[PATCH 2/3] x86/pci: Convert pci_mmcfg_{read,write}() to use pci_sbdf_t

[Andrew Cooper <andrew.cooper3@citrix.com>]

All callers now have an sbdf already.  Pass it down directly, rather than
splitting into three parameters.

In turn this shows that bus and devfn bounds checks were unreachable, making
them safe to drop.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <jbeulich@suse.com>
CC: Roger Pau Monné <roger@xenproject.org>
CC: Teddy Astie <teddy.astie@vates.tech>
---
 xen/arch/x86/pv/ro-page-fault.c   |  4 +---
 xen/arch/x86/x86_64/mmconfig_64.c | 18 ++++++++----------
 xen/arch/x86/x86_64/pci.c         | 12 ++++++------
 xen/include/xen/pci.h             |  8 ++++----
 4 files changed, 19 insertions(+), 23 deletions(-)

diff --git a/xen/arch/x86/pv/ro-page-fault.c b/xen/arch/x86/pv/ro-page-fault.c
index e70e09a6a6a1..c10541709e8b 100644
--- a/xen/arch/x86/pv/ro-page-fault.c
+++ b/xen/arch/x86/pv/ro-page-fault.c
@@ -331,9 +331,7 @@ static int cf_check mmcfg_intercept_write(
     offset &= 0xfff;
     if ( pci_conf_write_intercept(mmio_ctxt->sbdf.seg, mmio_ctxt->sbdf.bdf,
                                   offset, bytes, p_data) >= 0 )
-        pci_mmcfg_write(mmio_ctxt->sbdf.seg, mmio_ctxt->sbdf.bus,
-                        mmio_ctxt->sbdf.devfn, offset, bytes,
-                        *(uint32_t *)p_data);
+        pci_mmcfg_write(mmio_ctxt->sbdf, offset, bytes, *(uint32_t *)p_data);
 
     return X86EMUL_OKAY;
 }
diff --git a/xen/arch/x86/x86_64/mmconfig_64.c b/xen/arch/x86/x86_64/mmconfig_64.c
index 91b1a398e646..6477bf8b44bd 100644
--- a/xen/arch/x86/x86_64/mmconfig_64.c
+++ b/xen/arch/x86/x86_64/mmconfig_64.c
@@ -55,19 +55,18 @@ static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned i
      return addr + ((bus << 20) | (devfn << 12));
 }
 
-int pci_mmcfg_read(unsigned int seg, unsigned int bus,
-              unsigned int devfn, int reg, int len, u32 *value)
+int pci_mmcfg_read(
+    pci_sbdf_t sbdf, unsigned int reg, unsigned int len, uint32_t *value)
 {
     char __iomem *addr;
 
     /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
-    if (unlikely((bus > 255) || (devfn > 255) ||
-                 (reg + len > PCI_CFG_SPACE_EXP_SIZE))) {
+    if (unlikely(reg + len > PCI_CFG_SPACE_EXP_SIZE)) {
 err:        *value = -1;
         return -EINVAL;
     }
 
-    addr = pci_dev_base(seg, bus, devfn);
+    addr = pci_dev_base(sbdf.seg, sbdf.bus, sbdf.devfn);
     if (!addr)
         goto err;
 
@@ -86,17 +85,16 @@ err:        *value = -1;
     return 0;
 }
 
-int pci_mmcfg_write(unsigned int seg, unsigned int bus,
-               unsigned int devfn, int reg, int len, u32 value)
+int pci_mmcfg_write(
+    pci_sbdf_t sbdf, unsigned int reg, unsigned int len, uint32_t value)
 {
     char __iomem *addr;
 
     /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
-    if (unlikely((bus > 255) || (devfn > 255) ||
-                 (reg + len > PCI_CFG_SPACE_EXP_SIZE)))
+    if (unlikely(reg + len > PCI_CFG_SPACE_EXP_SIZE))
         return -EINVAL;
 
-    addr = pci_dev_base(seg, bus, devfn);
+    addr = pci_dev_base(sbdf.seg, sbdf.bus, sbdf.devfn);
     if (!addr)
         return -EINVAL;
 
diff --git a/xen/arch/x86/x86_64/pci.c b/xen/arch/x86/x86_64/pci.c
index 6298141c3ca7..970c010e12f6 100644
--- a/xen/arch/x86/x86_64/pci.c
+++ b/xen/arch/x86/x86_64/pci.c
@@ -17,7 +17,7 @@ uint8_t pci_conf_read8(pci_sbdf_t sbdf, unsigned int reg)
 
     if ( sbdf.seg || reg > 255 )
     {
-        pci_mmcfg_read(sbdf.seg, sbdf.bus, sbdf.devfn, reg, 1, &value);
+        pci_mmcfg_read(sbdf, reg, 1, &value);
         return value;
     }
 
@@ -30,7 +30,7 @@ uint16_t pci_conf_read16(pci_sbdf_t sbdf, unsigned int reg)
     {
         uint32_t value;
 
-        pci_mmcfg_read(sbdf.seg, sbdf.bus, sbdf.devfn, reg, 2, &value);
+        pci_mmcfg_read(sbdf, reg, 2, &value);
         return value;
     }
 
@@ -43,7 +43,7 @@ uint32_t pci_conf_read32(pci_sbdf_t sbdf, unsigned int reg)
     {
         uint32_t value;
 
-        pci_mmcfg_read(sbdf.seg, sbdf.bus, sbdf.devfn, reg, 4, &value);
+        pci_mmcfg_read(sbdf, reg, 4, &value);
         return value;
     }
 
@@ -53,7 +53,7 @@ uint32_t pci_conf_read32(pci_sbdf_t sbdf, unsigned int reg)
 void pci_conf_write8(pci_sbdf_t sbdf, unsigned int reg, uint8_t data)
 {
     if ( sbdf.seg || reg > 255 )
-        pci_mmcfg_write(sbdf.seg, sbdf.bus, sbdf.devfn, reg, 1, data);
+        pci_mmcfg_write(sbdf, reg, 1, data);
     else
         pci_conf_write(PCI_CONF_ADDRESS(sbdf, reg), reg & 3, 1, data);
 }
@@ -61,7 +61,7 @@ void pci_conf_write8(pci_sbdf_t sbdf, unsigned int reg, uint8_t data)
 void pci_conf_write16(pci_sbdf_t sbdf, unsigned int reg, uint16_t data)
 {
     if ( sbdf.seg || reg > 255 || !IS_ALIGNED(reg, 2) )
-        pci_mmcfg_write(sbdf.seg, sbdf.bus, sbdf.devfn, reg, 2, data);
+        pci_mmcfg_write(sbdf, reg, 2, data);
     else
         pci_conf_write(PCI_CONF_ADDRESS(sbdf, reg), reg & 2, 2, data);
 }
@@ -69,7 +69,7 @@ void pci_conf_write16(pci_sbdf_t sbdf, unsigned int reg, uint16_t data)
 void pci_conf_write32(pci_sbdf_t sbdf, unsigned int reg, uint32_t data)
 {
     if ( sbdf.seg || reg > 255 || !IS_ALIGNED(reg, 4) )
-        pci_mmcfg_write(sbdf.seg, sbdf.bus, sbdf.devfn, reg, 4, data);
+        pci_mmcfg_write(sbdf, reg, 4, data);
     else
         pci_conf_write(PCI_CONF_ADDRESS(sbdf, reg), 0, 4, data);
 }
diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h
index ade882caeef4..b7a35371a71a 100644
--- a/xen/include/xen/pci.h
+++ b/xen/include/xen/pci.h
@@ -258,10 +258,10 @@ void pci_conf_write16(pci_sbdf_t sbdf, unsigned int reg, uint16_t data);
 void pci_conf_write32(pci_sbdf_t sbdf, unsigned int reg, uint32_t data);
 uint32_t pci_conf_read(uint32_t cf8, uint8_t offset, uint8_t bytes);
 void pci_conf_write(uint32_t cf8, uint8_t offset, uint8_t bytes, uint32_t data);
-int pci_mmcfg_read(unsigned int seg, unsigned int bus,
-                   unsigned int devfn, int reg, int len, u32 *value);
-int pci_mmcfg_write(unsigned int seg, unsigned int bus,
-                    unsigned int devfn, int reg, int len, u32 value);
+int pci_mmcfg_read(
+    pci_sbdf_t sbdf, unsigned int reg, unsigned int len, uint32_t *value);
+int pci_mmcfg_write(
+    pci_sbdf_t sbdf, unsigned int reg, unsigned int len, uint32_t value);
 unsigned int pci_find_cap_offset(pci_sbdf_t sbdf, unsigned int cap);
 unsigned int pci_find_next_cap_ttl(pci_sbdf_t sbdf, unsigned int pos,
                                    const unsigned int caps[], unsigned int n,
-- 
2.39.5