include/linux/stmmac.h


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/*******************************************************************************

  Header file for stmmac platform data

  Copyright (C) 2009  STMicroelectronics Ltd

  This program is free software; you can redistribute it and/or modify it
  under the terms and conditions of the GNU General Public License,
  version 2, as published by the Free Software Foundation.

  This program is distributed in the hope it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  more details.

  You should have received a copy of the GNU General Public License along with
  this program; if not, write to the Free Software Foundation, Inc.,
  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

  The full GNU General Public License is included in this distribution in
  the file called "COPYING".

  Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
*******************************************************************************/

#ifndef __STMMAC_PLATFORM_DATA
#define __STMMAC_PLATFORM_DATA

/* platfrom data for platfrom device structure's platfrom_data field */

/* Private data for the STM on-board ethernet driver */
struct plat_stmmacenet_data {
	int bus_id;
	int pbl;
	int has_gmac;
	int enh_desc;
	void (*fix_mac_speed)(void *priv, unsigned int speed);
	void (*bus_setup)(unsigned long ioaddr);
#ifdef CONFIG_STM_DRIVERS
	struct stm_pad_config *pad_config;
#endif
	void *bsp_priv;
};

struct plat_stmmacphy_data {
	int bus_id;
	int phy_addr;
	unsigned int phy_mask;
	int interface;
	int (*phy_reset)(void *priv);
	void *priv;
};
#endif
/*P:800 Interrupts (traps) are complicated enough to earn their own file.
 * There are three classes of interrupts:
 *
 * 1) Real hardware interrupts which occur while we're running the Guest,
 * 2) Interrupts for virtual devices attached to the Guest, and
 * 3) Traps and faults from the Guest.
 *
 * Real hardware interrupts must be delivered to the Host, not the Guest.
 * Virtual interrupts must be delivered to the Guest, but we make them look
 * just like real hardware would deliver them.  Traps from the Guest can be set
 * up to go directly back into the Guest, but sometimes the Host wants to see
 * them first, so we also have a way of "reflecting" them into the Guest as if
 * they had been delivered to it directly. :*/
#include <linux/uaccess.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include "lg.h"

/* Allow Guests to use a non-128 (ie. non-Linux) syscall trap. */
static unsigned int syscall_vector = SYSCALL_VECTOR;
module_param(syscall_vector, uint, 0444);

/* The address of the interrupt handler is split into two bits: */
static unsigned long idt_address(u32 lo, u32 hi)
{
	return (lo & 0x0000FFFF) | (hi & 0xFFFF0000);
}

/* The "type" of the interrupt handler is a 4 bit field: we only support a
 * couple of types. */
static int idt_type(u32 lo, u32 hi)
{
	return (hi >> 8) & 0xF;
}

/* An IDT entry can't be used unless the "present" bit is set. */
static int idt_present(u32 lo, u32 hi)
{
	return (hi & 0x8000);
}

/* We need a helper to "push" a value onto the Guest's stack, since that's a
 * big part of what delivering an interrupt does. */
static void push_guest_stack(struct lg_cpu *cpu, unsigned long *gstack, u32 val)
{
	/* Stack grows upwards: move stack then write value. */
	*gstack -= 4;
	lgwrite(cpu, *gstack, u32, val);
}

/*H:210 The set_guest_interrupt() routine actually delivers the interrupt or
 * trap.  The mechanics of delivering traps and interrupts to the Guest are the
 * same, except some traps have an "error code" which gets pushed onto the
 * stack as well: the caller tells us if this is one.
 *
 * "lo" and "hi" are the two parts of the Interrupt Descriptor Table for this
 * interrupt or trap.  It's split into two parts for traditional reasons: gcc
 * on i386 used to be frightened by 64 bit numbers.
 *
 * We set up the stack just like the CPU does for a real interrupt, so it's
 * identical for the Guest (and the standard "iret" instruction will undo
 * it). */
static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
{
	unsigned long gstack, origstack;
	u32 eflags, ss, irq_enable;
	unsigned long virtstack;

	/* There are two cases for interrupts: one where the Guest is already
	 * in the kernel, and a more complex one where the Guest is in
	 * userspace.  We check the privilege level to find out. */
	if ((cpu->regs->ss&0x3) != GUEST_PL) {
		/* The Guest told us their kernel stack with the SET_STACK
		 * hypercall: both the virtual address and the segment */
		virtstack = cpu->esp1;
		ss = cpu->ss1;

		origstack = gstack = guest_pa(cpu, virtstack);
		/* We push the old stack segment and pointer onto the new
		 * stack: when the Guest does an "iret" back from the interrupt
		 * handler the CPU will notice they're dropping privilege
		 * levels and expect these here. */
		push_guest_stack(cpu, &gstack, cpu->regs->ss);
		push_guest_stack(cpu, &gstack, cpu->regs->esp);
	} else {
		/* We're staying on the same Guest (kernel) stack. */
		virtstack = cpu->regs->esp;
		ss = cpu->regs->ss;

		origstack = gstack = guest_pa(cpu, virtstack);
	}

	/* Remember that we never let the Guest actually disable interrupts, so
	 * the "Interrupt Flag" bit is always set.  We copy that bit from the
	 * Guest's "irq_enabled" field into the eflags word: we saw the Guest
	 * copy it back in "lguest_iret". */
	eflags = cpu->regs->eflags;
	if (get_user(irq_enable, &cpu->lg->lguest_data->irq_enabled) == 0
	    && !(irq_enable & X86_EFLAGS_IF))
		eflags &= ~X86_EFLAGS_IF;

	/* An interrupt is expected to push three things on the stack: the old
	 * "eflags" word, the old code segment, and the old instruction
	 * pointer. */
	push_guest_stack(cpu, &gstack, eflags);
	push_guest_stack(cpu, &gstack, cpu->regs->cs);
	push_guest_stack(cpu, &gstack, cpu->regs->eip);

	/* For the six traps which supply an error code, we push that, too. */
	if (has_err)
		push_guest_stack(cpu, &gstack, cpu->regs->errcode);

	/* Now we've pushed all the old state, we change the stack, the code
	 * segment and the address to execute. */
	cpu->regs->ss = ss;
	cpu->regs->esp = virtstack + (gstack - origstack);
	cpu->regs->cs = (__KERNEL_CS|GUEST_PL);
	cpu->regs->eip = idt_address(lo, hi);

	/* There are two kinds of interrupt handlers: 0xE is an "interrupt
	 * gate" which expects interrupts to be disabled on entry. */
	if (idt_type(lo, hi) == 0xE)
		if (put_user(0, &cpu->lg->lguest_data->irq_enabled))
			kill_guest(cpu, "Disabling interrupts");
}

/*H:205
 * Virtual Interrupts.
 *
 * maybe_do_interrupt() gets called before every entry to the Guest, to see if
 * we should divert the Guest to running an interrupt handler. */
void maybe_do_interrupt(struct lg_cpu *cpu)
{
	unsigned int irq;
	DECLARE_BITMAP(blk, LGUEST_IRQS);
	struct desc_struct *idt;

	/* If the Guest hasn't even initialized yet, we can do nothing. */
	if (!cpu->lg->lguest_data)
		return;