Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC 261517,261520:
Convert the license on files where I am the sole copyright holder to
2 clause BSD licenses.

MFC r259679:

vga_pci: Improve boot display detection

The previous code was checking the "VGA Enable" bit on the video card's
parent PCI-to-PCI bridge only. This didn't work for the case where the
video card is attached to the root PCI bus (ie. the card has no parent
PCI-to-PCI bridge).

Now, the new code:
1. checks the "VGA Enable" bit on the parent bridge only if it's a
PCI-to-PCI bridge;
2. always checks the "I/O" and "Memory address space decoding" bits
on the video card itself.

However, vendor-specific bits are not used.

This fixes the use of many integrated Radeon cards: without this patch,
we fail to detect them as the boot display and, when radeonkms looks for
the Video BIOS, it skips the shadow copy made by the System BIOS. It
then fails to fully initialize the card, because the shadow copy is the
only way to read the Video BIOS in these situations. A workaround was to
force the boot display selection using the "hw.pci.default_vgapci_unit"
tunable.

A previous version of this patch added a new function doing the checks.
Now, the vga_pci_is_boot_display() function is used to perform the
checks (only until the boot display is found) and return if the given
device is the boot display or not.

Furthermore, vga_pci_attach() logs "Boot video device" if the card being
attached it the Chosen One:
vgapci0: <VGA-compatible display> [...]
vgapci0: Boot video device

Reviewed by: kib@, jhb@ (both a previous version)
Tested by: lunatic_ (#freebsd-xorg, integrated Radeon card,
xmj (#freebsd-xorg, i915+NVIDIA cards)

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

vgapci: Use vga_pci_alloc_resource() to map PCI Expansion ROM

This is cleaner and fixes Video BIOS mapping when the given device isn't
the boot display.

Submitted by: jhb@
Approved by: re (kib)

vga_pci: Remove left-over debugging printf()'s

vga_pci: Add API to map the Video BIOS

Here are two new functions to map and unmap the Video BIOS:
void * vga_pci_map_bios(device_t dev, size_t *size);
void vga_pci_unmap_bios(device_t dev, void *bios);

The BIOS is either taken from the shadow copy made by the System BIOS at
boot time if the given device was used for the default display (i386,
amd64 and ia64 only), or from the PCI expansion ROM.

Additionally, one can determine if a given device was the default
display at boot time using the following new function:
void vga_pci_unmap_bios(device_t dev, void *bios);

Usnure that PCI bus BIS_GET_DMA_TAG() method sees the actual PCI
device which makes the request for dma tag, instead of some descendant
of the PCI device, by creating a pass-through trampoline for vga_pci
and ata_pci buses.

Sponsored by: The FreeBSD Foundation
Suggested by: jhb
Discussed with: jhb, mav
MFC after: 1 week

Proxy allocation requests for the PCI ROM BAR from child devices similar
to how the VGA bus driver currently proxies allocation requests for other
PCI BARs.

MFC after: 1 week

Add 'drmn' device as another drm child, to allow drm2 drivers to live
in parallel with drm1.

Sponsored by: The FreeBSD Foundation
MFC after: 1 month

Expand the set of APIs available for locating PCI capabilities:
- pci_find_extcap() is repurposed to be used for fetching PCI-express
extended capabilities (PCIZ_* constants in <dev/pci/pcireg.h>).
- pci_find_htcap() can be used to locate a specific HyperTransport
capability (PCIM_HTCAP_* constants in <dev/pci/pcireg.h>).
- Cache the starting location of the PCI-express capability for PCI-express
devices in PCI device ivars.

Don't whine about child drivers calling pci_enable_busmaster(). That is
perfectly normal.

MFC after: 1 week

Small whitespace fixes.

- Partially revert hackish r198964 and r199002.
- Add a proxy driver vgapm to help vgapci to save/load VGA state.
- Move device_set_desc() to the right place while we are here.

Reviewed by: jhb

Remove duplicate suspend/resume code from vga_pci.c and let vga(4) register
itself to an associated PCI device if it exists. It is little bit hackish
but it should fix build without frame buffer driver since r198964.
Fix some style(9) nits in vga_isa.c while we are here.

Save/restore VGA state from vga_pci.c instead of relying on vga_isa.c.
It was not working because we were saving its state after the device was
powered down. Simplify vesa_load_state() as the culprit is fixed now.

Rewrite x86bios and update its dependent drivers.

- Do not map entire real mode memory (1MB). Instead, we map IVT/BDA and
ROM area separately. Most notably, ROM area is mapped as device memory
(uncacheable) as it should be. User memory is dynamically allocated and
free'ed with contigmalloc(9) and contigfree(9). Remove now redundant and
potentially dangerous x86bios_alloc.c. If this emulator ever grows to
support non-PC hardware, we may implement it with rman(9) later.
- Move all host-specific initializations from x86emu_util.c to x86bios.c and
remove now unnecessary x86emu_util.c. Currently, non-PC hardware is not
supported. We may use bus_space(9) later when the KPI is fixed.
- Replace all bzero() calls for emulated registers with more obviously named
x86bios_init_regs(). This function also initializes DS and SS properly.
- Add x86bios_get_intr(). This function checks if the interrupt vector is
available for the platform. It is not necessary for PC-compatible hardware
but it may be needed later. ;-)
- Do not try turning off monitor if DPMS does not support the state.
- Allocate stable memory for VESA OEM strings instead of just holding
pointers to them. They may or may not be accessible always. Fix a memory
leak of video mode table while I am here.
- Add (experimental) BIOS POST call for vesa(4). This function calls VGA
BIOS POST code from the current VGA option ROM. Some video controllers
cannot save and restore the state properly even if it is claimed to be
supported. Usually the symptom is blank display after resuming from suspend
state. If the video mode does not match the previous mode after restoring,
we try BIOS POST and force the known good initial state. Some magic was
taken from NetBSD (and it was taken from vbetool, I believe.)
- Add a loader tunable for vgapci(4) to give a hint to dpms(4) and vesa(4)
to identify who owns the VESA BIOS. This is very useful for multi-display
adapter setup. By default, the POST video controller is automatically
probed and the tunable "hw.pci.default_vgapci_unit" is set to corresponding
vgapci unit number. You may override it from loader but it is very unlikely
to be necessary. Unfortunately only AGP/PCI/PCI-E controllers can be
matched because ISA controller does not have necessary device IDs.
- Fix a long standing bug in state save/restore function. The state buffer
pointer should be ES:BX, not ES:DI according to VBE 3.0. If it ever worked,
that's because BX was always zero. :-)
- Clean up register initializations more clearer per VBE 3.0.
- Fix a lot of style issues with vesa(4).

The recent PCI resource allocation fixes exposed a bug where the same
BAR could be allocated twice by different children of a vgapci0 device.
To fix this, change the vgapci0 device to track references on its associated
resources so that they are only allocated once from the parent PCI bus and
released when no children are using them. Previously this leaked a small
amount of KVA on at least some architectures.

pci_setup_intr() will only enable MSI/MSI-X for direct children. Add methods
to vga_pci.c to request on behalf of it's children. This causes vgapci to show
up as the interrupt owner in vmstat -i, rather than the child device.

Approved by: jhb(mentor)

Allow child devices of vgapci(4) to query VPD strings and use MSI/MSI-X
interrupts. For the MSI/MSI-X case, we only allow 1 child device to use
MSI or MSI-X at a time.

Tested by: rnoland

Don't add an agp child in vgapci's attach routine if the PCIY_AGP
capability is present as not all devices supported by the agp_i810 driver
(such as i915) have the AGP capability. Instead, add an identify routine
to the agp_i810 driver that uses the PCI ID to determine if it should
create an agp child device.

Return BUS_PROBE_GENERIC rather than 0 in the probe routine.

Requested by: marius

Add a vgapci(4) stub device driver for VGA PCI devices. This device serves
as a bus so that other drivers such as drm(4), acpi_video(4), and agp(4)
can attach to it thus allowing multiple drivers for the same device. It
also removes the need for the drmsub hack for the i8[13]0/i915 drm and agp
drivers.