[PATCH] Remove NACA fixed address constraint

Comments in head.S suggest that the iSeries naca has a fixed address,
because tools expect to find it there.  The only tool which appears to
access the naca is addRamDisk, but both the in-kernel version and the
version used in RHEL and SuSE in fact locate the NACA the same way as
the hypervisor does, by following the pointer in the hvReleaseData
structure.

Since the requirement for a fixed address seems to be obsolete, this
patch removes the naca from head.S and replaces it with a normal C
initializer.

For good measure, it removes an old version of addRamDisk.c which was
sitting, unused, in the ppc32 tree.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/ppc/boot/utils/addRamDisk.c

-#include <stdio.h>
-#include <stdlib.h>
-#include <netinet/in.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <string.h>
-
-#define ElfHeaderSize  (64 * 1024)
-#define ElfPages  (ElfHeaderSize / 4096)
-#define KERNELBASE (0xc0000000)
-
-void get4k(FILE *file, char *buf )
-{
-    unsigned j;
-    unsigned num = fread(buf, 1, 4096, file);
-    for (  j=num; j<4096; ++j )
-	buf[j] = 0;
-}
-
-void put4k(FILE *file, char *buf )
-{
-    fwrite(buf, 1, 4096, file);
-}
-
-void death(const char *msg, FILE *fdesc, const char *fname)
-{
-    printf(msg);
-    fclose(fdesc);
-    unlink(fname);
-    exit(1);
-}
-
-int main(int argc, char **argv)
-{
-    char inbuf[4096];
-    FILE *ramDisk = NULL;
-    FILE *inputVmlinux = NULL;
-    FILE *outputVmlinux = NULL;
-    unsigned i = 0;
-    u_int32_t ramFileLen = 0;
-    u_int32_t ramLen = 0;
-    u_int32_t roundR = 0;
-    u_int32_t kernelLen = 0;
-    u_int32_t actualKernelLen = 0;
-    u_int32_t round = 0;
-    u_int32_t roundedKernelLen = 0;
-    u_int32_t ramStartOffs = 0;
-    u_int32_t ramPages = 0;
-    u_int32_t roundedKernelPages = 0;
-    u_int32_t hvReleaseData = 0;
-    u_int32_t eyeCatcher = 0xc8a5d9c4;
-    u_int32_t naca = 0;
-    u_int32_t xRamDisk = 0;
-    u_int32_t xRamDiskSize = 0;
-    if ( argc < 2 ) {
-	printf("Name of RAM disk file missing.\n");
-	exit(1);
-    }
-
-    if ( argc < 3 ) {
-	printf("Name of vmlinux file missing.\n");
-	exit(1);
-    }
-
-    if ( argc < 4 ) {
-	printf("Name of vmlinux output file missing.\n");
-	exit(1);
-    }
-
-    ramDisk = fopen(argv[1], "r");
-    if ( ! ramDisk ) {
-	printf("RAM disk file \"%s\" failed to open.\n", argv[1]);
-	exit(1);
-    }
-    inputVmlinux = fopen(argv[2], "r");
-    if ( ! inputVmlinux ) {
-	printf("vmlinux file \"%s\" failed to open.\n", argv[2]);
-	exit(1);
-    }
-    outputVmlinux = fopen(argv[3], "w+");
-    if ( ! outputVmlinux ) {
-	printf("output vmlinux file \"%s\" failed to open.\n", argv[3]);
-	exit(1);
-    }
-    fseek(ramDisk, 0, SEEK_END);
-    ramFileLen = ftell(ramDisk);
-    fseek(ramDisk, 0, SEEK_SET);
-    printf("%s file size = %d\n", argv[1], ramFileLen);
-
-    ramLen = ramFileLen;
-
-    roundR = 4096 - (ramLen % 4096);
-    if ( roundR ) {
-	printf("Rounding RAM disk file up to a multiple of 4096, adding %d\n", roundR);
-	ramLen += roundR;
-    }
-
-    printf("Rounded RAM disk size is %d\n", ramLen);
-    fseek(inputVmlinux, 0, SEEK_END);
-    kernelLen = ftell(inputVmlinux);
-    fseek(inputVmlinux, 0, SEEK_SET);
-    printf("kernel file size = %d\n", kernelLen);
-    if ( kernelLen == 0 ) {
-	printf("You must have a linux kernel specified as argv[2]\n");
-	exit(1);
-    }
-
-    actualKernelLen = kernelLen - ElfHeaderSize;
-
-    printf("actual kernel length (minus ELF header) = %d\n", actualKernelLen);
-
-    round = actualKernelLen % 4096;
-    roundedKernelLen = actualKernelLen;
-    if ( round )
-	roundedKernelLen += (4096 - round);
-
-    printf("actual kernel length rounded up to a 4k multiple = %d\n", roundedKernelLen);
-
-    ramStartOffs = roundedKernelLen;
-    ramPages = ramLen / 4096;
-
-    printf("RAM disk pages to copy = %d\n", ramPages);
-
-    // Copy 64K ELF header
-      for (i=0; i<(ElfPages); ++i) {
-	  get4k( inputVmlinux, inbuf );
-	  put4k( outputVmlinux, inbuf );
-      }
-
-    roundedKernelPages = roundedKernelLen / 4096;
-
-    fseek(inputVmlinux, ElfHeaderSize, SEEK_SET);
-
-    for ( i=0; i<roundedKernelPages; ++i ) {
-	get4k( inputVmlinux, inbuf );
-	put4k( outputVmlinux, inbuf );
-    }
-
-    for ( i=0; i<ramPages; ++i ) {
-	get4k( ramDisk, inbuf );
-	put4k( outputVmlinux, inbuf );
-    }
-
-    /* Close the input files */
-    fclose(ramDisk);
-    fclose(inputVmlinux);
-    /* And flush the written output file */
-    fflush(outputVmlinux);
-
-    /* fseek to the hvReleaseData pointer */
-    fseek(outputVmlinux, ElfHeaderSize + 0x24, SEEK_SET);
-    if (fread(&hvReleaseData, 4, 1, outputVmlinux) != 1) {
-        death("Could not read hvReleaseData pointer\n", outputVmlinux, argv[3]);
-    }
-    hvReleaseData = ntohl(hvReleaseData); /* Convert to native int */
-    printf("hvReleaseData is at %08x\n", hvReleaseData);
-
-    /* fseek to the hvReleaseData */
-    fseek(outputVmlinux, ElfHeaderSize + hvReleaseData, SEEK_SET);
-    if (fread(inbuf, 0x40, 1, outputVmlinux) != 1) {
-        death("Could not read hvReleaseData\n", outputVmlinux, argv[3]);
-    }
-    /* Check hvReleaseData sanity */
-    if (memcmp(inbuf, &eyeCatcher, 4) != 0) {
-        death("hvReleaseData is invalid\n", outputVmlinux, argv[3]);
-    }
-    /* Get the naca pointer */
-    naca = ntohl(*((u_int32_t *) &inbuf[0x0c])) - KERNELBASE;
-    printf("naca is at %08x\n", naca);
-
-    /* fseek to the naca */
-    fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET);
-    if (fread(inbuf, 0x18, 1, outputVmlinux) != 1) {
-        death("Could not read naca\n", outputVmlinux, argv[3]);
-    }
-    xRamDisk = ntohl(*((u_int32_t *) &inbuf[0x0c]));
-    xRamDiskSize = ntohl(*((u_int32_t *) &inbuf[0x14]));
-    /* Make sure a RAM disk isn't already present */
-    if ((xRamDisk != 0) || (xRamDiskSize != 0)) {
-        death("RAM disk is already attached to this kernel\n", outputVmlinux, argv[3]);
-    }
-    /* Fill in the values */
-    *((u_int32_t *) &inbuf[0x0c]) = htonl(ramStartOffs);
-    *((u_int32_t *) &inbuf[0x14]) = htonl(ramPages);
-
-    /* Write out the new naca */
-    fflush(outputVmlinux);
-    fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET);
-    if (fwrite(inbuf, 0x18, 1, outputVmlinux) != 1) {
-        death("Could not write naca\n", outputVmlinux, argv[3]);
-    }
-    printf("RAM Disk of 0x%x pages size is attached to the kernel at offset 0x%08x\n",
-            ramPages, ramStartOffs);
-
-    /* Done */
-    fclose(outputVmlinux);
-    /* Set permission to executable */
-    chmod(argv[3], S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH);
-
-    return 0;
-}
-

arch/ppc64/kernel/LparData.c

@@ -51,6 +51,17 @@ struct HvReleaseData hvReleaseData = {
 		0xf4, 0x4b, 0xf6, 0xf4 },
 };
 
+/*
+ * The NACA.  The first dword of the naca is required by the iSeries
+ * hypervisor to point to itVpdAreas.  The hypervisor finds the NACA
+ * through the pointer in hvReleaseData.
+ */
+struct naca_struct naca = {
+	.xItVpdAreas = &itVpdAreas,
+	.xRamDisk = 0,
+	.xRamDiskSize = 0,
+};
+
 extern void system_reset_iSeries(void);
 extern void machine_check_iSeries(void);
 extern void data_access_iSeries(void);

arch/ppc64/kernel/head.S

@@ -30,7 +30,6 @@
 #include <asm/processor.h>
 #include <asm/page.h>
 #include <asm/mmu.h>
-#include <asm/naca.h>
 #include <asm/systemcfg.h>
 #include <asm/ppc_asm.h>
 #include <asm/offsets.h>
@@ -511,24 +510,10 @@ _GLOBAL(do_stab_bolted_pSeries)
 	mfspr	r12,SPRG2
 	EXCEPTION_PROLOG_PSERIES(PACA_EXSLB, .do_stab_bolted)
 
-	
-	/* Space for the naca.  Architected to be located at real address
-	 * NACA_PHYS_ADDR.  Various tools rely on this location being fixed.
-	 * The first dword of the naca is required by iSeries LPAR to
-	 * point to itVpdAreas.  On pSeries native, this value is not used.
-	 */
-	. = NACA_PHYS_ADDR
-	.globl __end_interrupts
-__end_interrupts:
-#ifdef CONFIG_PPC_ISERIES
-	.globl naca
-naca:
-	.llong	itVpdAreas
-	.llong	0		/* xRamDisk */
-	.llong	0		/* xRamDiskSize */
 
 	. = 0x6100
 
+#ifdef CONFIG_PPC_ISERIES
 /***  ISeries-LPAR interrupt handlers ***/
 
 	STD_EXCEPTION_ISERIES(0x200, machine_check, PACA_EXMC)

include/asm-ppc64/naca.h

@@ -12,8 +12,6 @@
 
 #include <asm/types.h>
 
-#ifndef __ASSEMBLY__
-
 struct naca_struct {
 	/* Kernel only data - undefined for user space */
 	void *xItVpdAreas;              /* VPD Data                  0x00 */
@@ -23,9 +21,4 @@ struct naca_struct {
 
 extern struct naca_struct naca;
 
-#endif /* __ASSEMBLY__ */
-
-#define NACA_PAGE      0x4
-#define NACA_PHYS_ADDR (NACA_PAGE<<PAGE_SHIFT)
-
 #endif /* _NACA_H */