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Subject[PATCH] ide-generic: handle probing of legacy io-ports v5 (was: Re: [PATCH 1/2] pata_legacy: export functionality to ide)
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On Thu, Aug 07, 2008 at 12:04:19AM +0400, Sergei Shtylyov wrote:

[.. ]

>>>>> Would have been probably enough to test only BAR0/2, don't you think?
>
>>>> I assume you're referring to the legacy ioports fixup in
>>>> drivers/pci/probe.c:pci_setup_device().
>
>>> And to the fact that the value 0x1f0 should only be ever seen in
>>> BAR0 and 0x170 in BAR2 even if they would have been read off the
>>> chips (some chips have these values reading back even in legacy mode,
>>> and even could malfunction if other values are written there), not
>>> fixed up there, and certainly not in BAR1 or BAR3, so it's quite
>>> pointless to look in these BARs too.
>
>> So the comment in there saying that in some cases BAR0-3 could contain junk is a
>> bogus?
>
> Don't know. The PCI IDE spec. said that those should be 0 in
> compatibility mode but I know that some controllers require the standard
> values of 0x1[f7]0 to be in BAR0/2 in compatibility mode. If my memory
> serves, NatSemi PC8741x were ones of those...
>
>> In other words, can we assume that one will always read 0x1f0 from BAR0
>> and 0x170 from BAR2 in compatibility mode.
>
> Certainly not. We can only rely on the workaround putting 0x1[f7]0 in
> the resources 0/2.
>
>> If so, the check is even simpler:
>
>> if (pci_resource_start(p, 0) == 0x1f0)
>> *primary = 1;
>> if (pci_resource_start(p, 2) == 0x170)
>> *secondary = 1;
>
> Yes, I think that should be enough...

Here's v5:

---
From: Borislav Petkov <petkovbb@gmail.com>
Date: Sun, 3 Aug 2008 18:46:35 +0200
Subject: [PATCH] ide-generic: handle probing of legacy io-ports v5

Avoid probing the io-ports in case an IDE PCI controller is present and it
uses the legacy iobases. If we still want to enforce the probing, we do

ide_generic.probe_mask=0x3f

on the kernel command line. The iobase checking code is
adapted from drivers/ata/pata_legacy.c after converting hex
pci ids into their corresponding macros in <linux/pci_ids.h>.

Also, check only BAR0/2 resources since those are guaranteed
by the workaround in drivers/pci/probe.c:pci_setup_device().

CC: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
---
drivers/ide/ide-generic.c | 56 +++++++++++++++++++++++++++++++++++++++++---
1 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/drivers/ide/ide-generic.c b/drivers/ide/ide-generic.c
index 8fe8b5b..608f353 100644
--- a/drivers/ide/ide-generic.c
+++ b/drivers/ide/ide-generic.c
@@ -19,6 +19,7 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/ide.h>
+#include <linux/pci_ids.h>

/* FIXME: convert m32r to use ide_platform host driver */
#ifdef CONFIG_M32R
@@ -27,7 +28,7 @@

#define DRV_NAME "ide_generic"

-static int probe_mask = 0x03;
+static int probe_mask;
module_param(probe_mask, int, 0);
MODULE_PARM_DESC(probe_mask, "probe mask for legacy ISA IDE ports");

@@ -100,19 +101,66 @@ static const u16 legacy_bases[] = { 0x1f0, 0x170, 0x1e8, 0x168, 0x1e0, 0x160 };
static const int legacy_irqs[] = { 14, 15, 11, 10, 8, 12 };
#endif

+static void ide_generic_check_pci_legacy_iobases(int *primary, int *secondary)
+{
+ struct pci_dev *p = NULL;
+ u16 val;
+
+ for_each_pci_dev(p) {
+
+ if (pci_resource_start(p, 0) == 0x1f0)
+ *primary = 1;
+ if (pci_resource_start(p, 2) == 0x170)
+ *secondary = 1;
+
+ /* Cyrix CS55{1,2}0 pre SFF MWDMA ATA on the bridge */
+ if (p->vendor == PCI_VENDOR_ID_CYRIX &&
+ (p->device == PCI_DEVICE_ID_CYRIX_5510 ||
+ p->device == PCI_DEVICE_ID_CYRIX_5520))
+ *primary = *secondary = 1;
+
+ /* Intel MPIIX - PIO ATA on non PCI side of bridge */
+ if (p->vendor == PCI_VENDOR_ID_INTEL &&
+ p->device == PCI_DEVICE_ID_INTEL_82371MX) {
+
+ pci_read_config_word(p, 0x6C, &val);
+ if (val & 0x8000) {
+ /* ATA port enabled */
+ if (val & 0x4000)
+ *secondary = 1;
+ else
+ *primary = 1;
+ }
+ }
+ }
+}
+
static int __init ide_generic_init(void)
{
hw_regs_t hw[MAX_HWIFS], *hws[MAX_HWIFS];
struct ide_host *host;
unsigned long io_addr;
- int i, rc;
+ int i, rc, primary = 0, secondary = 0;

#ifdef CONFIG_MIPS
if (!ide_probe_legacy())
return -ENODEV;
#endif
- printk(KERN_INFO DRV_NAME ": please use \"probe_mask=0x3f\" module "
- "parameter for probing all legacy ISA IDE ports\n");
+ ide_generic_check_pci_legacy_iobases(&primary, &secondary);
+
+ if (!probe_mask) {
+ printk(KERN_INFO DRV_NAME ": please use \"probe_mask=0x3f\" "
+ "module parameter for probing all legacy ISA IDE ports\n");
+
+ if (primary == 0)
+ probe_mask |= 0x1;
+
+ if (secondary == 0)
+ probe_mask |= 0x2;
+ } else {
+ printk(KERN_WARNING "%s: enforcing probing of io ports upon "
+ "user request.\n", DRV_NAME);
+ }

memset(hws, 0, sizeof(hw_regs_t *) * MAX_HWIFS);

--
1.5.5.4
--
Regards/Gruss,
Boris.


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