Initial source

1 files changed, 564 insertions, 0 deletions

diff --git a/i386/dos/i16/i16_vcpi.c b/i386/dos/i16/i16_vcpi.c
new file mode 100644
index 0000000..e021d6b
--- /dev/null
+++ b/i386/dos/i16/i16_vcpi.c
@@ -0,0 +1,564 @@
+/* 
+ * Copyright (c) 1995-1994 The University of Utah and
+ * the Computer Systems Laboratory at the University of Utah (CSL).
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify and distribute this software is hereby
+ * granted provided that (1) source code retains these copyright, permission,
+ * and disclaimer notices, and (2) redistributions including binaries
+ * reproduce the notices in supporting documentation, and (3) all advertising
+ * materials mentioning features or use of this software display the following
+ * acknowledgement: ``This product includes software developed by the
+ * Computer Systems Laboratory at the University of Utah.''
+ *
+ * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
+ * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
+ * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * CSL requests users of this software to return to csl-dist@cs.utah.edu any
+ * improvements that they make and grant CSL redistribution rights.
+ *
+ *      Author: Bryan Ford, University of Utah CSL
+ */
+
+#include <mach/boolean.h>
+#include <mach/vm_param.h>
+#include <mach/machine/code16.h>
+#include <mach/machine/vm_types.h>
+#include <mach/machine/paging.h>
+#include <mach/machine/eflags.h>
+#include <mach/machine/proc_reg.h>
+#include <mach/machine/far_ptr.h>
+#include <mach/machine/vcpi.h>
+#include <mach/machine/asm.h>
+
+#include "config.h"
+#include "i16.h"
+#include "i16_dos.h"
+#include "cpu.h"
+#include "real.h"
+#include "debug.h"
+#include "vm_param.h"
+
+#ifdef ENABLE_VCPI
+
+static boolean_t ems_page_allocated;
+static unsigned short ems_handle;
+
+static vm_offset_t vcpi_pdir, vcpi_ptable0;
+
+struct far_pointer_32 vcpi_pmode_entry = {0, VCPI_CS};
+struct vcpi_switch_data vcpi_switch_data;
+
+static struct pseudo_descriptor gdt_pdesc, idt_pdesc;
+
+static boolean_t pic_reprogrammed;
+
+/* Save area for the DOS interrupt vectors
+   that used to be in the place we relocated the master PIC to.  */
+static struct far_pointer_16 master_save_vecs[8];
+
+
+#ifdef ENABLE_PAGING
+#define VCPI_PAGING_INIT(pdir_pa, first_unmapped_pa) vcpi_paging_init(pdir_pa, first_unmapped_pa)
+#else
+#define VCPI_PAGING_INIT(pdir_pa, first_unmapped_pa) ((void)0)
+#endif
+
+#ifdef ENABLE_KERNEL_LDT
+#define KERNEL_LDT_INIT() (vcpi_switch_data.ldt_sel = KERNEL_LDT)
+#else
+#define KERNEL_LDT_INIT() ((void)0)
+#endif
+
+
+CODE16
+
+static void i16_vcpi_switch_to_pmode()
+{
+	extern vm_offset_t boot_image_pa;
+
+	i16_cli();
+
+	i16_assert(i16_get_ds() == i16_get_cs());
+	i16_assert(i16_get_es() == i16_get_cs());
+	i16_assert(i16_get_ss() == i16_get_cs());
+
+	/* Make sure the TSS isn't marked busy.  */
+	cpu[0].tables.gdt[KERNEL_TSS_IDX].access &= ~ACC_TSS_BUSY;
+
+	/* Ask the VCPI server to switch to protected mode.  */
+	asm volatile("
+		movl	%%esp,%%edx
+		int	$0x67
+	"SEXT(pmode_return)":
+		movl	%%edx,%%esp
+		movw	%2,%%dx
+		movw	%%dx,%%ss
+		movw	%%dx,%%ds
+		movw	%%dx,%%es
+		xorw	%%dx,%%dx
+		movw	%%dx,%%fs
+		movw	%%dx,%%gs
+	" :
+	  : "a" ((unsigned short)0xde0c),
+	    "S" (boot_image_pa + (vm_offset_t)&vcpi_switch_data),
+	    "i" (KERNEL_DS)
+	  : "eax", "edx", "esi");
+
+	/* Make sure the direction flag is still clear.  */
+	i16_cld();
+}
+
+static void i16_vcpi_switch_to_real_mode()
+{
+	i16_cli();
+
+	/* As requested by VCPI spec... */
+	i16_clts();
+
+	/* Perform the switch.  */
+	asm volatile("
+		movl	%%esp,%%edx
+		pushl	%1
+		pushl	%1
+		pushl	%1
+		pushl	%1
+		pushl	%1
+		pushl	%%edx
+		pushl	$0
+		pushl	%1
+		pushl	$1f
+		movw	%2,%%ds
+		lcall	%%ss:"SEXT(vcpi_pmode_entry)"
+	1:
+	" :
+	  : "a" ((unsigned short)0xde0c),
+	    "r" ((unsigned)real_cs),
+	    "r" ((unsigned short)LINEAR_DS)
+	  : "eax", "edx");
+
+	i16_assert(!(i16_get_eflags() & EFL_IF));
+	i16_assert(i16_get_ds() == i16_get_cs());
+	i16_assert(i16_get_es() == i16_get_cs());
+	i16_assert(i16_get_ss() == i16_get_cs());
+
+	/* Make sure the direction flag is still clear.  */
+	i16_cld();
+}
+
+CODE32
+
+static void vcpi_real_int(int intnum, struct real_call_data *rcd)
+{
+	do_16bit(
+		unsigned int eflags;
+
+		i16_vcpi_switch_to_real_mode();
+		i16_real_int(intnum, rcd);
+		i16_vcpi_switch_to_pmode();
+	);
+}
+
+static void vcpi_exit(int rc)
+{
+	do_16bit(
+		i16_vcpi_switch_to_real_mode();
+		i16_exit(rc);
+		while (1);
+	);
+}
+
+CODE16
+
+static inline void
+i16_vcpi_set_int_vecs(unsigned short master, unsigned short slave)
+{
+	unsigned short rc;
+
+	i16_assert(!(get_eflags() & EFL_IF));
+	asm volatile("int $0x67"
+		: "=a" (rc)
+		: "a" ((unsigned short)0xde0b),
+		  "b" ((unsigned short)master),
+		  "c" ((unsigned short)slave));
+	i16_assert((rc & 0xff00) == 0);
+	i16_assert(!(get_eflags() & EFL_IF));
+}
+
+/* Find a (hopefully) empty set of interrupt vectors
+   to use for the master hardware interrupts.
+   We assume that eight interrupt vectors in a row
+   that all have the same value are unused.
+   If VCPI servers weren't so brain-damaged
+   and took care of this during interrupt reflection
+   (like we do when running in raw mode),
+   this kludgery wouldn't be needed...  */
+static int i16_find_free_vec_range()
+{
+	/* i will track the first vector in a range;
+	   j will track the last.  */
+	int i, j;
+	struct far_pointer_16 iv, jv;
+
+	j = 0xff;
+	i16_dos_get_int_vec(j, &jv);
+
+	for (i = j-1; ; i--)
+	{
+		if (i == 0x50)
+		{
+			/* No completely free sets found.
+			   Stop here and just use 0x50-0x57.  */
+			break;
+		}
+
+		i16_dos_get_int_vec(i, &iv);
+		if ((iv.ofs != jv.ofs) || (iv.seg != jv.seg))
+		{
+			/* Vector contents changed.  */
+			j = i;
+			jv = iv;
+			continue;
+		}
+
+		if ((j-i+1 >= 8) && ((i & 7) == 0))
+		{
+			/* Found a free range.  */
+			break;
+		}
+	}
+
+	return i;
+}
+
+void i16_vcpi_check()
+{
+	extern vm_offset_t dos_mem_phys_free_mem;
+	extern vm_offset_t dos_mem_phys_free_size;
+	extern void pmode_return();
+	extern vm_offset_t boot_image_pa;
+	extern void (*i16_switch_to_real_mode)();
+	extern void (*i16_switch_to_pmode)();
+
+	unsigned short rc;
+	unsigned short first_free_pte;
+	unsigned short vcpi_ver;
+
+	i16_assert(boot_image_pa == kvtophys(0));
+
+	/* Check for presence of EMM driver.  */
+	{
+		int dev_info, out_status;
+		int fh;
+
+		fh = i16_dos_open("EMMXXXX0", 0);
+		if (fh < 0)
+			return;
+		dev_info = i16_dos_get_device_info(fh);
+		out_status = i16_dos_get_output_status(fh);
+		i16_dos_close(fh);
+		if ((dev_info < 0) || !(dev_info & 0x80)
+		    || (out_status != 0xff))
+			return;
+	}
+
+	/* Allocate an EMS page to force the EMM to be turned on.
+	   If it fails, keep going anyway -
+	   it may simply mean all the EMS pages are allocated.  */
+	asm volatile("int $0x67"
+			: "=a" (rc),
+			  "=d" (ems_handle)
+			: "a" ((unsigned short)0x4300),
+			  "b" ((unsigned short)1));
+	if (!(rc & 0xff00))
+		ems_page_allocated = TRUE;
+
+	/* Check for VCPI.  */
+	asm volatile("int $0x67" : "=a" (rc), "=b" (vcpi_ver) : "a" ((unsigned short)0xde00));
+	if (rc & 0xff00)
+		return;
+	i16_assert(vcpi_ver >= 0x0100);
+
+	/* OK, it's there - we're now committed to using VCPI.  */
+	i16_switch_to_real_mode = i16_vcpi_switch_to_real_mode;
+	i16_switch_to_pmode = i16_vcpi_switch_to_pmode;
+	real_int = vcpi_real_int;
+	real_exit = vcpi_exit;
+
+	do_debug(i16_puts("VCPI detected"));
+
+	/* Allocate a page directory and page table from low DOS memory.  */
+	{
+		vm_offset_t new_dos_mem;
+
+		new_dos_mem = ((dos_mem_phys_free_mem + PAGE_MASK) & ~PAGE_MASK)
+				+ PAGE_SIZE*2;
+		if ((!dos_mem_phys_free_mem)
+		    || (new_dos_mem - dos_mem_phys_free_mem
+		        > dos_mem_phys_free_size))
+			i16_die("not enough low DOS memory available");
+		dos_mem_phys_free_size -= new_dos_mem - dos_mem_phys_free_mem;
+		dos_mem_phys_free_mem = new_dos_mem;
+		vcpi_pdir = new_dos_mem - PAGE_SIZE*2;
+		vcpi_ptable0 = vcpi_pdir + PAGE_SIZE;
+	}
+
+	/* Initialize them.  */
+	{
+		int i;
+		pt_entry_t pde0 = vcpi_ptable0
+			| INTEL_PTE_VALID | INTEL_PTE_WRITE | INTEL_PTE_USER;
+
+		set_fs(vcpi_pdir >> 4);
+		asm volatile("movl %0,%%fs:(0)" : : "r" (pde0));
+		for (i = 1; i < NPDES + NPTES; i++)
+			asm volatile("movl $0,%%fs:(,%0,4)" : : "r" (i));
+	}
+
+	/* Initialize the protected-mode interface.  */
+	asm volatile("
+		pushw	%%es
+		movw	%4,%%es
+		int	$0x67
+		popw	%%es
+	"
+		: "=a" (rc),
+		  "=b" (vcpi_pmode_entry.ofs),
+		  "=D" (first_free_pte)
+		: "a" ((unsigned short)0xde01),
+		  "r" ((unsigned short)(vcpi_ptable0 >> 4)),
+		  "D" (0),
+		  "S" (&cpu[0].tables.gdt[VCPI_CS_IDX]));
+	i16_assert((rc & 0xff00) == 0);
+	i16_assert(get_ds() == get_cs());
+	i16_assert(get_es() == get_cs());
+
+#ifdef DEBUG
+	/* Sanity check: make sure the server did what it was supposed to do.  */
+
+	i16_assert((cpu[0].tables.gdt[VCPI_CS_IDX].access & ACC_P|ACC_CODE) == ACC_P|ACC_CODE);
+	if (cpu[0].tables.gdt[VCPI_CS_IDX].granularity & SZ_G)
+		i16_assert(vcpi_pmode_entry.ofs <
+			   (((vm_offset_t)cpu[0].tables.gdt[VCPI_CS_IDX].limit_high << 28)
+			    | ((vm_offset_t)cpu[0].tables.gdt[VCPI_CS_IDX].limit_low << 12)
+			    | (vm_offset_t)0xfff));
+	else
+		i16_assert(vcpi_pmode_entry.ofs <
+			   (((vm_offset_t)cpu[0].tables.gdt[VCPI_CS_IDX].limit_high << 16)
+			    | (vm_offset_t)cpu[0].tables.gdt[VCPI_CS_IDX].limit_low));
+
+	i16_assert(first_free_pte/sizeof(pt_entry_t) >= 1*1024*1024/PAGE_SIZE);
+	i16_assert(first_free_pte/sizeof(pt_entry_t) <= 4*1024*1024/PAGE_SIZE);
+
+	{
+		int i;
+
+		for (i = 0; i < 1*1024*1024/PAGE_SIZE; i++)
+		{
+			pt_entry_t entry;
+
+			set_ds(vcpi_ptable0 >> 4);
+			entry = ((pt_entry_t*)0)[i];
+			set_ds(get_cs());
+			i16_assert(entry & INTEL_PTE_VALID);
+			if (i < 0xf0000/PAGE_SIZE)
+				i16_assert(entry & INTEL_PTE_WRITE);
+			i16_assert(entry & INTEL_PTE_USER);
+			i16_assert(!(entry & INTEL_PTE_AVAIL));
+		}
+	}
+#endif /* DEBUG */
+
+	/* Find the VCPI server's hardware interrupt vector mappings.  */
+	asm volatile("int $0x67"
+		: "=a" (rc),
+		  "=b" (irq_master_base),
+		  "=c" (irq_slave_base)
+		: "a" ((unsigned short)0xde0a));
+	i16_assert((rc & 0xff00) == 0);
+	irq_master_base &= 0xffff;
+	irq_slave_base &= 0xffff;
+	i16_assert((irq_master_base & 7) == 0);
+	i16_assert((irq_master_base == 0x08) || (irq_master_base >= 0x20));
+	i16_assert((irq_slave_base & 7) == 0);
+	i16_assert(irq_slave_base >= 0x20);
+
+	/* If they're the usual DOS values, change them.  */
+	if (irq_master_base == 0x08)
+	{
+		pic_reprogrammed = TRUE;
+
+		i16_cli();
+
+		irq_master_base = i16_find_free_vec_range();
+
+		/* Save the old vectors in that range
+		   and set them to a copy of vectors 8-15.  */
+		{
+			int i;
+
+			for (i = 0; i < 8; i++)
+			{
+				struct far_pointer_16 hw_vec;
+
+				i16_dos_get_int_vec(irq_master_base+i,
+						    &master_save_vecs[i]);
+				i16_dos_get_int_vec(0x08+i, &hw_vec);
+				i16_dos_set_int_vec(irq_master_base+i, &hw_vec);
+			}
+		}
+
+		/* Reprogram the PIC.  */
+		i16_pic_set_master(irq_master_base);
+
+		/* Inform the VCPI server.  */
+		i16_vcpi_set_int_vecs(irq_master_base, irq_slave_base);
+	}
+
+	/* Initialize the switch-to-pmode data structure.  */
+	vcpi_switch_data.phys_pdir = vcpi_pdir;
+	vcpi_switch_data.lin_gdt = boot_image_pa+(vm_offset_t)&gdt_pdesc.limit;
+	vcpi_switch_data.lin_idt = boot_image_pa+(vm_offset_t)&idt_pdesc.limit;
+	vcpi_switch_data.tss_sel = KERNEL_TSS;
+	vcpi_switch_data.entry_eip = (unsigned short)(vm_offset_t)&pmode_return;
+	vcpi_switch_data.entry_cs = KERNEL_16_CS;
+
+	/* Initialize the GDT and IDT pseudo-descriptors.  */
+	gdt_pdesc.limit = sizeof(cpu[0].tables.gdt)-1;
+	gdt_pdesc.linear_base = boot_image_pa + (vm_offset_t)&cpu[0].tables.gdt;
+	idt_pdesc.limit = sizeof(cpu[0].tables.idt)-1;
+	idt_pdesc.linear_base = boot_image_pa + (vm_offset_t)&cpu[0].tables.idt;
+
+	/* Set the GDT to temporary settings
+	   just for getting into pmode the first time.  */
+	i16_gdt_init_temp();
+
+	/* VCPI insists on loading a TSS immediately on entering pmode,
+	   so initialize the KERNEL_TSS descriptor in the GDT.  */
+	i16_fill_gdt_descriptor(&cpu[0], KERNEL_TSS,
+				boot_image_pa + (vm_offset_t)&cpu[0].tables.tss,
+				sizeof(cpu[0].tables.tss)-1,
+				ACC_PL_K|ACC_TSS, 0);
+	cpu[0].tables.tss.io_bit_map_offset = sizeof(cpu[0].tables.tss);
+
+#if 0
+	/* Dump the various VCPI data structures, for debugging.  */
+	{
+		int i;
+
+		i16_puts("Switch data");
+		i16_writehexl(switch_data.phys_pdir); i16_putchar(' ');
+		i16_writehexl(switch_data.lin_gdt); i16_putchar(' ');
+		i16_writehexl(switch_data.lin_idt); i16_putchar(' ');
+		i16_writehexw(switch_data.ldt_sel); i16_putchar(' ');
+		i16_writehexw(switch_data.tss_sel); i16_putchar(' ');
+		i16_writehexl(switch_data.entry_eip); i16_putchar(' ');
+		i16_writehexw(switch_data.entry_cs); i16_puts("");
+
+		i16_puts("GDT pdesc");
+		i16_writehexw(gdt_pdesc.limit); i16_putchar(' ');
+		i16_writehexl(gdt_pdesc.linear_base); i16_puts("");
+
+		i16_puts("IDT pdesc");
+		i16_writehexw(idt_pdesc.limit); i16_putchar(' ');
+		i16_writehexl(idt_pdesc.linear_base); i16_puts("");
+
+		i16_puts("GDT");
+		for (i = 0; i < GDTSZ; i++)
+		{
+			i16_writehexw(i*8); i16_putchar(' ');
+			i16_writehexll(*((long long*)&cpu[0].tables.gdt[i]));
+			i16_puts("");
+		}
+	}
+#endif
+
+	/* Switch into pmode briefly to initialize the CPU tables and such.  */
+	i16_vcpi_switch_to_pmode();
+	i16_do_32bit(
+
+		/* Note that right now we can only access the first 1MB of memory,
+		   because paging is enabled and that's the only memory region that's been mapped.
+		   The rest of physical memory won't be mapped until VCPI_PAGING_INIT,
+		   but VCPI_PAGING_INIT requires allocating memory for page tables,
+		   and we can't call phys_mem_collect() to provide memory to the allocator
+		   until all physical memory can be read and written.
+		   To get out of this catch-22,
+		   we call dos_mem_collect() beforehand here
+		   to make low DOS memory available for allocation by VCPI_PAGING_INIT.
+		   The call to phys_mem_collect() later will cause dos_mem_collect
+		   to be called a second time, but it'll just do nothing then.  */
+		dos_mem_collect();
+
+		/* Initialize the basic CPU tables.  */
+		cpu_init(&cpu[0]);
+
+		/* Initialize the paging system.  */
+		VCPI_PAGING_INIT(vcpi_pdir, (vm_offset_t)first_free_pte / 4 * PAGE_SIZE);
+
+		/* Now that we can access all physical memory,
+		   collect the remaining memory regions we discovered while in 16-bit mode
+		   and add them to our free memory list.  */
+		phys_mem_collect();
+
+		/* Initialize the hardware interrupt vectors in the IDT.  */
+		idt_irq_init();
+
+		/* Now that we have an initialized LDT descriptor, start using it.  */
+		KERNEL_LDT_INIT();
+
+		/* Switch to real mode and back again once more,
+		   to make sure everything's loaded properly.  */
+		do_16bit(
+			i16_vcpi_switch_to_real_mode();
+			i16_vcpi_switch_to_pmode();
+		);
+
+		vcpi_start();
+	);
+}
+
+/* Shouldn't be necessary, but just in case the end of the above function,
+   containing the .code16, gets "optimized away"...  */
+CODE16
+
+void i16_vcpi_shutdown()
+{
+	if (pic_reprogrammed)
+	{
+		pic_reprogrammed = FALSE;
+
+		i16_cli();
+
+		i16_assert(irq_master_base >= 0x20);
+
+		/* Reprogram the PIC.  */
+		i16_pic_set_master(0x08);
+
+		/* Inform the VCPI server.  */
+		i16_vcpi_set_int_vecs(0x08, irq_slave_base);
+
+		/* Restore the old interrupt vectors.  */
+		{
+			int i;
+
+			for (i = 0; i < 8; i++)
+			{
+				i16_dos_set_int_vec(irq_master_base+i,
+						    &master_save_vecs[i]);
+			}
+		}
+
+		i16_sti();
+	}
+
+	if (ems_page_allocated)
+	{
+		ems_page_allocated = 0;
+		asm volatile("int $0x67" : : "a" (0x4500), "d" (ems_handle));
+	}
+}
+
+#endif ENABLE_VCPI
+