic()
+{
+#if PRINTF_TLB
+ osd_printf_debug("vtlb_flush_dynamic\n");
+#endif
+
+ // loop over live entries and release them from the table
+ for (int liveindex = 0; liveindex < m_dynamic; liveindex++)
+ if (m_live[liveindex] != 0)
+ {
+ offs_t tableindex = m_live[liveindex] - 1;
+ m_table[tableindex] = 0;
+ m_live[liveindex] = 0;
+ }
+}
+
+
+//-------------------------------------------------
+// vtlb_flush_address - flush knowledge of a
+// particular address from the VTLB
+//-------------------------------------------------
+
+void device_vtlb_interface::vtlb_flush_address(offs_t address)
+{
+ offs_t tableindex = address >> m_pageshift;
+
+#if PRINTF_TLB
+ osd_printf_debug("vtlb_flush_address %08X\n", address);
+#endif
+
+ // free the entry in the table; for speed, we leave the entry in the live array
+ m_table[tableindex] = 0;
+}
+
+
+
+//**************************************************************************
+// ACCESSORS
+//**************************************************************************
+
+//-------------------------------------------------
+// vtlb_table - return a pointer to the base of
+// the linear VTLB lookup table
+//-------------------------------------------------
+
+const vtlb_entry *device_vtlb_interface::vtlb_table() const
+{
+ return &m_table[0];
+}