Re: [PATCH v3 06/26] s390/pci: Use PCI_STD_NUM_BARS
From: Andrew Murray
Date: Wed Sep 18 2019 - 04:58:12 EST
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?
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
>