gwj / at91sam9263 · Commits

Commit 8098ed414ada4265f646e94d65eca063b3689f50

Authored by aurel32
1 parent 2231ef10

PCI: Mask writes to RO bits in the status reg of PCI config space 

The Status register in the PCI config space has some read-only bits.
Any writes to those bits should be masked out.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6091 c046a42c-6fe2-441c-8c8c-71466251a162
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Showing 2 changed files with 26 additions and 0 deletions
hw/pci.c
  View file @8098ed4
@@ -381,6 +381,7 @@ void pci_default_write_config(PCIDevice *d, @@ -381,6 +381,7 @@ void pci_default_write_config(PCIDevice *d,
381 case 0x0b: 381 case 0x0b:
382 case 0x0e: 382 case 0x0e:
383 case 0x10 ... 0x27: /* base */ 383 case 0x10 ... 0x27: /* base */
  384 + case 0x2c ... 0x2f: /* read-only subsystem ID & vendor ID */
384 case 0x30 ... 0x33: /* rom */ 385 case 0x30 ... 0x33: /* rom */
385 case 0x3d: 386 case 0x3d:
386 can_write = 0; 387 can_write = 0;
@@ -402,6 +403,7 @@ void pci_default_write_config(PCIDevice *d, @@ -402,6 +403,7 @@ void pci_default_write_config(PCIDevice *d,
402 case 0x0a: 403 case 0x0a:
403 case 0x0b: 404 case 0x0b:
404 case 0x0e: 405 case 0x0e:
  406 + case 0x2c ... 0x2f: /* read-only subsystem ID & vendor ID */
405 case 0x38 ... 0x3b: /* rom */ 407 case 0x38 ... 0x3b: /* rom */
406 case 0x3d: 408 case 0x3d:
407 can_write = 0; 409 can_write = 0;
@@ -413,6 +415,15 @@ void pci_default_write_config(PCIDevice *d, @@ -413,6 +415,15 @@ void pci_default_write_config(PCIDevice *d,
413 break; 415 break;
414 } 416 }
415 if (can_write) { 417 if (can_write) {
  418 + /* Mask out writes to reserved bits in registers */
  419 + switch (addr) {
  420 + case 0x06:
  421 + val &= ~PCI_STATUS_RESERVED_MASK_LO;
  422 + break;
  423 + case 0x07:
  424 + val &= ~PCI_STATUS_RESERVED_MASK_HI;
  425 + break;
  426 + }
416 d->config[addr] = val; 427 d->config[addr] = val;
417 } 428 }
418 if (++addr > 0xff) 429 if (++addr > 0xff)
hw/pci.h
  View file @8098ed4
@@ -54,6 +54,21 @@ typedef struct PCIIORegion { @@ -54,6 +54,21 @@ typedef struct PCIIORegion {
54 #define PCI_MIN_GNT 0x3e /* 8 bits */ 54 #define PCI_MIN_GNT 0x3e /* 8 bits */
55 #define PCI_MAX_LAT 0x3f /* 8 bits */ 55 #define PCI_MAX_LAT 0x3f /* 8 bits */
56 56
  57 +/* Bits in the PCI Status Register (PCI 2.3 spec) */
  58 +#define PCI_STATUS_RESERVED1 0x007
  59 +#define PCI_STATUS_INT_STATUS 0x008
  60 +#define PCI_STATUS_CAPABILITIES 0x010
  61 +#define PCI_STATUS_66MHZ 0x020
  62 +#define PCI_STATUS_RESERVED2 0x040
  63 +#define PCI_STATUS_FAST_BACK 0x080
  64 +#define PCI_STATUS_DEVSEL 0x600
  65 +
  66 +#define PCI_STATUS_RESERVED_MASK_LO (PCI_STATUS_RESERVED1 | \
  67 + PCI_STATUS_INT_STATUS | PCI_STATUS_CAPABILITIES | \
  68 + PCI_STATUS_66MHZ | PCI_STATUS_RESERVED2 | PCI_STATUS_FAST_BACK)
  69 +
  70 +#define PCI_STATUS_RESERVED_MASK_HI (PCI_STATUS_DEVSEL >> 8)
  71 +
57 struct PCIDevice { 72 struct PCIDevice {
58 /* PCI config space */ 73 /* PCI config space */
59 uint8_t config[256]; 74 uint8_t config[256];