On Thursday, August 29, 2013 6:10:20 am Jean-Sébastien Pédron wrote:
> On 26.08.2013 16:55, John Baldwin wrote:
> > On Sunday, August 25, 2013 2:09:12 pm Jean-Sebastien Pedron wrote:
> >> Author: dumbbell
> >> Date: Sun Aug 25 18:09:11 2013
> >> New Revision: 254882
> >> URL: http://svnweb.freebsd.org/changeset/base/254882
> >>
> >> Log:
> >> vga_pci: Add API to map the Video BIOS
> >
> > This won't actually work (the PCI bus will panic when you do the duplicate
> > alloc). Why not put this in the softc of the vga_pci device? In fact, it
> > is
> > already there. You just need to bump the vr_refs on the vga_bios resource
> > similar to what vga_pci_alloc_resource() does.
>
> Ok, so just calling vga_pci_alloc_resource() instead of
> bus_alloc_resource_any() in vga_pci_map_bios() would be enough to fix
> this first problem.
Yes.
> > Also, returning a void * for this API seems rather hacky. Have you
> > considered
> > returning a struct resource * instead (and requiring the caller to use
> > bus_space_* on it)? That would be more consistent with new-bus.
>
> You're right.
>
> > I can help with getting the right bus_alloc_resource() incantation to
> > alloc a struct resource * for the shadow copy if so.
>
> Yes please, I'd appreciate it :) I see that the function allocates
> resources from the parent device, but I'm not sure what to do with this,
> because the shadow copy is at a fixed physical address.
You can use bus_alloc_resource() to allocate a fixed range, but the trick in
this case is that we need to bypass the PCI bus as this isn't a BAR.
Here is an untested cut at this, it only changes these functions and doesn't
fix the callers to work with the returned struct resource, etc.:
Index: vga_pci.c
===================================================================
--- vga_pci.c (revision 255020)
+++ vga_pci.c (working copy)
@@ -46,11 +46,6 @@ __FBSDID("$FreeBSD$");
#include <sys/sysctl.h>
#include <sys/systm.h>
-#if defined(__amd64__) || defined(__i386__) || defined(__ia64__)
-#include <vm/vm.h>
-#include <vm/pmap.h>
-#endif
-
#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>
@@ -88,11 +83,10 @@ vga_pci_is_boot_display(device_t dev)
device_get_unit(dev) == vga_pci_default_unit);
}
-void *
-vga_pci_map_bios(device_t dev, size_t *size)
+struct resource *
+vga_pci_map_bios(device_t dev)
{
int rid;
- struct resource *res;
#if defined(__amd64__) || defined(__i386__) || defined(__ia64__)
if (vga_pci_is_boot_display(dev)) {
@@ -103,30 +97,30 @@ vga_pci_is_boot_display(device_t dev)
*
* We use this copy for the default boot device, because
* the original ROM may not be valid after boot.
+ *
+ * Allocate this from our grandparent to by-pass the
+ * checks for a valid rid in the PCI bus driver as this
+ * is not a BAR.
*/
-
- *size = VGA_PCI_BIOS_SHADOW_SIZE;
- return (pmap_mapbios(VGA_PCI_BIOS_SHADOW_ADDR, *size));
+ rid = 1;
+ return (BUS_ALLOC_RESOURCE(device_get_parent(
+ device_get_parent(dev)), dev, SYS_RES_MEMORY, &rid,
+ VGA_PCI_BIOS_SHADOW_ADDR,
+ VGA_PCI_BIOS_SHADOW_ADDR + VGA_PCI_BIOS_SHADOW_SIZE - 1,
+ VGA_PCI_BIOS_SHADOW_SIZE, RF_ACTIVE));
}
#endif
rid = PCIR_BIOS;
- res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
- if (res == NULL) {
- return (NULL);
- }
-
- *size = rman_get_size(res);
- return (rman_get_virtual(res));
+ return (vga_pci_alloc_resource(dev, NULL, SYS_RES_MEMORY, &rid, 0ul,
+ ~0ul, 1, RF_ACTIVE));
}
void
-vga_pci_unmap_bios(device_t dev, void *bios)
+vga_pci_unmap_bios(device_t dev, struct resource *res)
{
- int rid;
- struct resource *res;
- if (bios == NULL) {
+ if (res == NULL) {
return;
}
@@ -133,32 +127,13 @@ void
#if defined(__amd64__) || defined(__i386__) || defined(__ia64__)
if (vga_pci_is_boot_display(dev)) {
/* We mapped the BIOS shadow copy located at 0xC0000. */
- pmap_unmapdev((vm_offset_t)bios, VGA_PCI_BIOS_SHADOW_SIZE);
+ BUS_RELEASE_RESOURCE(device_get_parent(
+ device_get_parent(dev)), dev, SYS_RES_MEMORY, 1, res);
return;
}
#endif
-
- /*
- * FIXME: We returned only the virtual address of the resource
- * to the caller. Now, to get the resource struct back, we
- * allocate it again: the struct exists once in memory in
- * device softc. Therefore, we release twice now to release the
- * reference we just obtained to get the structure back and the
- * caller's reference.
- */
-
- rid = PCIR_BIOS;
- res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
-
- KASSERT(res != NULL,
- ("%s: Can't get BIOS resource back", __func__));
- KASSERT(bios == rman_get_virtual(res),
- ("%s: Given BIOS address doesn't match "
- "resource virtual address", __func__));
-
- bus_release_resource(dev, SYS_RES_MEMORY, rid, bios);
- bus_release_resource(dev, SYS_RES_MEMORY, rid, bios);
+ vga_pci_release_resource(dev, NULL, SYS_RES_MEMORY, PCIR_BIOS, res);
}
static int
--
John Baldwin
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