arch: Remove Itanium (IA-64) architecture

The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.

None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.

While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.

There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.

So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.

[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/

Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

6 files changed, 4 insertions, 283 deletions

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index b59e3041fd62..a79579fea6f0 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -77,30 +77,6 @@ config FIRMWARE_MEMMAP
 
       See also Documentation/ABI/testing/sysfs-firmware-memmap.
 
-config EFI_PCDP
-	bool "Console device selection via EFI PCDP or HCDP table"
-	depends on ACPI && EFI && IA64
-	default y if IA64
-	help
-	  If your firmware supplies the PCDP table, and you want to
-	  automatically use the primary console device it describes
-	  as the Linux console, say Y here.
-
-	  If your firmware supplies the HCDP table, and you want to
-	  use the first serial port it describes as the Linux console,
-	  say Y here.  If your EFI ConOut path contains only a UART
-	  device, it will become the console automatically.  Otherwise,
-	  you must specify the "console=hcdp" kernel boot argument.
-
-	  Neither the PCDP nor the HCDP affects naming of serial devices,
-	  so a serial console may be /dev/ttyS0, /dev/ttyS1, etc, depending
-	  on how the driver discovers devices.
-
-	  You must also enable the appropriate drivers (serial, VGA, etc.)
-
-	  See DIG64_HCDPv20_042804.pdf available from
-	  <http://www.dig64.org/specifications/> 
-
 config DMIID
     bool "Export DMI identification via sysfs to userspace"
     depends on DMI
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 28fcddcd688f..1d1eb671d805 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -8,7 +8,6 @@ obj-$(CONFIG_ARM_SDE_INTERFACE)	+= arm_sdei.o
 obj-$(CONFIG_DMI)		+= dmi_scan.o
 obj-$(CONFIG_DMI_SYSFS)		+= dmi-sysfs.o
 obj-$(CONFIG_EDD)		+= edd.o
-obj-$(CONFIG_EFI_PCDP)		+= pcdp.o
 obj-$(CONFIG_DMIID)		+= dmi-id.o
 obj-$(CONFIG_INTEL_STRATIX10_SERVICE) += stratix10-svc.o
 obj-$(CONFIG_INTEL_STRATIX10_RSU)     += stratix10-rsu.o
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 231f1c70d1db..cb374b2da9b7 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -4,7 +4,7 @@ menu "EFI (Extensible Firmware Interface) Support"
 
 config EFI_ESRT
 	bool
-	depends on EFI && !IA64
+	depends on EFI
 	default y
 
 config EFI_VARS_PSTORE
@@ -123,7 +123,7 @@ config EFI_BOOTLOADER_CONTROL
 
 config EFI_CAPSULE_LOADER
 	tristate "EFI capsule loader"
-	depends on EFI && !IA64
+	depends on EFI
 	help
 	  This option exposes a loader interface "/dev/efi_capsule_loader" for
 	  users to load EFI capsules. This driver requires working runtime
@@ -224,7 +224,7 @@ config EFI_DISABLE_PCI_DMA
 
 config EFI_EARLYCON
 	def_bool y
-	depends on SERIAL_EARLYCON && !ARM && !IA64
+	depends on SERIAL_EARLYCON && !ARM
 	select FONT_SUPPORT
 	select ARCH_USE_MEMREMAP_PROT
 
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 1599f1176842..47ca652f02f6 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -147,7 +147,7 @@ static ssize_t systab_show(struct kobject *kobj,
 	if (efi.smbios != EFI_INVALID_TABLE_ADDR)
 		str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
 
-	if (IS_ENABLED(CONFIG_IA64) || IS_ENABLED(CONFIG_X86))
+	if (IS_ENABLED(CONFIG_X86))
 		str = efi_systab_show_arch(str);
 
 	return str - buf;
@@ -777,7 +777,6 @@ int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr)
 	return 0;
 }
 
-#ifndef CONFIG_IA64
 static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor,
 						size_t size)
 {
@@ -793,10 +792,6 @@ static void __init unmap_fw_vendor(const void *fw_vendor, size_t size)
 {
 	early_memunmap((void *)fw_vendor, size);
 }
-#else
-#define map_fw_vendor(p, s)	__va(p)
-#define unmap_fw_vendor(v, s)
-#endif
 
 void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
 				     unsigned long fw_vendor)
@@ -900,11 +895,6 @@ char * __init efi_md_typeattr_format(char *buf, size_t size,
 }
 
 /*
- * IA64 has a funky EFI memory map that doesn't work the same way as
- * other architectures.
- */
-#ifndef CONFIG_IA64
-/*
  * efi_mem_attributes - lookup memmap attributes for physical address
  * @phys_addr: the physical address to lookup
  *
@@ -951,7 +941,6 @@ int efi_mem_type(unsigned long phys_addr)
 	}
 	return -EINVAL;
 }
-#endif
 
 int efi_status_to_err(efi_status_t status)
 {
diff --git a/drivers/firmware/pcdp.c b/drivers/firmware/pcdp.c
deleted file mode 100644
index 715a45442d1c..000000000000
--- a/drivers/firmware/pcdp.c
+++ /dev/null
@@ -1,135 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Parse the EFI PCDP table to locate the console device.
- *
- * (c) Copyright 2002, 2003, 2004 Hewlett-Packard Development Company, L.P.
- *	Khalid Aziz <khalid.aziz@hp.com>
- *	Alex Williamson <alex.williamson@hp.com>
- *	Bjorn Helgaas <bjorn.helgaas@hp.com>
- */
-
-#include <linux/acpi.h>
-#include <linux/console.h>
-#include <linux/efi.h>
-#include <linux/serial.h>
-#include <linux/serial_core.h>
-#include <asm/vga.h>
-#include "pcdp.h"
-
-static int __init
-setup_serial_console(struct pcdp_uart *uart)
-{
-#ifdef CONFIG_SERIAL_8250_CONSOLE
-	int mmio;
-	static char options[64], *p = options;
-	char parity;
-
-	mmio = (uart->addr.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
-	p += sprintf(p, "uart8250,%s,0x%llx",
-		mmio ? "mmio" : "io", uart->addr.address);
-	if (uart->baud) {
-		p += sprintf(p, ",%llu", uart->baud);
-		if (uart->bits) {
-			switch (uart->parity) {
-			    case 0x2: parity = 'e'; break;
-			    case 0x3: parity = 'o'; break;
-			    default:  parity = 'n';
-			}
-			p += sprintf(p, "%c%d", parity, uart->bits);
-		}
-	}
-
-	add_preferred_console("uart", 8250, &options[9]);
-	return setup_earlycon(options);
-#else
-	return -ENODEV;
-#endif
-}
-
-static int __init
-setup_vga_console(struct pcdp_device *dev)
-{
-#if defined(CONFIG_VT) && defined(CONFIG_VGA_CONSOLE)
-	u8 *if_ptr;
-
-	if_ptr = ((u8 *)dev + sizeof(struct pcdp_device));
-	if (if_ptr[0] == PCDP_IF_PCI) {
-		struct pcdp_if_pci if_pci;
-
-		/* struct copy since ifptr might not be correctly aligned */
-
-		memcpy(&if_pci, if_ptr, sizeof(if_pci));
-
-		if (if_pci.trans & PCDP_PCI_TRANS_IOPORT)
-			vga_console_iobase = if_pci.ioport_tra;
-
-		if (if_pci.trans & PCDP_PCI_TRANS_MMIO)
-			vga_console_membase = if_pci.mmio_tra;
-	}
-
-	if (efi_mem_type(vga_console_membase + 0xA0000) == EFI_CONVENTIONAL_MEMORY) {
-		printk(KERN_ERR "PCDP: VGA selected, but frame buffer is not MMIO!\n");
-		return -ENODEV;
-	}
-
-	conswitchp = &vga_con;
-	printk(KERN_INFO "PCDP: VGA console\n");
-	return 0;
-#else
-	return -ENODEV;
-#endif
-}
-
-extern unsigned long hcdp_phys;
-
-int __init
-efi_setup_pcdp_console(char *cmdline)
-{
-	struct pcdp *pcdp;
-	struct pcdp_uart *uart;
-	struct pcdp_device *dev, *end;
-	int i, serial = 0;
-	int rc = -ENODEV;
-
-	if (hcdp_phys == EFI_INVALID_TABLE_ADDR)
-		return -ENODEV;
-
-	pcdp = early_memremap(hcdp_phys, 4096);
-	printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, hcdp_phys);
-
-	if (strstr(cmdline, "console=hcdp")) {
-		if (pcdp->rev < 3)
-			serial = 1;
-	} else if (strstr(cmdline, "console=")) {
-		printk(KERN_INFO "Explicit \"console=\"; ignoring PCDP\n");
-		goto out;
-	}
-
-	if (pcdp->rev < 3 && efi_uart_console_only())
-		serial = 1;
-
-	for (i = 0, uart = pcdp->uart; i < pcdp->num_uarts; i++, uart++) {
-		if (uart->flags & PCDP_UART_PRIMARY_CONSOLE || serial) {
-			if (uart->type == PCDP_CONSOLE_UART) {
-				rc = setup_serial_console(uart);
-				goto out;
-			}
-		}
-	}
-
-	end = (struct pcdp_device *) ((u8 *) pcdp + pcdp->length);
-	for (dev = (struct pcdp_device *) (pcdp->uart + pcdp->num_uarts);
-	     dev < end;
-	     dev = (struct pcdp_device *) ((u8 *) dev + dev->length)) {
-		if (dev->flags & PCDP_PRIMARY_CONSOLE) {
-			if (dev->type == PCDP_CONSOLE_VGA) {
-				rc = setup_vga_console(dev);
-				goto out;
-			}
-		}
-	}
-
-out:
-	early_memunmap(pcdp, 4096);
-	return rc;
-}
diff --git a/drivers/firmware/pcdp.h b/drivers/firmware/pcdp.h
deleted file mode 100644
index e02540571c52..000000000000
--- a/drivers/firmware/pcdp.h
+++ /dev/null
@@ -1,108 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Definitions for PCDP-defined console devices
- *
- * For DIG64_HCDPv10a_01.pdf and DIG64_PCDPv20.pdf (v1.0a and v2.0 resp.),
- * please see <http://www.dig64.org/specifications/>
- *
- * (c) Copyright 2002, 2004 Hewlett-Packard Development Company, L.P.
- *	Khalid Aziz <khalid.aziz@hp.com>
- *	Bjorn Helgaas <bjorn.helgaas@hp.com>
- */
-
-#define PCDP_CONSOLE			0
-#define PCDP_DEBUG			1
-#define PCDP_CONSOLE_OUTPUT		2
-#define PCDP_CONSOLE_INPUT		3
-
-#define PCDP_UART			(0 << 3)
-#define PCDP_VGA			(1 << 3)
-#define PCDP_USB			(2 << 3)
-
-/* pcdp_uart.type and pcdp_device.type */
-#define PCDP_CONSOLE_UART		(PCDP_UART | PCDP_CONSOLE)
-#define PCDP_DEBUG_UART			(PCDP_UART | PCDP_DEBUG)
-#define PCDP_CONSOLE_VGA		(PCDP_VGA  | PCDP_CONSOLE_OUTPUT)
-#define PCDP_CONSOLE_USB		(PCDP_USB  | PCDP_CONSOLE_INPUT)
-
-/* pcdp_uart.flags */
-#define PCDP_UART_EDGE_SENSITIVE	(1 << 0)
-#define PCDP_UART_ACTIVE_LOW		(1 << 1)
-#define PCDP_UART_PRIMARY_CONSOLE	(1 << 2)
-#define PCDP_UART_IRQ			(1 << 6) /* in pci_func for rev < 3 */
-#define PCDP_UART_PCI			(1 << 7) /* in pci_func for rev < 3 */
-
-struct pcdp_uart {
-	u8				type;
-	u8				bits;
-	u8				parity;
-	u8				stop_bits;
-	u8				pci_seg;
-	u8				pci_bus;
-	u8				pci_dev;
-	u8				pci_func;
-	u64				baud;
-	struct acpi_generic_address	addr;
-	u16				pci_dev_id;
-	u16				pci_vendor_id;
-	u32				gsi;
-	u32				clock_rate;
-	u8				pci_prog_intfc;
-	u8				flags;
-	u16				conout_index;
-	u32				reserved;
-} __attribute__((packed));
-
-#define PCDP_IF_PCI	1
-
-/* pcdp_if_pci.trans */
-#define PCDP_PCI_TRANS_IOPORT	0x02
-#define PCDP_PCI_TRANS_MMIO	0x01
-
-struct pcdp_if_pci {
-	u8			interconnect;
-	u8			reserved;
-	u16			length;
-	u8			segment;
-	u8			bus;
-	u8			dev;
-	u8			fun;
-	u16			dev_id;
-	u16			vendor_id;
-	u32			acpi_interrupt;
-	u64			mmio_tra;
-	u64			ioport_tra;
-	u8			flags;
-	u8			trans;
-} __attribute__((packed));
-
-struct pcdp_vga {
-	u8			count;		/* address space descriptors */
-} __attribute__((packed));
-
-/* pcdp_device.flags */
-#define PCDP_PRIMARY_CONSOLE	1
-
-struct pcdp_device {
-	u8			type;
-	u8			flags;
-	u16			length;
-	u16			efi_index;
-	/* next data is pcdp_if_pci or pcdp_if_acpi (not yet supported) */
-	/* next data is device specific type (currently only pcdp_vga) */
-} __attribute__((packed));
-
-struct pcdp {
-	u8			signature[4];
-	u32			length;
-	u8			rev;		/* PCDP v2.0 is rev 3 */
-	u8			chksum;
-	u8			oemid[6];
-	u8			oem_tabid[8];
-	u32			oem_rev;
-	u8			creator_id[4];
-	u32			creator_rev;
-	u32			num_uarts;
-	struct pcdp_uart	uart[];	/* actual size is num_uarts */
-	/* remainder of table is pcdp_device structures */
-} __attribute__((packed));