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kernel-ark/arch/x86/pci/olpc.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Low-level PCI config space access for OLPC systems who lack the VSA
* PCI virtualization software.
*
* Copyright © 2006 Advanced Micro Devices, Inc.
*
* The AMD Geode chipset (ie: GX2 processor, cs5536 I/O companion device)
* has some I/O functions (display, southbridge, sound, USB HCIs, etc)
* that more or less behave like PCI devices, but the hardware doesn't
* directly implement the PCI configuration space headers. AMD provides
* "VSA" (Virtual System Architecture) software that emulates PCI config
* space for these devices, by trapping I/O accesses to PCI config register
* (CF8/CFC) and running some code in System Management Mode interrupt state.
* On the OLPC platform, we don't want to use that VSA code because
* (a) it slows down suspend/resume, and (b) recompiling it requires special
* compilers that are hard to get. So instead of letting the complex VSA
* code simulate the PCI config registers for the on-chip devices, we
* just simulate them the easy way, by inserting the code into the
* pci_write_config and pci_read_config path. Most of the config registers
* are read-only anyway, so the bulk of the simulation is just table lookup.
*/
#include <linux/pci.h>
#include <linux/init.h>
#include <asm/olpc.h>
#include <asm/geode.h>
#include <asm/pci_x86.h>
/*
* In the tables below, the first two line (8 longwords) are the
* size masks that are used when the higher level PCI code determines
* the size of the region by writing ~0 to a base address register
* and reading back the result.
*
* The following lines are the values that are read during normal
* PCI config access cycles, i.e. not after just having written
* ~0 to a base address register.
*/
static const uint32_t lxnb_hdr[] = { /* dev 1 function 0 - devfn = 8 */
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x281022, 0x2200005, 0x6000021, 0x80f808, /* AMD Vendor ID */
0x0, 0x0, 0x0, 0x0, /* No virtual registers, hence no BAR */
0x0, 0x0, 0x0, 0x28100b,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
};
static const uint32_t gxnb_hdr[] = { /* dev 1 function 0 - devfn = 8 */
0xfffffffd, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x28100b, 0x2200005, 0x6000021, 0x80f808, /* NSC Vendor ID */
0xac1d, 0x0, 0x0, 0x0, /* I/O BAR - base of virtual registers */
0x0, 0x0, 0x0, 0x28100b,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
};
static const uint32_t lxfb_hdr[] = { /* dev 1 function 1 - devfn = 9 */
0xff000008, 0xffffc000, 0xffffc000, 0xffffc000,
0xffffc000, 0x0, 0x0, 0x0,
0x20811022, 0x2200003, 0x3000000, 0x0, /* AMD Vendor ID */
0xfd000000, 0xfe000000, 0xfe004000, 0xfe008000, /* FB, GP, VG, DF */
0xfe00c000, 0x0, 0x0, 0x30100b, /* VIP */
0x0, 0x0, 0x0, 0x10e, /* INTA, IRQ14 for graphics accel */
0x0, 0x0, 0x0, 0x0,
0x3d0, 0x3c0, 0xa0000, 0x0, /* VG IO, VG IO, EGA FB, MONO FB */
0x0, 0x0, 0x0, 0x0,
};
static const uint32_t gxfb_hdr[] = { /* dev 1 function 1 - devfn = 9 */
0xff800008, 0xffffc000, 0xffffc000, 0xffffc000,
0x0, 0x0, 0x0, 0x0,
0x30100b, 0x2200003, 0x3000000, 0x0, /* NSC Vendor ID */
0xfd000000, 0xfe000000, 0xfe004000, 0xfe008000, /* FB, GP, VG, DF */
0x0, 0x0, 0x0, 0x30100b,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x3d0, 0x3c0, 0xa0000, 0x0, /* VG IO, VG IO, EGA FB, MONO FB */
0x0, 0x0, 0x0, 0x0,
};
static const uint32_t aes_hdr[] = { /* dev 1 function 2 - devfn = 0xa */
0xffffc000, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x20821022, 0x2a00006, 0x10100000, 0x8, /* NSC Vendor ID */
0xfe010000, 0x0, 0x0, 0x0, /* AES registers */
0x0, 0x0, 0x0, 0x20821022,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
};
static const uint32_t isa_hdr[] = { /* dev f function 0 - devfn = 78 */
0xfffffff9, 0xffffff01, 0xffffffc1, 0xffffffe1,
0xffffff81, 0xffffffc1, 0x0, 0x0,
0x20901022, 0x2a00049, 0x6010003, 0x802000,
0x18b1, 0x1001, 0x1801, 0x1881, /* SMB-8 GPIO-256 MFGPT-64 IRQ-32 */
0x1401, 0x1841, 0x0, 0x20901022, /* PMS-128 ACPI-64 */
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0xaa5b, /* IRQ steering */
0x0, 0x0, 0x0, 0x0,
};
static const uint32_t ac97_hdr[] = { /* dev f function 3 - devfn = 7b */
0xffffff81, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x20931022, 0x2a00041, 0x4010001, 0x0,
0x1481, 0x0, 0x0, 0x0, /* I/O BAR-128 */
0x0, 0x0, 0x0, 0x20931022,
0x0, 0x0, 0x0, 0x205, /* IntB, IRQ5 */
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
};
static const uint32_t ohci_hdr[] = { /* dev f function 4 - devfn = 7c */
0xfffff000, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x20941022, 0x2300006, 0xc031002, 0x0,
0xfe01a000, 0x0, 0x0, 0x0, /* MEMBAR-1000 */
0x0, 0x0, 0x0, 0x20941022,
0x0, 0x40, 0x0, 0x40a, /* CapPtr INT-D, IRQA */
0xc8020001, 0x0, 0x0, 0x0, /* Capabilities - 40 is R/O,
44 is mask 8103 (power control) */
0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
};
static const uint32_t ehci_hdr[] = { /* dev f function 4 - devfn = 7d */
0xfffff000, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0,
0x20951022, 0x2300006, 0xc032002, 0x0,
0xfe01b000, 0x0, 0x0, 0x0, /* MEMBAR-1000 */
0x0, 0x0, 0x0, 0x20951022,
0x0, 0x40, 0x0, 0x40a, /* CapPtr INT-D, IRQA */
0xc8020001, 0x0, 0x0, 0x0, /* Capabilities - 40 is R/O, 44 is
mask 8103 (power control) */
#if 0
0x1, 0x40080000, 0x0, 0x0, /* EECP - see EHCI spec section 2.1.7 */
#endif
0x01000001, 0x0, 0x0, 0x0, /* EECP - see EHCI spec section 2.1.7 */
0x2020, 0x0, 0x0, 0x0, /* (EHCI page 8) 60 SBRN (R/O),
61 FLADJ (R/W), PORTWAKECAP */
};
static uint32_t ff_loc = ~0;
static uint32_t zero_loc;
static int bar_probing; /* Set after a write of ~0 to a BAR */
static int is_lx;
#define NB_SLOT 0x1 /* Northbridge - GX chip - Device 1 */
#define SB_SLOT 0xf /* Southbridge - CS5536 chip - Device F */
static int is_simulated(unsigned int bus, unsigned int devfn)
{
return (!bus && ((PCI_SLOT(devfn) == NB_SLOT) ||
(PCI_SLOT(devfn) == SB_SLOT)));
}
static uint32_t *hdr_addr(const uint32_t *hdr, int reg)
{
uint32_t addr;
/*
* This is a little bit tricky. The header maps consist of
* 0x20 bytes of size masks, followed by 0x70 bytes of header data.
* In the normal case, when not probing a BAR's size, we want
* to access the header data, so we add 0x20 to the reg offset,
* thus skipping the size mask area.
* In the BAR probing case, we want to access the size mask for
* the BAR, so we subtract 0x10 (the config header offset for
* BAR0), and don't skip the size mask area.
*/
addr = (uint32_t)hdr + reg + (bar_probing ? -0x10 : 0x20);
bar_probing = 0;
return (uint32_t *)addr;
}
static int pci_olpc_read(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, uint32_t *value)
{
uint32_t *addr;
WARN_ON(seg);
/* Use the hardware mechanism for non-simulated devices */
if (!is_simulated(bus, devfn))
return pci_direct_conf1.read(seg, bus, devfn, reg, len, value);
/*
* No device has config registers past 0x70, so we save table space
* by not storing entries for the nonexistent registers
*/
if (reg >= 0x70)
addr = &zero_loc;
else {
switch (devfn) {
case 0x8:
addr = hdr_addr(is_lx ? lxnb_hdr : gxnb_hdr, reg);
break;
case 0x9:
addr = hdr_addr(is_lx ? lxfb_hdr : gxfb_hdr, reg);
break;
case 0xa:
addr = is_lx ? hdr_addr(aes_hdr, reg) : &ff_loc;
break;
case 0x78:
addr = hdr_addr(isa_hdr, reg);
break;
case 0x7b:
addr = hdr_addr(ac97_hdr, reg);
break;
case 0x7c:
addr = hdr_addr(ohci_hdr, reg);
break;
case 0x7d:
addr = hdr_addr(ehci_hdr, reg);
break;
default:
addr = &ff_loc;
break;
}
}
switch (len) {
case 1:
*value = *(uint8_t *)addr;
break;
case 2:
*value = *(uint16_t *)addr;
break;
case 4:
*value = *addr;
break;
default:
BUG();
}
return 0;
}
static int pci_olpc_write(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, uint32_t value)
{
WARN_ON(seg);
/* Use the hardware mechanism for non-simulated devices */
if (!is_simulated(bus, devfn))
return pci_direct_conf1.write(seg, bus, devfn, reg, len, value);
/* XXX we may want to extend this to simulate EHCI power management */
/*
* Mostly we just discard writes, but if the write is a size probe
* (i.e. writing ~0 to a BAR), we remember it and arrange to return
* the appropriate size mask on the next read. This is cheating
* to some extent, because it depends on the fact that the next
* access after such a write will always be a read to the same BAR.
*/
if ((reg >= 0x10) && (reg < 0x2c)) {
/* write is to a BAR */
if (value == ~0)
bar_probing = 1;
} else {
/*
* No warning on writes to ROM BAR, CMD, LATENCY_TIMER,
* CACHE_LINE_SIZE, or PM registers.
*/
if ((reg != PCI_ROM_ADDRESS) && (reg != PCI_COMMAND_MASTER) &&
(reg != PCI_LATENCY_TIMER) &&
(reg != PCI_CACHE_LINE_SIZE) && (reg != 0x44))
printk(KERN_WARNING "OLPC PCI: Config write to devfn"
" %x reg %x value %x\n", devfn, reg, value);
}
return 0;
}
static const struct pci_raw_ops pci_olpc_conf = {
.read = pci_olpc_read,
.write = pci_olpc_write,
};
int __init pci_olpc_init(void)
{
printk(KERN_INFO "PCI: Using configuration type OLPC XO-1\n");
raw_pci_ops = &pci_olpc_conf;
is_lx = is_geode_lx();
return 0;
}
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