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2019-10-28esp: add pseudo-DMA as used by MacintoshLaurent Vivier
There is no DMA in Quadra 800, so the CPU reads/writes the data from the PDMA register (offset 0x100, ESP_PDMA in hw/m68k/q800.c) and copies them to/from the memory. There is a nice assembly loop in the kernel to do that, see linux/drivers/scsi/mac_esp.c:MAC_ESP_PDMA_LOOP(). The start of the transfer is triggered by the DREQ interrupt (see linux mac_esp_send_pdma_cmd()), the CPU polls on the IRQ flag to start the transfer after a SCSI command has been sent (in Quadra 800 it goes through the VIA2, the via2-irq line and the vIFR register) The Macintosh hardware includes hardware handshaking to prevent the CPU from reading invalid data or writing data faster than the peripheral device can accept it. This is the "blind mode", and from the doc: "Approximate maximum SCSI transfer rates within a blocks are 1.4 MB per second for blind transfers in the Macintosh II" Some references can be found in: Apple Macintosh Family Hardware Reference, ISBN 0-201-19255-1 Guide to the Macintosh Family Hardware, ISBN-0-201-52405-8 Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Co-developed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Signed-off-by: Laurent Vivier <laurent@vivier.eu> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20191026164546.30020-4-laurent@vivier.eu>
2019-01-11scsi: esp: Defer command completion until previous interrupts have been handledGuenter Roeck
The guest OS reads RSTAT, RSEQ, and RINTR, and expects those registers to reflect a consistent state. However, it is possible that the registers can change after RSTAT was read, but before RINTR is read, when esp_command_complete() is called. Guest OS qemu -------- ---- [handle interrupt] Read RSTAT esp_command_complete() RSTAT = STAT_ST esp_dma_done() RSTAT |= STAT_TC RSEQ = 0 RINTR = INTR_BS Read RSEQ Read RINTR RINTR = 0 RSTAT &= ~STAT_TC RSEQ = SEQ_CD The guest OS would then try to handle INTR_BS combined with an old value of RSTAT. This sometimes resulted in lost events, spurious interrupts, guest OS confusion, and stalled SCSI operations. A typical guest error log (observed with various versions of Linux) looks as follows. scsi host1: Spurious irq, sreg=13. ... scsi host1: Aborting command [84531f10:2a] scsi host1: Current command [f882eea8:35] scsi host1: Queued command [84531f10:2a] scsi host1: Active command [f882eea8:35] scsi host1: Dumping command log scsi host1: ent[15] CMD val[44] sreg[90] seqreg[00] sreg2[00] ireg[20] ss[00] event[0c] scsi host1: ent[16] CMD val[01] sreg[90] seqreg[00] sreg2[00] ireg[20] ss[02] event[0c] scsi host1: ent[17] CMD val[43] sreg[90] seqreg[00] sreg2[00] ireg[20] ss[02] event[0c] scsi host1: ent[18] EVENT val[0d] sreg[92] seqreg[04] sreg2[00] ireg[18] ss[00] event[0c] ... Defer handling command completion until previous interrupts have been handled to fix the problem. Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2018-06-28esp: remove legacy esp_init() functionMark Cave-Ayland
Remove the legacy esp_init() function now that there are no more remaining users. Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Message-Id: <20180613094727.11326-3-mark.cave-ayland@ilande.co.uk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Tested-by: Hervé Poussineau <hpoussin@reactos.org>
2018-03-12hw/mips/jazz: Fix implicit creation of "-drive if=scsi" devicesThomas Huth
The global hack for creating SCSI devices has recently been removed, but this apparently broke SCSI devices on some boards that were not ready for this change yet. For the pica61 machine you now get: $ mips64-softmmu/qemu-system-mips64 -M pica61 -cdrom x.iso qemu-system-mips64: -cdrom x.iso: machine type does not support if=scsi,bus=0,unit=2 Fix it by calling scsi_bus_legacy_handle_cmdline() after creating the corresponding SCSI controller. Fixes: 1454509726719e0933c800fad00d6999752688ea Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <1520414644-11535-1-git-send-email-thuth@redhat.com> Reviewed-by: Hervé Poussineau <hpoussin@reactos.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-10-31esp: move TYPE_ESP and SysBusESPState from esp.c to esp.hMark Cave-Ayland
This enables them to be used outside of esp.c. Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> CC: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Artyom Tarasenko <atar4qemu@gmail.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2016-06-16scsi: esp: make cmdbuf big enough for maximum CDB sizePrasad J Pandit
While doing DMA read into ESP command buffer 's->cmdbuf', it could write past the 's->cmdbuf' area, if it was transferring more than 16 bytes. Increase the command buffer size to 32, which is maximum when 's->do_cmd' is set, and add a check on 'len' to avoid OOB access. Reported-by: Li Qiang <liqiang6-s@360.cn> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-12esp: Do not overwrite ESP_TCHI after resetHannes Reinecke
After a reset ESP_TCHI should contain the unique ID of the chip. This value will be overwritten with the current tranfer count if the transfer count has previously been set. So we should always return the chip id if ESP_TCHI has never been written to. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-04-08hw: move headers to include/Paolo Bonzini
Many of these should be cleaned up with proper qdev-/QOM-ification. Right now there are many catch-all headers in include/hw/ARCH depending on cpu.h, and this makes it necessary to compile these files per-target. However, fixing this does not belong in these patches. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>