Re: [PATCH v3 06/26] s390/pci: Use PCI_STD_NUM_BARS

From: Andrew Murray
Date: Thu Sep 19 2019 - 04:00:13 EST


On Wed, Sep 18, 2019 at 05:26:59PM +0300, Denis Efremov wrote:
> On 9/18/19 11:58 AM, Andrew Murray wrote:
> > On Mon, Sep 16, 2019 at 11:41:38PM +0300, Denis Efremov wrote:
> >> Remove local definition PCI_BAR_COUNT for the number of PCI BARs and use
> >> global one PCI_STD_NUM_BARS instead.
> >>
> >> Acked-by: Sebastian Ott <sebott@xxxxxxxxxxxxx>
> >> Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx>
> >> Signed-off-by: Denis Efremov <efremov@xxxxxxxxx>
> >> ---
> >> arch/s390/include/asm/pci.h | 5 +----
> >> arch/s390/include/asm/pci_clp.h | 6 +++---
> >> arch/s390/pci/pci.c | 16 ++++++++--------
> >> arch/s390/pci/pci_clp.c | 6 +++---
> >> 4 files changed, 15 insertions(+), 18 deletions(-)
> >>
> >> diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
> >> index a2399eff84ca..3a06c264ea53 100644
> >> --- a/arch/s390/include/asm/pci.h
> >> +++ b/arch/s390/include/asm/pci.h
> >> @@ -2,9 +2,6 @@
> >> #ifndef __ASM_S390_PCI_H
> >> #define __ASM_S390_PCI_H
> >>
> >> -/* must be set before including pci_clp.h */
> >> -#define PCI_BAR_COUNT 6
> >> -
> >> #include <linux/pci.h>
> >> #include <linux/mutex.h>
> >> #include <linux/iommu.h>
> >> @@ -138,7 +135,7 @@ struct zpci_dev {
> >>
> >> char res_name[16];
> >> bool mio_capable;
> >> - struct zpci_bar_struct bars[PCI_BAR_COUNT];
> >> + struct zpci_bar_struct bars[PCI_STD_NUM_BARS];
> >>
> >> u64 start_dma; /* Start of available DMA addresses */
> >> u64 end_dma; /* End of available DMA addresses */
> >> diff --git a/arch/s390/include/asm/pci_clp.h b/arch/s390/include/asm/pci_clp.h
> >> index 50359172cc48..bd2cb4ea7d93 100644
> >> --- a/arch/s390/include/asm/pci_clp.h
> >> +++ b/arch/s390/include/asm/pci_clp.h
> >> @@ -77,7 +77,7 @@ struct mio_info {
> >> struct {
> >> u64 wb;
> >> u64 wt;
> >> - } addr[PCI_BAR_COUNT];
> >> + } addr[PCI_STD_NUM_BARS];
> >> u32 reserved[6];
> >> } __packed;
> >>
> >> @@ -98,9 +98,9 @@ struct clp_rsp_query_pci {
> >> u16 util_str_avail : 1; /* utility string available? */
> >> u16 pfgid : 8; /* pci function group id */
> >> u32 fid; /* pci function id */
> >> - u8 bar_size[PCI_BAR_COUNT];
> >> + u8 bar_size[PCI_STD_NUM_BARS];
> >> u16 pchid;
> >> - __le32 bar[PCI_BAR_COUNT];
> >> + __le32 bar[PCI_STD_NUM_BARS];
> >> u8 pfip[CLP_PFIP_NR_SEGMENTS]; /* pci function internal path */
> >> u32 : 16;
> >> u8 fmb_len;
> >> diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
> >> index b0e3b9a0e488..aca372c8e34f 100644
> >> --- a/arch/s390/pci/pci.c
> >> +++ b/arch/s390/pci/pci.c
> >> @@ -43,7 +43,7 @@ static DECLARE_BITMAP(zpci_domain, ZPCI_NR_DEVICES);
> >> static DEFINE_SPINLOCK(zpci_domain_lock);
> >>
> >> #define ZPCI_IOMAP_ENTRIES \
> >> - min(((unsigned long) ZPCI_NR_DEVICES * PCI_BAR_COUNT / 2), \
> >> + min(((unsigned long) ZPCI_NR_DEVICES * PCI_STD_NUM_BARS / 2), \
> >> ZPCI_IOMAP_MAX_ENTRIES)
> >>
> >> static DEFINE_SPINLOCK(zpci_iomap_lock);
> >> @@ -294,7 +294,7 @@ static void __iomem *pci_iomap_range_mio(struct pci_dev *pdev, int bar,
> >> void __iomem *pci_iomap_range(struct pci_dev *pdev, int bar,
> >> unsigned long offset, unsigned long max)
> >> {
> >> - if (!pci_resource_len(pdev, bar) || bar >= PCI_BAR_COUNT)
> >> + if (bar >= PCI_STD_NUM_BARS || !pci_resource_len(pdev, bar))
> >> return NULL;
> >>
> >> if (static_branch_likely(&have_mio))
> >> @@ -324,7 +324,7 @@ static void __iomem *pci_iomap_wc_range_mio(struct pci_dev *pdev, int bar,
> >> void __iomem *pci_iomap_wc_range(struct pci_dev *pdev, int bar,
> >> unsigned long offset, unsigned long max)
> >> {
> >> - if (!pci_resource_len(pdev, bar) || bar >= PCI_BAR_COUNT)
> >> + if (bar >= PCI_STD_NUM_BARS || !pci_resource_len(pdev, bar))
> >> return NULL;
> >
> > This looks like a latent bug fix here. If 'bar' is out of range we return
> > NULL instead accessing an invalid item of an array. Should this not be
> > a separate patch and tagged as stable?
> >
>
> This fix was suggested by Bjorn in v1 review:
> https://lkml.org/lkml/2019/8/12/997
>

Ah yes, apologies - I'll re-read the previous threads next time.

Thanks,

Andrew Murray

>
> > Thanks,
> >
> > Andrew Murray
> >
> >>
> >> if (static_branch_likely(&have_mio))
> >> @@ -416,7 +416,7 @@ static void zpci_map_resources(struct pci_dev *pdev)
> >> resource_size_t len;
> >> int i;
> >>
> >> - for (i = 0; i < PCI_BAR_COUNT; i++) {
> >> + for (i = 0; i < PCI_STD_NUM_BARS; i++) {
> >> len = pci_resource_len(pdev, i);
> >> if (!len)
> >> continue;
> >> @@ -451,7 +451,7 @@ static void zpci_unmap_resources(struct pci_dev *pdev)
> >> if (zpci_use_mio(zdev))
> >> return;
> >>
> >> - for (i = 0; i < PCI_BAR_COUNT; i++) {
> >> + for (i = 0; i < PCI_STD_NUM_BARS; i++) {
> >> len = pci_resource_len(pdev, i);
> >> if (!len)
> >> continue;
> >> @@ -514,7 +514,7 @@ static int zpci_setup_bus_resources(struct zpci_dev *zdev,
> >> snprintf(zdev->res_name, sizeof(zdev->res_name),
> >> "PCI Bus %04x:%02x", zdev->domain, ZPCI_BUS_NR);
> >>
> >> - for (i = 0; i < PCI_BAR_COUNT; i++) {
> >> + for (i = 0; i < PCI_STD_NUM_BARS; i++) {
> >> if (!zdev->bars[i].size)
> >> continue;
> >> entry = zpci_alloc_iomap(zdev);
> >> @@ -551,7 +551,7 @@ static void zpci_cleanup_bus_resources(struct zpci_dev *zdev)
> >> {
> >> int i;
> >>
> >> - for (i = 0; i < PCI_BAR_COUNT; i++) {
> >> + for (i = 0; i < PCI_STD_NUM_BARS; i++) {
> >> if (!zdev->bars[i].size || !zdev->bars[i].res)
> >> continue;
> >>
> >> @@ -573,7 +573,7 @@ int pcibios_add_device(struct pci_dev *pdev)
> >> pdev->dev.dma_ops = &s390_pci_dma_ops;
> >> zpci_map_resources(pdev);
> >>
> >> - for (i = 0; i < PCI_BAR_COUNT; i++) {
> >> + for (i = 0; i < PCI_STD_NUM_BARS; i++) {
> >> res = &pdev->resource[i];
> >> if (res->parent || !res->flags)
> >> continue;
> >> diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
> >> index 9bdff4defef1..8b729b5f2972 100644
> >> --- a/arch/s390/pci/pci_clp.c
> >> +++ b/arch/s390/pci/pci_clp.c
> >> @@ -145,7 +145,7 @@ static int clp_store_query_pci_fn(struct zpci_dev *zdev,
> >> {
> >> int i;
> >>
> >> - for (i = 0; i < PCI_BAR_COUNT; i++) {
> >> + for (i = 0; i < PCI_STD_NUM_BARS; i++) {
> >> zdev->bars[i].val = le32_to_cpu(response->bar[i]);
> >> zdev->bars[i].size = response->bar_size[i];
> >> }
> >> @@ -164,8 +164,8 @@ static int clp_store_query_pci_fn(struct zpci_dev *zdev,
> >> sizeof(zdev->util_str));
> >> }
> >> zdev->mio_capable = response->mio_addr_avail;
> >> - for (i = 0; i < PCI_BAR_COUNT; i++) {
> >> - if (!(response->mio.valid & (1 << (PCI_BAR_COUNT - i - 1))))
> >> + for (i = 0; i < PCI_STD_NUM_BARS; i++) {
> >> + if (!(response->mio.valid & (1 << (PCI_STD_NUM_BARS - i - 1))))
> >> continue;
> >>
> >> zdev->bars[i].mio_wb = (void __iomem *) response->mio.addr[i].wb;
> >> --
> >> 2.21.0
> >>
>