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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /arch/x86/kernel/cpu/cyrix.c | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
Diffstat (limited to 'arch/x86/kernel/cpu/cyrix.c')
-rw-r--r-- | arch/x86/kernel/cpu/cyrix.c | 467 |
1 files changed, 467 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/cyrix.c b/arch/x86/kernel/cpu/cyrix.c new file mode 100644 index 000000000..9651275ae --- /dev/null +++ b/arch/x86/kernel/cpu/cyrix.c @@ -0,0 +1,467 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bitops.h> +#include <linux/delay.h> +#include <linux/isa-dma.h> +#include <linux/pci.h> +#include <asm/dma.h> +#include <linux/io.h> +#include <asm/processor-cyrix.h> +#include <asm/processor-flags.h> +#include <linux/timer.h> +#include <asm/pci-direct.h> +#include <asm/tsc.h> +#include <asm/cpufeature.h> +#include <linux/sched.h> +#include <linux/sched/clock.h> + +#include "cpu.h" + +/* + * Read NSC/Cyrix DEVID registers (DIR) to get more detailed info. about the CPU + */ +static void __do_cyrix_devid(unsigned char *dir0, unsigned char *dir1) +{ + unsigned char ccr2, ccr3; + + /* we test for DEVID by checking whether CCR3 is writable */ + ccr3 = getCx86(CX86_CCR3); + setCx86(CX86_CCR3, ccr3 ^ 0x80); + getCx86(0xc0); /* dummy to change bus */ + + if (getCx86(CX86_CCR3) == ccr3) { /* no DEVID regs. */ + ccr2 = getCx86(CX86_CCR2); + setCx86(CX86_CCR2, ccr2 ^ 0x04); + getCx86(0xc0); /* dummy */ + + if (getCx86(CX86_CCR2) == ccr2) /* old Cx486SLC/DLC */ + *dir0 = 0xfd; + else { /* Cx486S A step */ + setCx86(CX86_CCR2, ccr2); + *dir0 = 0xfe; + } + } else { + setCx86(CX86_CCR3, ccr3); /* restore CCR3 */ + + /* read DIR0 and DIR1 CPU registers */ + *dir0 = getCx86(CX86_DIR0); + *dir1 = getCx86(CX86_DIR1); + } +} + +static void do_cyrix_devid(unsigned char *dir0, unsigned char *dir1) +{ + unsigned long flags; + + local_irq_save(flags); + __do_cyrix_devid(dir0, dir1); + local_irq_restore(flags); +} +/* + * Cx86_dir0_msb is a HACK needed by check_cx686_cpuid/slop in bugs.h in + * order to identify the Cyrix CPU model after we're out of setup.c + * + * Actually since bugs.h doesn't even reference this perhaps someone should + * fix the documentation ??? + */ +static unsigned char Cx86_dir0_msb = 0; + +static const char Cx86_model[][9] = { + "Cx486", "Cx486", "5x86 ", "6x86", "MediaGX ", "6x86MX ", + "M II ", "Unknown" +}; +static const char Cx486_name[][5] = { + "SLC", "DLC", "SLC2", "DLC2", "SRx", "DRx", + "SRx2", "DRx2" +}; +static const char Cx486S_name[][4] = { + "S", "S2", "Se", "S2e" +}; +static const char Cx486D_name[][4] = { + "DX", "DX2", "?", "?", "?", "DX4" +}; +static char Cx86_cb[] = "?.5x Core/Bus Clock"; +static const char cyrix_model_mult1[] = "12??43"; +static const char cyrix_model_mult2[] = "12233445"; + +/* + * Reset the slow-loop (SLOP) bit on the 686(L) which is set by some old + * BIOSes for compatibility with DOS games. This makes the udelay loop + * work correctly, and improves performance. + * + * FIXME: our newer udelay uses the tsc. We don't need to frob with SLOP + */ + +static void check_cx686_slop(struct cpuinfo_x86 *c) +{ + unsigned long flags; + + if (Cx86_dir0_msb == 3) { + unsigned char ccr3, ccr5; + + local_irq_save(flags); + ccr3 = getCx86(CX86_CCR3); + setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */ + ccr5 = getCx86(CX86_CCR5); + if (ccr5 & 2) + setCx86(CX86_CCR5, ccr5 & 0xfd); /* reset SLOP */ + setCx86(CX86_CCR3, ccr3); /* disable MAPEN */ + local_irq_restore(flags); + + if (ccr5 & 2) { /* possible wrong calibration done */ + pr_info("Recalibrating delay loop with SLOP bit reset\n"); + calibrate_delay(); + c->loops_per_jiffy = loops_per_jiffy; + } + } +} + + +static void set_cx86_reorder(void) +{ + u8 ccr3; + + pr_info("Enable Memory access reorder on Cyrix/NSC processor.\n"); + ccr3 = getCx86(CX86_CCR3); + setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */ + + /* Load/Store Serialize to mem access disable (=reorder it) */ + setCx86(CX86_PCR0, getCx86(CX86_PCR0) & ~0x80); + /* set load/store serialize from 1GB to 4GB */ + ccr3 |= 0xe0; + setCx86(CX86_CCR3, ccr3); +} + +static void set_cx86_memwb(void) +{ + pr_info("Enable Memory-Write-back mode on Cyrix/NSC processor.\n"); + + /* CCR2 bit 2: unlock NW bit */ + setCx86(CX86_CCR2, getCx86(CX86_CCR2) & ~0x04); + /* set 'Not Write-through' */ + write_cr0(read_cr0() | X86_CR0_NW); + /* CCR2 bit 2: lock NW bit and set WT1 */ + setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x14); +} + +/* + * Configure later MediaGX and/or Geode processor. + */ + +static void geode_configure(void) +{ + unsigned long flags; + u8 ccr3; + local_irq_save(flags); + + /* Suspend on halt power saving and enable #SUSP pin */ + setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88); + + ccr3 = getCx86(CX86_CCR3); + setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */ + + + /* FPU fast, DTE cache, Mem bypass */ + setCx86(CX86_CCR4, getCx86(CX86_CCR4) | 0x38); + setCx86(CX86_CCR3, ccr3); /* disable MAPEN */ + + set_cx86_memwb(); + set_cx86_reorder(); + + local_irq_restore(flags); +} + +static void early_init_cyrix(struct cpuinfo_x86 *c) +{ + unsigned char dir0, dir0_msn, dir1 = 0; + + __do_cyrix_devid(&dir0, &dir1); + dir0_msn = dir0 >> 4; /* identifies CPU "family" */ + + switch (dir0_msn) { + case 3: /* 6x86/6x86L */ + /* Emulate MTRRs using Cyrix's ARRs. */ + set_cpu_cap(c, X86_FEATURE_CYRIX_ARR); + break; + case 5: /* 6x86MX/M II */ + /* Emulate MTRRs using Cyrix's ARRs. */ + set_cpu_cap(c, X86_FEATURE_CYRIX_ARR); + break; + } +} + +static void init_cyrix(struct cpuinfo_x86 *c) +{ + unsigned char dir0, dir0_msn, dir0_lsn, dir1 = 0; + char *buf = c->x86_model_id; + const char *p = NULL; + + /* + * Bit 31 in normal CPUID used for nonstandard 3DNow ID; + * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway + */ + clear_cpu_cap(c, 0*32+31); + + /* Cyrix used bit 24 in extended (AMD) CPUID for Cyrix MMX extensions */ + if (test_cpu_cap(c, 1*32+24)) { + clear_cpu_cap(c, 1*32+24); + set_cpu_cap(c, X86_FEATURE_CXMMX); + } + + do_cyrix_devid(&dir0, &dir1); + + check_cx686_slop(c); + + Cx86_dir0_msb = dir0_msn = dir0 >> 4; /* identifies CPU "family" */ + dir0_lsn = dir0 & 0xf; /* model or clock multiplier */ + + /* common case step number/rev -- exceptions handled below */ + c->x86_model = (dir1 >> 4) + 1; + c->x86_stepping = dir1 & 0xf; + + /* Now cook; the original recipe is by Channing Corn, from Cyrix. + * We do the same thing for each generation: we work out + * the model, multiplier and stepping. Black magic included, + * to make the silicon step/rev numbers match the printed ones. + */ + + switch (dir0_msn) { + unsigned char tmp; + + case 0: /* Cx486SLC/DLC/SRx/DRx */ + p = Cx486_name[dir0_lsn & 7]; + break; + + case 1: /* Cx486S/DX/DX2/DX4 */ + p = (dir0_lsn & 8) ? Cx486D_name[dir0_lsn & 5] + : Cx486S_name[dir0_lsn & 3]; + break; + + case 2: /* 5x86 */ + Cx86_cb[2] = cyrix_model_mult1[dir0_lsn & 5]; + p = Cx86_cb+2; + break; + + case 3: /* 6x86/6x86L */ + Cx86_cb[1] = ' '; + Cx86_cb[2] = cyrix_model_mult1[dir0_lsn & 5]; + if (dir1 > 0x21) { /* 686L */ + Cx86_cb[0] = 'L'; + p = Cx86_cb; + (c->x86_model)++; + } else /* 686 */ + p = Cx86_cb+1; + /* Emulate MTRRs using Cyrix's ARRs. */ + set_cpu_cap(c, X86_FEATURE_CYRIX_ARR); + /* 6x86's contain this bug */ + set_cpu_bug(c, X86_BUG_COMA); + break; + + case 4: /* MediaGX/GXm or Geode GXM/GXLV/GX1 */ + case 11: /* GX1 with inverted Device ID */ +#ifdef CONFIG_PCI + { + u32 vendor, device; + /* + * It isn't really a PCI quirk directly, but the cure is the + * same. The MediaGX has deep magic SMM stuff that handles the + * SB emulation. It throws away the fifo on disable_dma() which + * is wrong and ruins the audio. + * + * Bug2: VSA1 has a wrap bug so that using maximum sized DMA + * causes bad things. According to NatSemi VSA2 has another + * bug to do with 'hlt'. I've not seen any boards using VSA2 + * and X doesn't seem to support it either so who cares 8). + * VSA1 we work around however. + */ + + pr_info("Working around Cyrix MediaGX virtual DMA bugs.\n"); + isa_dma_bridge_buggy = 2; + + /* We do this before the PCI layer is running. However we + are safe here as we know the bridge must be a Cyrix + companion and must be present */ + vendor = read_pci_config_16(0, 0, 0x12, PCI_VENDOR_ID); + device = read_pci_config_16(0, 0, 0x12, PCI_DEVICE_ID); + + /* + * The 5510/5520 companion chips have a funky PIT. + */ + if (vendor == PCI_VENDOR_ID_CYRIX && + (device == PCI_DEVICE_ID_CYRIX_5510 || + device == PCI_DEVICE_ID_CYRIX_5520)) + mark_tsc_unstable("cyrix 5510/5520 detected"); + } +#endif + c->x86_cache_size = 16; /* Yep 16K integrated cache that's it */ + + /* GXm supports extended cpuid levels 'ala' AMD */ + if (c->cpuid_level == 2) { + /* Enable cxMMX extensions (GX1 Datasheet 54) */ + setCx86(CX86_CCR7, getCx86(CX86_CCR7) | 1); + + /* + * GXm : 0x30 ... 0x5f GXm datasheet 51 + * GXlv: 0x6x GXlv datasheet 54 + * ? : 0x7x + * GX1 : 0x8x GX1 datasheet 56 + */ + if ((0x30 <= dir1 && dir1 <= 0x6f) || + (0x80 <= dir1 && dir1 <= 0x8f)) + geode_configure(); + return; + } else { /* MediaGX */ + Cx86_cb[2] = (dir0_lsn & 1) ? '3' : '4'; + p = Cx86_cb+2; + c->x86_model = (dir1 & 0x20) ? 1 : 2; + } + break; + + case 5: /* 6x86MX/M II */ + if (dir1 > 7) { + dir0_msn++; /* M II */ + /* Enable MMX extensions (App note 108) */ + setCx86(CX86_CCR7, getCx86(CX86_CCR7)|1); + } else { + /* A 6x86MX - it has the bug. */ + set_cpu_bug(c, X86_BUG_COMA); + } + tmp = (!(dir0_lsn & 7) || dir0_lsn & 1) ? 2 : 0; + Cx86_cb[tmp] = cyrix_model_mult2[dir0_lsn & 7]; + p = Cx86_cb+tmp; + if (((dir1 & 0x0f) > 4) || ((dir1 & 0xf0) == 0x20)) + (c->x86_model)++; + /* Emulate MTRRs using Cyrix's ARRs. */ + set_cpu_cap(c, X86_FEATURE_CYRIX_ARR); + break; + + case 0xf: /* Cyrix 486 without DEVID registers */ + switch (dir0_lsn) { + case 0xd: /* either a 486SLC or DLC w/o DEVID */ + dir0_msn = 0; + p = Cx486_name[!!boot_cpu_has(X86_FEATURE_FPU)]; + break; + + case 0xe: /* a 486S A step */ + dir0_msn = 0; + p = Cx486S_name[0]; + break; + } + break; + + default: /* unknown (shouldn't happen, we know everyone ;-) */ + dir0_msn = 7; + break; + } + strcpy(buf, Cx86_model[dir0_msn & 7]); + if (p) + strcat(buf, p); + return; +} + +/* + * Handle National Semiconductor branded processors + */ +static void init_nsc(struct cpuinfo_x86 *c) +{ + /* + * There may be GX1 processors in the wild that are branded + * NSC and not Cyrix. + * + * This function only handles the GX processor, and kicks every + * thing else to the Cyrix init function above - that should + * cover any processors that might have been branded differently + * after NSC acquired Cyrix. + * + * If this breaks your GX1 horribly, please e-mail + * info-linux@ldcmail.amd.com to tell us. + */ + + /* Handle the GX (Formally known as the GX2) */ + + if (c->x86 == 5 && c->x86_model == 5) + cpu_detect_cache_sizes(c); + else + init_cyrix(c); +} + +/* + * Cyrix CPUs without cpuid or with cpuid not yet enabled can be detected + * by the fact that they preserve the flags across the division of 5/2. + * PII and PPro exhibit this behavior too, but they have cpuid available. + */ + +/* + * Perform the Cyrix 5/2 test. A Cyrix won't change + * the flags, while other 486 chips will. + */ +static inline int test_cyrix_52div(void) +{ + unsigned int test; + + __asm__ __volatile__( + "sahf\n\t" /* clear flags (%eax = 0x0005) */ + "div %b2\n\t" /* divide 5 by 2 */ + "lahf" /* store flags into %ah */ + : "=a" (test) + : "0" (5), "q" (2) + : "cc"); + + /* AH is 0x02 on Cyrix after the divide.. */ + return (unsigned char) (test >> 8) == 0x02; +} + +static void cyrix_identify(struct cpuinfo_x86 *c) +{ + /* Detect Cyrix with disabled CPUID */ + if (c->x86 == 4 && test_cyrix_52div()) { + unsigned char dir0, dir1; + + strcpy(c->x86_vendor_id, "CyrixInstead"); + c->x86_vendor = X86_VENDOR_CYRIX; + + /* Actually enable cpuid on the older cyrix */ + + /* Retrieve CPU revisions */ + + do_cyrix_devid(&dir0, &dir1); + + dir0 >>= 4; + + /* Check it is an affected model */ + + if (dir0 == 5 || dir0 == 3) { + unsigned char ccr3; + unsigned long flags; + pr_info("Enabling CPUID on Cyrix processor.\n"); + local_irq_save(flags); + ccr3 = getCx86(CX86_CCR3); + /* enable MAPEN */ + setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); + /* enable cpuid */ + setCx86(CX86_CCR4, getCx86(CX86_CCR4) | 0x80); + /* disable MAPEN */ + setCx86(CX86_CCR3, ccr3); + local_irq_restore(flags); + } + } +} + +static const struct cpu_dev cyrix_cpu_dev = { + .c_vendor = "Cyrix", + .c_ident = { "CyrixInstead" }, + .c_early_init = early_init_cyrix, + .c_init = init_cyrix, + .c_identify = cyrix_identify, + .c_x86_vendor = X86_VENDOR_CYRIX, +}; + +cpu_dev_register(cyrix_cpu_dev); + +static const struct cpu_dev nsc_cpu_dev = { + .c_vendor = "NSC", + .c_ident = { "Geode by NSC" }, + .c_init = init_nsc, + .c_x86_vendor = X86_VENDOR_NSC, +}; + +cpu_dev_register(nsc_cpu_dev); |