New patch to review for filo: 747369c Refactor flash locking for supported Intel chipsets

[Nico Huber]

Nico Huber ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3595

-gerrit

commit 747369c2646d851e83220e22f64dda37b4f695d4
Author: Nico Huber 
Date:   Wed Jul 3 15:10:58 2013 +0200

Refactor flash locking for supported Intel chipsets

This should make things more readable when support for more
    chipsets comes.

Change-Id: I6df6673fa1961ab20796210577950e7be6c12316
    Signed-off-by: Nico Huber 
---
 drivers/intel.c | 72 ++++++++++++++++++++++++++++++---------------------------
 1 file changed, 38 insertions(+), 34 deletions(-)

diff --git a/drivers/intel.c b/drivers/intel.c
index 62d23b5..d2153b7 100644
--- a/drivers/intel.c
+++ b/drivers/intel.c
@@ -49,25 +49,50 @@
 #define ICH9_SPI_OPTYPE		0x3896
 #define ICH9_SPI_OPMENU		0x3898

-typedef enum {
-	ICH7, ICH9,
-} ich_t;
-
-int intel_lockdown_flash(void)
+static void lockdown_flash_ich7(void)
 {
    u8 reg8;
    u32 reg32;
-	ich_t ich;

-	reg32 = pci_read_config32(PCI_DEV(0,0x1f, 0), 0);
+	debug("Locking BIOS to read-only... ");
+	reg8 = pci_read_config8(PCI_DEV(0,0x1f,0), 0xdc);	/* BIOS_CNTL */
+	debug(" BIOS Lockdown Enable: %s; BIOS Write-Enable: %s\n",
+			(reg8&2)?"on":"off", (reg8&1)?"rw":"ro");
+
+	reg8 &= ~(1 << 0);			/* clear BIOSWE */
+	pci_write_config8(PCI_DEV(0,0x1f,0), 0xdc, reg8);
+
+	reg8 |= (1 << 1);			/* set BLE */
+	pci_write_config8(PCI_DEV(0,0x1f,0), 0xdc, reg8);
+
+	reg32 = RCBA32(0x3410); /* GCS - General Control and Status */
+	reg32 |= 1;		/* BILD - BIOS Interface Lockdown */
+	RCBA32(0x3410) = reg32; /* Set BUC.TS and GCS.BBS to RO */
+}
+
+static void lockdown_flash_ich9_empty_ops(void)
+{
+	/* Lock SPI interface with empty opcode registers */
+	RCBA16(ICH9_SPI_PREOP)  = 0x0000;
+	RCBA16(ICH9_SPI_OPTYPE) = 0x0000;
+	RCBA32(ICH9_SPI_OPMENU + 0) = 0x00000000;
+	RCBA32(ICH9_SPI_OPMENU + 4) = 0x00000000;
+	RCBA16(ICH9_SPI_HSFS) |= ICH9_SPI_HSFS_FLOCKDN;
+}
+
+int intel_lockdown_flash(void)
+{
+	const u32 reg32 = pci_read_config32(PCI_DEV(0,0x1f, 0), 0);
    switch (reg32) {
+
    	/* ICH7 */
    case 0x27b08086:
    case 0x27b88086:
    case 0x27b98086:
    case 0x27bd8086:
-		ich = ICH7;
+		lockdown_flash_ich7();
    	break;
+
    	/* ICH9 */
    case 0x29128086:
    case 0x29148086:
@@ -75,38 +100,17 @@ int intel_lockdown_flash(void)
    case 0x29178086:
    case 0x29188086:
    case 0x29198086:
-		ich = ICH9;
+		lockdown_flash_ich7();
+		/* Coreboot doesn't use flash regions for ICH9 based
+		   boards, so we just lock empty SPI opcodes instead
+		   of setting up any write protection. */
+		lockdown_flash_ich9_empty_ops();
    	break;
    default:
    	debug("Not an ICH7 or ICH9 southbridge\n");
    	return -1;
    }

-	/* Now try this: */
-	debug("Locking BIOS to read-only... "); 
-	reg8 = pci_read_config8(PCI_DEV(0,0x1f,0), 0xdc);	/* BIOS_CNTL */
-	debug(" BIOS Lockdown Enable: %s; BIOS Write-Enable: %s\n",
-			(reg8&2)?"on":"off", (reg8&1)?"rw":"ro");
-
-	reg8 &= ~(1 << 0);			/* clear BIOSWE */
-	pci_write_config8(PCI_DEV(0,0x1f,0), 0xdc, reg8);
-
-	reg8 |= (1 << 1);			/* set BLE */
-	pci_write_config8(PCI_DEV(0,0x1f,0), 0xdc, reg8);
-
-	reg32 = RCBA32(0x3410); /* GCS - General Control and Status */
-	reg32 |= 1;		/* BILD - BIOS Interface Lockdown */
-	RCBA32(0x3410) = reg32; /* Set BUC.TS and GCS.BBS to RO */
-
-	/* Lock SPI interface with empty opcode registers on ICH9. */
-	if (ICH9 == ich) {
-		RCBA16(ICH9_SPI_PREOP)  = 0x0000;
-		RCBA16(ICH9_SPI_OPTYPE) = 0x0000;
-		RCBA32(ICH9_SPI_OPMENU + 0) = 0x00000000;
-		RCBA32(ICH9_SPI_OPMENU + 4) = 0x00000000;
-		RCBA16(ICH9_SPI_HSFS) |= ICH9_SPI_HSFS_FLOCKDN;
-	}
-
    debug("BIOS hard locked until next full reset.\n");

return 0;