Re: [SeaBIOS] [PATCH 1/2] pci: introduce pci_region to manage pci io/memory/prefmemory regions.

[Michael S. Tsirkin]

On Mon, Oct 18, 2010 at 06:34:22PM +0900, Isaku Yamahata wrote:
> This patch adds helper functions to manage pci area.
> Signed-off-by: Isaku Yamahata
>
> Makefile         |    3 +-
>  src/pci_region.c |   70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  src/util.h       |   15 +++++++++++
>  3 files changed, 87 insertions(+), 1 deletions(-)
>  create mode 100644 src/pci_region.c
>
> diff --git a/Makefile b/Makefile
> index 9d412f1..1663a5d 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -19,7 +19,8 @@ SRCBOTH=misc.c pmm.c stacks.c output.c util.c block.c floppy.c ata.c mouse.c \
>  SRC16=$(SRCBOTH) system.c disk.c font.c
>  SRC32FLAT=$(SRCBOTH) post.c shadow.c memmap.c coreboot.c boot.c \
>        acpi.c smm.c mptable.c smbios.c pciinit.c optionroms.c mtrr.c \
>  lzmadecode.c bootsplash.c jpeg.c usb-hub.c paravirt.c dev-i440fx.c
>  lzmadecode.c bootsplash.c jpeg.c usb-hub.c paravirt.c dev-i440fx.c \
>  pci_region.c
>
> SRC32SEG=util.c output.c pci.c pcibios.c apm.c stacks.c
>
> cc-option = $(shell if test -z "`$(1) $(2) -S -o /dev/null -xc \
> diff --git a/src/pci_region.c b/src/pci_region.c
> new file mode 100644
> index 0000000..a4e71d9
> --- /dev/null
> +++ b/src/pci_region.c
> @@ -0,0 +1,70 @@
> +// helper functions to manage pci io/memory/prefetch memory region
> +//
> +// Copyright (C) 2009 Isaku Yamahata <yamahata at valinux co jp>
> +//
> +// This file may be distributed under the terms of the GNU LGPLv3 license.
> +//
> +//
>
> +#include "util.h"
>
> +#define PCI_REGION_DISABLED     (-1)
>
> +void pci_region_init(struct pci_region *r, u32 start, u32 end)
> +{
> r->start = start;
> r->end = end;
> r->cur_end = start;
>
> +}
>
> +static u32 pci_region_alloc_align(struct pci_region *r, u32 size, u32 align)
> +{
> if (r->cur_end == PCI_REGION_DISABLED) {
>    return 0;
> }

So is special value PCI_REGION_DISABLED or cur_end?
> u32 s = ALIGN(r->cur_end, align);
> if (s > r->end || s < r->cur_end) {
>    return 0;
> }
> u32 e = s + size;
> if (e > r->end || e < s) {
>    return 0;
> }
> r->cur_end = e;
> return s;
>
> +}
>
> +u32 pci_region_alloc(struct pci_region *r, u32 size)
> +{
> return pci_region_alloc_align(r, size, size);
>
> +}
>
> +u32 pci_region_align(struct pci_region *r, u32 align)
> +{
> return pci_region_alloc_align(r, 0, align);
>
> +}
>
> +void pci_region_revert(struct pci_region *r, u32 addr)
> +{
> r->cur_end = addr;
>
> +}
>
> +u32 pci_region_disable(struct pci_region *r)
> +{
> return r->cur_end = PCI_REGION_DISABLED;
>
> +}
>
> +u32 pci_region_addr(const struct pci_region *r)
> +{
> if (r->cur_end == PCI_REGION_DISABLED){
>    return r->end;
> }
> return r->cur_end;
>
> +}
>
> +u32 pci_region_size(const struct pci_region *r)
> +{
> return r->end - r->start;
>
> +}
> diff --git a/src/util.h b/src/util.h
> index 5cc9f17..ecd1c16 100644
> --- a/src/util.h
> +++ b/src/util.h
> @@ -344,6 +344,21 @@ void qemu_prep_reset(void);
>  void smm_save_and_copy(void);
>  void smm_relocate_and_restore(void);
>
> +// pci_region.c
> +struct pci_region {
> u32 start;
> u32 end;
> u32 cur_end;
>
> +};
> +void pci_region_init(struct pci_region *r, u32 start, u32 end);
> +u32 pci_region_alloc(struct pci_region *r, u32 size);
> +u32 pci_region_align(struct pci_region *r, u32 align);
> +void pci_region_revert(struct pci_region *r, u32 addr);
> +u32 pci_region_disable(struct pci_region *r);
> +u32 pci_region_addr(const struct pci_region *r);
> +u32 pci_region_size(const struct pci_region *r);

Please document structure fields here and functions in the .c file.
> // pciinit.c
>  extern const u8 pci_irqs[4];
>  void pci_bios_allocate_regions(u16 bdf, void *arg);
> -- 
> 1.7.1.1

[PATCH 1/2] pci: introduce pci_region to manage pci io/memory/prefmemory regions.

[Isaku Yamahata]

On Mon, Oct 18, 2010 at 11:55:08AM +0200, Michael S. Tsirkin wrote:
> > +static u32 pci_region_alloc_align(struct pci_region *r, u32 size, u32 align)
> > +{
> > if (r->cur_end == PCI_REGION_DISABLED) {
> >    return 0;
> > }
>
> So is special value PCI_REGION_DISABLED or cur_end?

cur_end is in special state, and PCI_REGION_DISABLED was chosen
such that cur_end can't be PCI_REGION_DISABLED in normal case.